HIV infection is associated with reduced pulmonary diffusing capacity

HIV-associated disruption of lung cytokine networks is incompletely restored in asymptomatic HIV-infected Malawian adults on antiretroviral therapy

Disruption of lung cytokine networks during chronic HIV infection is incompletely restored in individuals on antiretroviral therapy.

Impact of HIV infection on α1-antitrypsin in the lung

Emphysema is one of the most common lung diseases in HIV⁺ individuals. The pathogenesis of HIV-associated emphysema remains unclear; however, radiographic distribution and earlier age of presentation of emphysema in the lungs of HIV⁺ patients are similar to deficiency of α₁-antitrypsin (A1AT), a key elastase inhibitor in the lung. Reduced levels of circulating A1AT in HIV⁺ patients suggest a potential mechanism for emphysema development. In the present study we asked if A1AT levels and activity in the bronchoalveolar lavage fluid (BALF) differ in HIV⁺ and HIV^- patients with and without emphysema. A1AT levels were measured by ELISA in plasma and BALF from a cohort of 21 HIV⁺ and 29 HIV^- patients with or without emphysematous changes on chest CT scan. To analyze A1AT function, we measured elastase activity in the BALF and assessed oxidation and polymerization of A1AT by Western blotting. Total A1AT was increased in the BALF, but not in the plasma, of HIV⁺ compared with HIV^- patients, regardless of the presence or absence of emphysema. However, antielastase activity was decreased in BALF from HIV⁺ patients, suggesting impaired A1AT function. Higher levels of the oxidized form of A1AT were detected in BALF from HIV⁺ than HIV^- patients, which may account for the decreased antielastase activity. These findings suggest that, in the lungs of HIV⁺ patients, posttranslational modifications of A1AT produce a "functional deficiency" of this critical elastase inhibitor, which may contribute to emphysema development.

HIV and ageing: improving quantity and quality of life

PURPOSE OF REVIEW

Evidence-based strategies are needed to address the growing complexity of care of those ageing with HIV so that as life expectancy is extended, quality of life is also enhanced.

RECENT FINDINGS

Modifiable contributing factors to the quantity and quality of life in adults ageing with HIV include: burden of harmful health behaviours, injury from HIV infection, HIV treatment toxicity and general burden of age-associated comorbidities. In turn, these factors contribute to geriatric syndromes including multimorbidity and polypharmacy, physiologic frailty, falls and fragility fractures and cognitive dysfunction, which further compromise the quality of life long before they lead to mortality.

SUMMARY

Viral suppression of HIV with combination antiviral therapy has led to increasing longevity but has not enabled a complete return to health among ageing HIV-infected individuals (HIV+). As adults age with HIV, the role of HIV itself and associated inflammation, effects of exposure to antiretroviral agents, the high prevalence of modifiable risk factors for age-associated conditions (e.g. smoking), and the effects of other viral coinfections are all influencing the health trajectory of persons ageing with HIV. We must move from the simplistic notion of HIV becoming a 'chronic controllable illness' to understanding the continually evolving 'treated' history of HIV infection with the burden of age-associated conditions and geriatric syndromes in the context of an altered and ageing immune system.

Association Between CD4+, Viral Load, and Pulmonary Function in HIV

PURPOSE

The antiretroviral therapy era has shifted the epidemiology of HIV-associated diseases, increasing the recognition of non-infectious pulmonary complications secondary to HIV. We aimed to determine the association between CD4⁺, viral load, and pulmonary function in individuals with uncontrolled HIV, and determine how changes in these parameters are associated with pulmonary function longitudinally.

METHODS

This is a retrospective observational study of individuals with HIV who underwent pulmonary function testing in an urban medical center between August 1997 and November 2015.

