Metabolic Rewiring in Hairy Cell Leukemia

Here's a link to an interesting article on "BRAF-V600E Metabolic Rewiring and Reprogramming."

http://www.sciencedirect.com/science/article/pii/S1097276515004384

BRAF-V600E is the mutation present in nearly 100% of the classic form of hairy cell leukemia (and is also common in 50% of melanoma cases).

The metabolic cycle shown in the diagram may imply that a diet which promotes ketogenesis (such as a high protein, low-carb diet), may promote BRAF-V600E/MEK1 binding and tumor cell proliferation.

I'd be interested in understanding how levels of HMGCL compare between patients and whether there is a correlation to treatment success.

Interestingly enough, an HMGCL antibody has been produced in rabbits:
http://www.sigmaaldrich.com/catalog/product/sigma/hpa004727?lang=en&region=US

I wonder if such an antibody could be used to safely regulate HMGCL levels during treatment and reduce cell proliferation. 

A common mistake a lot of people initially diagnosed with HCL (including myself) make is to assume that HCL is like solid tumors and feeds on sugar.  They then follow a low carb diet, which in turn causes the body to invoke ketogenesis to metabolize fat and protein.  In so doing, they promote cell proliferation instead of starving the HCL. 

This is the mistake I made when being treated.  I wonder if it is one of the reasons why I did not respond as quickly as others to treatment during chemotherapy and my first round of Rituxan.  I stopped the diet before my second treatment of Rituxan and ultimately got a complete remission.

Just remember, "liquid cancers" aren't like solid tumors.  Follow a balanced diet, and let the medicine do its job.
 

Trial Announcement for Multiply Relapsed Hairy Cell Leukemia Patients

Multiply Relapsed HCL Patients:
If you're a multiply relapsed HCL patient looking for a non-chemotherapy treatment, consider the Moxe clinical trial at NIH.  This is a Phase 3 trial.

Results from the Phase 1 trial indicate there is no toxicity, a complete remission rate of 57%, and a majority of those patients were able to eliminate all signs of malignancy. These results are superior to many other non-chemotherapy treatments for relapsed HCL. Check out the webpage or call Dr. Kreitman at 301-648-7375.

Here's a great link for patients that explains the trial and how the drug works.

"Moxetumomab is a nonchemotherapy treatment that can produce MRD-negative complete remissions where patients have a chance to be free of disease for a long duration," he explained. "We have patients who have been free of MRD for more than 5 years now on moxetumomab, and more than 10 years on the parent drug, BL22."

Here's a link to the clinical trial protocol details.

This referral letter explains the trial to doctors looking for treatment options for their multiply relapsed and refractory HCL patients.
 

Hairy Cell Leukemia: A Pleasant Surprise...

It's been a week since my restaging appointment at NIH.  Those of you in the trial know the routine:  CBC bloodraw in Phlebotomy, MRI and ultrasound in Imaging, then bone marrow biopsy and aspiration (my tenth) in Out-patient Procedures.  Get an X-ray and EKG in between those appointments. 

Waiting for results over the past week was nerve-wracking.  I got the CBC results that day.  My platelets were down slightly.  All white counts were normal, but looked like they were trending down too.  Red counts were fine, and they had certainly been pulling their share during all the recent hikes I've taken. 

Recovering from a head cold, I thought maybe that could account for the slight dip I perceived in the platelets and neutrophils.  Last year, 18 months after my final Rituxan treatment, my bone marrow aspirate came back slightly positive (.08%) for HCL.  At the time, Dr. K indicated that it might come back negative in a year, but I didn't think it would.  I assumed the cells would double every 3 weeks, and I'd have 60 to 80 weeks before I would need to be retreated.  Enough time to maybe let me get into an inhibitor trial and avoid chemo, which suppressed my marrow much longer than expected when I was first treated.  Thinking about going back for retreatment and the possibility of another chemo was starting to wear on me. 

Well, I'm pleased to report that both my peripheral blood and bone marrow aspirate flow results were negative for hairy cell leukemia - providing further data to show that using Rituxan to treat minimal residual disease (MRD) may allow the body to get an upper hand in keeping the disease in check.  In my case, chemo didn't get me into a partial or complete remission (CR), and a first cycle of Rituxan at 6 months post chemo to treat continued HCL infiltration allowed me to get a short-term CR.  A year later, when MRD first appeared, the second cycle of Rituxan had the opportunity to knock out what remained.

I've been in CR ever since that final treatment, and now there's no evidence of HCL at all!  My body is keeping it in check and appears to have eliminated the small amount that was detected last year.  Although the PCR lab was never able to clone my hairy cells to perform the hyper-sensitive MRD test and determine if HCL is completely eradicated from my body, I'm elated that I appear to have the upper-hand at this point.  The only supplement I take is 1000 IU of Vitamin D in the winter.  My diet is relaxed and normal, just no junk food or soda.  My ultrasound tech said my liver was now "textbook" and no longer fatty like it was when I was first diagnosed.

I couldn't have gotten to this point had I not participated in the NIH trial for newly diagnosed HCL patients.  I'm eternally grateful to Dr. K, Rita and the fantastic team at NIH.

Hairy Cell Leukemia: Making an Impact...

About 2.5 years ago, I blogged regarding a new drug I read about and brought to the attention of the Hairy Cell Consortium.  It's a Bruton's Tyrosine Kinase (BTK) inhibitor known as PCI-32765, and was inspired by a rare disease known as XLA, in which the body doesn't produce B-cells due to a BTK gene defect.  Developed to treat NHL, when I read about it, I thought the underlying mechanism warranted investigation for treating HCL.

Here's a link to the post:

http://jonshclblog.blogspot.com/2010/11/i-want-new-drug.html

Well, the email describing the mechanisms and potential of the drug that I sent to the Hairy Cell Consortium had an impact.  They performed in vitro studies of the drug, and it was found to be highly effective in stopping HCL proliferation!

http://files.shareholder.com/downloads/PCYC/0x0x620800/0228F1DA-BFD9-4E43-9CD4-3688E1ECB36A/SAT_Poster_HCL-ASH2012_Sivina_FINAL_Dec_3_APPROVED.pdf

Clinical trials using this drug to treat relapsed and refractory Hairy Cell Leukemia patients are now underway at The Ohio State University Medical Center (Go Buckeyes!!!) and The Karmanos Cancer Institute in Detroit Michigan!

http://www.clinicaltrials.gov/ct2/show/NCT01841723?term=Hairy+Cell+Leukemia&rank=4

The drug goes by the trade name Ibrutinib.  Let's hope it lives up to the potential I anticipated in my post back in 2010!  Seems like our arsenal and options are really piling up.  Translational medicine and targeted therapies are taking off, and will hopefully make chemo a distant memory someday soon. 

On a personal note:    Back in April, I went on a 5 day trek to the Royal Arch Loop of the Grand Canyon South Rim with some friends from work.  It was awesome!  The second to last day we hiked 13 hours in 80 degree weather and ran out of water, so we banded a team of 5 together for a 3-hour night hike down to the Colorado River to collect 40 liters of water for the rest of the team (9 of us altogether), so we could hike out the next day.  Awesome!  5 years ago, I couldn't climb 13 steps without stopping to catch my breath.  The last day of the Royal Arch trek, I hiked 4000 feet vertically with 32 pounds on my back for over 7 miles and felt fantastic!!!

I go for my annual re-staging at NCI/NIH on June 26th.  Wish me luck...

Elves' Chasm

Rappelling down a canyon wall

The Ravine to Royal Arch Creek

The Royal Arch!

Desert Blossom

Toltec Beach on The Colorado River

Night Hike and Water Filtering Mission

It's Been Awhile...

