Predictive Markers of Incident Tuberculosis in Close Contacts in Brazil and India.

There are insufficient predictors of progression to tuberculosis among contacts. A case-control study within RePORT-Brazil matched 20 QuantiFERON-positive progressors and 40 nonprogressors by sex, age, and exposure duration. Twentynine cytokines were measured using a Luminex assay with QuantiFERON-TB Gold Plus supernatants collected at baseline and evaluated using machine learning for tuberculosis prediction. The same markers were evaluated in 8 QuantiFERON-positive progressors and 12 nonprogressors from India. Interleukin 8, interleukin 10, and CCL3 levels predicted incident tuberculosis (area under the receiver operating characteristic curve, 0.75) in 2 years with sensitivity and specificity >80%, in both cohorts. This signature predicted tuberculosis progression in close contacts meeting World Health Organization goals.