Deficiency of autologous mixed lymphocyte reactions and serum thymic factor level in Down's syndrome.
The immune competence of the T lymphocyte system was studied in 28 noninstitutionalized subjects with Down's syndrome (DS) and were compared with sex- and age-matched healthy controls. The ability of enriched T lymphocytes to respond to 3 different T cell stimulants revealed a selective impairment of T lymphocyte subset(s). Subjects with DS showed normal responsiveness in allogeneic mixed lymphocyte reactions, but their response to phytohemagglutinin and in autologous mixed lymphocyte reactions was severely impaired. Non-T cells from DS subjects stimulated equally well both normal and DS allogeneic T lymphocytes. The blood concentration of serum thymic factor in the majority of DS subjects was much lower than that found in age-matched healthy controls. These data support the hypothesis that a deficiency of the T-dependent regulatory system is an intrinsic feature of DS and confirm the precocious aging of the immune system in these subjects.
D000293:Adolescent; D000328:Adult; D000375:Aging; D002648:Child; D004314:Down Syndrome; D005260:Female; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000276:immunology*; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology*; D013935:Thymic Factor, Circulating; D013936:Thymidine / Q000378:metabolism; D013951:Thymus Hormones
D010835:Phytohemagglutinins; D013951:Thymus Hormones; D013935:Thymic Factor, Circulating; D013936:Thymidine