HIV infection is associated with diffusing capacity impairment in women

Brief Report: The Implications of Removing Race From Interpretation of Pulmonary Function Among Persons With or Without HIV

BACKGROUND

Studies suggest that the use of race-specific pulmonary function reference equations may obscure racial inequities in respiratory health. Whether removing race from the interpretation of pulmonary function would influence analyses of HIV and pulmonary function is unknown.

SETTING

Pulmonary function measurements from 1067 men (591 with HIV) in the Multicenter AIDS Cohort Study and 1661 women (1175 with HIV) in the Women's Interagency HIV Study were analyzed.

METHODS

Percent-of-predicted values for spirometry and single-breath diffusing capacity of carbon monoxide (DLCO) measurements were generated with race-specific reference equations derived from the National Health and Nutrition Examination Survey and with the race-neutral application of reference equations derived from the Global Lung Function Initiative database. Regression models were used to evaluate the association between HIV and percent-of-predicted measures of pulmonary function. Alpaydin's F test was used to compare how well these values predicted self-reported respiratory health-related quality of life.

RESULTS

Persons with HIV were observed to have significantly lower percent-of-predicted diffusing capacity for carbon monoxide (DLCO) than those without HIV but no significant differences in spirometric measures of pulmonary function, regardless of whether a race-specific or race-neutral approach was used. Among men, but not women, the race-neutral application of reference equations to generate percent-of-predicted DLCO values performed better for predicting respiratory-related quality of life.

CONCLUSIONS

The race-neutral application of pulmonary function reference equations continues to identify lung function impairment in persons with or at risk for HIV and, for DLCO, may be superior to the use of race-specific reference equations in identifying clinically relevant impairments.

Interferon-signaling pathways are upregulated in people with HIV with abnormal pulmonary diffusing capacity (DL CO )

OBJECTIVE

People with HIV (PWH) are at greater risk of developing lung diseases even when they are antiretroviral therapy (ART)-adherent and virally suppressed. The most common pulmonary function abnormality in PWH is that of impaired diffusing capacity of the lungs for carbon monoxide (DL CO ), which is an independent risk factor for increased mortality in PWH. Earlier work has identified several plasma biomarkers of inflammation and immune activation to be associated with decreased DL CO . However, the underpinning molecular mechanisms of HIV-associated impaired DL CO are largely unknown.

DESIGN

Cross-sectional pilot study with PWH with normal DL CO (values greater than or equal to the lower limit of normal, DL CO  ≥ LLN, N = 9) or abnormal DL CO (DL CO  < LLN, N = 9).

METHODS

We compared the gene expression levels of over 900 inflammation and immune exhaustion genes in PBMCs from PWH with normal vs. abnormal DL CO using the NanoString technology.

RESULTS

We found that 26 genes were differentially expressed in the impaired DL CO group. These genes belong to 4 categories: 1. Nine genes in inflammation and immune activation pathways, 2. seven upregulated genes that are direct targets of the interferon signaling pathway, 3. seven B-cell specific genes that are downregulated, and 4. three miscellaneous genes. These results were corroborated using the bioinformatics tools DAVID (Database for Annotation, Visualization and Integrated Discovery) and GSEA (Gene Sets Enrichment Analysis).

CONCLUSION

The data provides preliminary evidence for the involvement of sustained interferon signaling as a molecular mechanism for impaired DL CO in PWH.

Hepatitis C Virus Clearance and Diffusing Capacity for Carbon Monoxide in Women With and Without Human Immunodeficiency Virus

Hepatitis C virus (HCV) infection is associated with extrahepatic effects, including reduced diffusing capacity of the lungs. It is unknown whether clearance of HCV infection is associated with improved diffusing capacity. In this sample of women with and without human immunodeficiency virus, there was no association between HCV clearance and diffusing capacity.

Pulmonary Function and Quality of Life in Aging Men With and Without HIV from the Multicenter AIDS Cohort Study

People living with HIV have greater pulmonary function impairments and decreased health-related quality of life (HRQoL) compared to uninfected peers. We examined whether pulmonary impairment was associated with HRQoL or respiratory health status. Using Multicenter AIDS Cohort Study data (2017-2019), associations between outcomes [HRQoL (36-Item Short Form Survey) and respiratory health status (St. George's Respiratory Questionnaire)] with pulmonary impairment [diffusing capacity for carbon monoxide (DLCO) and forced expiratory volume in 1 s (FEV1), defined as <80% predicted for both] were examined. Adjusted analyses utilized linear and zero-inflated beta regression, the latter summarized by odds ratio (OR) and quotient ratios (QRs). We also considered whether the subset of adjustment variables age, HIV serostatus, or smoking modified the relationships examined. Of 1048 men, 55% had HIV, with median age 57 [interquartile range (IQR) = 48, 64] years and 1.2 (IQR = 0, 18.1) smoking pack-years. Impaired DLCO, but not impaired FEV1, was significantly associated with lower physical HRQoL [-2.71 (-4.09, -1.33); -1.46 (-3.45, 0.54), respectively]. Pulmonary impairment was associated with higher odds of any St. George's Respiratory Questionnaire (SGRQ) (total score) limitation [DLCO OR = 1.53 (1.15, 2.04); FEV1 OR = 2.48 (1.16, 5.30)] and was elevated in individuals with more severe SGRQ limitations [DLCO QR = 1.13 (0.94, 1.36); FEV1 QR = 1.27 (0.98, 1.64)]. HIV did not modify any associations examined. Age modified the DLCO and any respiratory limitation (SGRQ symptom score) association for every 10 mL CO/min/mmHg decrease in DLCO [age 30 OR = 1.03 (0.51, 2.08); age 50 OR = 1.85 (1.27, 3.85); and age 70 OR = 3.45 (2.00, 5.88)]. Similarly, age modified the DLCO and any respiratory limitation (SGRQ total score) association. FEV1 associations with SGRQ and HRQoL scores were similar across all ages. Impaired pulmonary function was associated with lower HRQoL and greater respiratory impairments. Future studies can determine if interventions aimed at preserving pulmonary function are effective in improving HRQoL and respiratory health among aging men with and without HIV.

COPD in People with HIV: Epidemiology, Pathogenesis, Management, and Prevention Strategies

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disorder characterized by airflow limitation and persistent respiratory symptoms. People with HIV (PWH) are particularly vulnerable to COPD development; PWH have demonstrated both higher rates of COPD and an earlier and more rapid decline in lung function than their seronegative counterparts, even after accounting for differences in cigarette smoking. Factors contributing to this HIV-associated difference include chronic immune activation and inflammation, accelerated aging, a predilection for pulmonary infections, alterations in the lung microbiome, and the interplay between HIV and inhalational toxins. In this review, we discuss what is known about the epidemiology and pathobiology of COPD among PWH and outline screening, diagnostic, prevention, and treatment strategies.

Sex modifies the risk of HIV-associated obstructive lung disease in Ugandans postpneumonia

OBJECTIVES

Spirometric abnormalities are frequent, and obstructive lung disease (OLD) is a common comorbidity among people with HIV (PWH). HIV increases the risk of many comorbidities to a greater degree in women than in men. Few studies have evaluated whether sex modifies the HIV-associated risk of OLD.

DESIGN AND METHODS

To evaluate the associations between sex and HIV with abnormal lung function, women and men with and without HIV underwent spirometric testing after completing therapy for pneumonia, including tuberculosis (TB), in Kampala, Uganda. OLD was defined as a postbronchodilator forced expiratory volume in the first second to forced vital capacity (FEV 1 /FVC) ratio less than 0.70. Associations between sex, HIV, and lung function were evaluated using multivariable regression models including sex-by-HIV interaction terms after adjusting for age, BMI, smoking status, and TB status.

RESULTS

Among 348 participants, 147 (42%) were women and 135 (39%) were HIV-positive. Sixteen (11%) women and 23 men (11%) had OLD. The HIV-sex interaction was significant for obstructive lung disease ( P  = 0.04). In the adjusted stratified analysis, women with HIV had 3.44 (95% CI 1.11-12.0; P  = 0.04) increased odds of having OLD compared with men with HIV. Women without HIV did not have increased odds of having OLD compared with men without HIV.

