|MadSci Network: Medicine|
Carol, It is strange that I was sent this question because we were talking about SCID in my immunology class just the other day. I was asking some of my classmates if they had ever seen "the Boy in the Plastic Bubble" and to my surprise none of them had ever heard of it! Anyway these coincidences often seem like fate. To answer your question quickly, I don't know. I have been searching around the medical databases to find something about how David died, and I can't seem to find a thing. What I do know is that the Doctor who performed the transplant was named Robert Good. What I can suppose about how David died is based out of my immunology text book. To paraphrase the book, within the first year of life these children are plagued with oral infections caused by the Candida albicans(a type of yeast), chronic diarrhea, and eventually very serious infections from various viruses, bacteria, and parasites. Without bone marrow transplants the life expectancy is about 1 year unless placed in a germ free environment. Now David died in 1984 at the age of 12 after a bone marrow transplant. Several things could have happened. First is that at that time the success rate of bone marrow transplants were pretty low due to the fact that science had not fully understood the importance of matching what are called HLA haplotypes between the donor and the host. Now if the donor was a family member, that improves the chances of these haplotypes being similar, but not by much. What happens when they don't match up is that the new immune system begins to work against the host in what is called Graft versus host disease (GVHD for short). Every cell in your body has protiens and other substances on their membrane surface so that the immune system can recognize "self" from "non-self". When something like a bacteria or parasite invades the body, white blood cells go to the site of infection to check out what is happening. If they encounter something they don't recognize as self, they start the immune response to get rid of whatever it is. In David's case it could have been that the new white blood cells from the donor didn't recognize these specific tissue proteins on the surface of his cells, and thought that an invasion of foreign material was taking place. This causes the white blood cells to kick into action and destroy what they perceive to be the invaders, all of his cells. As you can imagine this is not a good thing. Of course, they probably could have stopped this from killing him by radiation and chemotherapy treatment which would kill off all of the new white blood cells and stop the attack. What most likely happened is that the bone marrow transplant didn't work, why I don't know, and didn't give him the immunity they had hoped. In this case he most likely died from a opportunistic or viral infection. It could have been any number of things that killed him, even the common cold. I am sorry that I couldn't find out the absolute answer for you. You can do more investigating on your own at this site for the SCID Homepage. As far as books, well the only ones I know are pretty technical at your stage so I think the information in this site and links should work fine. Good luck, Mark Sullivan
Try the links in the MadSci Library for more information on Medicine.