PET Imaging Reveals Early Pulmonary Perfusion Abnormalities in HIV Infection Similar to Smoking

Chronic obstructive pulmonary disease (COPD) is the most common noninfectious pulmonary disease among people living with HIV, independent of smoking. However, the cause for this enhanced susceptibility remains unclear, and the effects of HIV on pulmonary perfusion and ventilation are unknown. Methods: We used PET/CT in 46 smokers and nonsmokers, 23 of whom had documented HIV infection. Emphysema was assessed by CT and perfusion by N-13 ((NN)-N-13) PET scans. After removal of image noise, vertical and axial gradients in perfusion were calculated. We tested for differences in the total spatial heterogeneity of perfusion (CVQtotal2) and its components (CVQtotal22 = CVQvgrad2 [vertical gradient] + CVQzgrad2 [axial gradient] + CVQr2 [residual heterogeneity]) among groups. Results: There were no significant differences in demographic parameters among groups, and all subjects had minimal radiographic evidence of emphysema. Compared with controls, nonsmokers living with HIV had a significantly greater CVQr2/CVQtotal2 (0.48 vs. 0.36, P = 0.05) and reduced CVQvgrad2/CVQtotal2 (0.46 vs. 0.65, P = 0.038). Smokers also had a reduced CVQvgrad2/CVQtotal2, however, there was no significant difference in CVQvgrad2/CVQtotal2 between smokers living with and without HIV (0.39 vs. 0.34, P = 0.58), despite a decreased vertical perfusion gradient (Qv(grad))in smokers living with HIV. Conclusion: In nonsmokers living with well-controlled HIV and minimal radiographic emphysema, HIV infection contributes to pulmonary perfusion abnormalities similar to smokers. These data indicate the onset of subclinical pulmonary perfusion abnormalities that could herald the development of significant lung disease in these susceptible individuals.

Automated summary

In this study, researchers used PET/CT technology to examine 46 smokers and non-smokers, including 23 with known HIV infection. The results showed that non-smokers living with HIV had more prominent abnormalities in pulmonary perfusion compared to the control group, suggesting similarities to smokers.