RESUMEN
HLA typing of Class I antigens (HLA - A & -B loci) was done for 65 patients suffering from nonspecific aortoarteritis, in Indian population. The diagnosis of these patients was based on clinical findings and confirmed by angiographic studies. Decreased phenotype frequency of HLA-A19 (p less than 0.005, relative risk 0.28), increased frequency of HLA-B5 (p less than 0.005, relative risk 2.46) and B21 (p less than 0.005, relative risk 3.25) was observed when compared with the control group. A decreased frequency of two other alleles of B locus i.e. B35 (p less than 0.005, relative risk 0.27) and B40 (p less than 0.05, relative risk 0.04) was seen in patient group as compared to control. The data indicate the possible association of HLA-B5 and B21 antigens with the nonspecific aortoarteritis.