Clinical Effect of Emphysema in Individuals With HIV

Although the presence of HIV infection was not independently associated with emphysema, the clinical effect of emphysema was greater in people living with HIV compared with individuals without HIV, according to the results of the prospective Copenhagen Comorbidity in HIV Infection (COCOMO; ClinicalTrials.gov Identifier: NCT02382822) study that were published in the European Respiratory Journal.

In the current study, which was designed to evaluate the prevalence, incidence, and pathogenesis of non-AIDS-related comorbidities in individuals with HIV, spirometry was performed in all participants, regardless of HIV status. Chest computed tomography (CT) was performed from February 2015 to April 2016 in persons living with HIV and from November 2015 to October 2016 in individuals without HIV. The individuals without HIV were recruited from the Copenhagen General Population Study.

Lung emphysema was quantified by densitometry with the use of low attenuation area (%LAA) below −950 Hounsfield units (HU). %LAA-950, which is the proportion of lung voxels of low density below a threshold of −950 HU, increases with worsening emphysema. In this study, emphysema was defined primarily as %LAA-950 >10%, but a threshold of 5% was used as well. The 15th percentile density index (PD15) was also used to quantify emphysema, which was assessed with the use of semiquantitative visual scales.

According to the %LAA-950 threshold, 21.2% and 4.7% of the 742 people living with HIV had emphysema (cut-offs at >5% and >10%, respectively). In contrast, among the 470 individuals without HIV, the same values were 24.3% (P =.23) and 4.0% (P =.68). On the basis of these findings, the presence of HIV infection was not associated with emphysema (adjusted odds ratio, 1.25; 95% CI, 0.68-2.36) for %LAA-950 >10%, by PD15, or by visually assessed emphysema.

No interaction was reported between HIV and cumulative smoking. Sputum production and breathlessness were observed more often in people living with HIV who had emphysema. Moreover, emphysema appeared to have a higher prevalence in individuals with HIV who had airflow limitations.

The investigators concluded that although HIV was not considered to be independently associated with emphysema, the clinical effect of emphysema was greater in people living with HIV than in people without HIV.

Reference

Ronit A, Kristensen T, Hoseth VS, et al. Computed tomography quantification of emphysema in people living with HIV and uninfected controls [published online June 7, 2018]. Eur Respir J. doi:10.1183/13993003.00296-2018