Contributors to diffusion impairment in HIV-infected persons

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.

Pathogenesis and management of emphysema in people with HIV

INTRODUCTION

Since early in the HIV epidemic, emphysema has been identified among people with HIV (PWH) and has been associated with increased mortality. Smoking cessation is key to risk reduction. Health maintenance for PWH and emphysema should ensure appropriate vaccination and lung cancer screening. Treatment should adhere to inhaler guidelines for the general population, but inhaled corticosteroid (ICS) should be used with caution. Frontiers in treatment include targeted therapeutics. Major knowledge gaps exist in the epidemiology of and optimal care for PWH and emphysema, particularly in low and middle-income countries (LMIC).

AREAS COVERED

Topics addressed include risk factors, pathogenesis, current treatment and prevention strategies, and frontiers in research.

EXPERT OPINION

There are limited data on the epidemiology of emphysema in LMIC, where more than 90% of deaths from COPD occur and where the morbidity of HIV is most heavily concentrated. The population of PWH is aging, and age-related co-morbidities such as emphysema will only increase in salience. Over the next 5 years, the authors anticipate novel trials of targeted therapy for emphysema specific to PWH, and we anticipate a growing body of evidence to inform optimal clinical care for lung health among PWH in LMIC.

Brief Report: HIV Is Associated With Impaired Pulmonary Diffusing Capacity Independent of Emphysema

BACKGROUND

HIV is associated with accelerated decline in lung function and increased risk for chronic obstructive pulmonary disease (COPD). Recently, there has been growing attention toward the impairment in the diffusing capacity of the lungs for carbon monoxide (DLCO), a marker of pulmonary gas exchange, observed among persons living with HIV. Although increased emphysema can contribute to the DLCO impairment observed, other factors may drive this association.

METHODS

Using cross-sectional data from the Study of HIV in the Etiology of Lung Disease, we studied the association between HIV and DLCO independent of emphysema. We also analyzed the joint influence of HIV and COPD on DLCO impairment. An analysis was conducted among 339 participants (229 with HIV) with lung function and chest CT imaging data. Multivariable regression models were generated with percent predicted DLCO and odds of DLCO impairment as outcomes.

RESULTS

After adjusting for confounders, including emphysema severity, HIV was associated with lower DLCO (β -4.02%; P = 0.020) and higher odds of DLCO impairment (odds ratio 1.93; P = 0.017). Even among those without COPD, HIV was independently associated with lower DLCO (β -3.89%; P = 0.049). Compared with HIV-uninfected participants without COPD, those with both HIV and COPD experienced the greatest impairment in DLCO (β -14.81; P < 0.001).

CONCLUSIONS

HIV is associated with impaired pulmonary gas exchange independent of emphysema severity. Our data also suggest a potentially additive influence between HIV and COPD on DLCO impairment. Further studies should investigate the other factors, including pulmonary vascular disease, which may contribute to DLCO impairment among persons living with HIV.

The burden and determinants of post-TB lung disease

BACKGROUND: Post-TB lung disease (PTLD) is an important but under-recognised chronic respiratory disease in high TB burden settings such as Tanzania.METHODS: This was a cross-sectional survey of adults within 2 years of completion of TB treatment in Kilimanjaro, Tanzania. Data were collected using questionnaires (symptoms and exposures), spirometry and chest radiographs to assess outcome measures, which were correlated with daily life exposures, including environment and diet.RESULTS: Of the 219 participants enrolled (mean age: 45 years ± 10; 193 88% males), 98 (45%) reported chronic respiratory symptoms; 46 (22%) had received treatment for TB two or more times; and HIV prevalence was 35 (16%). Spirometric abnormalities were observed in 146 (67%). Chest X-ray abnormalities occurred in 177 (86%). A diagnosis of PTLD was made in 200 (91%), and half had clinically relevant PTLD. The prevalence of mMRC ≥Grade 3 chronic bronchitis and dyspnoea was respectively 11% and 26%. Older age, multiple episodes of TB and poverty indicators were linked with clinically relevant PTLD.CONCLUSIONS: We found a substantial burden of PTLD in adults who had recently completed TB treatment in Tanzania. There is a pressing need to identify effective approaches for both the prevention and management of this disease.

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.

Association of Lung Function With HIV-Related Quality of Life and Health Care Utilization in a High-Risk Cohort

BACKGROUND

Chronic respiratory disease represents an important comorbidity for persons living with HIV (PLWH). HIV itself is associated with greater impairment in lung function. We aimed to determine the association between declining lung function and both quality of life (QOL) and health care utilization for PLWH.

