Association Between CD4+, Viral Load, and Pulmonary Function in HIV.

Abstract

The antiretroviral therapy era has shifted the epidemiology of HIV-associated diseases, increasing the recognition of non-infectious pulmonary complications secondary to HIV. We aimed to determine the association between CD4+, viral load, and pulmonary function in individuals with uncontrolled HIV, and determine how changes in these parameters are associated with pulmonary function longitudinally. This is a retrospective observational study of individuals with HIV who underwent pulmonary function testing in an urban medical center between August 1997 and November 2015. Of the 146 participants (mean age 52±10years), 49% were Hispanic, 56% were men, and 44% were current smokers. CD4+ <200cells/μl was associated with significant diffusion impairment compared to CD4+ ≥200cells/μl (DLCO 56 vs. 70%, p=<0.01). VL (viral load) ≥75copies/ml was associated with significant diffusion impairment compared to VL <75copies/ml (DLCO 60 vs. 71%, p=<0.01). No difference in FEV1, FEV1/FVC, or TLC was noted between groups. In univariate analysis, CD4+ and VL correlated with DLCO (r=+0.33; p=<0.01; r=-0.26; p=<0.01) and no correlation was noted with FEV1, FEV1/FVC, or TLC. Current smoking and history of AIDS correlated with DLCO (r=-0.20; p=0.03; r=-0.20; p=0.04). After adjusting for smoking and other confounders, VL ≥75copies/ml correlated with a 11.2 (CI 95% [3.03-19.4], p=<0.01) decrease in DLCO. In Spearman's Rank correlation, there was a negative correlation between change in VL and change in DLCO over time (ρ=-0.47; p=<0.01). The presence of viremia in individuals with HIV is independently associated with impaired DLCO. Suppression of VL may allow for recovery in diffusing capacity over time, though the degree to which this occurs requires further investigation.