CONCLUSION

HIV appears to increase the risk of OLD to a greater degree in women than in men in an urban Ugandan setting. The mechanistic explanation for this interaction by sex remains unclear and warrants further study.

Isolated abnormal diffusing capacity for carbon monoxide (iso↓DLco) is associated with increased respiratory symptom burden in people with HIV infection

OBJECTIVES

An isolated reduction in the diffusing capacity for carbon monoxide (DLco; iso↓DLco) is one of the most common pulmonary function test (PFT) abnormalities in people living with HIV (PWH), but its clinical implications are incompletely understood. In this study, we explored whether iso↓DLco in PWH is associated with a greater respiratory symptom burden.

STUDY DESIGN

Cross-sectional analysis.

METHODS

We used ATS/ERS compliant PFTs from PWH with normal spirometry (post-bronchodilator FEV1/FVC ≥0.7; FEV1, FVC ≥80% predicted) from the I AM OLD cohort in San Francisco, CA and Seattle, WA, grouped by DLco categorized as normal (DLco ≥lower limit of normal, LLN), mild iso↓DLco (LLN >DLco >60% predicted), and moderate-severe iso↓DLco (DLco ≤60% predicted). We performed multivariable analyses to test for associations between DLco and validated symptom-severity and quality of life questionnaires, including the modified Medical Research Council dyspnea scale (mMRC), the COPD Assessment Test (CAT), and St. George's Respiratory Questionnaire (SGRQ), as well as between DLco and individual CAT symptoms.

RESULTS

Mild iso↓DLco was associated only with a significantly higher SGRQ score. Moderate-severe iso↓DLco was associated with significantly higher odds of mMRC ≥2 and significantly higher CAT and SGRQ scores. PWH with moderate-severe iso↓DLco had increased odds of breathlessness, decreased activity, lower confidence leaving home, and less energy.

CONCLUSIONS

Iso↓DLco is associated with worse respiratory symptom scores, and this association becomes stronger with worsening DLco, suggesting that impaired gas exchange alone has a significant negative impact on the quality of life in PWH. Additional studies are ongoing to understand the etiology of this finding and design appropriate interventions.

No long-term effect of past Pneumocystis jirovecii pneumonia on pulmonary function in people with HIV

OBJECTIVE

To assess the impact of past Pneumocystis jirovecii pneumonia (PJP) on the pulmonary diffusion capacity in people with HIV (PWH) with a history of advanced immunodeficiency.

DESIGN

Prospective cross-sectional study.

METHODS

Adult PWH with past PJP >1 year ago were included as the study group. The control group consisted of PWH with a nadir CD4 + lymphocyte count <200 cells/mm 3 , matched by age, sex, smoking status and time since HIV diagnosis. All PWH completed a pulmonary function test (PFT) consisting of pre-bronchodilation spirometry, body plethysmography and single-breath carbon monoxide transfer factor (TLCO) measurement. TLCO, diffusion impairment (defined as a TLCO Z -score <-1.645), total lung capacity (TLC) and forced expiratory volume in one second/forced vital capacity (FEV1/FVC) Z -scores were assessed. Multivariable regression analyses were conducted with Z -scores and odds of diffusion impairment as outcomes.

RESULTS

PFTs of 102 participants were analyzed, 51 of whom had past PJP with a median of 10 years since PJP. Mean TLCO Z -score and diffusion impairment rate did not differ significantly between groups ( P  = 0.790; P  = 0.650). Past PJP was not independently associated with TLCO Z -score [ β = 0.14; 95% confidence interval (CI) -0.30-0.57], diffusion impairment (odds ratio 1.00; 95% CI 0.36-2.75) nor TLC or FEV1/FVC Z -scores, whereas current (vs. never) smoking was associated with more diffusion impairment and lower TLCO Z -scores.

CONCLUSION

In our study, past PJP was not associated with long-term diffusion impairment. Our findings suggest that smoking plays a more important role in persistent pulmonary function impairment whereas PJP-related changes seem to be reversible.

Lung Function in Women With and Without Human Immunodeficiency Virus

BACKGROUND

Prior studies have found that human immunodeficiency virus (HIV) infection is associated with impaired lung function and increased risk of chronic lung disease, but few have included large numbers of women. In this study, we investigate whether HIV infection is associated with differences in lung function in women.

METHODS

This was a cross-sectional analysis of participants in the Women's Interagency HIV Study, a racially and ethnically diverse multicenter cohort of women with and without HIV. In 2018-2019, participants at 9 clinical sites were invited to perform spirometry. Single-breath diffusing capacity for carbon monoxide (DLCO) was also measured at selected sites. The primary outcomes were the post-bronchodilator forced expiratory volume in 1 second (FEV1) and DLCO. Multivariable regression modeling was used to analyze the association of HIV infection and lung function outcomes after adjustment for confounding exposures.

RESULTS

FEV1 measurements from 1489 women (1062 with HIV, 427 without HIV) and DLCO measurements from 671 women (463 with HIV, 208 without HIV) met standards for quality and reproducibility. There was no significant difference in FEV1 between women with and without HIV. Women with HIV had lower DLCO measurements (adjusted difference, -0.73 mL/min/mm Hg; 95% confidence interval, -1.33 to -.14). Among women with HIV, lower nadir CD4 + cell counts and hepatitis C virus infection were associated with lower DLCO measurements.

CONCLUSIONS

HIV was associated with impaired respiratory gas exchange in women. Among women with HIV, lower nadir CD4 + cell counts and hepatitis C infection were associated with decreased respiratory gas exchange.

Pulmonary Function Trajectories in People with HIV: Analysis of the Pittsburgh HIV Lung Cohort

Rationale: Human immunodeficiency virus (HIV) infection is associated with chronic lung disease and impaired pulmonary function; however, longitudinal pulmonary function phenotypes in HIV are undefined. Objectives: To identify pulmonary function trajectories, their determinants, and outcomes. Methods: We used data from participants with HIV in the Pittsburgh HIV Lung Cohort with three or more pulmonary function tests between 2007 and 2020. We analyzed post-bronchodilator forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC, and diffusing capacity of the lung for carbon monoxide (DlCO) using group-based trajectory modeling to identify subgroups of individuals whose measurements followed a similar pattern over time. We examined the association between participant characteristics and trajectories using multivariable logistic regression. In exploratory adjusted analyses restricted to individuals with available plasma cytokine data, we investigated the association between 18 individual standardized cytokine concentrations and trajectories. We compared mortality, dyspnea prevalence, respiratory health status, and 6-minute-walk distance between phenotypes. Results: A total of 265 participants contributed 1,606 pulmonary function measurements over a median follow-up of 8.1 years. We identified two trajectories each for FEV1 and FVC: "low baseline, slow decline" and "high baseline, rapid decline." There were three trajectory groups for FEV1/FVC: "rapid decline," "moderate decline," and "slow decline." Finally, we identified two trajectories for DlCO: "baseline low" and "baseline high." The low baseline, slow decline FEV1 and FVC, rapid decline, and moderate decline FEV1/FVC, and baseline low DlCO phenotypes were associated with increased dyspnea prevalence, worse respiratory health status, and decreased 6-minute-walk distance. The baseline low DlCO phenotype was also associated with worse mortality. Current smoking and pack-years of smoking were associated with the adverse FEV1, FEV1/FVC, and DlCO phenotypes. Detectable viremia was the only HIV marker associated with the adverse DlCO phenotype. C-reactive protein and endothelin-1 were associated with the adverse FEV1 and FVC phenotypes, and endothelin-1 trended toward an association with the adverse DlCO phenotype. Conclusions: We identified novel, distinct longitudinal pulmonary function phenotypes with significant differences in characteristics and outcomes. These findings highlight the importance of lung dysfunction over time in people with HIV and should be validated in additional cohorts.