It's hard to believe my last post dates back to July, 2011.  So much has happened since then.  Shortly after my last post, I experienced a significant drop in a type of white blood cell known as neutrophils, which I attribute to an effect known as Rituxan-related late-onset-neutropenia (LON).  I quickly recovered with the help of the expert staff at NIH, where I am being treated.  The neutrophil count of 700 that I alluded to in my last post was just the beginning.  I dipped all the way down to 0 but recovered quickly with the help of neupogen (aka: Neulasta), a hormone that induces the marrow to produce neutrophils.  Everything worked out fine in just a few days.  I'm grateful for everyone at NIH who treated me and helped me recover.  They are fantastic!

Otherwise, I've been working hard and just enjoying life.  Great progress has been made with respect to early treatments using Vemurafenib  (aka PLX-4032), the BRAF V-600E inhibitor that targets the mutation specific to nearly 100% of hairy cell classic cases.  UVA rays from sunlight induce the mutation (the same one that causes 50% of melanoma cases).  In other words, the cause of hairy cell leukemia is sun exposure.  A refractory patient in Germany was the first I know of to receive Vemurafenib, and now a patient in England -- an incredibly courageous individual who has seen more hardship over the past two years than I can imagine.  He's a pathfinder and an inspiration to many of us.  Both patients had given up hope of achieving a meaningful remission with the known chemotherapies (Cladribine, Pentostatin, and Bendamustine) and tried the Vemurafenib as a last hope.  I believe one of them got down to a platelet count of 10 (out of 160,000) when he started treatment.  This new drug appears to be working well -- melting away the refractory hairy cells, and also is being investigated to treat papillary thyroid cancer, which is also associated with the BRAF V600 mutations (thus probably caused by excess UVA exposure). 

NIH is preparing to start a trial in March, 2013 for refractory and relapsed patients that will investigate two other BRAF V600 inhibitors to treat HCL.  I will post a link to that trial and protocol when it becomes available.  Interested individuals should contact Dr. Kreitman at NIH. He always welcomes direct calls from patients (see his number in the blog sidebar). 

Personally, everything is well with me.  My counts are still great, and I had a peripheral blood flow cytometry test last week which was negative for hairy cells.  My last bone marrow biopsy was in June, 2012.  The core was negative for hairy cells, and the aspirate only showed 0.08% hairies, if I recall correctly.  I've started rowing 2 to 4 miles every day and hope to join a local rowing club soon.  The only daily supplement I take is 1000 IU of Vitamin D in the winter and early Spring.

I continue to highly endorse NIH for both new and refractory/relapsed patients.  The Cladribine + Rituxan trial has had a 100% remission rate for new patients (over 70 now), which is amazing.  I know I'd be in a very different position right now had I not received both rounds of Rituxan when I did -- to treat minimal residual disease instead of relapse.  My participation in the trial made all the difference in the world between achieving a CR (complete remission) and being among the 20% of patients who do not with just standard chemotherapy. 

All first time HCL patients should call Dr. Kreitman at NIH to discuss treatment options and submit research samples before proceeding with treatment, regardless of whether they decide to seek treatment at their local hemoncologist or NIH.

Just one more thing:  Here is a link to 15-year-old Jack Andraka's TED talk.  At 3-cents, his carbon nanotube antibody-based sensor (patent pending) costs 1/26000th that of the $800, 60-year-old ELISA test for pancreatic cancer and is 100 times more sensitive.  The possible applications cover a broad spectrum -- from water contamination to HIV detection, and will improve the lives of billions.  He's showing us that innovation can bridge the gap between providing services and cutting costs.  Glad Intel and the school systems are still supporting and promoting science fairs.  This is one helluva return on investment!!!


Happy New Year to All!

- Jon

Here are some articles related to the BRAF V600E mutation and HCL Classic:

The BRAF V600E Mutation in Hairy Cell Leukemia

BRAF Inhibition in Refractory Hairy-Cell Leukemia

 

Hairy Cell Leukemia: Mission Accomplished!

I was going to call this post "A Little Bit of Everything", but fortunately my plans have changed! 

I did it!, or should I say "Dr. Kreitman and The NIH Trial to Treat First Time HCL Patients did it!"  All of my tests are now negative:  peripheral blood flow (looks for hairies in your veins), bone marrow and most importantly bone marrow aspirate (the liquid in your bones where cells develop) are all negative!  I couldn't have done it without the NIH trial.  If you recall, it's taken me a little over two years to get here. 

The initial treatment with Cladribine only led to a partial remission, and I still had 30% bone marrow infiltration and positive blood flows at 6-months post-chemo (November 2009).  At that point, I had my first Rituxan treatment (8 rounds over 8 weeks).  I achieved a complete remission (CR) 6 months later, in May 2010, but still had hairy cells in my bone marrow aspirate (a value not included in determining CR).  That 1st CR was short lived.  The cells in my aspirate continued to proliferate and upon restaging in December 2010, my bone marrow infiltration was back up to 5% and the peripheral blood flow showed .04% hairies.  Although my complete blood counts (CBCs) were at remission levels, the marrow infiltration indicated it was no longer a CR and positive flow results for hairy cell indicated minimal residual disease (MRD), so I was retreated with Rituxan for the second and final time in accordance with the trial's protocol.  This latest treatment wiped out the hairies in all areas to undetectable levels.  I'm not completely out of the woods.  Time will tell if this is a durable remission, but one thing's for sure:  The combination of Cladribine and Rituxan did what Cladribine alone could not without waiting for relapse or subjecting me to multiple rounds of chemo.

Although I've wiped out the hairies, I have one more minor hurdle to jump.  As I discovered and wrote last year, there is a documented phenomenon that occurred in 20% of lymphoma patients, who received combined chemo and Rituxan therapy, known as Rituxan-related late onset neutropenia (LON).  The nadir (low point in counts) typically occurs 14 weeks after the last dose of Rituxan when the counts dip to about 660 (average).  The effect lasts for about 4 weeks.  I noticed a similar effect happened to me after my first Rituxan treatment and blogged about it then.  You'll also recall that I've been interested in seeing if it would happen again.  Well, it happened again!  My 6-month CBC (16 weeks after my last Rituxan dose or 24 weeks after I started this cycle) indicates that my neutrophils are at 750.  Although it appears to be slightly later by 2 weeks, I don't get CBCs often enough to say whether the low-point occured at 14 weeks or not. 

Still, it is statistically in keeping with the findings of the lymphoma study.  I believe I've discovered and am the first documented case of this occuring in an HCL patient.  Time will tell as my recovery and other patients are studied.  I expect to be at a remission level in 3 weeks, when I have my next CBC.  So technically, I'm not in a CR until the neuts jump back up, but I don't really care.  Everything else is in great shape.  Based on my first experience and knowledge of RTX LON, I consider it a nuance that will quickly recover; however, I won't be surprised if the duration of this neutropenia is slightly longer than the first time.

So far it's been a great summer.  My youngest daughter, who was born a year after I was first treated, started walking on her first birthday and can now say the letters in her name.  My 3-year old is doing great and having lots of fun with her garden and playing in the sand and taking swim lessons.  We recently headed up to Lancaster, PA to visit Dutch Wonderland and the Thomas the Train event at Strasburg railroad in our new Swagger Wagon (a Honda Odyssey). 

The sun and I have also come to terms.  I'm going to wear sunscreen and s/he's going to lay off me for awhile.  Likewise, I've set up a portable 60 Watt solar panel array to charge all my mobile devices and run my low power electronics to pay her/him hommage.  Yes, I'm a gadget geek, but if the power ever goes out, I'll still have my iTunes!  I also just bought a kayak and will be taking lots of late afternoon trips on the Potomac this summer.

