CD4+ cell count responses to antiretroviral therapy are not impaired in HIV-infected individuals with tuberculosis co-infection.

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.