DR-POSITIVE T-CELLS IN AUTISM - ASSOCIATION WITH DECREASED PLASMA-LEVELS OF THE COMPLEMENT C4B PROTEIN

Autism is a developmental disorder characterized by severe communicati on, social and behavioral abnormalities. Over the past several years a fair amount of evidence has accumulated suggesting that some cases of autism may be associated with immune abnormalities and with products of the HLA complex including the C4B gene located in the class III reg ion of HLA. This study sought additional evidence for an association o f autoimmune processes with autism by investigating the presence of ac tivated T cells in 26 autistic subjects. Fourteen of the autistic subj ects had DR+ T cells, an indicator of activated T cells, but none of t he autistic subjects had T cells expressing the interleukin-2 receptor , another indicator of T cell activation. Similar findings of complete or partial T cell activation have been reported in autoimmune disorde rs and in a recent study of autism. In the current investigation, the DR+ T cells were not found to be associated with age of the autistic p atients but were inversely correlated with a decreased plasma level of the C4B protein. In conclusion, this study provides additional eviden ce for the involvement of an autoimmune mechanism in autism.