The Differential Impact of Emphysema on Respiratory Symptoms and 6-Minute Walk Distance in HIV Infection

Abstract

Background Emphysema is more prevalent in HIV-infected (HIV+) patients independent of smoking behavior. Nonetheless, health effects of emphysema in this population are poorly understood. We determined whether emphysema is associated with a greater burden of pulmonary symptoms and a lower six-minute walk distance (6MWD) in HIV+ compared to HIV-uninfected (HIV−) subjects. Methods We performed a cross-sectional analysis of 170 HIV+ and 153 HIV− subjects in the Examinations of HIV Associated Lung Emphysema (EXHALE) cohort study. Subjects completed a self-assessment of respiratory symptoms, pulmonary function testing, and 6MWD testing as well as a CT scan to determine emphysema severity. We used regression models to determine the association of emphysema with respiratory symptoms and 6MWD in HIV+ subjects and compared this to HIV− subjects. Results Models stratified by HIV status demonstrated an association between >10% radiographic emphysema and chronic cough and/or phlegm and 6MWD in HIV+ subjects. These associations persisted among the subset without airflow obstruction: those with emphysema had 4.2 (95% CI 1.3, 14) times the odds of chronic cough and/or phlegm and walked 60m (95% CI 26, 93) less distance than those without emphysema. There was no association between >10% emphysema and symptoms or 6MWD in HIV− subjects. Conclusions In our cohort, >10% radiographic emphysema was associated with chronic cough and phlegm and lower 6MWD in HIV+ but not HIV− subjects. These findings were robust even amongst HIV+ subjects with milder forms of emphysema and those without airflow obstruction, highlighting the clinical impact of emphysema in these patients.

A Low Peripheral Blood CD4/CD8 Ratio Is Associated with Pulmonary Emphysema in HIV

“…For this study, we dichotomized the variable as >10% emphysema (mild or greater emphysema) or ≤10% (trace to no emphysema) for the main analyses, similar to prior studies. [4,12] We selected this dichotomized score as it represents the median score in our cohort, and there were few patients with the highest 2 categories of emphysema severity (n = 13 for subjects with emphysema >50%). We examined the trend of CD4/CD8 ratio across the 5 emphysema severity categories using Cuzick’s non-parametric test for trend [13] and differences in distribution and pattern of emphysema by CD4/CD8 ratio group.…”

Markers of chronic obstructive pulmonary disease are associated with mortality in people living with HIV

“…[51][52][53] We have previously shown that emphysema is associated with increased immune activation and inflammation, [25,54] and increased functional limitation in PLWH. [26] Our study adds to this literature by establishing that multiple markers of COPD and the emphysema subtype are associated with increased mortality among PLWH. While the majority of cohort deaths were not directly related to respiratory causes, as above, COPD is an important contributor or co-factor in other causes of death from chronic disease.…”

“…The median VACS Index was 29 in PLWH compared to [18][19][20][21][22][23][24][25][26][27] in the uninfected (p<0.001). There was a trend towards higher pack years of smoking in PLWH.…”

“…[24] Methods This study utilizes the Examinations of HIV-Associated Lung Emphysema (EXHALE) Study, a pulmonary substudy of VACS described in detail elsewhere. [25,26] VACS subjects were enrolled into EXHALE at 4 Veterans Affairs (VA) Medical Centers (VAMCs) between 2009-2012. PLWH and uninfected subjects were recruited matched on smoking status.…”

Emphysema in HIV Positive Patient: Diagnostic and Therapeutic Conduct

“…In his work Triplette [6] presents the results found in HIV+ patients, with radiographic emphysema >10% where it was associated with an increase in respiratory symptoms such as chronic cough and/or phlegm, as well as a decrease in walking test of 6-minute, this finding is similar in our patient who consults for exacerbation of his dyspnea and cough and in the walk test of 6-minutes the amount of meters travelled by less than the theoretical value in more than 60 meters as recorded in the literature and according to the Borg scale reached its highest level.…”