Pulmonary and physical function limitations in aging men with and without HIV from the Multicenter AIDS Cohort Study (MACS)

PURPOSE

We examined the associations between pulmonary impairments and physical function and whether age, HIV serostatus, or smoking modified these relationships.

METHODS

Using Multicenter AIDS Cohort Study data, we examined associations between pulmonary function (diffusing capacity for carbon monoxide [DLCO], one-second forced expiratory volume [FEV1]) and subsequent physical outcomes (gait speed, grip strength, frailty [non-frail, pre-frail, frail]) using mixed models.

RESULTS

Of 1,048 men, 55% were living with HIV, median age was 57(IQR=48,64) and median cumulative pack-years was 1.2(IQR = 0,18.1); 33% and 13% had impaired DLCO and FEV1(<80% predicted), respectively. Participants with impaired DLCO had 3.5 kg (95%CI: -4.6, -2.4) weaker grip strength, 0.04 m/sec (95%CI: -0.06, -0.02) slower gait speed and 4.44-fold (95%CI: 1.81, 10.93) greater odds of frailty compared to participants with normal DLCO. Participants with impaired FEV1 had 3.1 kg (95%CI: -4.8, -1.4) weaker grip strength, similar gait speed (-0.001 m/sec [95%CI: -0.04, 0.03]) and 5.72-fold (95%CI: 1.90, 17.19) greater odds of frailty compared to participants with normal FEV1. Age, but not smoking or HIV, significantly modified the DLCO effect on gait speed and grip strength.

CONCLUSIONS

Pulmonary impairment and decreased physical function were associated. Preserving pulmonary function may help preserve physical function in aging men with and without HIV.

Associations of HIV persistence, cigarette smoking, inflammation, and pulmonary dysfunction in people with HIV on antiretroviral therapy

We aimed to investigate the relationship between measures of HIV persistence with antiretroviral therapy (ART) and cigarette smoking, systemic markers of inflammation, and pulmonary function. Retrospective study of 82 people with HIV (PWH) on ART for a median of 6.9 years (5.6-7.8) and plasma HIV RNA levels <50 copies/mL. HIV DNA and cell-associated HIV RNA (CA-RNA) were measured in peripheral blood mononuclear cells (PBMC) and plasma HIV RNA was measured by single-copy assay (SCA). Plasma levels of 17 inflammatory mediators were measured by Bio-Plex, and standard pulmonary function tests (PFT) were performed in all participants. Median age was 52 years and 41% were women. Most had preserved CD4+ T cell counts (median (IQR) 580 (361-895) cells/mm3). Median plasma HIV RNA was 1.3 (0.7-4.6) copies/mL, and median levels of HIV DNA and CA-RNA in PBMC were 346 (140-541) copies and 19 (3.7-49) copies per 1 million PBMC, respectively. HIV DNA was higher in smokers than in nonsmokers (R = 0.3, P < 0.05), and smoking pack-years positively correlated with HIV DNA and CA-RNA (R = 0.3, P < 0.05 and R = 0.4, P < 0.01, respectively). HIV DNA, CA-RNA, and plasma HIV RNA were not significantly associated with any measure of pulmonary function or inflammation. Cigarette smoking was associated with HIV DNA and CA-RNA levels in blood, but measures of HIV persistence were not associated with pulmonary function or inflammation.

Brief Report: Association Between Pain, Pulmonary Function, and Respiratory Symptoms in People With HIV

BACKGROUND

People with HIV (PWH) experience chronic pain and respiratory symptoms, which are closely related in the general population. Pain may affect the impaired pulmonary function seen in PWH beyond its association with HIV alone. Our objective was to investigate the relationship of pain severity to pulmonary function, respiratory symptoms, and sleep disturbance in PWH.

SETTING

Study sites included the University of Pittsburgh, University of California San Francisco, and University of Washington.

METHODS

Pain, dyspnea, and sleep were assessed using the Brief Chronic Pain Questionnaire, St. George's Respiratory Questionnaire, and Pittsburgh Sleep Quality Index. Participants performed prebronchodilator and postbronchodilator spirometry and 6-minute walk test. Associations between pain severity, lung function, dyspnea, and sleep were assessed with bivariate and multiple quantile regression analysis adjusted for age, sex, race, body mass index, and smoking status.

RESULTS

Of 159 PWH, the median age was 56 years with 30.8% women. Two-thirds experienced pain in the past week, with 40.3% reporting chronic pain. Pain severity was higher with female sex (P = 0.038), non-White race (P = 0.005), current smoking (P = 0.003), and lower CD4+ count (P = 0.035). In adjusted analysis, higher pain severity was correlated with reduced postbronchodilator forced expiratory volume in 1 second %predicted (P = 0.008), reduced postbronchodilator forced vital capacity %predicted (P = 0.019), and chronic obstructive pulmonary disease (P = 0.032). Greater pain severity was strongly associated with a higher St. George's Respiratory Questionnaire score (P < 0.001) and sleep disturbance (P < 0.001).

CONCLUSIONS

In PWH, pain is common and associated with airflow obstruction, dyspnea, and sleep disturbance. Future studies assessing pain severity and pulmonary function over time could clarify the direction of this association and the impact on quality of life.

Markers of inflammation and immune activation are associated with lung function in a multi-center cohort of persons with HIV

OBJECTIVES

Studies have shown that people with HIV (PWH) may be at increased risk for chronic lung diseases and lung function abnormalities, which may be associated with immune activation. We tested the association of a panel of 12 immune activation and inflammation biomarkers with spirometry and single-breath diffusing capacity for carbon monoxide (DLco).

DESIGN

Cross-sectional, observational study.

METHODS

Participants were enrolled from the Inflammation, Aging, Microbes and Obstructive Lung Disease cohort of PWH at two US sites. Biomarkers were examined and standardized spirometry and DLco testing were performed. We tested associations between each biomarker and lung function, examined individually and in combination, using multi-variable linear and logistic regression.

RESULTS

Among 199 participants, median forced expiratory volume in 1 s (FEV1) was normal (90% predicted) and median DLco was abnormal (69% predicted). The most common lung function abnormality (57%) was a normal FEV1 to forced vital capacity ratio with an abnormal DLco of 80% or less predicted (iso↓DLco). Two markers (IL-6, high-sensitivity C-reactive protein) were associated with FEV1% predicted, whereas eight markers (soluble CD14, soluble CD163, inducible protein-10, soluble CD27, IL-6, soluble tumor necrosis factor receptors 1 and 2, D-dimer) were associated with DLco% predicted. Compared with those participants with normal spirometry and DLco, five markers (soluble CD14, soluble CD163, interferon gamma inducible protein-10, soluble tumor necrosis factor receptors 1 and 2) were associated with iso↓DLco.

CONCLUSION

Among PWH, different markers of immune activation and inflammation are associated with FEV1% predicted than with DLco% predicted and with an iso↓DLco, representing possible unique pathways of chronic lung disease. Identifying plausible drivers of these inflammatory pathways may clarify mechanisms underlying impaired lung function in HIV infection and may identify therapeutic avenues.

Chronic obstructive pulmonary disease in HIV

Introduction: Chronic obstructive pulmonary disease (COPD) is more prevalent in people with HIV (PWH) than in the general population and leads to an increased burden of morbidity and mortality in this population. The mechanisms behind COPD development and progression in PWH are not fully elucidated, and there are no PWH-specific guidelines for COPD management. Areas covered: The goal of this broad narrative review is to review the epidemiology of COPD in PWH globally, highlight proposed pathways contributing to increased COPD prevalence and progression in PWH, discuss structural and functional changes in the lungs in this population, assesses the excess mortality and comorbidities in PWH with COPD, and address management practices for this unique population. Expert opinion: Understanding how a chronic viral infection leads to COPD, independent of cigarette smoking, is of critical scientific importance. Further research should focus on the pathophysiology of the interaction between HIV and COPD, and determine the role of disease-modifying risk factors such as opportunistic pneumonia and air pollution, as well as generate data from randomized clinical trials on the safety and efficacy of specific therapies for this vulnerable patient population.