RESULTS

Of the 146 participants (mean age 52 ± 10 years), 49% were Hispanic, 56% were men, and 44% were current smokers. CD4⁺ <200 cells/μl was associated with significant diffusion impairment compared to CD4⁺ ≥200 cells/μl (DL_CO 56 vs. 70%, p = <0.01). VL (viral load) ≥75 copies/ml was associated with significant diffusion impairment compared to VL <75 copies/ml (DL_CO 60 vs. 71%, p = <0.01). No difference in FEV1, FEV1/FVC, or TLC was noted between groups. In univariate analysis, CD4⁺ and VL correlated with DL_CO (r = +0.33; p = <0.01; r = -0.26; p = <0.01) and no correlation was noted with FEV₁, FEV₁/FVC, or TLC. Current smoking and history of AIDS correlated with DL_CO (r = -0.20; p = 0.03; r = -0.20; p = 0.04). After adjusting for smoking and other confounders, VL ≥75 copies/ml correlated with a 11.2 (CI 95% [3.03-19.4], p = <0.01) decrease in DL_CO. In Spearman's Rank correlation, there was a negative correlation between change in VL and change in DL_CO over time (ρ = -0.47; p = <0.01).

CONCLUSION

The presence of viremia in individuals with HIV is independently associated with impaired DL_CO. Suppression of VL may allow for recovery in diffusing capacity over time, though the degree to which this occurs requires further investigation.

Lung Function in South African Adolescents Infected Perinatally with HIV and Treated Long-Term with Antiretroviral Therapy

RATIONALE

Lung disease is a common cause of mortality and morbidity in HIV-infected adolescents, but there is limited information on the spectrum of lung function impairment in adolescents on antiretroviral therapy.

OBJECTIVES

To investigate lung function in HIV-infected adolescents on antiretroviral therapy in the Cape Town Adolescent Antiretroviral Cohort (Cape Town, South Africa).

METHODS

A total of 515 South African adolescents, aged 9-14 years, stable on antiretroviral therapy for at least 6 months, underwent baseline lung function testing. Measures included spirometry, nitrogen multiple-breath washout, forced oscillation technique, 6-minute walk test, single-breath carbon monoxide diffusion testing, and bronchodilator response testing. A comparator group of 110 age- and ethnicity-matched HIV-uninfected adolescents was also tested.

RESULTS

For the HIV-infected adolescents (mean [SD] age 12 [1.6] years, 52% male), the median (interquartile range) duration of antiretroviral therapy was 7.6 (4.6-9.2) years. The median (interquartile range) nadir CD4 was 510.5 (274-903) cells/mm3. HIV-infected adolescents had significantly lower FEV1, FVC, FEV1/FVC, diffusing capacity of carbon monoxide, respiratory system compliance, and functional residual capacity than HIV-uninfected adolescents (P < 0.05 for all associations). HIV-infected adolescents had higher airway resistance and lung clearance index than HIV-uninfected adolescents (P < 0.05 for all associations). Although generally small in magnitude, these differences remained significant after adjusting for age, sex, and height. In addition, age, sex, height, and history of past lower respiratory tract infection or pulmonary tuberculosis were associated with reduced lung function.

CONCLUSIONS

Perinatally infected South African HIV-infected adolescents on antiretroviral therapy have lower lung function than uninfected adolescents. Prior lower respiratory tract infection or pulmonary tuberculosis is associated with lower lung function.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Use of rosuvastatin in HIV-associated chronic obstructive pulmonary disease

OBJECTIVES

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

DESIGN

Randomized, placebo-controlled, triple-blinded trial.

METHODS

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

RESULTS

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

CONCLUSION

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

Non-infectious pulmonary disorders in HIV

INTRODUCTION

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

HIV Infection Is Independently Associated with Increased CT Scan Lung Density

RATIONALE AND OBJECTIVES

Noninfectious pulmonary complications are common among HIV-infected individuals and may be detected early by quantitative computed tomography (CT) scanning. The association of HIV disease markers with CT lung density measurement remains poorly understood.

MATERIALS AND METHODS

One hundred twenty-five participants free of spirometry-defined lung disease were recruited from a longitudinal cohort study of HIV-infected and HIV-uninfected individuals to undergo standardized CT scan of the chest. Parenchymal density for the entire lung volume was calculated using computerized software. Qualitative assessment of CT scans was conducted by two radiologists masked to HIV status. Linear regression models were developed to determine the independent association of markers of HIV infection on inspiratory scan mean lung density (MLD).

