My Chronic Lymphocytic Leukemia (CLL): More Good News
I still have CLL, but less of it.
It's in remission and it's actively retreating, but I still have residual disease.
Today I learned that my flow cytometry showed that I have a few cancer cells floating in my blood stream.
Here's how I know.
Essentially all B cells, good or bad, cancerous or benign, have a CD19 marker but are not supposed to have the CD5+ marker on their surface. That's usually found only on T cells. Those that have both are my abnormal CLL cancer cells.
Flow cytometry which looks very deeply at thousands of cells was able to find only 28 of such cells per 10,000 cells. That means only 0.28% of my lymphocytes are clonal.
Let's do the math. I am a little shaky on my assumptions here, so please correct me if I'm wrong. Of every 10,000 lymphocytes that I have, only 28 are my CLL clone. That is an amount a microscope could never find, but the flow cytometry lasers can spot easily. If my nodes and bone marrow were clean (not likely but I can hope), I would be in a complete remission (CR), but minimal residual disease or MRD+. How important it is to be MRD- in the era of TKIs is a matter of debate.With FCR, it was very important in terms of prognosis.
There are 1,400 lymphocytes per millionth of each liter of my blood and of course there are a million microliters in every liter. We we all have about 5.6 liters of blood, so 1,400 x 1,000,000 x 5.6 x 0.028 = about 22,000,000 cancer cells lolling around in my blood stream. Sounds like a lot, but it's nothing.
Those millions and millions of peripheral white blood cells are not even the one that are proliferating. That's done mostly in the nodes, so my nodes are pumping out less cancer now. I know that because in October, the same count was 47. That's a 43% drop in the last 6 months, suggesting my CLL is still responding nicely to the ibrutinib.
After nearly two years, it is still working its magic inhibiting the B cell communication pathways needed to survive and reproduce.
That's truly great news.
Quite remarkable if we stop and think about it. Almost two years out and this gentle giant of a therapy is still dropping my leukemic cell count.
To get some perspective on my results, compared to my measly 220,000,00 cells in my entire blood stream, some of my friends with active disease can have half a million lymphocytes or more in each and every millionth of a liter of blood and nearly everyone of those is a part of the evil clone's posse. 500,000 x 1,000,000 x 5.6 is a big number. The counts of almost anyone with active disease is several orders of magnitude greater than mine. My count of CD19/CD5+ cells is trivial in comparison.
The other good news is that my overall T cell count is climbing with appropriate CD4/CD8 ratios. This could mean my ability to fight off infections is improving and more importantly my bone marrow and the rest of my immune system is healing.
My CLL has always been more nodal, hidden in my belly, so the CT scan at the end of June will be critical, but this is a positive harbinger. Makes sense that if I harbored any significantly growing nodes that were resisting the ibrutinib, they would be pumping more cancer out into the blood and the exact opposite is happening. But the relationship between the size of the nodes and the CLL count in the blood is not always so tight. Still it is good news.
I will be posting more videos from ASH soon and am preparing to attend ASCO in Chicago at the end of May.