The aim of this retrospective study was to evaluate Western Blot (WB) antibody response against HIV-1 Pol proteins in people on ≥12 months of Antiretroviral Therapy (ART) and factors associated with a negative HIV-1 Pol response or with its seroreversion from positive to negative. Multivariate logistic regression models were performed to assess factors associated with a negative HIV-1 Pol or with HIV-1 Pol seroreversion. A negative HIV-1 Pol was found in 88 (16.6%) of the 530 individuals evaluated. At multivariate analysis, a negative Pol result was associated with an early ART start [adjusted odds ratio (AOR) per 3-months longer = 0.95, 95% CI=0.90-0.99] and a greater CD4+ recovery since ART start [AOR per 100-cells/μL/year higher=1.11, 95%CI=1.01-1.24]. In a subgroup of 140 patients with WB analysis performed both at HIV-1 diagnosis and after a median of 69 months, Pol seroreverted from positive to negative in 22 (15.7%) patients and was associated with a greater CD4+ recovery [AOR per 100-cells/μL/year higher =2.50 (95%CI=1.28-4.87)]. In conclusion, a negative HIV-1 Pol and a seroreversion from positive to negative were observed in more than 15% of subjects included and were associated with a better immunological profile, suggesting a lower viral exposure to the immune system over time.
Keywords: ART; HIV-1; Pol proteins; Western blot.