Associations Found Between HIV Infection and Impaired Pulmonary Gas Exchange

Impaired pulmonary gas exchange was found to be independently associated with HIV infection, regardless of emphysema severity, according to results of a post-hoc analysis published in the Journal of Acquired Immune Deficiency Syndromes.

Investigators used cross-sectional data from the Study of HIV in the Etiology of Lung Disease (SHIELD), a longitudinal cohort study conducted between 2012 and 2015 that assessed the relationship between HIV infection and the diffusing capacity of the lungs for carbon monoxide (DLCO) — a reflection of abnormalities at the alveolar-capillary surface — in participants with and without HIV infection. In addition, participants were aged 18 years and older, had a history of injection drug use, and underwent DLCO measurement and a computed tomography scan of the chest.

The investigators in this study aimed to determine whether there is an association between HIV infection and DLCO independent of emphysema, as well as identify the influence HIV infection has on DLCO impairment in participants with and without comorbid chronic obstructive pulmonary disease (COPD). They used multivariable regression models to analyze the outcomes of percent predicted DLCO and odds of DLCO impairment.

The analysis included a total of 339 participants, 229 of whom had HIV infection. After adjustment for confounders, including emphysema severity, HIV infection was found to be associated with decreased DLCO (mean difference [ß], -4.02%; P =.020) and an increased odds of DLCO impairment (odds ratio, 1.93; P =.017). Of note, among participants without COPD, HIV infection was independently associated with decreased DLCO (ß, -3.89%; P =.049). Participants with HIV infection and comorbid COPD exhibited the greatest DLCO impairment compared with those without either condition (ß, -14.81; P <.001).

This study was limited by its potential lack of generalizability due the proportion of participants who were active smokers with concomitant lung disease.

Based on these findings, the investigators suggested that “a history of opportunistic infections may be a larger contributor to long term lung injury, given that the greatest DLCO impairment was observed amongst those with [decreased] CD4+ T-cell counts.” In addition, “further studies should investigate the other factors, including pulmonary vascular disease, which may contribute to DLCO impairment among [individuals with HIV infection],” the investigators concluded.

Reference

Raju S, Astemborski J, Drummond MB, et al. HIV is associated with impaired pulmonary diffusing capacity independent of emphysema. J Acquir Immune Defic Syndr. Published online September 24, 2021. doi:10.1097/QAI.0000000000002818.