MadSci Network: Medicine

Re: Original David,Boy in Bubble, with SCIDS length of life outside of bubble?

Date: Mon Feb 21 01:28:11 2000
Posted By: Mark Sullivan, Medical Student
Area of science: Medicine
ID: 950653483.Me

     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


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