Lung function in men with and without HIV

OBJECTIVES

Initial studies suggest HIV-positive persons may be at increased risk for chronic lung diseases such as chronic obstructive pulmonary disease, but have commonly relied on single-center designs, lacked HIV-negative controls, or assessed lung function with only spirometry. We tested differences in spirometry and single-breath diffusing capacity for carbon monoxide (DLCO) in persons with and without HIV.

DESIGN

Cross-sectional, observational study.

METHODS

Participants were enrolled from the Multicenter AIDS Cohort Study, a longitudinal cohort study of men who have sex with men (both HIV-positive and HIV-negative) at four sites in the United States. Standardized spirometry and DLCO testing were performed in all eligible, consenting participants at routine study visits. We tested associations between HIV status and spirometry and DLCO results, using linear and logistic regression.

RESULTS

Among 1067 men, median age was 57 years, prevalence of current marijuana (30%), and cigarette (24%) use was high, and another 45% were former cigarette smokers. Median forced expiratory volume in 1 s was 97% of predicted normal and DLCO was 85% of predicted normal. HIV-positive persons demonstrated no statistical difference in forced expiratory volume in 1 s compared with HIV-negative persons, but had worse DLCO (adjusted difference -2.6% of predicted; 95% confidence interval: -4.7 to -0.6%) and a higher risk of DLCO impairment (odds ratio for DLCO < 60% of predicted 2.97; 95% confidence interval: 1.36-6.47). Lower DLCO was associated with lower nadir CD4 cell counts.

CONCLUSION

HIV-positive men are at increased risk of abnormal gas exchange, indicated by low DLCO, compared with men without HIV.

Chronic Obstructive Pulmonary Disease Prevalence and Associated Factors in a Setting of Well-Controlled HIV, A Cross-Sectional Study

In Sub-Saharan Africa, COPD remains prevalent but its association with HIV is not well characterized especially in rural settings. We assessed for COPD prevalence, associated factors and lung function profile among HIV-infected individuals attending ART clinics in rural Nakaseke district of Uganda. We enrolled HIV-positive participants from four HIV treatment centers in rural Uganda. Participants underwent spirometry testing following standard guidelines. We defined COPD as a post-bronchodilator FEV1/FVC ratio less than the fifth percentile of the NHANES III African-American reference. We assessed for factors associated with COPD and lung function profiles using multivariable logistic and linear regression analyses. We analyzed data from 722 HIV-positive participants (mean age 48.0 years, 59.7% women). Over 90% of participants were on ART for a median duration of 4 years (IQR 2-7 years), with a median viral load of 0 copies/mL (IQR 0-0 copies/mL), current and baseline CD4 + T cell count of 478 cells/mm3 (IQR 346-663 cells/mm3) and 335 cells/mm3 (IQR 187-523 cells/mm3) respectively. The prevalence of COPD was 6.22%. COPD was associated with worse respiratory symptoms and health status. History of pulmonary tuberculosis was strongly associated with COPD (adjusted OR = 4.92, 95% CI 1.71 to 14.15, p = 0.003) and reduced lung function. Use of ART, CD4+T cell count and viral load were not associated with COPD or reduced lung function. In conclusion, we report a COPD prevalence of 6.22% in HIV-infected individuals in rural Uganda. Pulmonary tuberculosis remains the strongest predictor of COPD risk and reduced lung function in well-controlled HIV.

Pathogenesis of HIV-Related Lung Disease: Immunity, Infection, and Inflammation

Despite anti-retroviral therapy (ART), human immunodeficiency virus-1 (HIV)-related pulmonary disease continues to be a major cause of morbidity and mortality for people living with HIV (PLWH). The spectrum of lung diseases has changed from acute opportunistic infections resulting in death to chronic lung diseases for those with access to ART. Chronic immune activation and suppression can result in impairment of innate immunity and progressive loss of T cell and B cell functionality with aberrant cytokine and chemokine responses systemically as well as in the lung. HIV can be detected in the lungs of PLWH and has profound effects on cellular immune functions. In addition, HIV-related lung injury and disease can occur secondary to a number of mechanisms including altered pulmonary and systemic inflammatory pathways, viral persistence in the lung, oxidative stress with additive effects of smoke exposure, microbial translocation, and alterations in the lung and gut microbiome. Although ART has had profound effects on systemic viral suppression in HIV, the impact of ART on lung immunology still needs to be fully elucidated. Understanding of the mechanisms by which HIV-related lung diseases continue to occur is critical to the development of new preventive and therapeutic strategies to improve lung health in PLWH.

Pneumoproteins are associated with pulmonary function in HIV-infected persons

BACKGROUND

COPD is a common HIV comorbidity, and HIV-infected individuals have a higher incidence and earlier onset of COPD compared to HIV-uninfected individuals. While the pathogenesis of HIV-associated COPD is largely unknown, chronic inflammation may contribute. Four pneumoproteins known to be markers of lung injury and inflammation have been associated with COPD in HIV-uninfected individuals: PARC/CCL-18, SP-D, CC-16, and sRAGE.

OBJECTIVE

To determine whether these pneumoproteins are also associated with pulmonary function and COPD Assessment Test (CAT) scores in HIV-infected individuals.

METHODS

Associations between plasma pneumoprotein levels and pulmonary function were determined in a cross-sectional study of otherwise healthy HIV-infected individuals enrolled between September 2016 and June 2017. Covariates included HIV-associated (antiretroviral therapy, CD4 count, and viral load) and COPD-associated (smoking and BMI) covariates.

RESULTS

Among 65 participants, 78.5% were male, 50.8% had undetectable viral load, and 76.9% were ever-smokers. Mean post-bronchodilator FEV1/FVC was 0.71, and mean DLco%predicted was 61%. Higher PARC/CCL-18 was associated with lower DLco%predicted and higher CAT score. Higher CC-16 was associated with lower DLco%predicted and lower FVC%predicted.

CONCLUSIONS

This exploratory analysis is the first to characterize associations between these four pneumoproteins and pulmonary function in an HIV-infected cohort. Our findings suggest the pathogenesis of HIV-associated COPD may differ from that of non-HIV-associated COPD due to HIV-specific inflammatory changes affecting DLco. PARC/CCL-18 is associated with structural and functional pulmonary abnormalities and may be an important COPD biomarker candidate in HIV infection. Our study is a preliminary step toward finding clinically relevant COPD biomarkers in high-risk populations.

Obstructive Lung Disease in HIV-Phenotypes and Pathogenesis

PURPOSE OF REVIEW

In the antiretroviral therapy era, people living with HIV (PLWH) are surviving to older ages. Chronic illnesses such as chronic obstructive pulmonary disease (COPD) occur more frequently. COPD is often described as a single entity, yet multiple manifestations may be considered phenotypes. HIV is an independent risk factor for certain COPD phenotypes, and mechanisms underlying pathogenesis of these phenotypes may differ and impact response to therapy.

RECENT FINDINGS

Impaired diffusing capacity, airflow obstruction, and radiographic emphysema occur in PLWH and are associated with increased mortality. Age, sex, tobacco, and HIV-specific factors likely modulate the severity of disease. An altered lung microbiome and residual HIV in the lung may also influence phenotypes. COPD is prevalent in PLWH with multiple phenotypes contributing to the burden of disease. HIV-specific factors and the respiratory microbiome influence disease pathogenesis. As tobacco use remains a significant risk factor for COPD, smoking cessation must be emphasized for all PLWH.

