Doubled risk of TB diagnosis in Nigerians with poor ART response
Nigerian adults with a poor CD4 or virologic response to antiretroviral therapy (ART) had a doubled or tripled risk of a new TB diagnosis, according to results of a 5000-person study.
Tuberculosis remains a grave threat to HIV-positive people even after they begin ART. To assess the impact of ART, CD4 count, and viral load on TB incidence (the new-diagnosis rate), researchers retrospectively studied 5093 people treated for at least 1 year in Jos, Nigeria.
The investigators divided study participants into four groups according to response to ART: Group 1: CD4 count at or above 350 cells/µL and viral load at or below 400 copies/mL, Group 2: CD4 count at or above 350 cells/µL and viral load above 400 copies/mL, Group 3: CD4 count below 350 cells/µL and viral load at or below 400 copies/mL, and Group 4: CD4 count below 350 cells/µL and viral load 400 copies/mL.
About two thirds of the study group (68.4%) were women, and age averaged 35.1 years (standard deviation 9.1 years). During 4 years and 3 months of follow-up, 98 people got diagnosed with TB. Overall TB incidence measured 8.7 cases per 1000 person-years, meaning about 9 of every 1000 people got diagnosed with TB every year.
Compared with people in Group 1, those in Groups 2, 3, and 4 had a higher risk of a new TB diagnosis, at the following adjusted hazards ratios (aHR) (and 95% confidence intervals):
• Group 2: aHR 2.11 (95% CI 0.97 to 4.61, not significant)
• Group 3: aHR 2.05 (95% CI 1.10 to 3.79)
• Group 4: aHR 3.65 (95% CI 1.15 to 5.06)
“Tuberculosis incidence in patients on ART is driven by poor immunologic and/or virologic response,” the researchers conclude. They recommend that “optimization of HIV treatment should be prioritized to reduce the burden of TB in this high-risk population.”
Source: Maxwell O. Akanbi, Chad J. Achenbach, Joe Feinglass, Babafemi Taiwo, Adamu Onu, Mai T. Pho, Oche Agbaji, Phyllis Kanki, Robert L. Murphy. Tuberculosis after one year of combination antiretroviral therapy in Nigeria: a retrospective cohort study AIDS Research and Human Retroviruses. 2013;29:931-937.
For the study abstract
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Source: IAS
