Everything the pediatrician ever wanted to know about HLA but was afraid to ask.

Following a description of the genetic aspects of the human histocompatibility antigens system HLA and its principle typing methods, this paper reviews the relationship between HLA antigens, transplantation immunology and certain diseases. In particular, the role of the lymphocyte-defined antigens of the HLA-D system is emphasized on the basis of a special typing method, the PLT test, used in our laboratory. Aside from its necessity in bone marrow and kidney transplantation, HLA typing can be used as an additional diagnostic or prognostic tool for certain diseases. Among the pediatric age group, this includes rheumatic fever and other rheumatic diseases, insulin-dependent juvenile diabetes mellitus, some forms of Addison's disease, thyrotoxicosis, myasthenia gravis, celiac disease, and some complement deficiency disorders. Close linkage of the HLA system with steroid 21-hydroxylase deficiency has made it possible to diagnose this form of congenital adrenal hyperplasia in utero. This approach is illustrated in a large family at risk for this disorder.