Yippeekayay !!!

All Hail Ra

I know it's been too long since my last post!

I've got lots to discuss and I'm short on time right now, but I wanted to share an interesting "Science Daily" article that I just found.

http://www.sciencedaily.com/releases/2011/06/110608195159.htm

It states:

The researchers demonstrated that B-cells are deficient in one of the main DNA repair pathways, known as Nucleotide Excision Repair. This pathway repairs a lot of different DNA lesions, including UV-induced damage and chemical adducts (e.g. from air pollution and cigarette smoke). Their model therefore explains why strong UV exposure (e.g. unprotected sun bathing) is the number one environmental risk factor for lymphoma and also supports the evidence that exposure to air pollution and smoking are also risk factors.

Dr Nouspikel said: "Lymphoma is one of the ten most frequent cancers in adults in the UK, and the third among children. If we want to come up with efficient strategies for prevention and therapy, it is crucial to understand what causes it. The novel mechanism we have discovered potentially accounts for the development of many different types of lymphoma. It may also explain why strong exposure to sunlight is the main environmental risk factor for this cancer."

This supports my theory than sunlight may cause mutations (specifically cytosine deamination to uracil in RNA) that cause HCL!  Likewise, it reinforces my hypothesis that the reason they can't sequence my hairy cell DNA is because there is a mutation in my DNA corresponding to the primer they're using which the DNA repair enzymes either failed or don't attempt to repair.
I've got lots more to talk about, like mcl-1 inhibitors and new data at 15 weeks after my last Rituxan treatment that supports my Rituxan-related late onset neutropenia (LON) hypothesis, but it'll have to wait until I have more time.  I'm still waiting to get my latest flow results.

There was a huge Coronal Mass Ejection (CME) 2 days ago that spanned half the surface of the sun and is headed our way, so wear sunscreen!

Later.
6/11/2011 update

Wow!  Just one day later, one of my fellow HCL'ers (shout out to Vincent) found this announcement:

http://www.medpagetoday.com/HematologyOncology/Leukemia/27009

It states that HCL has been narrowed down to a single common gene mutation, BRAF V600E.  BRAF is a gene most widely known for its involvement in melanoma.  This is groundbreaking, and since the leading cause of BRAF V600 mutation is excessive sun exposure, gives further credence to my hypothesis that sun exposure is a leading cause of HCL.  All these studies are starting to add up and reinforce that hypothesis.  It also means that clinical trials with BRAF V600E inhibitors like PLX-4720, which are highly active in treating melanoma, are warranted in patients with refractory and relapsed HCL.  Perhaps a PLX4720-assisted Cladribine / GA-101 trial in refractory and relapsed HCL'ers is in the future...

Here's the published study.

These findings may lead to the development of mouse models for HCL research: 

"On the basis of our findings, it should be feasible to develop murine models of HCL by activating the RAS–RAF–MAPK signaling pathway in specific B-cell subpopulation."

"Strikingly, a T→A transversion occurring at position 1860 of the messenger RNA RefSeq NM_004333.4 and resulting in the V600E variant was found in samples from all 47 patients with HCL..."

I'm hypothesizing that the transversion is sunlight induced.  It will be interesting to see if research related to the first study I cited can determine whether DNA excision repair related to BRAF V600 is inactive during certain stages of B-cell maturation (specifically en route or at the germinal center stage).

It's all coming together.  Needless to say Eddie Vedder's "Hard Sun" is going to be the backup soundtrack for my next bloodcount video...

I Got Chills...They're Multiplyin' ...

You've got to be kidding me!!! Two flus in 1 month ???!!!!

I couldn't believe it.  The baby came down with flu A on February 28th.  I started developing symptoms 2 days later and went to see my PCP.  The quick flu test was negative, and it's supposed to be accurate to 90+%, so he told me it was probably a bacterial infection.  Still, they did a culture to be on the safe side.  I started back on Tamiflu just to make sure I wouldn't get the flu again since the baby had it.  That night, I sweated profusely, just like with flu B two weeks prior.  I was skeptical that I didn't have the flu, and I continued to feel pretty lousy the rest of the week -- fevers up to 102, etc.

That Saturday, my PCP sent me a message saying it WAS flu A, so I increased the Tamiflu dose to 2 pills a day.  It seemed to do little good, and I took over a week to recover.  I later read that flu A can mutate to isolates that don't respond to Tamiflu (it says so on the info packet), so I assume that's what happened.  My recovery from flu B was much faster and had far less Tamiflu-related nausea.

I just had my 3 month Rituxan follow up on March 28th.  The blood counts are looking great!  The WBC is almost back to normal for a normal person, and that's pretty good considering how low my lymphocyte count still is.  Since the hairy cells are B-lymphocytes, you want that count (aka "ALC") to be low.  My neutrophils are holding steady, and my monocytes are really doing well.  I'm sure that getting the flu twice in 1 month didn't hurt getting the monocyte count up, but they're still high 1 month later, so I'm not complaining.  Hopefully, that will assist the ADCC mediated by Rituxan and kill more hairies.

I've lost a lot of time at work dealing with the two flus and taking care of the baby.  She's had chronic ear infections for several months in addition to the flu.  She's finally going to get ear tubes on Monday.  It worked wonders for her big sister, so we're looking forward to it.

Here's the latest video of my blood counts.  Overall, I'm really happy with the results, but my phosphorus level has dipped below normal several times since RTX#2.  I'm not sure if that has to do with marrow replenishment or over-excretion in the urine due to a vitamin D deficiency.  Time will tell, but if it continues to trend downward, I may consult a endocrinologist and try to find out what's causing it.



In other news, it looks like things may be moving forward with a Rituxan vs. GA-101 trial for Hairy Cell in refractory and relapsed patients!  GA-101 is the Type II anti-CD20 antibody I found in September, while studying "lipid rafts", and brought to Dr. K's attention.  It's engineered to have a wider elbow angle which is able to mediate cell death 5 to 100 times more effectively than Rituxan. It's also less toxic.  I'll let you know as I find out more.

Here's a table of drugs for which I'd like to see more data regarding effectiveness in treating HCL:

Rituxan, Flu and a Spike in Counts too ...

I've been holding off this post until I had enough new data to share to make it worthwhile, but  I didn't realize I'd get the flu while I was waiting.  Between treatments 6 and 7, I got hit hard with influenza B.  No doubt my youngest brought it home from daycare.  The youngest had a mild fever two days before I came down with it.  Fortunately, everyone (including myself) had been vaccinated earlier in the season, but since I've anihilated my B-cells, there wasn't much benefit left from the vaccine.  I started feeling aches on that Saturday, but it didn't hit hard until Superbowl Sunday.  I got in bed around 10 am, couldn't really move and stopped drinking enough fluids.  Once my fever spiked to 102 around 3 pm, I called the NIH day hospital, and they asked me to come in.

I got to Bethesda around 4:30 pm.  My fever went up and down between 98 and 103 several times while there.  They ran CBC, chemistry and cultures and hooked me up to an IV.  4 hours, 3 bags of saline and a digital X-ray later, I was good to go with Tamiflu and Tylenol in hand.  The next morning at 6 am, I started sweating profusely on my upper body.  At 7 am, I was awake enough to take off my T-shirt, which I could have rung out to get a couple cups of water in a bucket.  I continued to have roller coaster fevers for the remainder of the day, but my temperature finally recovered later that evening, and I was able to go back to NIH the next day (Tuesday) to receive treatment #7.

