Predicting the Probability of Chlamydia Reinfection in African-American Women using Immunologic and Genetic Determinants in a Bayesian Model.

BACKGROUND African Americans have the highest rates of Chlamydia trachomatis (CT) infection in the U.S. and also high reinfection rates. The primary objective of this study was to develop a Bayesian model to predict the probability of CT reinfection in African-American women using immunogenetic data. METHODS We analyzed data from a cohort of CT-infected African-American women enrolled at the time they returned to a clinic in Birmingham, AL, for treatment of a positive routine CT test. We modeled the probability of CT reinfection within 6 months after treatment using logistic regression in a Bayesian framework. Predictors of interest were presence or absence of an HLA-DQB1*06 allele and CT-specific CD4+ IFN-γ response, both of which we had previously reported were independently associated with CT reinfection risk. RESULTS Among 99 participants evaluated, the probability of reinfection for those with a CT-specific CD4+ IFN-γ response and no HLA-DQB1*06 alleles was 14.1% (95% credible interval [CI]: 3.0% - 45.0%), whereas probability of reinfection for those without a CT-specific CD4+ IFN-γ response and at least one HLA-DQB1*06 allele was 61.5% (95% CI: 23.1% - 89.7%). CONCLUSIONS Our model demonstrated that presence or absence of an HLA-DQB1*06 allele and CT-specific CD4+ IFN-γ response can have an impact on the predictive probability of CT reinfection in African-American women.