Associations between human leukocyte antigens and leprosy in the Turkish population

Leprosy is a chronic infection caused by an intracellular microorganism. Genetic predisposition to both disease susceptibility and to host immunological response has been postulated for many years. The aim of this study was to determine whether there is HLA-linked susceptibility to leprosy and its different types. HLA-class I (A, B, C) and II (DR, DQ) antigen frequencies in 80 patients with leprosy (35 borderline lepromatous, 25 lepromatous, 15 borderline tuberculoid, five tuberculoid) were compared with those in 120 healthy individuals. HLA-class I antigens A9, A10, A32, B5, B21, Bw4, Bw6, Cw1, Cw2 and HLA-class II antigens DR9, DR10, DRw52, DQ1, DQ3 were found to be significantly more frequent in patients with leprosy, whereas HLA-class I antigens A3, B44, B49 and HLA-class II antigen DQ5 were so in controls. However, there was no significant difference in HLA-class I and II antigen frequencies between subtypes of leprosy. HLA-A null antigen was found to have weak expression in patients with leprosy. In conclusion, factors other than HLA-class I and class II antigens may have a more critical role in the pathophysiology of leprosy infection in man.