HIV infection among women in the United States: 2000-2017

Although HIV diagnoses among women have declined in recent years in the United States (U.S.), women accounted for 19% of new HIV diagnoses in 2016. In addition, women comprise 24% of the 973,846 persons living with HIV infection in the U.S. However, HIV prevention interventions targeting women are limited. We performed a review on HIV infection in women to increase awareness, improve overall care, and inform intervention development. A systematic literature review was conducted using literature published in PubMed, PsychINFO (EBSCO), and Scopus from July 2000 and June 2017. We included studies that: (1) were conducted in the U.S., (2) enrolled at least 50 HIV-positive women, and (3) utilized a case-control, cohort, or surveillance study design. Of 7497 articles, 48 articles met inclusion criteria. HIV diagnoses among women declined 32% between 2001 and 2016. In 2016, 61% of diagnoses in women were among African American women, and 56% were in the South. Women reported barriers to HIV care largely due to psychosocial challenges and social/structural determinants of health (SDH) barriers. Though new diagnoses among women have declined, racial and regional disparities remain. HIV prevention and research efforts with women are vital to inform interventions and reduce disparities.

Decreased Lung Function and All-Cause Mortality in HIV-infected Individuals

RATIONALE

Human immunodeficiency virus (HIV) infection is associated with pulmonary disease and worse lung function, but the relationship of lung function with survival in HIV is unknown.

OBJECTIVES

To determine whether lung function is associated with all-cause mortality in HIV-infected individuals.

METHODS

HIV-infected participants from cohorts in three locations underwent pre- and post-bronchodilator spirometry and determination of single-breath diffusing capacity of the lung for carbon monoxide (Dl_CO) in 2008-2009, computed tomographic (CT) scanning of the chest for quantitative emphysema and airway measures, and echocardiography for estimated left ventricular systolic and diastolic function and tricuspid regurgitant velocity. Bivariate analysis and multivariable Cox proportional hazards models were used to determine whether decreased lung function was independently associated with increased all-cause mortality. Models were adjusted for covariates including age, sex, body mass index, smoking status, self-reported hepatitis C status, HIV viral levels, CD4⁺ T-cell counts, hemoglobin, antiretroviral therapy, and illicit drug use.

RESULTS

Overall, 396 HIV-infected participants underwent pulmonary function testing. Thirty-two participants (8%) died during a median follow-up period of 69 months. A post-bronchodilator FEV₁-to-FVC ratio less than 0.7 (hazard ratio [HR], 2.47; 95% confidence interval [CI], 1.10-5.58) and a Dl_CO less than 60% (HR, 2.28; 95% CI, 1.08-4.82) were independently associated with worse mortality. Also, hepatitis C (HR, 2.68; 95% CI, 1.22-5.89) and baseline plasma HIV RNA level (HR per ln RNA copies/ml, 1.50; 95% CI, 1.22-1.86) were associated with mortality in HIV-infected participants. The only CT or echocardiographic measure associated with greater mortality in univariate analysis was greater wall thickness of medium-sized airways (HR for wall area percent, 1.08; 95% CI, 1.00-1.18; P = 0.051), but none of the CT or echocardiogram measures were associated with mortality in multivariable analysis.

CONCLUSIONS

Airflow obstruction and impaired diffusing capacity appear to be associated with all-cause mortality in HIV-infected persons over an average of 6 years of follow-up. These data highlight the importance of lung dysfunction in HIV-infected persons and should be confirmed in larger cohorts and with extended follow-up periods. Clinical trial registered with www.clinicaltrials.gov (NCT00869544, NCT01326572).

Tropheryma whipplei colonization in HIV-infected individuals is not associated with lung function or inflammation

Studies demonstrate that Tropheryma whipplei (T. whipplei) is present in the lungs of healthy individuals without acute respiratory symptoms or acute respiratory infection and is more common in the lungs of HIV-infected individuals and in smokers. The impact of T. whipplei colonization in the lung on local inflammation and pulmonary dysfunction in HIV-infected individuals is currently unknown. In this study, we performed specific polymerase chain reaction (PCR) and sequencing for T. whipplei in bronchoalveolar lavage (BAL) and induced sputum (IS) samples in 76 HIV-infected participants from three clinical sites. Pulmonary function and proinflammatory cytokine and chemokine levels in BAL were measured. Frequency of T. whipplei in either BAL or IS was 43.4%. The sensitivity and specificity of IS compared to BAL for detection of T. whipplei was 92.3% and 84.2%, respectively, and isolates of T. whipplei in the BAL and IS in the same subject shared genetic identity. Pulmonary function measures were not associated with T. whipplei colonization, and proinflammatory cytokine and chemokine levels in BAL and plasma as well as percentages of inflammatory cells in BAL and IS were not higher in colonized individuals. Overall, these results indicate that T. whipplei colonization in the lung is common, but may not be associated with decreased pulmonary function or inflammation in HIV-infected individuals.

Pulmonary disease in HIV-infected adults in the era of antiretroviral therapy

: HIV in the antiretroviral therapy era is characterized by multimorbidity and the frequent occurrence of HIV-associated non-AIDS chronic health conditions. Respiratory symptoms and chronic pulmonary diseases, including chronic obstructive pulmonary disease, asthma, and cardiopulmonary dysfunction, are among the conditions that may present in persons living with HIV. Tobacco smoking, which is disproportionately high among persons living HIV, strongly contributes to the risk of pulmonary disease. Additionally, features associated with and at times unique to HIV, including persistent inflammation, immune cell activation, oxidative stress, and dysbiosis, may also contribute. This review summarizes the available literature regarding epidemiology of and risk factors for respiratory symptoms and chronic pulmonary disease in the current era.

Prevalence of chronic obstructive pulmonary disease in the global population with HIV: a systematic review and meta-analysis

BACKGROUND

In recent years, the concept has been raised that people with HIV are at risk of developing chronic obstructive pulmonary disease (COPD) because of HIV infection. However, much remains to be understood about the relationship between COPD and HIV infection. We aimed to investigate this association by assessing studies that reported the prevalence of COPD in the global population with HIV.

METHODS

In this systematic review and meta-analysis, we assessed observational studies of COPD in people with HIV. We searched PubMed, Embase, Web of Science, and Global Index Medicus, with no language restriction, to identify articles published until June 21, 2017, and we searched the reference lists of the retrieved articles. Eligible studies reported the prevalence of COPD or had enough data to compute these estimates. We excluded studies in subgroups of participants selected on the basis of the presence of COPD; studies that were limited to other specific groups or populations, such as people with other chronic respiratory diseases; and case series, letters, reviews, commentaries, editorials, and studies without primary data or an explicit description of methods. The main outcome assessed was prevalence of COPD. Each study was independently reviewed for methodological quality. We used a random-effects model to pool individual studies and assessed heterogeneity (I²) using the χ² test on Cochrane's Q statistic. This study is registered with PROSPERO, number CRD42016052639.

FINDINGS

Of 4036 studies identified, we included 30 studies (151 686 participants) from all WHO regions in the meta-analysis of COPD prevalence. 23 studies (77%) had low risk of bias, six (20%) had moderate risk of bias, and one (3%) had high risk of bias in their methodological quality. The overall prevalence of COPD was 10·5% (95% CI 6·2-15·7; I²=97·2%; six studies) according to the lower limit of normal definition of COPD, and 10·6% (6·9-15·0; 94·7%; 16 studies) according to the fixed-ratio definition. COPD prevalence was higher in Europe and among current and ever smokers, and increased with level of income and proportion of participants with detectable HIV viral load. Prevalence of COPD was significantly higher in patients with HIV than in HIV-negative controls (pooled odds ratio 1·14, 95% CI 1·05-1·25, I²=63·5%; 11 studies), even after adjustment for tobacco consumption (2·58, 1·05-6·35, 74·9%; four studies).

INTERPRETATION

Our findings suggest a high prevalence of COPD in the global population with HIV, and an association with HIV. As such, COPD deserves more attention from HIV health-care providers, researchers, policy makers, and stakeholders for improved detection, overall proper management, and efficient control of COPD in people with HIV. Efforts to address this burden should focus on promoting the decrease of tobacco consumption and adherence to highly active antiretroviral therapy to reduce viral load.

FUNDING

None.