METHODS

Using longitudinal data from the Study of HIV Infection in the Etiology of Lung Disease 2009-2017, we studied the association between changes in lung function and both QOL and acute care events (emergency department visit or hospitalization). The Medical Outcomes Studies-HIV Questionnaire provided QOL domains. Multivariable regression models were performed with generalized estimating equations accounting for 1499 participants, 485 with HIV, contributing 10,825 spirometry visits.

RESULTS

Among PLWH, decreased FEV1 was associated with worse physical health for those with higher viral load [β: -1.66, 95% confidence interval (CI): -3.11 to -0.39] compared to those with viral suppression (β: -0.58, 95% CI: -1.06 to -0.162), even in those without airflow obstruction. Lower FEV1 was also associated with increased odds of both emergency department (odds ratio: 1.21, 95% CI: 1.09 to 1.34) and inpatient (odds ratio: 1.26, 95% CI: 1.12 to 1.42) hospitalizations for PLWH. Lung function was not associated with increased odds of acute care events for HIV-uninfected participants.

CONCLUSIONS

FEV1 declines represent an independent predictor of QOL and acute care events among PLWH. Although the generalizability of these results may be limited, because of the high-risk population included, findings suggest that care for PLWH should involve monitoring FEV1 over time, especially in those with poor virologic control, with emphasis on the development and implementation of interventions to mitigate lung function decline.

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.

Development of chronic lung impairment in Mozambican TB patients and associated risks

BACKGROUND

Pulmonary tuberculosis (PTB) is frequently associated with chronic respiratory impairment despite microbiological cure. There are only a few clinical research studies that describe the course, type and severity as well as associated risk factors for lung impairment (LI) in TB patients.

METHODS

A prospective cohort study was conducted at TB Research Clinic of Instituto Nacional de Saúde in Mavalane, Maputo, from June 2014 to June 2016. PTB patients were prospectively enrolled and followed for 52 weeks after TB diagnosis. Lung function was evaluated by spirometry at 8, 26 and 52 weeks after TB treatment initiation, and spirometric values of below the lower limit of normality were considered as LI. Descriptive statistical analysis was performed to summarize the proportion of patients with different lung outcomes at week 52, including type and severity of LI. Risk factors were analysed using multinomial regression analysis.

RESULTS

A total of 69 PTB patients were enrolled, of which 62 had a valid spirometry result at week 52 after TB treatment start. At week 8, 26 and 52, the proportion of patients with LI was 78, 68.9 and 64.5%, respectively, and 35.5% had moderate or severe LI at week 52. The majority of patients with LI suffered from pulmonary restriction. Female sex, low haemoglobin and heavy smoking were significantly associated with LI.

CONCLUSION

Moderate or severe LI can be observed in a third of cured TB patients. Further research is urgently needed to gain deeper insight into the characteristics of post TB LI, the causal pathways and potential treatment strategies.

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.

Significant chronic airway abnormalities in never-smoking HIV-infected patients

OBJECTIVES

The aim of the study was to describe chronic lung disease in HIV-infected never-smokers by looking at clinical, structural and functional abnormalities.

METHODS

This comparative cross-sectional study included 159 HIV-infected never-smoking patients [mean (± standard deviation) age 54.6 ± 9.1 years; 13.2% female; 98.1% with undetectable viral load] and 75 nonmatched never-smoking controls [mean (± standard deviation) age 52.6 ± 6.9 years; 46.7% female]. We examined calcium scoring computer tomography (CT) scans or chest CT scans, all with a lung-dedicated algorithm reconstruction, to assess emphysema and airway disease (respiratory bronchiolitis and/or bronchial wall thickening), tested pulmonary function using spirometry, lung volumes and the diffusion lung capacity of carbon monoxide (DLCO), and assessed respiratory symptoms using the Chronic Obstructive Pulmonary Disease (COPD) Assessment Test (CAT).

RESULTS

Twenty-five (17.2%) of the HIV-infected patients versus two (2.7%) of the controls had a CAT score > 10. Only 5% of the HIV-infected patients showed FEV1% < 80%, and 25% had DLCO < 75% of the predicted value. Based on the CT scans, they had increased prevalences, compared with the controls, of airway disease (37% versus 7.9%, respectively) and emphysema (18% versus 4%, respectively), with more severe and more frequent centrilobular disease. After correction for age, sex and clinical factors, HIV infection was significantly associated with CAT > 10 [odds ratio (OR) 7.7], emphysema (OR 4), airway disease (OR 4.5) and DLCO < 75% of predicted (OR 4).

CONCLUSIONS

Although comparisons were limited by the different enrolment methods used for HIV-infected patients and controls, the results suggest that never-smoking HIV-infected patients may present with chronic lung damage characterized by CT evidence of airway disease. A minority of them showed respiratory symptoms, without significant functional abnormalities.

