CD4 lymphocyte dynamics in Tanzanian pulmonary tuberculosis patients with and without hiv co-infection

BACKGROUND: The interaction of HIV and tuberculosis (TB) on CD4 levels over time is complex and has been divergently reported. METHODS: CD4 counts were assessed from time of diagnosis till the end of TB treatment in a cohort of pulmonary TB patients with and without HIV co-infection and compared with cross-sectional data on age- and sex-matched non-TB controls from the same area. RESULTS: Of 1,605 study participants, 1,250 were PTB patients and 355 were non-TB controls. At baseline, HIV was associated with 246 (95% CI: 203; 279) cells per μL lower CD4 counts. All PTB patients had 100 cells per μL lower CD4 counts than the healthy controls. The CD4 levels were largely unchanged during a five-month of TB treatment. HIV infected patients not receiving ART at any time and those already on ART at baseline had no increase in CD4 counts after 5 months of TB treatment, whereas those prescribed ART between baseline and 2 months, and between 2 and 5 months increased by 69 (22;117) and 110 (52; 168) CD4 cells per μL after 5 months. CONCLUSIONS: The increase in circulating CD4 levels observed in PTB in patients is acquired after 2 months of treatment irrespective of HIV status. Initiation of ART is the strongest factor correlated with CD4 increase during TB treatment. TRIAL REGISTRATION NUMBER: Clinical trials.gov: NCT00311298