Respiratory health status is impaired in UK HIV-positive adults with virologically suppressed HIV infection

OBJECTIVES

We sought to evaluate whether people living with HIV (PLWH) using effective antiretroviral therapy (ART) have worse respiratory health status than similar HIV-negative individuals.

METHODS

We recruited 197 HIV-positive and 93 HIV-negative adults from HIV and sexual health clinics. They completed a questionnaire regarding risk factors for respiratory illness. Respiratory health status was assessed using the St George's Respiratory Questionnaire (SGRQ) and the Medical Research Council (MRC) breathlessness scale. Subjects underwent spirometry without bronchodilation.

RESULTS

PLWH had worse respiratory health status: the median SGRQ Total score was 12 [interquartile range (IQR) 6-25] in HIV-positive subjects vs. 6 (IQR 2-14) in HIV-negative subjects (P < 0.001); breathlessness was common in the HIV-positive group, where 47% compared with 24% had an MRC breathlessness score ≥ 2 (P = 0.001). Eighteen (11%) HIV-positive and seven (9%) HIV-negative participants had airflow obstruction. In multivariable analyses (adjusted for age, gender, smoking, body mass index and depression), HIV infection remained associated with higher SGRQ and MRC scores, with an adjusted fold-change in SGRQ Total score of 1.54 [95% confidence interval (CI) 1.14-2.09; P = 0.005] and adjusted odds ratio of having an MRC score of ≥ 2 of 2.45 (95% CI 1.15-5.20; P = 0.02). Similar findings were obtained when analyses were repeated including only HIV-positive participants with a viral load < 40 HIV-1 RNA copies/mL.

CONCLUSIONS

Despite effective ART, impaired respiratory health appears more common in HIV-positive adults, and has a significant impact on health-related quality of life.

Use of rosuvastatin in HIV-associated chronic obstructive pulmonary disease

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) is more prevalent in HIV-infected individuals and is associated with persistent inflammation. Therapies unique to HIV are lacking. We performed a pilot study of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor rosuvastatin to determine effects on lung function.

DESIGN

Randomized, placebo-controlled, triple-blinded trial.

METHODS

HIV-infected individuals with abnormal lung function were recruited from an ongoing lung function study. Participants were randomized to 24 weeks of placebo (n = 11) or rosuvastatin (n = 11) using an adaptive randomization based on change in peripheral C-reactive protein levels at 30 days of treatment. Forced expiratory volume in 1 s (FEV1) and diffusing capacity for carbon monoxide (DLco)%-predicted were compared to baseline at 24 weeks in the two groups using a Wilcoxon rank-sum test. The %-predicted change at 24 weeks in pulmonary function variables was compared between groups using simulated randomization tests.

RESULTS

The placebo group experienced a significant decline in FEV1%-predicted (P = 0.027), and no change in DLco%-predicted over 24 weeks. In contrast, FEV1%-predicted remained stable in the rosuvastatin group, and DLco%-predicted increased significantly (P = 0.027). There was no significant difference in absolute change in either measure between placebo and rosuvastatin groups.

CONCLUSION

In a pilot study, the use of rosuvastatin for 24 weeks appeared to slow worsening of airflow obstruction and to improve DLco in HIV-infected individuals with abnormal lung function, although comparison of absolute changes between the groups did not reach significance. This study is the first to test a therapy for COPD in an HIV-infected population, and large-scale clinical trials are needed.

Non-infectious pulmonary disorders in HIV

INTRODUCTION

Since the advent of antiretroviral therapy (ART), non-infectious pulmonary disorders have become common comorbidities in the human immunodeficiency virus (HIV) positive population. Clinicians caring for those with HIV disease should be aware of the prevalence of non-infectious pulmonary disorders. A comprehensive understanding is required to diagnosis and manage these syndromes appropriately. Areas covered: This review focuses on the epidemiology, risk factors, pathogenesis, clinical feature and diagnosis, and treatment of HIV-related chronic obstructive pulmonary disease (COPD), lung cancer, pulmonary hypertension. Expert Commentary: The prevalence of COPD in the HIV population is frequent and requires appropriate diagnosis and treatment. HIV-positive individuals with lung cancer carry a poorer prognosis and require early diagnosis and treatment. A complex condition exists with pulmonary hypertension in the HIV population and requires a high degree of clinical suspicion for early diagnosis.

Respiratory symptoms in people living with HIV and the effect of antiretroviral therapy: a systematic review and meta-analysis

Background

Antiretroviral therapy (ART) has significantly altered the pattern of acute and chronic HIV-related disease. However, it is not clear what this means in terms of respiratory symptoms. We sought to investigate the association between HIV status and respiratory symptoms and how these have changed with the availability of ART.

Methods

We searched Cochrane, Medline and Embase databases for studies published between 1946 and August 2015 comparing the prevalence of respiratory symptoms in populations with and without HIV infection. We undertook random effects meta-analysis of the main symptoms reported. We studied heterogeneity and completed sensitivity analyses and funnel plots.

Results

From 5788 unique references identified, 24 papers provided relevant data: 18 documented the prevalence of cough and 11 examined the prevalence of breathlessness among other symptoms reported. Compared with the HIV negative, people living with HIV (PLWH) were more likely to have respiratory symptoms with pooled ORs for the prevalence of cough of 3.05 (95% CI 2.24 to 4.16) in resource-limited populations without access to ART; 2.18 (1.56 to 3.18) in resource-rich populations without access to ART and 1.11 (0.99 to 1.24) in resource-rich populations with access to ART. In resource-rich settings, although the availability of ART was associated with a reduction in the difference between HIV-positive and HIV-negative individuals, PLWH were more likely to report breathlessness, OR 1.39 (95% CI 1.11 to 1.73).

Conclusions

Respiratory symptoms are more common in PLWH than controls. This association persists although at a reduced level in populations with access to ART.

Widespread activation of immunity and pro-inflammatory programs in peripheral blood leukocytes of HIV-infected patients with impaired lung gas exchange

HIV infection is associated with impaired lung gas transfer as indicated by a low diffusing capacity (DLCO), but the mechanisms are not well understood. We hypothesized that HIV-associated gas exchange impairment is indicative of system-wide perturbations that could be reflected by alterations in peripheral blood leukocyte (PBL) gene expression. Forty HIV-infected (HIV(+)) and uninfected (HIV(-)) men with preserved versus low DLCO were enrolled. All subjects were current smokers and those with acute illness, lung diseases other than COPD or asthma were excluded. Total RNA was extracted from PBLs and hybridized to whole-genome microarrays. Gene set enrichment analysis (GSEA) was performed between HIV(+) versus HIV(-) subjects with preserved DLCO and those with low DLCO to identify differentially activated pathways. Using pathway-based analyses, we found that in subjects with preserved DLCO, HIV infection is associated with activation of processes involved in immunity, cell cycle, and apoptosis. Applying a similar analysis to subjects with low DLCO, we identified a much broader repertoire of pro-inflammatory and immune-related pathways in HIV(+) patients relative to HIV(-) subjects, with up-regulation of multiple interleukin pathways, interferon signaling, and toll-like receptor signaling. We confirmed elevated circulating levels of IL-6 in HIV(+) patients with low DLCO relative to the other groups. Our findings reveal that PBLs of subjects with HIV infection and low DLCO are distinguished by widespread enrichment of immuno-inflammatory programs. Activation of these pathways may alter the biology of circulating leukocytes and play a role in the pathogenesis of HIV-associated gas exchange impairment.

Novel relationships of markers of monocyte activation and endothelial dysfunction with pulmonary dysfunction in HIV-infected persons

OBJECTIVE

Chronic obstructive pulmonary disease is a common comorbidity in HIV, with prevalence and severity of disease incompletely explained by risk factors such as smoking and age. Unique HIV-associated factors, including microbial translocation, monocyte activation, and endothelial dysfunction, have been described in other comorbidities, but have not been investigated in relation to pulmonary abnormalities in HIV. This study assessed the relationship of these pathologic processes to pulmonary function in HIV-infected and uninfected individuals and determined if relationships were unique to HIV.