Needless to say, my counts spiked as shown above. On the plus side, I had a normal WBC for the first time since collecting counts.  Same with the platelets.  I'm hoping the short term boost may have benefited my ADCC response to the Rituxan treatments too. It can't hurt to have all those extra neutrophils and monocytes available to recognize and target the hairy cells...

Lots of HCL patients have anecdotally commented that when they got viral infections, their counts improved for awhile; however, my response was short-lived and only lasted as long as the viral infection.  One exception -- my platelets seem to have gotten a significant and more durable boost, and are at the best level I've ever measured. Hopefully, that's a sign of good things to come.

I've got lots more to add to this post, including another potential treatment that uses a protein known as CD-19L, found on T cells, to kill leukemia cells that express CD19.  Scientists have now bioengineered CD19-L in a solution without T-cells and shown it to kill ALL cells in vitro.  Since hairy cells express CD19 too, I'm hoping CD19-L will bind to and destroy them.  Hopefully, this bioengineered protein will continue to be developed and result in treatments for ALL and possibly HCL too.

I've been studying somatic hypermutation (SHM) associated with the variable heavy-chain region of B-cell immunoglobulins and wondering if the random production of Ig antibody is somehow associated with HCL mutations.  This has led me to postulate some new theories on the cause of HCL.  I think HCL may be caused by RNA cytosine nucleoside exposure to sunlight that results in deamination of cytosine to uracil.  Next thing you know, the alteration causes a protein to fold improperly, chromosomes mix with the wrong crowd, locks get picked with mutated keys and genes start translocating all over the place.  Before you know it, you've got just the right random blend of mishaps and a self-sustaining HCL mutation on your hands.

Dr. John Sutherland, a Professor of Organic Chemistry at the University of Manchester, England has recently shown that RNA may be the starting point for life and that sunlight alone can deaminate cytosine in RNA to uracil.  This was discussed on a recent episode of NOVA Science Now.  I wonder if sunburn inflammation and UVA/UVB exposure as some B-cells divert through capillaries on their way from the marrow to the germinal centers could cause hairy cell leukemia mutations?  Hairy cellers are generally active, outdoor-types and tend to engage in activities that can result in excessive sun exposure.  White males with fair traits have the greatest incidence of classic HCL.  Likewise, HCLers have a higher incidence of basal cell carcinoma (BCC), another disease associated with people with fair traits and excess sun exposure.

      My HCL recipe:
          Ingredients:
               one part genetic disposition (fair trait genes)
                age
                excessive UVA/UVB or sunburn (or maybe high frequency RF since electrical engineers have 8x more incidence than most people)
           Directions:
                 Mix well until random RNA cytosine deamination causes a protein production train wreck and HCL-related gene translocations. 

Perhaps patients that have a durable remission beyond 15 years but then relapse aren't really relapsing, but instead have a new HCL mutation caused again by excessive sun exposure.  Sequencing and comparing the patients' HCL DNA at initial diagnosis and the later onset would determine if the relapse is a clone of the original occurence or derived from a new progenitor.

I wonder if the difficulty in sequencing my hairy cell DNA and generating a PCR primer might be due to an unusually rare cytosine deamination to uracil in my DNA (rather than RNA) that the DNA repair enzyme somehow freakishly failed to catch and repair.  I'm hoping they make some progress soon and can tell me what's different about my sequence.  Regardless, I'm exceedingly grateful for the opportunity to participate in the NIH clinical trial, and all the effort and help Dr. Kreitman and his staff have put into helping me.

Now that I've completed all the treatment provided by this trial, I'm in the watchful waiting stage -- anxiously looking forward to my next bone marrow biopsy and aspiration in June.  Hopefully this time, I'll be negative for hairies on all three tests -- peripheral blood, bone marrow and aspirate.

Wish me luck!

Hairy Cell Leukemia Trivia

Thought I'd put together a few trivia questions for those of you who want to test your hairy cell leukemia knowledge:

Questions:
1) What causes hairy cell leukemia?
2) Who discovered hairy cell leukemia?
3) In what year was hairy cell leukemia discovered?
4) Where was hairy cell leukemia discovered?
5) What is the formal name of hairy cell leukemia?
6) What protein is overexpressed on hairy cells and the main target of monoclonal antibody therapy?
7) What does the "CD" in "CD20" stand for?
8) Name the primary chemotherapies for hairy cell leukemia?
9) When is Pentostatin typically used in lieu of Cladribine?
10) What's the term for treatment with a monoclonal antibody (mAb)?
11) What is the primary mAb used to treat hairy cell?
12) What other surface proteins are also targeted in hairy cell?
13) Name a well known HCL immunotoxin?
14) Who is Ira Pastan?
15) What is the bacterial toxin used in HA22, and what's its origin?
16) What is the typical cause of fever after treatment with Cladribine (commonly misdiagnosed as "a mystery infection")?
17) What are the three modes of cell death mediated by Rituxan?
18) Who invented Cladribine?
19) Which is the more effective approach for administering Cladribine?
              5 day x 2 hour IV
              or 24x7 drip?
20) At what stage of cellular development is the malignant mutation of hairy cell believed to occur?
21) What is the median age of an HCL patient at diagnosis?
22) Is HCL more prevalent in men or women?
23) What type of cells are hairy cells from?
24) What is the average period of remission for HCL after Cladribine chemotherapy?
25) What percentage of patients receiving Cladribine have a complete remission, partial remission, and no response?
26) How rare is hairy cell leukemia?
27) What does MRD stand for?
28) Is there a cure for hairy cell leukemia?
29) The first case of patient/doctor genetic rights involved hairy cell leukemia and what university?
30) What's the life expectancy of the average hairy cell leukemia patient?
31) When should hairy cell leukemia be treated?
32) What is Hairy Cell Leukemia?
33) What is Bruton's Tyrosine Kinase (BTK)?
34) What Hairy Cell Leukemia (HCL) treatment options are available to multiply relapsed and refractory patients who don't respond to chemotherapy?

Answers:
1) Most cases of classic HCL have a BRAF V600E DNA mutation, caused by a photon from sunlight inducing an RNA translation error in a B-cell (a type of white blood cell) during replication.  This mutation is also common to 50% of melanoma cases, but in that case, it affects a skin cell.  The causes of other variants of HCL are unknown.
2) Bertha A. Bouroncle, MD
3) 1958
4) Ohio State University
5) Reticuloendotheliosis
6) CD20
7) "Cluster of Differentiation"
8) Cladribine and Pentostatin
9) When a patient's counts are so low or health is so weak that a less sudden drop in counts is needed; however, it is sometimes used if a patient doesn't respond to Cladribine.  Pentostatin is administered over several weeks whereas Cladribine is administered in 5 or 7 days.
10) mAb therapy
11) Rituximab (aka: Rituxan)
12) CD25, CD22
13) HA22
14) Head of NCI laboratory of molecular biology and immunotoxin development
15) Pseudomonas Exotoxin from Pseudomonas aeruginosa
16) Tumor Lysis (hairy cells dying)
17) Apoptosis (cell suicide), antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC)
18) Dr. Dennis Carson
19) Both are considered equally effective
20) Later in the differentiation process at the level of the germinal center B-cells, likely in the process of differentiating to a Memory B-cell (per Basso, et al, p.62, col 1).
21) 52
22) Men, by a ratio of 4:1
23)  B-cells, a type of lymphocyte.
24) Ten years.
25) 80%, 15% and 5% respectively.
26) HCL accounts for only 2% of diagnosed/reported cases of leukemia.  However, it may be more prevelant since it can remain "in-check" in many people without ever being diagnosed.
27) Minimal Residual Disease.
28) Not yet, but there are hairy cell clinical trials trying to establish a cure curve.
29) UCLA (link to court case)
30) The average patient will have a normal life expectancy.
31) In general, HCL should be treated when blood counts indicate one of the following conditions:
                 Platelets (PLT) < 100 K/uL
                 Hemoglobin (HGB) < 10 g/dL
                 Absolute Neutrophils (ANC) < 1.0 K/uL
       however, Dr. Michael Grever, in his paper "How I treat Hairy Cell Leukemia (Blood, 10/2009)" states the following:

