Failure of lymphocyte-membrane HLA-A and -B expression in two siblings with combined immunodeficiency

Abstract

A diagnosis of partial combined immunodeficiency was made in two Turkish siblings with a history of multiple pyogenic infections and persistent candidiasis. They demonstrated severe hypo-γ-globulinemia, with B-lymphocytes, but deficient plasma cell differentiation. T-Lymphocytes were decreased in number and did not respond to antigens, but did proliferate in cultures with lectins and allogeneic cells. HLA-A and -B determinants were not detected on blood lymphocytes, but they were expressed by cultured lymphoblasts, cultured fibroblasts, and were present in serum. MLR-Stimulatory capacity was intermediate and only two of six anti-HLA-DRw7 antisera demonstrated B-cell reactivity. β-2-Microglobulin (B2M) was not detected on the surface of T-lymphocytes, but was found in cross-sectioned T-cell membranes. B-lymphocytes carried B2M normally. The absence of HLA-A and -B determinants on lymphocytes of patients with similar immunodeficiency syndromes suggests a role for HLA determinants in lymphocyte differentiation.