T-cell immunodeficiency syndrome

T-cell immunodeficiency syndrome

Any of a group of immunodeficiency states arising from partial or absolute defects in T-cell function; T-cell defects are generally more severe than B-cell defects, have no effective therapy and are characterized by recurrent opportunistic infections–eg, by Pneumocystis carinii, cutaneous anergy, growth retardation, ↓ life span, wasting/'runting', diarrhea, ↑ susceptibility to GVHD, potentially fatal reactions to live viral or BCG vaccinations and an ↑ risk of malignancy; TCISs include DiGeorge syndrome–thymic hypoplasia, Nezelof syndrome–cellular immunodeficiency with immunoglobulins, and T-cell defects–eg, absence of inosine phosphorylase or purine nucleoside phosphorylase