                   "Therefore, I recommend that therapy be initiated when a declining trajectory predicts that the patient will reach a platelet count less than 100,000/uL or an absolute granulocyte count consistently below 1,000/uL."
32)  HCL is an uncommon, chronic, neoplastic (malignant) disorder of B lymphocytes (a type of white blood cell) that predominantly afflicts middle-aged men. The patient usually presents with pancytopenia (broad spectrum reduction in blood counts -- low platelets, low white blood cells, low red blood cells). In the U.S., there are 500 to 800 cases of HCL annually, representing just 2% of all leukemias. Although it is incurable, it is highly treatable, with an average remission of 10 years.
33) BTK is an enzyme that's critical to the maturation of B-cells.  Inhibiting it, with drugs like Ibrutinib, has proven to be a well-tolerated and effective means of targeting a variety of leukemias and lymphomas.  Clinical trials using Ibrutinib to target hairy cell leukemia in relapsed and refractory patients are now underway.
34)  Multiply relapsed and refractory Hairy Cell Leukemia (HCL) patients should consider the moxetumomab (moxe) clinical trial at NIH.  A majority of patients have achieved complete remissions and in many cases eliminated MRD.
 

Kinected

A lot has happened since my last post:

•        Christmas
•        New Years
•        Birthdays (Howard Recombinant DNA Experiment #1 turned 3, and my wife had a birthday too)
•        4 Rounds of Rituxan

The Rituxan treatments have gone well, although I've had to deal with several failed IV placements (including 3 blown veins).  The only significant change in my blood counts so far has been a dramatic increase in monocytes as shown below, but this has me very excited.  It's believed that monocytes may mediate the antibody-dependent cell-mediated cytotoxicity (ADCC) by Rituximab, and a cursory analysis of my counts leads me to believe this may be the case.  Specifically, my monocyte counts increased dramatically after both Rituxan treatments were initiated (see highlighted areas).

I believe this increase in monocytes is directly correlated to the administration of the Rituxan as they begin to kill the hairies through antibody attack (see picture below).  The monocytes increase in numbers as Rituxan (RTX) is introduced into the bloodstream and then they level off as they morph into phagocytes and ADCC is evoked.  As you can see in the highlighted areas above, the pattern for this cycle (RTX #2)  is similar to the first RTX treatment in 2009, but the initial level of monocytes is much higher.  Given that my spleen is now 40% of its prior volume (no longer infiltrated with hairies), and the monocyte level is 9 times higher than when I started RTX treatment #1, I think this round may have a much bigger impact in reducing the hairy cell burden in my marrow aspirate!  

Monocyte Mediated ADCC

Starting in week 5 of RTX treatment #1, my neutrophil level increased dramatically as the monocyte levels began to top off.  Hopefully, the same increase will occur over the next few weeks.  If so, I think the response correlation with RTX treatment #1 will be another strong indicator of monocyte mediated ADCC.  It may take awhile for it to complete the job, but fortunately Rituxan's half-life is two weeks, so it will remain in my bloodstream for months and during that time > 99% remains in the peripheral blood looking for B-cells and hairies to destroy, so it's readily available for quite awhile as the layers of the hairy clumps are peeled away.

Then again, since neutrophils are the first to attack (neutrophils are microphages, ie: small eaters), they may be pulled out of the peripheral blood stream to mediate Rituxan-induced complement-dependent cytoxicity (CDC) and attach to C3b proteins -- causing a drop in their blood levels.  Perhaps the monocytes are being released into my blood stream in response to the transient decrease in neutrophils. Monocytes are held in reserve in the splenic red pulp for just such an emergency.  As the monocytes morph into macrophages (ie: big eaters) to mediate ADCC induced by Rituxan, the neutrophils are no longer needed as much and stay in the blood and increase in numbers as marrow function improves. 

I watched the Dr. Najeeb lecture series on the complement system, and now I'm wondering if an overzealous complement system response to Rituxan aggregates immune complexes (Ig's, anaphylatoxins like C3a, mast cell activation products, etc.) in the skin that lead to the non-itchy rashes often seen in patients who take Rituxan.  I had several during my first round in 2009.  This cycle I noticed a small dime-sized one on my left arm a couple days after the first round that's still there.  They're small patches that usually take 5 to 8 weeks to clear.

Here's a video on Rituxan's mode of action that covers direct cell death, ADCC and complement.  However, the video indicates NK cells are responsible for ADCC whereas I'm postulating that monocytes may also play a significant role.

Rituxan Method of Action

My fascination with GA101 continues to grow.  It's a third generation monoclonal antibody (mAb) that mediates ADCC 5 to 100 times more effectively than Rituxan.  Not only is this antibody humanized, but it's elbow region has been engineered to provide better cross-linking of CD-20 antigens, which appears to dramatically improve apoptosis (cell suicide) as stated in a citation from a prior post.  This mAb has now undergone Phase II trials in indolent/refractory non-Hodgkin's lymphoma with very good results.  I'm lobbying and anxious for in-vitro studies to occur in HCL. 

[Credit: Robert Marcus, Kings College Hospital, London]

Aside from that, I've become quite a gadget geek.  I bought a PS3 to support my http://folding.stanford.edu/ hobby and an Xbox Kinect for working out.  It's seems to be doing the trick too.  My creatine kinase levels went from 109 to 315 over the past week.  CK is an enzyme that's secreted when you workout and convert ATP to ADP to release energy.  The Kinect is an imaging sensor that allows you to play games without a controller.  It's truly amazing.  The technology is still in its infancy, but you can use it to workout and keep/manage all your workout metrics, and it provides real-time analysis of your form that's better than a personal trainer's.  I predict it will make P90x obsolete within a year, and I'm anxious for a yoga application to be released.  I'm hoping some yoga and regular stretching will keep things fluid in my marrow and increase the hairy clump surface area to volume ratio, but that's just a WAG.  I figure it can't hurt.

I'm so grateful and glad I'm participating in the NIH clinical trial!  Not treating my somewhat difficult case with Rituxan by monitoring MRD would probably have led to more Cladribine treatments and marrow suppression.  I think that my case shows that just blindly adding Rituxan at 6 months post-Cladribine and taking a wait-and-see approach by monitoring counts to determine relapse is risky -- especially for younger patients.  Rather, monitoring and treating MRD is the way to go, and right now, only NIH has the facilities to do that -- especially the hypersensitive PCR MRD test.  Likewise, NIH provides 2 8-week cycles of Rituxan to treat MRD -- something regular oncologists won't be able to justify to insurance companies until the NIH study is completed.

The family's doing well.  My youngest (8 mo's) is already cruising and lifting herself up on tables, and the eldest is starting to read and play computer games (Dora and Cat in the Hat).  I've had a couple weeks as Mr. Mom over the past month while my wife's been on travel.  The first time was a breeze, but the baby had an earache the second time, so things were a little more exhausting.  I've been working on Ka-band science downlink designs for future Deep Space Discovery Missions and the S-band command and telemetry link for the GEMS program.  Overall, things are going well.
Happy New Year, and here's to a fruitful 2011!

Rewind...

I had a clinic appointment yesterday and got my FACS and BMBx results:

Peripheral blood flow is unchanged over the past 3 months and holding at .04% hairies.
Aspirate flow is at 4% -- up from 2% last May.
BMBx immunostaining shows 5% infiltration.  That means I'm no longer in remission.

