This week we are celebrating the Jewish holiday of Chanukah, which celebrates (among other things) a miracle: After destruction of the temple, the Jews used the last remaining oil they had left to light the menorah, with the flame rising from the menorah in the midst of ruins as a symbol of their resilience despite great hardship and against all odds. They believed the oil would last only one day, but it lasted eight days. To this day, Jews light candles on menorahs around the world for eight days to commemorate this miracle of survival, resilience, and another seven days of light.
On the 8th and last day of Chanukah, by coincidence, we are headed to Duke to test whether Idan’s remaining donor t-cells, which are so few in number but are nonetheless hanging on, are, like the oil, sufficient. This would be a miracle indeed.
As we mentioned in our last update in September, we are working with our medical team to plan Idan’s second transplant. As time goes by, it looks more and more likely that we will be heading back to Seattle this Spring for transplant. Idan has been doing great, growing and thriving and we have been able to keep him healthy with his weekly infusions of antibodies. He receives home-school services from the New York State Board of Education, and has been learning to read quite impressively for a 3 yr old (we kid you not). So we are once again headed towards transplant with a healthy, active child, and we are once again gearing up for all the challenges that lie ahead.
Before we decide whether to move forward with a second transplant, however, we need to first conclusively determine that it is absolutely necessary. While he has lost almost all his donor graft, there is around 8-10% of the donor’s t-cells still showing up in his chimerism tests. Although in a perfect world, 10% donor t-cells could in theory be sufficient to provide an individual with a functioning immune system, it appears that the donor t-cells in Idan’s graft are not binding to the B-cells, which is necessary in order to create an antibody response. For this reason, we assume that a 2nd transplant is imminent. However, the tests that have been run so far are not 100% conclusive, and, before going into a second bone marrow transplant, which is without a doubt a life-threatening procedure, we and our team of doctors feel that we need to be absolutely sure that the remaining donor cells lingering in Idan are in fact insufficient to provide Idan with a functioning immune system.
It is not easy to determine whether Idan can make antibodies with the small amount of donor cells left. He receives weekly infusions of subcutaneous immunoglobulins (SCIG), which provides him with a high level of antibodies. One way to test if he can create antibodies is to give him a vaccine (any of those childhood vaccines we all get). However, because of the constant infusion of antibodies through SCIG, he has a full repertoire of antibodies for almost any vaccine, meaning we would not be able to determine whether he was responding to the vaccine or whether the antibody is from the SCIG.
There is one test that is only available in the United States in Seattle and at Duke called the bacteriophage φX174 or Phage. Essentially we would be giving Idan a *fake* vaccine (through an IV) that contains a small amount of a virus that is used to fight bacterial infections. This is not a virus that people are exposed to, and it is not part of vaccinations anyone gets, so antibodies to this virus would not exist in the SCIG he receives weekly. If Idan can make a response to this vaccine, it will show up as distinct immunoglobulin (antibodies) for this phage and can be measured.
After much research and debate we decided to head down to Duke to do this test. It is a short 24 hour visit, and we will send blood samples back to Duke over the next 6 weeks. Then we will head to Duke again in late January for a 2nd dose and repeat blood tests back in NYC. Sometime in March, Duke will send all the samples to Seattle’s immunology lab for testing and we should get results right before the tentative date of the 2nd planned transplant.
Two and a half years after our first expedition to Duke to find a cure for Idan, we are headed back to Duke this Sunday to test if Idan might perhaps be cured. Based on all lab tests it is very unlikely that Idan will make a response to this vaccine. But, if by some miracle his small percentage of donor T-cells can make a response, this might mean that we can postpone 2nd transplant and see if his donor cells can provide him with enough immune function on its own.
We will begin this test on the 8th day of Chanukah, a holiday commemorating that miracle long ago whereby a very small amount of substance that should have lasted only for 1 day lit the Menorah in the temple for 8 full days. Let’s hope that Idan’s small amount of donor cells can pull off the same kind of miracle.