Prevalence of obstructive lung disease in HIV population: A cross sectional study

Novel Approach to Exploring Protease Activity and Targets in HIV-associated Obstructive Lung Disease using Combined Proteomic-Peptidomic Analysis

Background

Obstructive lung disease (OLD) is increasingly prevalent among persons living with HIV (PLWH). However, the role of proteases in HIV-associated OLD remains unclear.

Methods

We combined proteomics and peptidomics to comprehensively characterize protease activities. We combined mass spectrometry (MS) analysis on bronchoalveolar lavage fluid (BALF) peptides and proteins from PLWH with OLD (n=25) and without OLD (n=26) with a targeted Somascan aptamer-based proteomic approach to quantify individual proteases and assess their correlation with lung function. Endogenous peptidomics mapped peptides to native proteins to identify substrates of protease activity. Using the MEROPS database, we identified candidate proteases linked to peptide generation based on binding site affinities which were assessed via z-scores. We used t-tests to compare average forced expiratory volume in 1 second per predicted value (FEV1pp) between samples with and without detection of each cleaved protein and adjusted for multiple comparisons by controlling the false discovery rate (FDR).

Findings

We identified 101 proteases, of which 95 had functional network associations and 22 correlated with FEV1pp. These included cathepsins, metalloproteinases (MMP), caspases and neutrophil elastase. We discovered 31 proteins subject to proteolytic cleavage that associate with FEV1pp, with the top pathways involved in small ubiquitin-like modifier mediated modification (SUMOylation). Proteases linked to protein cleavage included neutrophil elastase, granzyme, and cathepsin D.

Interpretations

In HIV-associated OLD, a significant number of proteases are up-regulated, many of which are involved in protein degradation. These proteases degrade proteins involved in cell cycle and protein stability, thereby disrupting critical biological functions.

Lung proteome and metabolome endotype in HIV-associated obstructive lung disease

Purpose

Obstructive lung disease is increasingly common among persons with HIV, both smokers and nonsmokers. We used aptamer proteomics to identify proteins and associated pathways in HIV-associated obstructive lung disease.

Methods

Bronchoalveolar lavage fluid (BALF) samples from 26 persons living with HIV with obstructive lung disease were matched to persons living with HIV without obstructive lung disease based on age, smoking status and antiretroviral treatment. 6414 proteins were measured using SomaScan® aptamer-based assay. We used sparse distance-weighted discrimination (sDWD) to test for a difference in protein expression and permutation tests to identify univariate associations between proteins and forced expiratory volume in 1 s % predicted (FEV₁ % pred). Significant proteins were entered into a pathway over-representation analysis. We also constructed protein-driven endotypes using K-means clustering and performed over-representation analysis on the proteins that were significantly different between clusters. We compared protein-associated clusters to those obtained from BALF and plasma metabolomics data on the same patient cohort.

Results

After filtering, we retained 3872 proteins for further analysis. Based on sDWD, protein expression was able to separate cases and controls. We found 575 proteins that were significantly correlated with FEV₁ % pred after multiple comparisons adjustment. We identified two protein-driven endotypes, one of which was associated with poor lung function, and found that insulin and apoptosis pathways were differentially represented. We found similar clusters driven by metabolomics in BALF but not plasma.

Conclusion

Protein expression differs in persons living with HIV with and without obstructive lung disease. We were not able to identify specific pathways differentially expressed among patients based on FEV₁ % pred; however, we identified a unique protein endotype associated with insulin and apoptotic pathways.

Lung and Plasma Metabolome in HIV-Associated Obstructive Lung Disease

BACKGROUND

HIV is a risk factor for obstructive lung disease (OLD), independent of smoking. We used mass spectrometry (MS) approaches to identify metabolomic biomarkers that inform mechanistic pathogenesis of OLD in persons with HIV (PWH).

METHODS

We obtained bronchoalveolar lavage fluid (BALF) samples from 52 PWH, in case:control (+OLD/-OLD) pairs matched on age, smoking status, and antiretroviral treatment. Four hundred nine metabolites from 8 families were measured on BALF and plasma samples using a MS-based Biocrates platform. After filtering metabolites with a high proportion of missing values and values below the level of detection, we performed univariate testing using paired t tests followed by false discovery rate corrections. We used distance-weighted discrimination (DWD) to test for an overall difference in the metabolite profile between cases and controls.