HIV infection is an independent risk factor for decreased 6-minute walk test distance

Background

Ambulatory function predicts morbidity and mortality and may be influenced by cardiopulmonary dysfunction. Persons living with HIV (PLWH) suffer from a high prevalence of cardiac and pulmonary comorbidities that may contribute to higher risk of ambulatory dysfunction as measured by 6-minute walk test distance (6-MWD). We investigated the effect of HIV on 6-MWD.

Methods

PLWH and HIV-uninfected individuals were enrolled from 2 clinical centers and completed a 6-MWD, spirometry, diffusing capacity for carbon monoxide (DL_CO) and St. George’s Respiratory Questionnaire (SGRQ). Results of 6-MWD were compared between PLWH and uninfected individuals after adjusting for confounders. Multivariable linear regression analysis was used to determine predictors of 6-MWD.

Results

Mean 6-MWD in PLWH was 431 meters versus 462 in 130 HIV-uninfected individuals (p = 0.0001). Older age, lower forced expiratory volume (FEV₁)% or lower forced vital capacity (FVC)%, and smoking were significant predictors of decreased 6-MWD in PLWH, but not HIV-uninfected individuals. Lower DL_CO% and higher SGRQ were associated with lower 6-MWD in both groups. In a combined model, HIV status remained an independent predictor of decreased 6-MWD (Mean difference = -19.9 meters, p = 0.005).

Conclusions

HIV infection was associated with decreased ambulatory function. Airflow limitation and impaired diffusion capacity can partially explain this effect. Subjective assessments of respiratory symptoms may identify individuals at risk for impaired physical function who may benefit from early intervention.

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.

The impact of HIV on the prevalence of asthma in Uganda: a general population survey

Background

HIV and asthma are highly prevalent diseases in Africa but few studies have assessed the impact of HIV on asthma prevalence in high HIV burden settings. The objective of this analysis was to compare the prevalence of asthma among persons living with HIV (PLHIV) and those without HIV participating in the Uganda National Asthma Survey (UNAS).

Methods

UNAS was a population-based survey of persons aged ≥12 years. Asthma was diagnosed based on either self-reported current wheeze concurrently or within the prior 12 months; physician diagnosis; or use of asthma medication. HIV was defined based on confidential self-report. We used Poisson regression with robust standard errors to estimate asthma prevalence and the prevalence ratio (PR) for HIV and asthma.

Results

Of 3416 participants, 2067 (60.5%) knew their HIV status and 103 (5.0%) were PLHIV. Asthma prevalence was 15.5% among PLHIV and 9.1% among those without HIV, PR 1.72, (95%CI 1.07–2.75, p = 0.025). HIV modified the association of asthma with the following factors, PLHIV vs. not PLHIV: tobacco smoking (12% vs. 8%, p = < 0.001), biomass use (11% vs. 7%, p = < 0.001), allergy (17% vs. 11%, p = < 0.001), family history of asthma (17% vs. 11%, p = < 0.001), and prior TB treatment (15% vs. 10%, p = < 0.001).

Conclusion

In Uganda the prevalence of asthma is higher in PLHIV than in those without HIV, and HIV interacts synergistically with other known asthma risk factors. Additional studies should explore the mechanisms underlying these associations. Clinicians should consider asthma as a possible diagnosis in PLHIV presenting with respiratory symptoms.

Tuberculosis and lung damage: from epidemiology to pathophysiology

A past history of pulmonary tuberculosis (TB) is a risk factor for long-term respiratory impairment. Post-TB lung dysfunction often goes unrecognised, despite its relatively high prevalence and its association with reduced quality of life. Importantly, specific host and pathogen factors causing lung impairment remain unclear. Host immune responses probably play a dominant role in lung damage, as excessive inflammation and elevated expression of lung matrix-degrading proteases are common during TB. Variability in host genes that modulate these immune responses may determine the severity of lung impairment, but this hypothesis remains largely untested. In this review, we provide an overview of the epidemiological literature on post-TB lung impairment and link it to data on the pathogenesis of lung injury from the perspective of dysregulated immune responses and immunogenetics.

Host factors driving lung injury in TB likely contribute to variable patterns of pulmonary impairment after TBhttp://ow.ly/a3of30hBsxB

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.

Non-infectious Pulmonary Diseases and HIV

Pulmonary complications remain among the most frequent causes of morbidity and mortality for individuals with HIV despite the advent of antiretroviral therapy (ART) and improvement in its efficacy and availability. The prevalence of non-infectious pulmonary diseases is rising in this population, reflecting both an increase in smoking and the independent risk associated with HIV. The unique mechanisms of pulmonary disease in these patients remain poorly understood, and direct effects of HIV, genetic predisposition, inflammatory pathways, and co-infections have all been implicated. Lung cancer, chronic obstructive pulmonary disease (COPD), and pulmonary hypertension are the most prevalent non-infectious pulmonary diseases in persons with HIV, and the risk of each of these diseases is higher among HIV-infected (HIV+) persons than in the general population. This review discusses the latest advances in the literature on these important complications of HIV infection.

