Objective: To investigate whether HIV-infected individuals diagnosed with tuberculosis (HIV-TB) around the time of starting antiretroviral therapy (ART) have impaired CD4 cell responses to treatment.
Design: Analysis of a national cohort of HIV-infected adults, linked to the national TB surveillance system for England, Wales and Northern Ireland, including individuals starting ART from 2005 to 2009.
Methods: We compared CD4 cell responses in HIV-infected individuals starting ART with a TB diagnosis ('HIV-TB cohort') with those not known to have TB ('TB-free cohort'). The TB-free cohort was frequency-matched to the HIV-TB cases for sex, age strata, baseline CD4 strata and ethnicity. Median change in CD4 cell count from baseline (ΔCD4) was calculated at 6-monthly intervals until 36 months.
Results: There were 593 and 1779 individuals in the HIV-TB and TB-free cohorts, respectively (median follow-up 3.8 years). In both cohorts, median age was 36 years, 49.2% were women and 74.9% were black-African. Median baseline CD4 at the start of treatment was similar in the HIV-TB and TB-free cohorts (74 vs. 80 cells/μl). Median ΔCD4 was similar in HIV-TB and TB-free cohorts at all time points [294 (inter-quartile range 198-424) cells/μl in HIV-TB cohort; 296 (inter-quartile range 196-431) cells/μl in TB-free cohort after 3 years of ART]. A higher proportion of the HIV-TB cohort than the TB-free cohort died during follow-up (4.2 vs. 2.2%; P = 0.01); 78.5% of all individuals who died had a baseline CD4 cell count below 100 cells/μl.
Conclusions: Long-term CD4 cell recovery during ART appears similar in HIV-TB and TB-free patients. Significant mortality in both cohorts highlights the need for earlier HIV diagnosis and ART initiation.