CD4 and tuberculosis: In adults, meta-analyses of cohorts of HIV patients suggest exponentially increasing IRR for TB with declining CD4 cell count,9 and current CD4 cell counts on ART strongly predict TB incidence.81 A systematic review and meta-analysis of the protective effect of ART against TB found a HR of 0.35 (0.28–0.44) across all baseline CD4 cell counts,10 comparable to our result for children.