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.

Maintaining lung health with longstanding HIV

PURPOSE OF REVIEW

Human immunodeficiency virus (HIV) is now managed as a chronic disease. Non-infectious pulmonary conditions have replaced infection as the biggest threat to lung health, particularly as HIV cohorts age, but there is no consensus on how best to maintain long-term lung health. We review the epidemiology and pathogenesis of chronic obstructive pulmonary disease (COPD), pulmonary arterial hypertension (PAH), and lung cancer in HIV-seropositive individuals.

RECENT FINDINGS

Diagnoses of COPD are now up to 50% more prevalent in HIV-seropositive individuals than HIV-uninfected controls, and prospective pulmonary function studies find significant impairment in 7% to more than 50% of HIV-seropositive individuals. The prevalence of HIV-PAH is 0.2-0.5%, and lung cancer is two to three times more prevalent in HIV-seropositive individuals. Although host factors such as age and smoking have a role, HIV is an independent contributor to the pathogenesis of COPD, PAH, and lung cancer. Chronic inflammation, immune senescence, oxidative stress, and direct effects of viral proteins are all potential pathogenetic mechanisms. Despite their prevalence, non-infectious lung diseases remain underrecognized and evidence for effective screening strategies in HIV-seropositive individuals is limited.

SUMMARY

COPD, PAH, and lung cancer are a growing threat to lung health in the highly active antiretroviral therapy era necessitating early recognition.

Adiposity influences airway wall thickness and the asthma phenotype of HIV-associated obstructive lung disease: a cross-sectional study

Background

Airflow obstruction, which encompasses several phenotypes, is common among HIV-infected individuals. Obesity and adipose-related inflammation are associated with both COPD (fixed airflow obstruction) and asthma (reversible airflow obstruction) in HIV-uninfected persons, but the relationship to airway inflammation and airflow obstruction in HIV-infected persons is unknown. The objective of this study was to determine if adiposity and adipose-associated inflammation are associated with airway obstruction phenotypes in HIV-infected persons.

Methods

We performed a cross-sectional analysis of 121 HIV-infected individuals assessed with pulmonary function testing, chest CT scans for measures of airway wall thickness (wall area percent [WA%]) and adipose tissue volumes (mediastinal and subcutaneous), as well as HIV- and adipose-related inflammatory markers. Participants were defined as COPD phenotype (post-bronchodilator FEV₁/FVC < lower limit of normal) or asthma phenotype (doctor-diagnosed asthma or bronchodilator response). Pearson correlation coefficients were calculated between adipose measurements, WA%, and pulmonary function. Multivariable logistic and linear regression models were used to determine associations of airflow obstruction and airway remodeling (WA%) with adipose measurements and participant characteristics.

Results

Twenty-three (19 %) participants were classified as the COPD phenotype and 33 (27 %) were classified as the asthma phenotype. Body mass index (BMI) was similar between those with and without COPD, but higher in those with asthma compared to those without (mean [SD] 30.7 kg/m² [8.1] vs. 26.5 kg/m² [5.3], p = 0.008). WA% correlated with greater BMI (r = 0.55, p < 0.001) and volume of adipose tissue (subcutaneous, r = 0.40; p < 0.001; mediastinal, r = 0.25; p = 0.005). Multivariable regression found the COPD phenotype associated with greater age and pack-years smoking; the asthma phenotype with younger age, female gender, smoking history, and lower adiponectin levels; and greater WA% with greater BMI, younger age, higher soluble CD163, and higher CD4 counts.

Conclusions

Adiposity and adipose-related inflammation are associated with an asthma phenotype, but not a COPD phenotype, of obstructive lung disease in HIV-infected persons. Airway wall thickness is associated with adiposity and inflammation. Adipose-related inflammation may play a role in HIV-associated asthma.

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

INTRODUCTION

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.

OBJECTIVES

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

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

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).

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.

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.

Heart-lung interaction via infection

Lung and cardiovascular disease are increasingly recognized to occur in the same patient populations. Infections, either through stimulation of inflammation or through direct infection, can lead to end-organ damage and have been postulated as a potential link between lung and cardiovascular diseases. Mechanisms by which infections may link lung and cardiac diseases include effects of systemic infections, microbial translocation of pathogens from the gastrointestinal tract or other sites, damaging effects of metabolic products, or influences of smoking on the microbiome. Other mechanisms, such as alterations in the local microbiome, environmental exposures, or immune regulation by microbial communities, may be important. These relationships are likely quite complex, with multiple routes between infection and disease possible. A better understanding of the links of infection to lung and heart disease can improve our understanding of the pathogenesis of these disorders and uncover novel therapeutic approaches.