Immunodeficiency, Partial Combined, With Absence Of Hla Determinants And Beta-2-Microglobulin From Lymphocytes

Schuurman et al. (1979) described a brother and sister (in a family from an isolated Turkish village) with multiple pyogenic infections and persistent candidiasis. Although B-lymphocytes were present, plasma cell differentiation was deficient and severe hypogammaglobulinemia was found. T-lymphocytes were decreased in number and did not respond to antigens, but did proliferate in cultures with lectins and allogeneic cells. HLA-A, HLA-B and HLA-C determinants were not detected on blood lymphocytes, but they were expressed by cultured lymphoblasts and fibroblasts and were present in serum. Beta-2-microglobulin (109700) was not found in cross-sectioned T-cell membranes. B-lymphocytes carried normal B2M. Chromosome 6 was grossly normal in karyotypes. Other gene products coded by chromosome 6 (C2, C4, Chido, Rodgers, Factor B, PGM3 and glyoxalase) were normal. B2M is required for expression of HLA-A and HLA-B determinants on lymphocytes (Arce-Gomez et al., 1978). The authors suggested that the patients have an immunologically undetectable structural defect in B2M or a membrane defect, leading, in either case, to defective 'anchorage' of B2M on the T-cell membrane. The findings indicate the interrelationship between lymphocyte differentiation and HLA determinants and B2M on lymphocyte membranes. Touraine et al. (1978) reported a strikingly similar case in an Algerian infant with consanguineous parents. HLA typing showed that a healthy sib had the same genotype as the patient. Thus, the genetic defect cannot be linked to the major histocompatibility complex.