Risk Factors Associated With Quantitative Evidence of Lung Emphysema and Fibrosis in an HIV-Infected Cohort

The disease spectrum for HIV-infected individuals has shifted toward comorbid non-AIDS conditions including chronic lung disease, but quantitative image analysis of lung disease has not been performed.

To quantify the prevalence of structural changes of the lung indicating emphysema or fibrosis on radiographic examination.

A cross-sectional analysis of 510 HIV-infected participants in the multicenter Lung-HIV study was performed. Data collected included demographics, biological markers of HIV, pulmonary function testing, and chest computed tomographic examinations. Emphysema and fibrosis-like changes were quantified on computed tomographic images based on threshold approaches.

In our cohort, 69% was on antiretroviral therapy, 13% had a current CD4 cell count less than 200 cells per microliter, 39% had an HIV viral load greater than 500 copies per milliliter, and 25% had at least a trace level of emphysema (defined as >2.5% of voxels <-950HU). Trace emphysema was significantly correlated with age, smoking, and pulmonary function. Neither current CD4 cell count nor HIV viral load was significantly correlated with emphysema. Fibrosis-like changes were detected in 29% of the participants and were significantly correlated with HIV viral load (Pearson correlation coefficient = 0.210; P < 0.05); current CD4 cell count was not associated with fibrosis. In multivariable analyses including age, race, and smoking status, HIV viral load remained significantly correlated with fibrosis-like changes (coefficient = 0.107; P = 0.03).

A higher HIV viral load was significantly associated with fibrosis-like changes, possibly indicating early interstitial lung disease, but emphysematous changes were not related to current CD4 cell count or HIV viral load.