title: HLA-DR4 and Gm 1;21 haplotypes are associated with pseudolupus induced by venopyronum dragées.
abstract: The phenotypic frequencies of human major histocompatibility complex class I, II, and III antigens and immunoglobulin allotypes (Gm factors) were determined in 56 patients (55 women, 1 man) who had lupus-like disease induced by venopyronum dragées. The findings in these patients were compared with those of a control group. We found a significant increase of HLA-DR4 (57.1% versus 26.5%, relative risk [RR] 3.7) and a decrease of HLA-DR3 (3.6% versus 19.1%, RR 0.16) in the patient group. In addition, the haplotype Gm 1;21 (60.7% versus 32.9%, RR 3.2), and the phenotype Gm 1,3;5,21 (46.4% versus 25.8%, RR 2.5) were significantly increased. Both the haplotype Gm 1;21 and the phenotype Gm 1,3;5,21 are associated with HLA-DR4 in pseudolupus patients but not in controls. The coincidence of HLA-DR4 and Gm 1;21 markedly increases the risk of acquiring pseudolupus (RR 6.9). We conclude that the pathogenesis of pseudolupus is influenced by at least 2 independent genetic factors. A similar HLA association has been described in hydralazine-induced lupus, and this suggests a common pathogenic mechanism.
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006681:HLA-D Antigens / Q000032:analysis*; D006684:HLA-DR Antigens / Q000032:analysis*; D015804:HLA-DR4 Antigen; D006239:Haplotypes; D006801:Humans; D007129:Immunoglobulin Gm Allotypes / Q000235:genetics / Q000378:metabolism*; D008177:Lupus Vulgaris / Q000139:chemically induced / Q000235:genetics / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D010653:Phenylbutazone / Q000031:analogs & derivatives; D012306:Risk
chemical_list: D006681:HLA-D Antigens; D006684:HLA-DR Antigens; D015804:HLA-DR4 Antigen; D007129:Immunoglobulin Gm Allotypes; C010619:phenopyrazone; D010653:Phenylbutazone