Factors associated with long-term CD4 cell recovery in HIV-infected patients on successful antiretroviral therapy.

Objectives: The aim of the study was to study the factors associated with immunological recovery in HIV-infected patients with suppressed viral load.

Methods: Nadir and current CD4 cell counts were recorded in 821 patients, as well as many demographic, epidemiological, lifestyle, clinical, therapeutic, genetic, laboratory, liver fibrosis and viral hepatitis parameters.

Results: The median age of the patients was 44.4 years [interquartile range (IQR) 40.3-48.0 years], the median time since HIV diagnosis was 15.3 years (IQR 10.5-18.9 years), the median time of suppressed viral load was 7.0 years (IQR 4.0-10.0 years) and the median time on the current antiretroviral regimen was 2.8 years (IQR 1.4-4.7 years). The median nadir and current CD4 counts were 193.0 (IQR 84.0-301.0) and 522.0 (IQR 361.0-760) cells/μL, respectively, separated by a median period of 10.2 years (IQR 5.9-12.9 years). The median CD4 count gain during follow-up was 317.0 (IQR 173.0-508.0) cells/μL. Many variables were associated with CD4 cell gains in univariate analyses, including age, gender, epidemiology, prior clinical conditions, fibrosis stage, transient elastometry, aspartate aminotransferase (AST), nadir CD4 count and hepatitis B and C virus infections and genotypes, as well as the durations of follow-up since nadir CD4 count, overall antiretroviral treatment, current antiretroviral regimen, protease inhibitor therapy and suppression of viral load. Multivariate analysis revealed that longer duration of HIV suppression (P < 0.0001), more advanced clinical Centers for Disease Control and Prevention (CDC) stages (P < 0.0001), younger age (P = 0.0003), hepatitis C virus genotypes 1 and 4 (P = 0.003), sexual acquisition of HIV (P = 0.004), and lower transient elastometry values (P = 0.03) were independent predictors of CD4 cell gains. Overall, the model accounted for 14.2% of the variability in CD4 count.

Conclusions: In addition to the duration of HIV suppression, HIV-related diseases, HIV epidemiology, age, hepatitis C virus genotypes, and liver fibrosis were independently associated with long-term immunological recovery.