RESULTS

After filtering, there were 252 BALF metabolites for analysis from 8 metabolite families. DWD testing found that collectively, BALF metabolites differentiated cases from controls, whereas plasma metabolites did not. In BALF samples, we identified 3 metabolites that correlated with OLD at the false discovery rate of 10%; all were in the phosphatidylcholine family. We identified additional BALF metabolites when analyzing lung function as a continuous variable, and these included acylcarnitines, triglycerides, and a cholesterol ester.

CONCLUSIONS

Collectively, BALF metabolites differentiate PWH with and without OLD. These included several BALF lipid metabolites. These findings were limited to BALF and were not found in plasma from the same individuals. Phosphatidylcholine, the most common lipid component of surfactant, was the predominant lipid metabolite differentially expressed.

Interplay between the Lung Microbiome, Pulmonary Immunity and Viral Reservoirs in People Living with HIV under Antiretroviral Therapy

Pulmonary dysbiosis may predispose people living with HIV (PLWH) to chronic lung disease. Herein, we assessed whether intrapulmonary HIV reservoir size and immune disruption are associated with reduced bacterial lung diversity in PLWH. Bacterial DNA was extracted and PCR-amplified from cell-free bronchoalveolar lavage (BAL) fluid from 28 PLWH and 9 HIV-negative controls. Amplicon sequence variant (ASV) relative abundances and taxonomic identities were analyzed using joint species distribution modeling. HIV-DNA was quantified from blood and pulmonary CD4+ T-cells using ultra-sensitive qPCR. Immunophenotyping of BAL T-cells was performed using flow cytometry. Lung microbiome diversity was lower in smokers than non-smokers and microbiome composition was more variable in PLWH than HIV-negative individuals. Frequencies of effector memory BAL CD4+ and CD8+ T-cells positively correlated with abundance of several bacterial families while frequencies of BAL activated CD4+ T-cells negatively correlated with abundance of most lung bacterial families. Higher HIV-DNA levels in blood, but not in BAL, as well as frequencies of senescent CD4+ T-cells were associated with reduced bacterial diversity. These findings suggest that HIV infection may weaken the relationship between the lung microbiome and smoking status. Viral reservoir and immune activation levels may impact the lung microbiome, predisposing PLWH to pulmonary comorbidities.

Diagnosis and Management of HIV-Associated Pulmonary Diseases in a Ryan White-Funded Primary Care Setting

Despite widespread use of antiretroviral therapy (ART), people with HIV (PWH) continue to suffer substantial morbidity and mortality from pulmonary diseases. We sought to evaluate the prevalence of pulmonary symptoms, evaluations, and diagnoses (both infectious and noninfectious) among PWH receiving care at one of the largest HIV clinics in the United States. All PWH seen at the Infectious Disease Program in Atlanta, Georgia, from July 2013 to June 2018 were included. Multivariable logistic regression was used to assess the odds of all-cause mortality. Among 8387 patients, median age was 48 years, 35% had documented smoking, 74% were male, and the 47% with ≥1 pulmonary symptom or diagnosis were older and had higher rates of smoking compared to those without any symptoms or diagnoses (p-values <0.0001). Percent on ART was 97% and 81% for individuals with and without symptoms or diagnoses, respectively (p-value <0.0001). Patients with an infectious diagnosis were more likely to have a diagnostic test ordered than those with a noninfectious diagnosis (p-value <0.0001). After adjustment for demographic and clinical risk factors, odds of death were 2.1 times greater [95% confidence interval (CI) = 1.3-3.5] among those with a pulmonary symptom or diagnosis compared to those without. Despite a high prevalence of pulmonary symptoms and diagnoses in this large cohort of PWH, many did not have a complete diagnostic evaluation, particularly those with noninfectious diagnoses. Greater awareness of evaluation and treatment of noninfectious pulmonary diseases among HIV care providers will be critical to improving long-term outcomes for PWH.