It could be that my aspirate and blood flows always had hairies, but they were just masked by Rituxan until it detached from the cells and flushed out of my system.  Still, the Rituxan treatments had an effect.  Prior to Rituxan, my bone marrow infiltration at 6 months post-chemo was 30%.  Now it's just 5%.  Likewise, my blood counts are now about the best they've been since treatment started and they got a real boost after the Rituxan treatments.

The protocol calls for another round of Rituxan treatments at 6 months post-Rituxan if the peripheral blood flow is positive, so I'll be going in to NIH next Tuesday to get some more aspirate drawn for the PCR lab, then I'll start the first of 8 more Rituxan treatments (1 a week for 8 weeks) in the early afternoon.

The basic gist is this:  given that my hairies' DNA doesn't bind to the baseline PCR primer used for the hyper-sensitive MRD analysis (and any variants they may have tried), my HCL genome is likely mutated from the norm such that they don't die as easily as most, even though they have more than 100,000 CD20 antigens and bind really well with the Rituxan.  The exact nature of the mutation is still not known.

Since I was slow in responding to Cladribine and didn't get a knock-out punch from Rituxan, I wonder if the assumed mutation affects lipid raft function and restricts the biochemical reaction associated with hairy cell apoptosis and antibody-dependent cellular cytotoxicity (ADCC), but there's no way to know that for sure (for now anyway).  Likewise, the high and fairly steady flow in the aspirate leads me to wonder if there is a significant physiological change or maturation of the cells as they move from the aspirate into the marrow and peripheral blood that makes the pb and marrow cells easier to kill (a more normal lipid raft structure)?  Regardless, the prevailing theory is that the hairies in the aspirate are clumped together in a ball and the Rituxan can't peel away enough layers of the onion to eliminate them completely.

In any case, I'm hoping this round will provide more of a wallop since the bone marrow infiltration is less than before.  Still, at 4%, the aspirate flow is the same as when I started Rituxan treatments in November of '09, so it's anyone's guess as to what we'll see a year from now. 

Til then, I'll keep pushing the rock!

Merry Christmas to all and a Happy New Year too!

Restaging

Monday was a busy morning for restaging at NIH:
        1) 17 vials of blood at 7 am
        2) 45 minutes in the MRI hotdog chamber at 8 am (sounded like I was surrounded by a swarm of helicopters)
        3) Ultrasound at 9 am.
        4) Bone Marrow Biopsy at 10 am.
        5) EKG at 11
        6) Back to work at 1

I should get my FACS results for the bone marrow aspirate and peripheral blood in a couple days.  The good news is that ultrasound of my spleen shows that it now measures 10 cm.  That's down from 13.4 cm at diagnosis, and means the overall volume at diagnosis was 2.4 times what it is now -- comparitively large although a spleen size of 13.4 cm isn't abnormal for a tall man.  This bodes well for having delivered a fairly strong punch to the hairies.

The bone marrow biopsy was the most pain-free so far, but mine was still done by hand -- not the new bone marrow drill that gets the job done in just 10 seconds.  NIH started using the drill recently, but they didn't have any bits left from the initial order, so I'll have to wait until next August (biopsy #7)  to see if the drill is as fast and painless as claimed.

My CBC results were very good.  The WBC is back up to 3.74, platelets are up to 139 and ANC is at 2.5.  There is no sign of any fat in my liver and my AST and ALT are still great at 20 and 30, respectively.

We're assuming the FACS will be positive, so I'm scheduled for a clinic appointment next Wednesday and will start my second round of Rituxan on the 28th -- 8 cycles over 8 weeks.  When I'm done this round, I'll have received 16 cycles of Rituxan over the course of 16 months.

I'll post my FACS results as soon as they come in.

Hairy Cell Leukemia: I Want a New Drug ...

I want a new drug... 

Okay, maybe not yet, but it looks like there are lots of new potential candidates for treating HCL that still have yet to be explored.  Two posts ago, I mentioned a new third-generation antibody that has the potential of being 5 to 100 times more powerful than Rituxan but hasn't been used to treat HCL yet.  I'm hoping some preliminary in-vitro studies will be conducted soon.

Today, I found another one -- a Btk (Bruton's tyrosine kinase) Inhibitor, PCI-32765, that is currently in Phase I clinical trials in patients with B cell malignancies (specifically Non-Hodgkin's Lymphoma).  Btk is an essential signalling factor needed for the development of  B-cells.  By inhibiting it, the Btk protein production is blocked and B-cells can't develop.  The inspiration for developing the drug was born from a disease, XLA, in which B-cells are absent from the peripheral blood because Btk is not produced due to a Btk gene defect. 

What's great about this drug is that it's a pill, taken orally, that inhibits Btk production and thus B-cell production.  Since HCL is a B-cell malignancy, I've asked the Hairy Cell Consortium if they are familiar with the drug and whether it may be a candidate for a Phase 1 trial to treat relapsed and refractory HCL patients.  I'll let you know if they respond. 

"This is a very selective compound for B-cells, and it could represent an important alternative to rituximab therapy for the treatment of B-cell NHL. Other obvious applications include autoimmune disorders such as rheumatoid arthritis and lupus, and Pharmacyclics also has strong preclinical efficacy with PCI-32765 in these disease models," said Dr. Mark Genovese, Professor of Medicine and Co-Chief of the Division of Immunology and Rheumatology at Stanford University Medical Center and member of Pharmacyclics' Scientific Advisory Board. [Taken from Pharmacyclics Press Release dated April 13, 2009]


Wouldn't it be great if we HCL'ers could knock out minimal residual disease (MRD) and then take a pill as maintenance therapy so that we'd never have to worry about it ever coming back?  Even better if it could act as the first-line therapy someday and eliminate the need for chemotherapy altogether (and side-effects like increased secondary cancer risk and impact to T-cell counts), or provide  a new treatment alternative for patients with HCL-V (the variant form of HCL that doesn't respond as well to Cladribine).

Prediction?...Pain!

After months of putting it off, I finally went to a new dentist last week.  He told me to see another endodontist to get a second opinion about the root canal and fistula that never resolved after the retreat 18 months ago.  The endodontist told me he's stymied, that it's not good to let the fistula linger because of possible bone damage, and to get the tooth (#14 molar) pulled.  Since the tooth extends into my nasal cavity, they may have to sew in some new bone to make it heal faster.  Once it heals, they'll install a post and a false tooth. 

Oh, and my dentist found a cavity under a cracked filling. 

The tooth extraction and filling cover the first week of December.  The following week, Dr.K is going to restage my progress in case they need to retreat with another round of Rituxan, which means another bone marrow biopsy (#6) on the 13th. 

My good friend Mr. T would like to have a few words:

Prediction? ... Pain!

The protocol has officially been ammended to allow two rounds of Rituxan for the delayed Rituxan cohort (the one that I'm in).  It's a simple one-line addition:  "Also may repeat for those with blood MRD six months after delayed Rituxan."  My flow was negative at 6 months post-Rituxan but has now been positive for 3 months, and will likely still be positive when I restage, so I'll probably receive another 8 rounds of Rituxan starting in January.   I'm very hopeful that this round may be even more effective than last year's since my counts are in good shape and my neutrophil level is much higher.

A high neutrophil count has been shown to correlate with improved antibody-dependent cell-mediated cytotoxicity (ADCC). In other words, the more neutrophils you have when you start Rituxan therapy, the more they can help kill the cells that are tagged with Rituxan. I'll be interested in seeing if I have another incidence of Rituxan-Related Late Onset Neutropenia (RRLON) at week 14 this time around.

