Answer
death in early childhood ( fatal disease = lethal )
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Severe Combined Immunodeficiency ( SCID )
- this may be due to failure of differentiation of stem
cells into T and B cells
however the explanation of this failure is not known.
- both humoral and cell mediated immunity are
deficient.
- these infants suffer from all kinds of opportunistic
infections : viral, bacterial, fungal and protozoal.
- death occurs early in childhood ( before 1 year ).
- the disease may be inherited in an X-linked
recessive or autosomal recessive manner, however
sporadic forms occur.
# Immunologic Findings :
1- Hypoplasia of the Thymus as shown by chest
X-ray.
2- Lymphopenia and decreased T cell number and
functions:
- impaired response to Phytohemagglutinin
( PHA ).
- Impaired Delayed Hypersensitivity reactions.
3- Decreased B cell number and function :
- Serum Immunogloulins are absent or decreased
- No response to antigenic stimuli.
# Treatment :
patients may be made completely normal by grafting
with histocompatible bone marrow from a sibling.
incompatible grafts will lead to a fatal " graft versus
host " ( GVH ) reactions.
- Gammaglobulins may be administered.
- Antibiotics are used for treatment of infections.