DESIGN

Longitudinal observational study.

METHODS

Total 274 participants completed pulmonary function testing. Markers of inflammation (IL-6, IL-8, and TNFα), microbial translocation (lipopolysaccharide, sCD14), monocyte activation (sCD163, sCD14, and IL-2 receptor), and endothelial dysfunction (endothelin-1) were measured at baseline. Cross-sectional and longitudinal analyses were performed, adjusting for pertinent covariates.

RESULTS

In HIV-infected individuals, higher IL-6 and endothelin-1 associated with worse forced expiratory volume in one second (FEV1) percentage-predicted, and higher sCD163 associated with worse FEV1/forced vital capacity. IL-6, TNFα, lipopolysaccharide, sCD163, IL-2 receptor, and endothelin-1 associated with diffusing impairment. sCD163 and endothelin-1 interacted with HIV status in relationship to pulmonary function. In HIV-infected individuals only, baseline endothelin-1 was associated with lower FEV1, and sCD163 and endothelin-1 were associated with lower diffusing capacity during follow-up.

CONCLUSION

Circulating markers of HIV-associated humoral abnormalities are associated with airflow obstruction and diffusing impairment and baseline measures of monocyte activation and endothelial dysfunction associate with lower pulmonary function over time in HIV-infected persons. These findings suggest mechanisms of the disproportionate burden of chronic obstructive pulmonary disease in HIV-infected persons.

Obstructive Lung Diseases in HIV: A Clinical Review and Identification of Key Future Research Needs

HIV infection has shifted from what was once a disease directly impacting short-term mortality to what is now a chronic illness controllable in the era of effective combination antiretroviral therapy (ART). In this setting, life expectancy for HIV-infected individual is nearly comparable to that of individuals without HIV. Subsequent to this increase in life expectancy, there has been recognition of increased multimorbidity among HIV-infected persons, with prevalence of comorbid chronic illnesses now approaching 65%. Obstructive lung diseases, including chronic obstructive pulmonary disease (COPD) and asthma, are prevalent conditions associated with substantial morbidity and mortality in the United States. There is overlap in risk factors for HIV acquisition and chronic lung diseases, including lower socioeconomic status and the use of tobacco and illicit drugs. Objectives of this review are to (1) summarize the current state of knowledge regarding COPD and asthma among HIV-infected persons, (2) highlight implications for clinicians caring for patients with these combined comorbidities, and (3) identify key research initiatives to reduce the burden of obstructive lung diseases among HIV-infected persons.

Correlation of the lung microbiota with metabolic profiles in bronchoalveolar lavage fluid in HIV infection

BACKGROUND

While 16S ribosomal RNA (rRNA) sequencing has been used to characterize the lung's bacterial microbiota in human immunodeficiency virus (HIV)-infected individuals, taxonomic studies provide limited information on bacterial function and impact on the host. Metabolic profiles can provide functional information on host-microbe interactions in the lungs. We investigated the relationship between the respiratory microbiota and metabolic profiles in the bronchoalveolar lavage fluid of HIV-infected and HIV-uninfected outpatients.

RESULTS

Targeted sequencing of the 16S rRNA gene was used to analyze the bacterial community structure and liquid chromatography-high-resolution mass spectrometry was used to detect features in bronchoalveolar lavage fluid. Global integration of all metabolic features with microbial species was done using sparse partial least squares regression. Thirty-nine HIV-infected subjects and 20 HIV-uninfected controls without acute respiratory symptoms were enrolled. Twelve mass-to-charge ratio (m/z) features from C18 analysis were significantly different between HIV-infected individuals and controls (false discovery rate (FDR) = 0.2); another 79 features were identified by network analysis. Further metabolite analysis demonstrated that four features were significantly overrepresented in the bronchoalveolar lavage (BAL) fluid of HIV-infected individuals compared to HIV-uninfected, including cystine, two complex carbohydrates, and 3,5-dibromo-L-tyrosine. There were 231 m/z features significantly associated with peripheral blood CD4 cell counts identified using sparse partial least squares regression (sPLS) at a variable importance on projection (VIP) threshold of 2. Twenty-five percent of these 91 m/z features were associated with various microbial species. Bacteria from families Caulobacteraceae, Staphylococcaceae, Nocardioidaceae, and genus Streptococcus were associated with the greatest number of features. Glycerophospholipid and lineolate pathways correlated with these bacteria.

CONCLUSIONS

In bronchoalveolar lavage fluid, specific metabolic profiles correlated with bacterial organisms known to play a role in the pathogenesis of pneumonia in HIV-infected individuals. These findings suggest that microbial communities and their interactions with the host may have functional metabolic impact in the lung.

Factors associated with abnormal spirometry among HIV-infected individuals

OBJECTIVE

HIV-infected individuals are susceptible to development of chronic lung diseases, but little is known regarding the prevalence and risk factors associated with different spirometric abnormalities in this population. We sought to determine the prevalence, risk factors and performance characteristics of risk factors for spirometric abnormalities among HIV-infected individuals.

DESIGN

Cross-sectional cohort study.

METHODS

We analyzed cross-sectional US data from the NHLBI-funded Lung-HIV consortium - a multicenter observational study of heterogeneous groups of HIV-infected participants in diverse geographic sites. Logistic regression analysis was performed to determine factors statistically significantly associated with spirometry patterns.

RESULTS

A total of 908 HIV-infected individuals were included. The median age of the cohort was 50 years, 78% were men and 68% current smokers. An abnormal spirometry pattern was present in 37% of the cohort: 27% had obstructed and 10% had restricted spirometry patterns. Overall, age, smoking status and intensity, history of Pneumocystis infection, asthma diagnosis and presence of respiratory symptoms were independently associated with an abnormal spirometry pattern. Regardless of the presence of respiratory symptoms, five HIV-infected participants would need to be screened with spirometry to diagnose two individuals with any abnormal spirometry pattern.

CONCLUSIONS

Nearly 40% of a diverse US cohort of HIV-infected individuals had an abnormal spirometry pattern. Specific characteristics including age, smoking status, respiratory infection history and respiratory symptoms can identify those at risk for abnormal spirometry. The high prevalence of abnormal spirometry and the poor predictive capability of respiratory symptoms to identify abnormal spirometry should prompt clinicians to consider screening spirometry in HIV-infected populations.

Topographic diversity of the respiratory tract mycobiome and alteration in HIV and lung disease

RATIONALE

Microbiome studies typically focus on bacteria, but fungal species are common in many body sites and can have profound effects on the host. Wide gaps exist in the understanding of the fungal microbiome (mycobiome) and its relationship to lung disease.

OBJECTIVES

To characterize the mycobiome at different respiratory tract levels in persons with and without HIV infection and in HIV-infected individuals with chronic obstructive pulmonary disease (COPD).

METHODS

Oral washes (OW), induced sputa (IS), and bronchoalveolar lavages (BAL) were collected from 56 participants. We performed 18S and internal transcribed spacer sequencing and used the neutral model to identify fungal species that are likely residents of the lung. We used ubiquity-ubiquity plots, random forest, logistic regression, and metastats to compare fungal communities by HIV status and presence of COPD.

MEASUREMENTS AND MAIN RESULTS

Mycobiomes of OW, IS, and BAL shared common organisms, but each also had distinct members. Candida was dominant in OW and IS, but BAL had 39 fungal species that were disproportionately more abundant than in the OW. Fungal communities in BAL differed significantly by HIV status and by COPD, with Pneumocystis jirovecii significantly overrepresented in both groups. Other fungal species were also identified as differing in HIV and COPD.

CONCLUSIONS

This study systematically examined the respiratory tract mycobiome in a relatively large group. By identifying Pneumocystis and other fungal species as overrepresented in the lung in HIV and in COPD, it is the first to determine alterations in fungal communities associated with lung dysfunction and/or HIV, highlighting the clinical relevance of these findings. Clinical trial registered with www.clinicaltrials.gov (NCT00870857).