I had a physical at my PCP on the 3rd.  Everything checked out fine.  My liver enzymes are holding steady at 22 for both the AST and ALT and my HDL is back up to 40 for the first time in 2 years!  I received 3 vaccinations:  tetanus, pneumonia, and flu.  I couldn't move my left arm for 4 days, but now I feel great.

Aside from that, I've been dabbling in some new favorite hobbies: studying organic chemistry, molecular cell biology, genetics and bioinformatics so that I can better understand some of the papers I've been reading on antibody research and lipid rafts.  I wish I could go back to school full time. 
(12/2/2010)  Tooth Extraction Follow-Up:  Had the tooth pulled.  Everything went fine, and the major bleeding stopped within minutes, although there was a very slow trickle afterward.  I'm hoping this means that there is continued improvement in my platelet count.  I was able to go without any gauze within 3 hours (probably sooner if I hadn't been so cautious).  There were several cysts (about 1 to 1.5 mm) that had formed at each root tip and had to be rigorously scraped off the bone after the roots were extracted.  The worst part was the high pitched squeal of the drill used to segment the root sections so they could be pulled individually.  1 day later, everything feels fine.  I just need to eat soft foods and avoid that side of my mouth for a few days.  In 2 to 3 months, I'll have an exam to verify the bone has grown back and then get a post installed.

A New Hope

Good news!  The latest FACS results from blood taken on September 30th indicate no change in the peripheral blood hairy cell burden or the percentage of lymphocytes that express the hairy cell phenotype (characteristics).  This gives more credence to the hypothesis that the positive FACS results are due to the Rituxan monoclonal antibodies (mAbs) detaching from the residual hairy cells and clearing my system.  The hairy cells may have always been there, but now they are no longer masked by the Rituxan and are once again detectable by FACS.  The important point is that the percentage of hairy cells in the blood remained unchanged at .04%, so the malignancy is not dividing/growing in numbers.  We'll continue to monitor over the months to come, but given that the results are identical to those from 4 weeks ago, I'm very hopeful.

Here's a video of my latest bloodcounts.  Please excuse the melodramatic soundtrack,  I was just indulging in some creative publishing ...
In other news, I'm very excited about a drug I found while researching the relationship between lipid rafts and anti-CD20 monoclonal antibodies.  It may have significant potential in treating HCL -- perhaps 5 to 100 times greater potency than Rituxan.  Pursuant to my inquiries, HCL investigators, who were previously unaware that the drug existed, are now performing detailed analysis of its potential in treating HCL that could lead to some preliminary in vitro laboratory studies.  If all goes well, it may be used in a Phase 1 trial to treat HCL patients who otherwise would have to resort to palliative treatment options.  Maybe several years down the road, it will also become part of the standard arsenal in treating this disease. 

We HCL'ers are fortunate to have so many options and doctors who are willing to listen to and pursue our questions.  It's a good feeling to know that in some small way we can help fight the war on cancer and not be its victims.

Double Trouble

The tumor load in my peripheral bloodstream doubled over the past 3 weeks.  I had a FACS done on August 31st, and the report indicated the percentage of hairy cells increased to .04% from .02%. If the cells are really doubling every three weeks, then I'll have an appreciable burden (around 1%) by January.  Currently, about 5% of my lymphocytes are hairy cells.  I just got the flow results today and haven't talked to Dr. K yet about what it all means.  Still, I've asked to have another flow on Sept. 21st.  If the burden doubles yet again, then I'd like to get another bone marrow biopsy in early October to see if the cells are back in the core.

On the bright side, my counts are continuing to improve, so at least the hairy burden is currently low enough so as not to significantly impair my marrow function.  My WBC is at 4.03, my neutrophils are at 2.6 and my platelets are at 141 -- an all time high since treatment.  I'm still hopeful that I might be able to get another Rituxan treatment while the overall burden and clump sizes are low.

I've read some interesting articles on leukemia using fat as fuel as well as fatty acid involvement in hairy cell membrane morphology.  A study demonstrated how drugs that inhibit fatty acid oxidation may sensitize leukemic cells to drugs that induce apoptosis.   I'm very interested in finding out whether there is a relationship between fatty acid oxidation, body mass index (BMI) and the effectivity of Cladribine.  If one could show that people with lower BMI respond better to Cladribine chemotherapy, then perhaps general approaches to reducing BMI prior to treatment with 2CDA could result in better outcomes for all patients.  My crazy brain at work.  (Afternote:  Turns out there is a basis for my query regarding a correlation between BMI and chemotherapy, although it's not directly related to HCL.  A study of childhood leukemia patients showed that patients with high BMIs were less likely to respond to chemotherapy.  While the theory reported is that cancer cells sequester in body fat, I have my feelings that cellular membrane factors may be involved as well.)

Time to go exercise...

(More random thoughts, 9/9/10) I've been reading about cellular plasma membrane structures called "lipid rafts."  Although these structures are readily observed in cultured cells, they have not been observed in live cells, and their existence in live cells is considered controversial; however, I wonder if hairy cell filopodia (aka villi -- the fine hair-like projections of hairy cells) are actually extrusions of cytoplasmic material from lipid rafts which have large cholesterol concentrations (remember -- hairy cells have high cholesterol content).  I read an abstract from a study entitled "Lipid Raft Disruption Prevents Apoptosis Induced by Cladribine."  It indicates that although leukemic test cells completely absorb Cladribine, disrupting the lipid rafts inhibited the flow of calcium ions through the plasma membrane and reduced the apoptotic effects of Cladribine.  Although the study used ALL cells, I wonder if this is a reason why Cladribine doesn't work well for some HCL patients (the lipid rafts are disrupted or vary in some way that prevents proper biochemical flow to induce apoptosis).  Still, the study probably used cultured cells, so it's hard to know if it applies to live cells.  I'd like to get the full article and learn more about the causes of lipid raft disruption to find out if there are things that can be done to make Cladribine more effective for all patients.  Who knows, maybe this is a factor in HCL-V, and figuring out a way to open the ion pathways will make Cladribine effective in that variant of the disease too.

Similarly, treatment with interferon-alpha has been shown to reduce HCL cholesterol content and villi length.  This would support my theory since lipid rafts are assumed to contain large amounts of cholesterol.  Reducing the cholesterol content of the lipid raft would reduce its area and correspondingly, the amount of material extruded to form the villi would be reduced -- resulting in shorter villi.  I don't know why I write this stuff.  Aside from the fact that I'm desperate to kill these hairy bastards, I suppose I'm hoping a grad student will take it on as a project or at least comment on its plausibility.

(Even more random thoughts, 9/10/2010)  This is kind of cool.  I just found an abstract for a study entitled "Microvilli structures on B lymphocytes: inducible functional domains", which states:  "We also discovered that depletion of cholesterol, using b-methyl-cyclodextrin, lowered the number of microvilli, indicating that intact lipid rafts are required for their expression."  This applies to the microvilli of normal cells, but it is in keeping with my hypothesis regarding unusually large lipid rafts as the source of the filopodia (aka villi of hairy cells.  Perhaps my hypothesis is right.  Now if only I could win the lottery and fund my own studies...

Interestingly enough, there is a patent for a formulation of Cladribine that uses b-cyclodextrin as the soluble agent in lieu of the original benzyl alcohol and propylene glycol cosolvent soluble agent combination.  This is a similar compound as that referred to in the paragraph above (Both β-cyclodextrin and Methyl-β-cyclodextrin (MβCD) remove cholesterol from cultured cells) and it's used to deplete cholesterol and reduce the number of microvilli on B lymphocytes.  If hairy cell villi are indicative of lipid rafts, and lipid rafts are necessary to allow ion flow and induce apoptosis, then perhaps this formulation of Cladribine is slightly less effective than the original version.  I'd like to know which version of the drug I was given.  If b-methyl-cyclodextrin acts as a lipid raft disrupter, then maybe the original formulation is more effective in patients with variant lipid raft function.

