Incidence of Severe Neutropenia in HIV-Infected People Starting Antiretroviral Therapy in West Africa

Background: In sub-Saharan Africa, antiretroviral therapy (ART) including drugs with potential toxicity such as Zidovudine (ZDV) are routinely prescribed. This study aimed at estimating the incidence of severe neutropenia and associated factors after ART initiation in five West African countries.

Methods: A retrospective cohort analysis was conducted within the international epidemiologic database to evaluate AIDS (IeDEA) collaboration in West Africa. All HIV-infected adults, initiating ART between 2002 and 2014, with a baseline and at least one follow-up absolute neutrophil count (ANC) measurement were eligible. Incidence of severe neutropenia (ANC <750 cells/mm3) was estimated with 95% confidence interval (CI) according to age, gender, HIV clinic, hemoglobin, CD4 count, clinical stage, and ART duration. A Cox proportional hazard model was used to identify factors associated with severe neutropenia, expressed with their adjusted hazard ratios (aHR).

Results: Between 2002 and 2014, 9,426 HIV-infected adults were enrolled. The crude incidence rate of a first severe neutropenia was 9.1 per 100 person-years (95% CI: 8.6-9.8). Factors associated with severe neutropenia were exposure to ZDV <6 months (aHR = 2.2; 95% CI: 1.8-2.6), ≥6-12 months (aHR = 2.1; 95% CI: 1.6-2.8) and ≥12 months (aHR = 1.6; 95% CI: 1.2-2.2) [Ref. no ZDV exposure], CD4 count <350 cells/mm3 (aHR = 1.3; 95% CI: 1.1-1.5) and advanced clinical stage at ART initiation (aHR = 1.2; 95% CI: 1.0-1.4).

Conclusion: The incidence of severe neutropenia after ART initiation in West Africa is high and associated with ZDV exposure and advanced HIV disease. In this context, efforts are needed to scale-up access to less toxic first-line ART drugs and to promote early ART initiation.