Chest imaging findings of chronic respiratory disease in HIV-infected adolescents on combined anti retro viral therapy

Early treatment with combination antiretroviral therapy (cART) has improved survival of children perinatally infected with HIV into adolescence. This population is at risk of long term complications related to HIV infection, particularly chronic respiratory disease. Limited data on chest imaging findings in HIV-infected adolescents, suggest that the predominant disease is of small and large airways: predominantly bronchiolitis obliterans or bronchiectasis. Single cases of emphysema have been reported. Lung fibrosis, lymphocytic interstitial pneumonitis, post tuberculous apical fibrocystic changes and malignancies do not feature in this population. Chest radiograph (CXR) is easily accessible and widely used, especially in resource limited settings, such as sub Saharan Africa, where the greatest burden of HIV disease occurs. Lung ultrasound has been described for the diagnosis of pneumonia in children, pulmonary oedema and interstitial lung disease [1-3]. The use of this modality in chronic respiratory disease in adolescents where the predominant finding is small airway disease and bronchiectasis has however not been described. CXR is useful to evaluate structural/post infective changes, parenchymal opacification and nodules, hyperinflation or extensive bronchiectasis. CXR however, is inadequate for diagnosing small airway disease, for which high resolution computed tomography (HRCT) is the modality of choice. Where available, low dose HRCT should be used early in the course of symptomatic disease in adolescents and for follow up in children who are non responsive to treatment or clinically deteriorating. This article provides a pictorial review of the spectrum of CXR and HRCT imaging findings of chronic pulmonary disease in perinatally HIV-infected adolescents on cART and guidelines for imaging.

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.

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.

Use of Smoking Cessation Aids in a Convenience Sample of PLHIV in a Canadian Tertiary Care Clinic

Background:

Tobacco smoking is among the most significant predictors of cardiovascular disease and lung cancer in People Living with HIV (PLHIV). Smoking rates in this population are high, necessitating more effective smoking cessation strategies. We conducted a descriptive analysis of tobacco-related clinical and sociodemographic characteristics of smokers at a tertiary care HIV clinic in Montreal and an exploratory analysis of smoking cessation methods in order to identify potential areas of improvement in the clinic’s approach to smoking cessation.

Methods:

A convenience sample of patients completed a 10-minute questionnaire on tobacco-related behaviours and outcomes. Use of smoking cessation methods was compared using McNemar’s exact test with a Bonferroni correction for multiple testing (p<0.01 considered significant).

Results:

Seventy-two PLHIV participated. Two-thirds of our total participants were interested in quitting within six months, but the use of effective cessation strategies was low, particularly for counseling and oral therapy. Overall, oral therapy (e.g. varenicline) (16.7%) and counseling for cessation (5.6%) were used less than nicotine patches (50.0%) or ‘other’ methods (50.0%), which included abstinence and nicotine gum (p<0.001).

Conclusion:

Despite a small and potentially unrepresentative sample of HIV positive tobacco smokers at our clinic, this study could help guide further research aiming to determine and address barriers to smoking cessation and access to effective smoking cessation aids in PLHIV. Future studies might consider factors that affect motivation to quit, such as co-morbid mental health and substance use disorders, or the attitudes of HIV healthcare providers.

Prevalence and predictors of airflow obstruction in an HIV tertiary care clinic in Montreal, Canada: a cross-sectional study

Objectives

The reported prevalence of chronic obstructive pulmonary disease (COPD) in people living with HIV (PLWHIV) varies widely. Our objective was to estimate the prevalence of airflow obstruction and COPD in unselected PLWHIV and identify characteristics that increase the risk of nonreversible airflow obstruction in order to guide case finding strategies for COPD.

Methods

All adults attending the Chronic Viral Illness Service were invited to participate in the study, regardless of smoking status or history of known COPD/asthma. Individuals underwent spirometric testing both before and after use of a salbutamol bronchodilator. Airflow obstruction was defined as forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) < 0.7 post‐bronchodilation, whereas COPD was defined as FEV₁/FVC < 0.7 post‐bronchodilation and Medical Research Council (MRC) score > 2. Multivariate logistic regression was used to evaluate risk factors associated with airflow obstruction, reported as adjusted odds ratios (aORs).

Results

Five hundred and three participants successfully completed spirometry testing. The median (Q1; Q3) age was 52 (44; 58) years. The median (Q1; Q3) CD4 count was 598 (438; 784) cells/μL and the median (Q1; Q3) nadir CD4 count was 224 (121; 351) cells/μL. There were 119 (24%) current smokers and 145 (29%) former smokers. Among those screened, 54 (11%) had airflow obstruction whereas three (1%) of the participants had COPD. Factors that were associated with airflow obstruction included a history of smoking [aOR 2.2; 95% confidence interval (CI) 1.1; 4.7], older age (aOR 1.6; 95% CI 1.2; 2.2), and lower CD4 count (aOR 0.8; 95% CI 0.7; 1.0).

