Human Leukocyte Antigen and Cytokine Gene Variants as Predictors of RecurrentChlamydia trachomatisInfection in High‐Risk Adolescents

Antigen presentation and immune activation are essential to the effective control of infectious diseases. In 485 North American adolescents at high risk for genital Chlamydia trachomatis infection, we found 2 human leukocyte antigen variants (DRB1*03-DQB1*04 and DQB1*06) to be associated with recurrent Chlamydia infection (adjusted relative odds [RO], >2.0; P<.01, for both variants). A G-C-C haplotype corresponding to variants at IL10 (encoding interleukin-10 [IL-10]) promoter positions -1082, -819, and -592 was underrepresented in individuals with recurrent infection (RO, 0.59; P=.046). These genetic associations were independent of nongenetic factors, including number of sex partners, race, sex, duration of follow-up, and human immunodeficiency virus type 1 seropositivity. Consistent with the observed IL10 association, cervical secretions in female adolescents without the IL10 G-C-C haplotype had elevated IL-10 concentrations after Chlamydia infection, which may reflect involvement of a Chlamydia-specific mechanism for genetically mediated, differential IL-10 expression in the genital tract.