Relationships of pulmonary function, inflammation, and T-cell activation and senescence in an HIV-infected cohort

OBJECTIVE

To determine associations between circulating markers of immune activation, immune cell senescence, and inflammation with HIV-associated abnormalities of pulmonary function.

DESIGN

HIV infection is an independent risk factor for abnormal pulmonary function. Immune activation, immune senescence, and chronic inflammation are characteristics of chronic HIV infection that have been associated with other HIV-associated comorbidities and may be related to pulmonary disease in this population.

METHODS

Participants from an HIV-infected cohort (n = 147) completed pulmonary function testing (PFT). Markers of T-cell activation and senescence were determined by flow cytometry, and plasma levels of interleukin-6, interleukin-8, and C-reactive protein (CRP) were measured, as was telomere length of peripheral blood mononuclear cells (PBMC). Regression models adjusting for clinical risk factors were constructed to examine relationships between biomarkers and PFT outcomes.

RESULTS

Activated CD25(+) T cells and activated/senescent CD69(+)/CD57(+)/CD28(null) CD4(+) T cells, interleukin-6, and CRP were associated with PFT abnormalities. Shortening of PBMC telomere length correlated with airflow obstruction and diffusing impairment. Paradoxically, circulating senescent CD57(+)/CD28(null) CD8(+) T cells were associated with better PFT outcomes.

CONCLUSION

Circulating T cells expressing markers of activation and inflammatory cytokine levels are independently correlated with PFT abnormalities in HIV-infected persons. Overall telomere shortening was also associated with pulmonary dysfunction. The paradoxical association of senescent CD8(+) T cells and better PFT outcomes could suggest an unrecognized beneficial compensatory function of such cells or a redistribution of these cells from the circulation to local compartments. Further studies are needed to differentiate and characterize functional subsets of local pulmonary and circulating T-cell populations in HIV-associated pulmonary dysfunction.

Pulmonary Function in HIV-Infected Recreational Drug Users in the Era of Anti-Retroviral Therapy

BACKGROUND

Individuals with HIV infection commonly have pulmonary function abnormalities, including airflow obstruction and diffusion impairment, which may be more prevalent among recreational drug users. To date, the relationship between drug use and pulmonary function abnormalities among those with HIV remains unclear.

OBJECTIVE

To determine associations between recreational drug use and airflow obstruction, diffusion impairment, and radiographic emphysema in men and women with HIV.

METHODS

Cross-sectional analysis of pulmonary function and self-reported recreational drug use data from a cohort of 121 men and 63 women with HIV. Primary outcomes were the presence (yes/no) of: 1) airflow obstruction, (pre- or post-bronchodilator forced expiratory volume in 1 second/forced vital capacity<0.70); 2) moderate diffusion impairment (diffusing capacity for carbon monoxide <60% predicted); and 3) radiographic emphysema (>1% of lung voxels <-950 Hounsfield units). Exposures of interest were frequency of recreational drug use, recent (since last study visit) drug use, and any lifetime drug use. We used logistic regression to determine associations between recreational drug use and the primary outcomes.

RESULTS

HIV-infected men and women reported recent recreational drug use at 56.0% and 31.0% of their study visits, respectively, and 48.8% of men and 39.7% of women reported drug use since their last study visit. Drug use was not associated with airway obstruction or radiographic emphysema in men or women. Recent crack cocaine use was independently associated with moderate diffusion impairment in women (odds ratio 17.6; 95% confidence interval 1.3-249.6, p=0.03).

CONCLUSIONS

In this cross-sectional analysis, we found that recreational drug use was common among HIV-infected men and women and recent crack cocaine use was associated with moderate diffusion impairment in women. Given the increasing prevalence of HIV infection, any relationship between drug use and prevalence or severity of chronic pulmonary diseases could have a significant impact on HIV and chronic disease management.

Lung function abnormalities in HIV-infected adults and children

Despite the advent of antiretroviral therapy (ART), the human immunodeficiency virus (HIV) epidemic remains a global health crisis with a high burden of respiratory disease among infected persons. While the early complications of the epidemic were dominated by opportunistic infections, improved survival has led to the emergence of non-infectious conditions that are associated with chronic respiratory symptoms and pulmonary disability. Obstructive ventilatory defects and reduced diffusing capacity are common findings in adults, and the association between HIV and chronic obstructive pulmonary disease is increasingly recognized. There is synergism between viral factors, opportunistic infections, conventional influences like tobacco smoke and biomass fuel exposure, and potentially, the immunological effects of ART on the development of HIV-associated chronic obstructive lung disease. Pulmonary function data for HIV-infected infants and children are scarce, but shows that bronchiectasis and obliterative bronchiolitis with severe airflow limitation are major problems, particularly in the developing world. However, studies from these regions are sorely lacking. There is thus a major unmet need to understand the influences of chronic HIV infection on the lung in both adults and children, and to devise strategies to manage and prevent these diseases in HIV-infected individuals. It is important for clinicians working with HIV-infected individuals to have an appreciation of their effects on measurements of lung function. This review therefore summarizes the lung function abnormalities described in HIV-positive adults and children, with an emphasis on obstructive lung disease, and examines potential pathogenic links between HIV and the development of chronic pulmonary disability.

HIV and noncommunicable cardiovascular and pulmonary diseases in low- and middle-income countries in the ART era: what we know and best directions for future research

With the advent of effective antiretroviral therapy (ART), HIV is becoming a chronic disease. HIV-seropositive (+) patients on ART can expect to live longer and, as a result, they are at risk of developing chronic noncommunicable diseases related to factors, such as aging, lifestyle, long-term HIV infection, and the potential adverse effects of ART. Although data are incomplete, evidence suggests that even in low- and middle-income countries (LMICs), chronic cardiovascular and pulmonary diseases are increasing in HIV-positive patients. This review summarizes evidence-linking HIV infection to the most commonly cited chronic cardiovascular and pulmonary conditions in LMICs: heart failure, hypertension, coronary artery disease/myocardial infarction, stroke, obstructive lung diseases, and pulmonary arterial hypertension. We describe the observed epidemiology of these conditions, factors affecting expression in LMICs, and key populations that may be at higher risk (ie, illicit drug users and children), and finally, we suggest that strategic areas of research and training intended to counter these conditions effectively. As access to ART in LMICs increases, long-term outcomes among HIV-positive persons will increasingly be determined by a range of associated chronic cardiovascular and pulmonary complications. Actions taken now to identify those conditions that contribute to long-term morbidity and mortality optimize early recognition and diagnosis and implement effective prevention strategies and/or disease interventions are likely to have the greatest impact on limiting cardiovascular and pulmonary disease comorbidity and improving population health among HIV-positive patients in LMICs.

HIV-associated obstructive lung diseases: insights and implications for the clinician

The effectiveness of antiretroviral therapy to control HIV infection has led to the emergence of an older HIV population who are at risk of chronic diseases. Through a comprehensive search of major databases, this Review summarises information about the associations between chronic obstructive pulmonary disease (COPD), asthma, and HIV infection. Asthma and COPD are more prevalent in HIV-infected populations; 16-20% of individuals with HIV infection have asthma or COPD, and poorly controlled HIV infection worsens spirometric and diffusing capacity measurements, and accelerates lung function decline by about 55-75 mL/year. Up to 21% of HIV-infected individuals have obstructive ventilatory defects and reduced diffusing capacity is seen in more than 50% of HIV-infected populations. Specific pharmacotherapy considerations are needed to care for HIV-infected populations with asthma or COPD-protease inhibitor regimens to treat HIV (such as ritonavir) can result in systemic accumulation of inhaled corticosteroids and might increase pneumonia risk, exacerbating the toxicity of this therapy. Therefore, it is essential for clinicians to have a heightened awareness of the increased risk and manifestations of obstructive lung diseases in HIV-infected patients and specific therapeutic considerations to care for this population. Screening spirometry and tests of diffusing capacity might be beneficial in HIV-infected people with a history of smoking or respiratory symptoms.