Conclusions

Airflow obstruction was relatively uncommon. Our findings suggest that PLWHIV who are ≥50 years old, smokers and those with nadir CD4 counts ≤ 200 cells/μL could be targeted to undergo spirometry to diagnose chronic airflow obstruction.

Increasing burden of noninfectious lung disease in persons living with HIV: a 7-year study using the French nationwide hospital administrative database

An overall reduction in the incidence of AIDS and a change in the spectrum of lung disease have been noticed in persons living with HIV (PLHIV). Our aim was to provide an epidemiological update regarding the prevalence of lung diseases in PLHIV hospitalised in France.We analysed the prevalence of lung disease in PLHIV hospitalised in France from 2007 to 2013, from the French nationwide hospital medical information database, and assessed the association between HIV and incident noninfectious disease over 4 years of follow-up.A total of 52 091 PLHIV were hospitalised in France between 2007 and 2013. Among PLHIV hospitalised with lung disease, noninfectious lung diseases increased significantly from 45.6% to 54.7% between 2007 and 2013, whereas the proportion of patients with at least one infectious lung disease decreased significantly. In 2010, 10 067 prevalent hospitalised PLHIV were compared with 8 244 682 hospitalised non-PLHIV. In 30-49-year-old patients, HIV infection was associated with chronic obstructive pulmonary disease (COPD), chronic respiratory failure, emphysema, lung fibrosis and pulmonary arterial hypertension (PAH) even after adjustment for smoking.The emergence of noninfectious lung disease, in particular COPD, emphysema, lung fibrosis, PAH and chronic respiratory disease, in PLHIV would justify mass screening in this population.

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

OBJECTIVE

Aging people living with HIV (PLWH) face an increased burden of comorbidities, including chronic obstructive pulmonary disease (COPD). The impact of COPD on mortality in HIV remains unclear. We examined associations between markers of COPD and mortality among PLWH and uninfected study participants.

DESIGN

Longitudinal analysis of the Examinations of HIV-Associated Lung Emphysema (EXHALE) cohort study.

METHODS

EXHALE includes 196 PLWH and 165 uninfected smoking-matched study participants who underwent pulmonary function testing and computed tomography (CT) to define COPD and were followed. We determined associations between markers of COPD with mortality using multivariable Cox regression models, adjusted for smoking and the Veterans Aging Cohort Study (VACS) Index, a validated predictor of mortality in HIV.

RESULTS

Median follow-up time was 6.9 years; the mortality rate was 2.7/100 person-years among PLWH and 1.7/100 person-years among uninfected study participants (P = 0.11). The VACS Index was associated with mortality in both PLWH and uninfected study participants. In multivariable models, pulmonary function and CT characteristics defining COPD were associated with mortality in PLWH: those with airflow obstruction (forced expiratory volume in 1 s/ forced vital capacity <0.7) had 3.1 times the risk of death [hazard ratio 3.1 (95% confidence interval 1.4-7.1)], compared with those without; those with emphysema (>10% burden) had 2.4 times the risk of death [hazard ratio 2.4 (95% confidence interval 1.1-5.5)] compared with those with ≤ 10% emphysema. In uninfected subjects, pulmonary variables were not significantly associated with mortality, which may reflect fewer deaths limiting power.

CONCLUSION

Markers of COPD were associated with greater mortality in PWLH, independent of the VACS Index. COPD is likely an important contributor to mortality in contemporary PLWH.

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.

Plasma sphingolipids in HIV-associated chronic obstructive pulmonary disease

Introduction

Chronic obstructive pulmonary disease (COPD) is a significant cause of morbidity in persons living with HIV (PLWH) and HIV appears to uniquely cause COPD, independent of smoking. The mechanisms by which HIV leads to COPD are not clear. The objective of this study was to identify metabolomic biomarkers and potential mechanistic pathways of HIV-associated COPD (HIV-COPD).

Methods

We performed case–control metabolite profiling via mass spectrometry in plasma from 38 individuals with HIV-COPD (cases), comparing to matched controls with/without HIV and with/without COPD. Untargeted metabolites of interest were identified with liquid chromatography with mass spectrometry (LC-MS/mass spectrometry (MS)), and targeted metabolomics for tryptophan (Trp) and kynurenine (Kyn) were measured by selective reaction monitoring (SRM) with LC-MS/MS. We used mixed-effects models to compare metabolite concentrations in cases compared with controls while controlling for relevant biological variables.