RESULTS

HIV-infected participants had a significantly higher MLD (denser lung) compared to HIV-uninfected participants (-815 Hounsfield unit [HU] vs -837 HU; P = 0.002). After adjusting for relevant covariates, HIV infection was independently associated with 19.9 HU higher MLD (95% CI 6.04 to 33.7 HU; P = 0.005). In qualitative assessment, only ground glass attenuation and cysts were noted more commonly among HIV-infected individuals compared to HIV-uninfected individuals (34% vs 17% [P = 0.045] and 27% vs 10% [P = 0.03], respectively). No qualitative radiographic abnormalities attenuated the association between HIV infection and increased MLD.

CONCLUSIONS

HIV infection is independently associated with increased lung density. Although qualitative CT abnormalities were common in this cohort, only ground glass attenuation and cysts were noted more frequently in HIV-infected participants, suggesting that the increased lung density observed among HIV-infected individuals may be associated with subclinical inflammatory lung changes.

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

BACKGROUND

Emphysema is more prevalent in HIV-infected (HIV+) patients independent of smoking behavior. Nonetheless, health effects of emphysema in this population are poorly understood. We determined whether emphysema is associated with a greater burden of pulmonary symptoms and a lower 6-minute walk distance (6MWD) in HIV+ compared with HIV-uninfected (HIV-) subjects.

METHODS

We performed a cross-sectional analysis of 170 HIV+ and 153 HIV- subjects in the Examinations of HIV-Associated Lung Emphysema (EXHALE) cohort study. Subjects completed a self-assessment of respiratory symptoms, pulmonary function testing, and 6MWD testing as well as a chest computed tomography to determine emphysema severity. We used regression models to determine the association of emphysema with respiratory symptoms and 6MWD in HIV+ subjects and compared this to HIV- subjects.

RESULTS

Models stratified by HIV status demonstrated an association between >10% radiographic emphysema and chronic cough and/or phlegm and 6MWD in HIV+ subjects. These associations persisted among the subset without airflow obstruction: those with emphysema had 4.2 (95% confidence interval: 1.3 to 14) times the odds of chronic cough and/or phlegm and walked 60 m (95% confidence interval: 26 to 93) less distance than those without emphysema. There was no association between >10% emphysema and symptoms or 6MWD in HIV- subjects.

CONCLUSIONS

In our cohort, >10% radiographic emphysema was associated with chronic cough and/or phlegm and lower 6MWD in HIV+ but not HIV- subjects. These findings were robust even among HIV+ subjects with milder forms of emphysema and those without airflow obstruction, highlighting the clinical impact of emphysema in these patients.

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

Background

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

Methods

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

Results

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

Conclusions

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

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.

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

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

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.

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

OBJECTIVE

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

DESIGN

Longitudinal observational study.

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

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

BACKGROUND

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

RESULTS

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

CONCLUSIONS

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

Highly active antiretroviral therapy reduces pulmonary IL-8 in HIV-positive women smokers

Increased levels of the proinflammatory cytokine IL-8 are detected in the sputum of patients with chronic obstructive pulmonary disease (COPD) and during the pathological pulmonary manifestations of HIV infection : To explore a potential interrelationship between smoking, highly active antiretroviral therapy (HAART) and HIV immune status, we collected sputum samples, along with complete pulmonary function tests from groups of HIV-infected women smokers who were either on or off HAART. Analysis of the patient's sputum for cell count along with quantitative measures of IL-8 was performed and correlated with concurrent assessment of pulmonary function test (PFT). We found that HIV-positive smokers had decreased measurements on PFT of the diffusing capacity of the lung for carbon monoxide (D(LCO)) compared to standard reference values that did not differ with HAART usage. HAART, when controlled for CD4, showed a suppressive effect on the levels of pro inflammatory cytokine IL-8 in sputum. We conclude that in the era of HAART, HIV along with concurrent tobacco smoking is associated with declines in PFT in HIV-infected women. The use of HAART in patients appears to mitigate the increases in IL-8 levels in relation to immune status based on CD4 count.

Factors associated with abnormal spirometry among HIV-infected individuals

OBJECTIVE

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

DESIGN

Cross-sectional cohort study.

