Effect of Sex and Age on Outcomes Among HIV-2-infected Patients Starting Antiretroviral Therapy in West Africa

Objectives: HIV-2-infected individuals usually initiate antiretroviral therapy (ART) at an advanced age compared with HIV-1 patients, with a potential impact on treatment outcomes. This study aimed to investigate the effect of sex and age on mortality and loss to follow-up (LTFU) among HIV-2-infected individuals initiating ART.

Methods: Analyses were conducted using the database of the International Epidemiological Databases to Evaluate AIDS's collaboration in West Africa. LTFU was considered if the interval between the last visit and the closing date for this analysis was more than 180 days. Probability of death and LTFU were estimated with Kaplan-Meier methods. A Cox regression model was used to identify factors associated with death and LTFU over the first 24 months on ART.

Results: A total of 1825 HIV-2-infected individuals, including 60% women were considered for this analysis. The median age, baseline CD4 cell count, and follow-up duration were 45 years [interquartile range (IQR; 38-52)], 185 cells/μl [IQR (95-297)], and 28.8 months [IQR (9.8-58.9)], respectively. Over the first 24 months, the mortality rate was 5.2/100 person-years of observation [95% confidence interval (CI; 4.4-6.1)] and 469 (25.7%) were LTFU. Male sex [hazard ratio (HR) = 1.9; 95% CI (1.4; 2.8)], baseline CD4 cell count less than 100 cell/μl [HR = 4.4 95% CI (1.7; 11.1); ref at least 350 cell/μl], haemoglobin 7.5-10 g/dl [HR = 2.4 95% CI (1.3; 4.4); ref at least 12 g/dl], and BMI less than 18 kg/m [HR = 2.1 95% CI (1.3; 3.4); ref = 18-25 kg/m] were associated with higher mortality over the first 24 months. Similar associations were found for LTFU.

Conclusion: Mortality and LTFU are high among ART-receiving HIV-2-infected individuals and higher in men than in women. There is a critical need to further determine the causes of poor retention and implement sex-specific solutions that improve outcomes in HIV-2 ART programmes.