(9/11/2010)  I found another great article:  "CD20-mediated apoptosis: signalling through lipid rafts," which seems to imply that in order for Rituxan to induce apoptosis, it must cross-link CD20 proteins that are located in separate lipid rafts.  My initial thought was "does this mean that if your cells have fewer rafts or if the rafts are too large, the drug will be less effective?" and this thought turned out to be mirrored in the final thoughts of the study report: "Finally, it will be important to test the prediction that the size or abundance of lipid rafts in B-cell membranes is a contributing factor to the susceptibility or resistance of patients to CD20-mediated B-cell depletion."  This study's findings resonate a common theme with the other studies I've referenced regarding the involvement of lipid rafts in apoptosis.

Much of this report seems to read as if the high cholesterol content of the cells is necessary in order to allow the calcium ion flow needed for apoptosis to work properly.  This would indicate that going on a low-cholesterol diet during therapy to try to starve the hairies may be counter-productive.  Since the underlying apoptotic biochemical process seems to be the same for Cladribine induced apoptosis as it is for anti-CD20 induced apoptosis, maybe cholesterol gets synthesized into other chemicals during apoptosis -- causing the hairies to suck in more cholesterol from the peripheral blood as they try to survive.  Maybe this explains why my blood cholesterol dropped precipitously during Cladribine chemotherapy (HDL went from 30 to 18 in a matter of days, LDL went from 90s to  high 60s).  I'm guessing that partial apoptosis biochemical processes started and consumed cholesterol, but the calcium mobilization was inhibited so as the cells survived, they consumed more cholesterol from my peripheral blood to reconstitute themselves.  Ultimately, many of them died after six months (went from 80% bone marrow infiltration at 1 month post chemo to 30% at 6 months) probably due to DNA damage and slow but sure calcium mobilization, but too many survived.

I found another article which reinforces and provides further detail on the involvement of cholesterol in B-cell apoptosis: "Cholesterol depletion inhibits src family kinase-dependent calcium mobilization and apoptosis induced by Rituximab crosslinking."

Hmmm....does this mean I should eat Ben and Jerry's Vanilla ice cream during therapy?  Of course not, fat and cholesterol are different substances.  Maybe shrimp is a good compromise -- low in fat, but high in cholesterol.  Leukemia is so paradoxical to the conventional mindset.  This is interesting because studies in many solid tumors (like prostate cancer) show that cholesterol depletion aids in apoptosis.  The differences between leukemia and solid tumors are fascinating.  Time to go watch Woody Allen's "Sleeper" -- turns out chocolate cake is good for you after all...

(9/18/2010)  I got a great reply from the "Hairy Cell Consortium" regarding some questions I had regarding lipid raft research for HCL:

My e-mail to them read as follows:
      Given the findings of the following studies:
          "CD20-mediated apoptosis: signalling through lipid rafts"
          http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1782791/pdf/imm0107-0176.pdf

          and

         "Lipid raft disruption prevents apoptosis induced by Cladribine"
          http://www.ncbi.nlm.nih.gov/pubmed/16730061

          isn't it possible that lipid raft disruption may play a
          significant role in why these drugs
          are are not effective for some patients?
          Why isn't there more research to characterize
          HCL lipid rafts and determine the role that lipid
          rafts have in the disease?

Here's their reply:
 
         Dear Mr. Howard:

        
         The question that you pose about the potential
         importance of "lipid rafts" and response to therapy
         in hairy cell leukemia is excellent. To our knowledge,
         the characterization of "lipid rafts" in hairy cell
         leukemia has not been published. In contrast, lipid
         rafts have been explored in chronic lymphocytic leukemia
         by several investigators. The presence of lipid rafts has
         been correlated with response to cladribine as well
         as response to monoclonal antibodies in vitro. The
         monoclonal antibodies that have been studied include
         both Rituximab and Alemtuzumab. Since both of these
         agents may have some benefit in this disease, all patients
         have not responded. It would be interesting to
         correlate the responsiveness to these agents as well
         as to the purine nucleoside analogues. This is the type
         of study that might be conducted within the Hairy Cell
         Leukemia Consortium. Your question has merit
         because it might provide predictive biomarkers to
         determine who will and will not respond to these agents.

       Regards,
       The HCL Consortium Team

This response made me very happy.  Hopefully, they'll perform some studies.  Who knows, maybe the research will not only provide predictive biomarkers but ways to tailor the structure of antibodies to conform to variances in lipid raft size and placement that fall outside the range accomodated by the current antibodies' structures.

The FACS of Life

You knew it was only a matter of time before I had to use that corny title for a blogpost, but bear with me, it follows a coherent theme.

Other candidate titles for this post included:
      Dirty Hairy
      From Hairy to Eternity
      The Good, The Bad, and The Hairy
      Gone Today, Hairy Tomorrow
      The Cells that Wouldn't Die
      Protocol
      and Hair We Go Again

Simply put: you take the good, you take the bad, you take 'em both and there you have the FACS of life...

The Good:  The Rituxan treatments worked really well and as I wrote in my last post, the hairy cell burden in my May bone marrow biopsy was zero (although the bone marrow aspirate [liquid] showed 2.1% hairies).  Likewise, I just had a complete blood count last week and my counts are at historical highs since diagnosis, so my marrow is continuing to rebound and keep me healthy.

The Bad:  My FACS results from last week showed some hairies in the peripheral bloodstream (.02% of the peripheral blood monoclonal cells), but there are several reasons for why that may be.

The Theories:
     #1: It's very possible that the few hairies which were bound with Rituxan but not completely killed via apoptosis or immune system attack, were undetectable in prior FACS tests due to the effects of the Rituxan covering the surface.  Now that the Rituxan is flushing out of my system and coming unbound from the hairies, those cells are once again detectable.
     #2:  The cancer that wasn't killed by the Rituxan (some of the cells in the aspirate) are starting to proliferate again and seep into my peripheral bloodstream.

The analysis:
     Usually the simple answer is the correct one (unfortunately #2 is the simplest), but we are sailing in uncharted territory right now, and there is plenty of time to perform more tests over the coming months and really get a feel for what is going on.  Theory #1 is highly optimistic but still plausible, and it's still very possible that as my marrow rebuilds, my immune system will either keep the remaining HCL in-check or attack and destroy it.  Time will tell.

What's next:
     Given how well Rituxan worked the first time considering my HCL burden after Cladribine chemotherapy was still substantial, I believe I would benefit from a second round of Rituxan treatments if they are offered to me.  The possibility of adapting the protocol accordingly for my cohort is being considered (the simultaneous chemo/Rituxan cohort is allowed two rounds of Rituxan, but my delayed Rituxan cohort is currently allowed only one).
    In the meantime, I'm interested in seeing how my body will respond to the remaining hairies and feel that doing some more FACS tests to see if the burden increases or becomes undetectable again will help to substantiate or disprove theory #1.  Over the next few months, we'll run some more FACS tests and see what happens.  Let's hope my immune system kicks it.

Here's a slide show of my latest blood count results:

Since my last post in May, I've really been enjoying life.  Taking lots of time to be with the family, a trip up to Hershey Park, and enjoying the weekends when the heat or rain doesn't make that impossible.  It's been an incredibly happy time and given that the blood counts are continuing to improve, I really don't care about the few cells that were found in the peripheral bloodstream.

I should have another FACS in 4 to 6 weeks.  I'll let you know how it goes.