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

RATIONALE

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

OBJECTIVES

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

METHODS

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

MEASUREMENTS AND MAIN RESULTS

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

CONCLUSIONS

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

Screening for Chronic Obstructive Pulmonary Disease (COPD) in an Urban HIV Clinic: A Pilot Study

Increased smoking and a detrimental response to tobacco smoke in the lungs of HIV/AIDS patients result in an increased risk for COPD. We aimed to determine the predictive value of a COPD screening strategy validated in the general population and to identify HIV-related factors associated with decreased lung function. Subjects at least 35 years of age at an HIV clinic in New York City completed a COPD screening questionnaire and peak flow measurement. Those with abnormal results and a random one-third of normal screens had spirometry. 235 individuals were included and 89 completed spirometry. Eleven (12%) had undiagnosed airway obstruction and 5 had COPD. A combination of a positive questionnaire and abnormal peak flow yielded a sensitivity of 20% (specificity 93%) for detection of COPD. Peak flow alone had a sensitivity of 80% (specificity 80%). Abnormal peak flow was associated with an AIDS diagnosis (p=0.04), lower nadir (p=0.001), and current CD4 counts (p=0.001). Nadir CD4 remained associated in multivariate analysis (p=0.05). Decreased FEV1 (<80% predicted) was associated with lower CD4 count nadir (p=0.04) and detectable current HIV viral load (p=0.01) in multivariate analysis. Questionnaire and peak flow together had low sensitivity, but abnormal peak flow shows potential as a screening tool for COPD in HIV/AIDS. These data suggest that lung function may be influenced by HIV-related factors.

Increased risk of radiographic emphysema in HIV is associated with elevated soluble CD14 and nadir CD4

BACKGROUND

The association between HIV and emphysema remains incompletely understood. We sought to determine whether HIV is an independent risk factor for emphysema severity and whether markers of HIV severity and systemic biomarkers of inflammation (IL-6), altered coagulation (D-dimer), and immune activation (soluble CD14) are associated with emphysema.

METHODS

We performed a cross-sectional analysis of 114 participants with HIV infection and 89 participants without HIV infection in the Examinations of HIV-Associated Lung Emphysema (EXHALE) study. Participants underwent chest CT imaging with blinded semiquantitative interpretation of emphysema severity, distribution, and type. We generated multivariable logistic regression models to determine the risk of HIV for radiographic emphysema, defined as > 10% lung involvement. Similar analyses examined associations of plasma biomarkers, HIV RNA, and recent and nadir CD4 cell counts with emphysema among participants with HIV infection.

RESULTS

Participants with HIV infection had greater radiographic emphysema severity with increased lower lung zone and diffuse involvement. HIV was associated with significantly increased risk for > 10% emphysema in analyses adjusted for cigarette smoking pack-years (OR, 2.24; 95% CI, 1.12-4.48). In multivariable analyses restricted to participants with HIV infection, nadir CD4 < 200 cells/μL (OR, 2.98; 95% CI, 1.14-7.81), and high soluble CD14 level (upper 25th percentile) (OR, 2.55; 95% CI, 1.04-6.22) were associated with increased risk of > 10% emphysema. IL-6 and D-dimer were not associated with emphysema in HIV.

CONCLUSIONS

HIV is an independent risk factor for radiographic emphysema. Emphysema severity was significantly greater among participants with HIV infection. Among those with HIV, nadir CD4 < 200 cells/μL and elevated soluble CD14 level were associated with emphysema, highlighting potential mechanisms linking HIV with emphysema.

Activation-induced cell death drives profound lung CD4(+) T-cell depletion in HIV-associated chronic obstructive pulmonary disease

RATIONALE

As overall survival improves, individuals with HIV infection become susceptible to other chronic diseases, including accelerated chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To determine whether individuals with HIV-associated COPD exhibit dysregulated lung mucosal T-cell immunity compared with control subjects.

METHODS

Using flow cytometry, we evaluated peripheral blood and lung mucosal T-cell immunity in 14 HIV(+)COPD(+), 13 HIV(+)COPD(-), and 7 HIV(-)COPD(+) individuals.

