After one treatment with Rituxan, FACS results indicate that the percentage of hairy cells in my peripheral bloodstream plummeted from .4% to .05% -- a reduction of 87.5%! I can only hope that it's having the same effect on my marrow infiltration, but I believe it is.
I've now had 3 treatments with Rituxan, so one can expect that the percentage of hairies has now reduced to undectable levels with the standard FACS MRD detection technique. Blood for the next FACS will be taken prior to the Week 5 treatment, so we should know those results in about 3 weeks. It's likely the malignancy will be undetectable!
I also had my Pentamadine (lung antibiotic) treatment yesterday, and it went very well too. The taste was slightly bitter but tolerable. The Pentamadine is a nebulized once monthly treatment in lieu of Bactrim, to prevent the possibility of respiratory infection while being treated.
I'm still trying to figure out why my liver enzymes are elevated. I've been off Bactrim for 10 days, but my last chem20 panel indicated that both the AST and ALT liver enzyme levels went up slightly. I avoid all pain-killers except when they're required for my treatment. Gluten intolerance is also associated with tinnitus and elevated liver enzymes. I think the next step is to go strictly 100% gluten free -- pretty much live off fresh vegetables and meat all cooked at home for two weeks and see if the levels drop significantly.
Anyway, the good news is that the Rituxan is working very well. The FACS count after cycle 1 was .35 cells/uL. Assuming there are 6 liters of peripheral blood, this translates to approximately 2.1 million circulating hairy cells. This means the total HCL count went from 24 million down to 2.1 million in just 1 week.
If the kill process is arithmetic, and the kill capacity per cycle is only dependent on the available volume of Rituxan, then the second cycle may have already killed off the remaining circulating hairy cells; but if the reduction rate continues at 87% of the remaining cells per cycle, I'll still have a few circulating cells left in the near term after cycle 8 (the final cycle). As the cumulative concentration of Rituxan in my system continues its hairy cell search and destroy mission in the months that follow, the remaining cells should be annihilated.
Otherwise, if each round is only half as effective as the previous round, then the total peripheral load would be reduced by 95% in the short term after round 8, which is still really good, but may leave 10 to 20 thousand hairies remaining in the peripheral blood and possibly a hundred thousand or so in the marrow. That's why I need the hyper-sensitive MRD test.
Here's a semilog plot of the FACS cell count per micro-liter since I was diagnosed. If my estimates are correct, then at it's peak, I had 471 million circulating hairies. Now they're getting hard to count.
The treatments are going well. Let's hope all the cycles are as effective as the first one was!
I've got a lot to be thankful for this Thanksgiving!
Three down, five to go...
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