Results

We identified 1689 analytes associated with HIV-COPD at a false discovery rate (FDR) of 10%. In PLWH, we identified 263 analytes (10% FDR) between those with and without COPD. LC MS/MS identified Trp and 17 lipids, including sphingolipids and diacylglycerol. After adjusting for relevant covariates, the Kyn/Trp ratio measured by SRM was significantly higher in PLWH (p=0.022), but was not associated with COPD status (p=0.95).

Conclusions

There is a unique metabolite profile in HIV-COPD that includes sphingolipids. Trp metabolism is increased in HIV, but does not appear to independently contribute to HIV-COPD.

Trial registration numbers

NCT01810289, NCT01797367, NCT00608764.

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.

COPD in HIV-Infected Patients: CD4 Cell Count Highly Correlated

Background

COPD is a frequent and significant cause of respiratory morbidity in HIV-infected patients despite the control of HIV. We aimed to analyze the factors correlated with COPD in this population to evaluate the existence of specific indicators of vulnerability in this population.

Methods and Findings

623 HIV-infected outpatients were enrolled during one year. This population was characterised by a dedicated questionnaire and electronic patient records. COPD screening was performed according to recommended spirometric criteria. The prevalence of COPD was 9.0%. Age and smoking were independently correlated with COPD (OR, 1.61 per 10 years increase, P = 0.007; OR, 1.28 per 10 pack-year increase, P = 0.003, respectively). Body mass index (BMI) and CD4 cell-count were independently and negatively correlated with COPD (OR, 0.78, P < 0.001; 0R, 0.77 per 100 cell/mm³ increase, P < 0.001, respectively). Among COPD patients, 77% did not know their diagnosis. Five COPD-patients never smoked and 44.2% did not have any respiratory symptoms and so were not eligible to perform a spirometry according to the guidelines.

Conclusions

In addition to known risk factors, immune defect through CD4 cell count was independently and strongly correlated with COPD. COPD is largely underdiagnosed and thus unmanaged. However, early management and urgent smoking cessation are essential to improve prognosis. Clinicians’ awareness on the particular vulnerability for COPD in HIV-infected patients is crucial. Moreover, indications to perform conventional spirometry to diagnose COPD may include more parameters than tobacco-smoking and respiratory complaints with a particular concern toward patients with a profound CD4 cell count defect.

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.

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.

Chronic obstructive pulmonary disease and HIV: are we appropriately screening?

Individuals with human immunodeficiency virus (HIV) represent a population that is at a higher risk of developing chronic obstructive pulmonary disease (COPD). In this study, we sought to determine the effects of smoking on respiratory symptoms and diseases among HIV-positive patients and to determine if symptomatic patients are being appropriately screened for COPD. HIV-positive individuals completed a self-administered questionnaire. The effects of smoking on respiratory symptoms and diseases were reported as odds ratios (ORs). The COPD screening criteria were adapted from the Canadian Thoracic Society (CTS) guidelines. Two hundred and forty-seven participants were recruited. The median age was 49 years; 75% were male and 92% were on highly active antiretroviral therapy. Smokers represented 66% of the population. Smoking had a statistically significant effect on respiratory symptoms including wheeze (OR 4.8 [95% confidence interval (CI) 1.6-14.2]), phlegm production (OR 4.9 [95% CI: 2.2-10.5]), cough (OR 7.0 [95% CI: 3.0-16.2]), and dyspnea (OR 7.2 [95% CI: 1.7-31.2]). Smoking had a higher odds of respiratory diseases including COPD (OR 4.9 [95% CI: 1.1-21.9]) and bronchitis (OR 3.8 [95% CI: 1.9-7.7]). Among HIV-positive smokers, 40% met the CTS screening criteria, while only 12% self-reported a diagnosis of COPD. The burden of smoking in the HIV population is significant. HIV-positive smokers are more likely to report both respiratory symptoms and diseases than HIV-positive non-smokers. A discrepancy exists between patients who met the CTS screening criteria and those who were diagnosed with COPD, raising the concern for under-recognition and under-diagnosis of COPD in this population.

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.

Pulmonary function in an international sample of HIV-positive, treatment-naïve adults with CD4 counts > 500 cells/μL: a substudy of the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

The aim of the study was to describe the prevalence and correlates of chronic obstructive pulmonary disease (COPD) in a multicentre international cohort of persons living with HIV (PLWH).

