CD4 count stratification to guide tuberculosis preventive therapy for people living with HIV.

OBJECTIVES: In 2018, Brazilian guidelines changed to recommend tuberculosis (TB) preventive therapy for all people with HIV and a CD4≤350 cells/μL, but only for those with a positive tuberculin skin test (TST) if CD4> 350 cells/μL. We determined the potential effectiveness of CD4-based guidelines for TB testing and preventive therapy.

DESIGN: Secondary analysis of the stepped-wedge, cluster-randomized THRio trial for isoniazid preventive therapy (IPT).

METHODS: We analyzed data from 4,114 newly-registered patients with HIV in 29 clinics followed until TB diagnosis, death, or administrative censoring. We compared incidence rates of TB and TB/death between CD4, TST, IPT, and antiretroviral therapy (ART) categories.

RESULTS: Initial CD4 count was ≤350 in 2,138 (52%) and > 350 in 1,976 (48%) patients. TST was performed for 2,922 (71%), of whom 657 (16%) were TST-positive (278 [13%] CD4≤350 vs. 379 [19%] CD4> 350). A total of 619 (15%) received IPT and 2,806 (68%) received ART. For patients with CD4≤350 who did not receive IPT, the incidence rate of TB was 1.79/100 person-years (pys) and TB/death was 3.89/100pys. For patients with CD4> 350 who did not receive IPT, the incidence rates of TB and TB/death were 0.57/100pys and 1.49/100pys for TST-negatives, and 1.05/100pys and 1.64/100pys for TST-unknowns.

CONCLUSIONS: TB incidence was high among all patients who did not receive IPT, including those with CD4> 350 and negative or unknown TST results. TB preventive therapy should be provided to all PLWH in medium burden settings, regardless of CD4 count and TST status.