Serum biomarkers of treatment response within a randomized clinical trial for pulmonary tuberculosis

RationaleBiomarkers for monitoring response to anti-tuberculosis treatment are needed. We explored immune markers previously published as having predictive capability for 8 week culture status in 39 adults enrolled in a clinical trial in Kampala, Uganda.MethodsWe consecutively selected 20 HIV-negative pulmonary TB subjects with positive cultures, and 19 subjects with negative cultures at the end of intensive phase therapy. At baseline and after 8 weeks, serum was assayed for nine cytokines and soluble cytokine receptors using multiplexed platforms or ELISA. We evaluated their association with week 8 culture status first using single-variable logistic models, then using cross-validated estimates of the C-statistic, a measure of discrimination, of candidate models including 2 or 3 analytes in addition to age.ResultsAll but one analyte decreased from baseline to week 8 (all p0.2).ConclusionExploratory post-hoc models including sTNF-R1, CRP, and age, classified 8 week culture status with promising accuracy.