METHODS

We performed a cross-sectional analysis of adult PLWH, naïve to HIV treatment, with baseline CD4 cell count > 500 cells/μL enrolled in the Pulmonary Substudy of the Strategic Timing of AntiRetroviral Treatment (START) trial. We collected standardized, quality-controlled spirometry. COPD was defined as forced expiratory volume in 1 s:forced vital capacity (FEV1 :FVC) ratio less than the lower limit of normal.

RESULTS

Among 1026 participants from 80 sites and 20 countries, the median age was 36 [interquartile range (IQR) 30, 44] years, 29% were female, and the median time since HIV diagnosis was 1.2 (IQR 0.4, 3.5) years. Baseline median CD4 cell count was 648 (IQR 583, 767) cells/μL, median viral load was 4.2 (IQR 3.5, 4.7) log10 HIV-1 RNA copies/mL, and 10% had a viral load ≤ 400 copies/mL despite lack of HIV treatment. Current/former/never smokers comprised 28%/11%/61% of the cohort, respectively. COPD was present in 6.8% of participants, and varied by age, smoking status and region. Forty-eight per cent of those with COPD reported lifelong nonsmoking. In multivariable regression, age and pack-years of smoking had the strongest associations with FEV1 :FVC ratio (P < 0.0001). There was a significant effect of region on FEV1 :FVC ratio (P = 0.010).

CONCLUSIONS

Our data suggest that, among PLWH who were naïve to HIV treatment and had CD4 cell counts > 500 cells/μL, smoking and age were important factors related to COPD. Smoking cessation should remain a high global priority for clinical care and research in PLWH.

Profiles of Risk Among HIV-Infected Youth in Clinic Settings

Despite the rising number of new HIV infections among youth, few tailored interventions for youth living with HIV (YLH) have been developed and rigorously tested. Developing tailored interventions necessitates identifying different profiles of YLH and understanding how risk and protective factors cluster together. Obtaining this critical information requires accessing a sufficiently large sample of YLH from diverse geographic settings such as those available through the Adolescent Trials Network for HIV Interventions (ATN). We recruited a cross-sectional sample of 1,712 YLH from ATN clinics; participants completed a survey on psychosocial and health factors. Using latent class analysis on nine composite variables representing risk factors, we identified five classes distinguished by substance use, sexual behavior, and pregnancy history and differing on health outcomes. Findings suggest a need for tailored interventions addressing multiple risky behaviors of HIV-infected youth and research to clarify how intervention effectiveness may differ by risk profile.

Chronic obstructive pulmonary disease in patients with HIV: an emerging problem

People with well-controlled HIV now have normal life expectancies and physicians managing these patients are increasingly encountering co-existing chronic obstructive pulmonary disease. This article reviews similarities with this disease in the general population and highlights key differences including significant drug-drug interactions.

Noninfectious pulmonary complications of human immunodeficiency virus infection

Human immunodeficiency virus type 1 (HIV-1) is the retrovirus responsible for the development of AIDS. Its profound impact on the immune system leaves the host vulnerable to a wide range of opportunistic infections not seen in individuals with a competent immune system. Pulmonary infections dominated the presentations in the early years of the epidemic, and infectious and noninfectious lung diseases remain the leading causes of morbidity and mortality in persons living with HIV despite the development of effective antiretroviral therapy. In addition to the long known immunosuppression and infection risks, it is becoming increasingly recognized that HIV promotes the risk of noninfectious pulmonary diseases through a number of different mechanisms, including direct tissue toxicity by HIV-related viral proteins and the secondary effects of coinfections. Diseases of the airways, lung parenchyma and the pulmonary vasculature, as well as pulmonary malignancies, are either more frequent in persons living with HIV or have atypical presentations. As the pulmonary infectious complications of HIV are generally well known and have been reviewed extensively, this review will focus on the breadth of noninfectious pulmonary diseases that occur in HIV-infected individuals as these may be more difficult to recognize by general medical physicians and subspecialists caring for this large and uniquely vulnerable population.

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.

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-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.

