HLA-DQB1*06 is a risk marker for chlamydia reinfection in African American women.

Associations between human leukocyte antigen (HLA) variants and chlamydia-related outcomes have been inconsistent. We previously identified HLA-DQB1*06 as a risk marker for chlamydia reinfection in a cohort of predominately HIV-infected adolescents. As chlamydia reinfection can lead to reproductive complications, validation of this finding in HIV-seronegative women may help reveal the underlying biology. We performed HLA-DQB1 genotyping in HIV-seronegative, chlamydia-infected African American women who were evaluated for reinfection at 3- and 6-month visits after treatment. Of 185 evaluable women for whom HLA-DQB1 genotyping was performed, only HLA-DQB1*06 was associated with chlamydia reinfection (P = 0.009), with no evidence of a dose-response effect for this allele. African American women with HLA-DQB1*06 may warrant more frequent chlamydia screening. More comprehensive genotyping of HLA class II and neighboring genes is needed to establish whether HLA-DQB1*06 is a causal variant for chlamydia reinfection or a surrogate for other causal variants in the major histocompatibility complex.