HLA-CLASS-I AND HLA-CLASS-II POLYMORPHISMS AND TRACHOMATOUS SCARRING IN A CHLAMYDIA-TRACHOMATIS ENDEMIC POPULATION

Immune responses to Chlamydia trachomatis contribute to protection fro m infection and to immunopathologic disease, To test whether subjects' HLA class I (A, B, and Cw) or class II (DR beta 1 and DQ beta 1) type s influence risk of trachomatous scarring from chronic infection with C. trachomatis, 153 cases and pair-matched controls in Gambia were stu died, No HLA type was associated with protection from scarring, indica ting that protective immune responses are not limited to only one or a few HLA-restricted epitopes in C. trachomatis antigens, One class I a ntigen, HLA-A28, was significantly more common among cases than contro ls (25.8% vs, 15.9%, respectively; McNemar's odds ratio [OR], 1.88; 95 % confidence interval [CI] = 1.01-3.49; P = .046). In DNA subtyping of the A28 specificity, the A6801 allele was equally common among cases and controls, but the A6802 allele was significantly overrepresented among cases (McNemar's OR, 3.14; 95% CI = 1.32-7.44; P = .009). This association may be due to an immunopathologic HLA-A6802-restricted cy totoxic T lymphocyte response.