The determinants of poor respiratory health status in adults living with human immunodeficiency virus infection

The increased longevity afforded by combination antiretroviral therapy in developed countries has led to an increased concern regarding senescence-related diseases in patients with human immunodeficiency virus (HIV) infection. Previous epidemiologic analyses have demonstrated an increased risk of chronic obstructive pulmonary disease, as well as a significant burden of respiratory symptoms in HIV-infected patients. We performed the St. George's Respiratory Questionnaire (SGRQ) in 199 HIV-positive men, and determined the predominant factors contributing to poor respiratory-related health status. In univariate analyses, worse SGRQ scores were associated with respiratory-related variables such as greater smoking pack-year history (p=0.028), lower forced expiratory volume in 1 second (FEV1) (p<0.001), and worse emphysema severity as quantified by computed tomographic imaging (p=0.017). In addition, HIV-specific variables, such as a history of plasma viral load >100,000 copies/mL (p=0.043), lower nadir CD4 cell count (p=0.040), and current CD4 cell count ≤350 cells/μL (p=0.005), as well as elevated levels of inflammatory markers, specifically plasma interleukin (IL)-6 (p=0.002) and alpha-1 antitrypsin (p=0.005) were also associated with worse SGRQ scores. In a multiple regression model, FEV1, current CD4 count ≤350 cells/μL, and IL-6 levels remained significant contributors to reduced respiratory-related health status. HIV disease activity as measured by HIV-related immunosuppression in conjunction with the triggering of key inflammatory pathways may be important determinants of worse respiratory health status among HIV-infected individuals. Limitations of this analysis include the absence of available echocardiograms, diffusion capacity and lung volume testing, and an all-male cohort due to the demographics of the clinic population.

HIV infection is associated with diffusing capacity impairment in women

Respiratory dysfunction is common with HIV infection, but few studies have directly assessed whether HIV remains an independent risk factor for pulmonary function abnormalities in the antiretroviral therapy era. Additionally, few studies have focused on pulmonary outcomes in HIV+ women. We tested associations between risk factors for respiratory dysfunction and pulmonary outcomes in 63 HIV+ and 36 HIV-uninfected women enrolled in the Women's Interagency HIV Study. Diffusing capacity (DL(CO)) was significantly lower in HIV+ women (65.5% predicted vs. 72.7% predicted, P = 0.01), and self-reported dyspnea in HIV+ participants was associated with both DL(CO) impairment and airflow obstruction. Providers should be aware that DL(CO) impairment is common in HIV infection, and that either DL(CO) impairment or airflow obstruction may cause respiratory symptoms in this population.

Persistent HIV-1 replication is associated with lower antiretroviral drug concentrations in lymphatic tissues

Antiretroviral therapy can reduce HIV-1 to undetectable levels in peripheral blood, but the effectiveness of treatment in suppressing replication in lymphoid tissue reservoirs has not been determined. Here we show in lymph node samples obtained before and during 6 mo of treatment that the tissue concentrations of five of the most frequently used antiretroviral drugs are much lower than in peripheral blood. These lower concentrations correlated with continued virus replication measured by the slower decay or increases in the follicular dendritic cell network pool of virions and with detection of viral RNA in productively infected cells. The evidence of persistent replication associated with apparently suboptimal drug concentrations argues for development and evaluation of novel therapeutic strategies that will fully suppress viral replication in lymphatic tissues. These strategies could avert the long-term clinical consequences of chronic immune activation driven directly or indirectly by low-level viral replication to thereby improve immune reconstitution.

Vanishing Lung Syndrome in a Patient with HIV Infection and Heavy Marijuana Use

Vanishing lung syndrome (VLS) is a rare and distinct clinical syndrome that usually affects young men. VLS leads to severe progressive dyspnea and is characterized by extensive, asymmetric, peripheral, and predominantly upper lobe giant lung bullae. Case reports have suggested an additive role of marijuana use in the development of this disease in young male tobacco smokers. We herein report a case of a 65-year-old Hispanic male previously diagnosed with severe emphysema and acquired immune deficiency syndrome (AIDS), with a history of intravenous heroin use and active marijuana smoking who presents to the emergency department with severe progressive shortness of breath he was found to have multiple large subpleural bullae occupying more than one-third of the hemithorax on chest computerized tomography (CT), characteristic of vanishing lung syndrome. The patient was mechanically ventilated and later developed a pneumothorax requiring chest tube placement and referral for surgical bullectomy. Surgical bullectomy has shown high success rates in alleviating the debilitating symptoms and preventing the life threatening complications of this rare syndrome. This case further emphasizes the importance of recognizing VLS in patients with severe emphysema and heavy marijuana smoking.

Will expanded ART use reduce the burden of HIV-associated chronic lung disease?

