Last week, a blood sample from Brad was sent off to check his degree of chimerism—that is, what proportion of Brad’s blood now has the DNA of James, his donor. (A chimera, scientifically and medically speaking, is an organism containing two types of genetic material—and post-transplant, if all goes well and the graft succeeds, patients will have their own and their donors’ DNA in perpetuity.) Although this test is done routinely after allogeneic transplants, we were a bit concerned about it, because over the last few weeks Brad’s once-high white blood cell counts (remember those? the things we were so focused on before he got terrible graft-versus-host disease?) have been steadily dropping.
His physicians said this could indicate that the graft was failing or sputtering out, though, they said, that would be very surprising given his level of GVHD: the disease-causing activity of the graft was a pretty good indication that it is hard at work in his body. Still, however slim the chances, we weren’t enjoying hearing about that possibility. After all, every single piece of bad news or medical setback that Brad has experienced during his cancer diagnosis and treatment has been preceded by a doctor (sometimes more than one doctor) telling us that whatever eventually proved to be the case would really be very surprising.
Well, the chimerism test came back last night, and its results, for once, did not follow this rule. Brad is, officially, 100 percent a chimera and aspiring no more: all of his blood cells are the product of the graft and display James’s genetic material. This is great news, obviously; any problem with the graft would have presented Brad’s doctors and us with some very difficult choices regarding whether to give Brad more stem cells (thus risking more severe GVHD). Happily, those are choices we now don’t have to face. It’s not entirely clear what is causing the lower white counts, but they are now holding steady and since Brad is still on an extremely large number of medications, it’s likely one of them is the culprit.
In other news, small improvements continue with his eating, though his gut symptoms remain and progress is very slow. I’m making him a lot of broth and easy-to-eat things like chicken soup with tiny pasta. Yesterday I stirred an egg into some soup for a little more protein and that went over well. Today I brought in some buttered toast strips for dipping (a hit) and a bit of homemade apple puree (no verdict yet). The total volume he’s eating is still very small, but he is enjoying the taste of food, which is great to see. It all reminds me a little of starting a baby on eating solid foods, though I’m thankful to say Brad is a much less messy eater and is much handier with a spoon than your average infant.
Unfortunately, Brad’s eyes continue to be a problem and his vision has not measurably improved, though the eye doctors are saying that the Prokera rings are continuing to heal—just very, very slowly. The GVHD in his eyes apparently stripped away the epithelial layer of the eye, just as it stripped away the epithelium in his gut, and healing for both will be a long, long process. But for today, we are very pleased that Brad has fulfilled his long-held goal of becoming a chimera.