MEASUREMENTS AND MAIN RESULTS

HIV(+)COPD(+) individuals demonstrated profound CD4(+) T-cell depletion with reduced CD4/CD8 T-cell ratios in bronchoalveolar lavage-derived lung mononuclear cells, not observed in peripheral blood mononuclear cells, and diminished CD4(+) T cell absolute numbers, compared with control subjects. Furthermore, HIV(+)COPD(+) individuals demonstrated decreased pulmonary HIV-specific and staphylococcal enterotoxin B-reactive CD4(+) memory responses, including loss of multifunctionality, compared with HIV(+)COPD(-) control subjects. In contrast, lung mucosal HIV-specific CD8(+) T-cell responses were preserved. Lung CD4(+) T cells from HIV(+)COPD(+) individuals expressed increased surface Fas death receptor (CD95) and programmed death-1, but similar bronchoalveolar lavage viral loads as control subjects. However, programmed death-1 expression inversely correlated with HIV-specific lung CD4(+)IFN-γ(+) T-cell responses, suggesting functional exhaustion. Moreover, lung CD4(+) T cells from HIV(+)COPD(+) patients demonstrated increased basal and HIV antigen-induced expression of the early apoptosis marker annexin V compared with control subjects, which was significantly attenuated with anti-Fas blockade. Lastly, lung mucosal, but not blood, CD4(+)/CD8(+) ratios from HIV(+) patients significantly correlated with the FEV1, but not in HIV(-)COPD(+) patients.

CONCLUSIONS

Together, our results provide evidence for profound lung mucosal CD4(+) T-cell depletion via a Fas-dependent activation-induced cell death mechanism, along with impaired HIV-specific CD4(+) immunity as immunologic features of HIV-associated COPD.

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.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Lung function abnormalities in HIV-infected adults and children

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

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

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

Association of chronic cough and pulmonary function with 6-minute walk test performance in HIV infection

OBJECTIVE

Chronic lung disease has been associated with greater impairment in self-reported physical function in HIV-infected patients. We sought to study this association using objective measures of physical function and pulmonary function.

DESIGN

Baseline data from the Examinations of HIV Associated Lung Emphysema study, a multicenter observational cohort of HIV-infected and uninfected veterans.

METHODS

We assessed the association between clinical, laboratory, and pulmonary function measures with 6-minute walk test (6-MWT). Multivariable linear regression models were generated to identify factors associated with 6-MWT performance.

RESULTS

Three hundred forty participants completed 6-MWT (mean age 55 years), with 68% blacks, 94% men, and 62% current smokers. Overall, 180 (53%) were HIV-infected and 63 (19%) had spirometry-defined chronic obstructive pulmonary disease. In a multivariable model, age, current smoking, and obesity (body mass index > 30) were independently associated with lower 6-MWT performance, but HIV infection was not; there was a significant interaction between HIV and chronic cough, such that distance walked among HIV-infected participants with chronic cough was 51.76 m less (P = 0.04) compared with those without cough or HIV. Among HIV-infected participants, the forced expiratory volume in 1 second (FEV1, percent predicted), to a greater extent than total lung capacity or diffusing capacity, attenuated the association with chronic cough; decreased FEV1 was independently associated with lower 6-MWT performance in those with HIV.

CONCLUSIONS

Older age, current smoking, and airflow limitation were important determinants of 6-MWT performance in the HIV-infected participants. These findings suggest that potential interventions to improve physical function may include early management of respiratory symptoms and airflow limitation.

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.

Human immunodeficiency virus and acquired immunodeficiency syndrome: recent developments and their implications for pediatric surgeons

Advances in medical management have enhanced both the quality and the quantity of life currently enjoyed by HIV-infected infants and children. Advances in surgical treatment have complemented these advances and contributed to the improving prognosis of HIV disease in the pediatric population. The resultant "aging" of the pediatric HIV population means that pediatric surgeons can expect to encounter HIV-infected patients on an ever-increasing basis. This article reviews the new advances in diagnosis and treatment of pediatric HIV disease most relevant to pediatric surgical practice.