PURPOSE OF REVIEW

The pulmonary complications of chronic HIV infection have shifted from infectious complications toward noninfectious pulmonary complications, predominantly chronic obstructive pulmonary disease (COPD). Although the best-established COPD risk factor is cigarette smoking, emerging data suggest that HIV infection also independently increases COPD risk. The purpose of this article is to review these data and the conflicting data regarding the role of antiretroviral therapy (ART) in modifying COPD risk.

RECENT FINDINGS

Observational studies favor HIV as an independent risk factor for COPD, particularly when viral load is high. The mechanisms underlying these associations are unclear, but untreated HIV infection is associated with pulmonary inflammatory responses similar to those seen in non-HIV COPD. ART reduces this pulmonary inflammation, but the clinical benefit of such reduction is unknown. Some observational studies suggest that ART users are at lower risk of COPD, whereas other studies suggest the opposite scenario.

SUMMARY

The effect of ART in causing COPD or reducing COPD risk is unknown, but is currently being tested in a randomized trial. Smoking cessation should remain of high priority.

Human immunodeficiency virus-associated obstructive lung diseases

In the era of effective antiretroviral therapy (ART), epidemiologic studies have found that persons infected with human immunodeficiency virus (HIV) have a higher prevalence and incidence of chronic obstructive pulmonary disease than HIV-uninfected persons. In comparison with HIV-uninfected persons and those with well-controlled HIV disease, HIV-infected persons with poor viral control or lower CD4 cell count have more airflow obstruction, a greater decline in lung function, and possibly more severe diffusing impairment. This article reviews the evidence linking HIV infection to obstructive lung disease, and discusses management issues related to the treatment of obstructive lung disease in HIV-infected patients.

Future directions: lung aging, inflammation, and human immunodeficiency virus

Chronic lung diseases, including chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH), are unusually prevalent among persons infected with human immunodeficiency virus (HIV). Often these disease states are identified at younger ages than would be expected in the general population. Recent epidemiologic, basic scientific, and cross-sectional clinical data have implicated immune dysfunction and cellular senescence as potential drivers of advanced presentations of age-related diseases in HIV-infected persons. This article describes how HIV-associated COPD and PH may fit into a paradigm of immunosenescence, and outlines the hypothesized associations among chronic HIV infection, immune dysfunction and senescence, and cardiopulmonary outcomes.

Pathogenesis of HIV and the lung

Antiretroviral therapy has improved longevity for HIV-infected persons, but long-term HIV infection is now complicated by increased rates of chronic medical conditions including pulmonary disorders. Chronic obstructive pulmonary disease, lung cancer, asthma, and pulmonary hypertension are becoming common comorbidities of HIV infection, and these diseases may develop as a result of HIV-related risk factors, such as antiretroviral drug toxicities, colonization by infectious organisms, HIV viremia, immune activation, or immune dysfunction. It also appears that the ability to control HIV infection does not completely eliminate the risk for infectious complications, such as bacterial pneumonia and tuberculosis. The effect of HIV infection on lung-specific immune responses is being elucidated to help develop better prevention and treatment strategies in HIV-infected persons.

Changes in lung function of HIV-infected patients: a 4.5-year follow-up study

OBJECTIVE

To investigate the development of lung function in HIV-infected patients.

METHODS

In a prospective cohort study, 88 HIV-infected patients had a lung function test performed and 63 patients (72%) had their LFT repeated with a median follow-up period of 4.4 years. Forty-eight per cent were smokers, and at the re-examination, 97% were on combination antiretroviral therapy.

RESULTS

Carbon monoxide diffusion capacity was reduced and decreased over time in both smokers and non-smokers. Alveolar volume decreased and forced vital capacity increased similarly in both smokers and non-smokers. No changes were observed in forced expiratory volume or peak flow, but smokers had reduced values compared with those of the non-smokers at both examinations. FEV1/FVC was reduced especially in smokers and declined in both smokers and non-smokers.

CONCLUSIONS

Carbon monoxide diffusion capacity is reduced in HIV-infected patients and seems to decline over time. Additionally, signs of obstructive lung disease are present in HIV-infected patients and seem to increase over time, although only modestly.

Updating our understanding of pulmonary disease associated with HIV infection

The introduction of highly active antiretroviral therapy (HAART) has resulted in a reduction of opportunistic infections associated with cellular and humoral immunosuppression. However, what is still unclear is the impact of HAART on the development of other diseases not associated with AIDS, such as lung cancer and COPD. The aim of this paper is to review the most innovative and relevant aspects of lung pathology in patients infected with HIV.