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

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

OBJECTIVE

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSION

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

Exhaled nitric oxide is associated with inflammatory biomarkers and risk of acute respiratory exacerbations in children with HIV-associated chronic lung disease

OBJECTIVES

Chronic lung disease is a recognized complication in children with HIV. Acute respiratory exacerbations (ARE) are common among this group and cause significant morbidity. Exhaled nitric oxide (eNO) is a known marker of local airway inflammation. We investigated the association between eNO and ARE, biomarkers of systemic inflammation, and the effect of azithromycin on eNO levels.

METHODS

Individuals aged 6-19 years with HIV-associated chronic lung disease in Harare, Zimbabwe, were enrolled in a placebo-controlled randomized trial investigating the effect of 48-week azithromycin treatment on lung function and ARE. eNO levels and biomarkers were measured at inclusion and after treatment in a consecutively enrolled subset of participants. Linear regression and generalized linear models were used to study associations between eNO and ARE, biomarkers, and the effect of azithromycin on eNO levels.

RESULTS

In total, 172 participants were included in this sub-study, 86 from the placebo group and 86 from the azithromycin group. Participants experiencing at least one ARE during follow-up had significantly higher eNO levels at baseline than participants who did not (geometric mean ratio 1.13, 95% confidence interval [CI] 1.03-1.24, p = 0.015), adjusted for trial arm, age, sex and history of tuberculosis. Matrix metalloproteinase (MMP)-3, -7, and -10 were significantly associated with higher baseline eNO levels. At 48 weeks, azithromycin treatment did not affect eNO levels (geometric mean ratio 0.86, 95% CI 0.72-1.03, p = 0.103).

CONCLUSION

Higher baseline eNO levels were a risk factor for ARE. eNO was associated with proinflammatory biomarkers previously found to contribute to the development of chronic lung disease. The potential use of eNO as a marker of inflammation and risk factor for ARE in HIV-associated chronic lung disease needs further investigation.

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

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

Elevated Levels of Interleukin-1β and Interleukin-10 Are Associated With Faster Lung Function Decline in People With Well-Treated Human Immunodeficiency Virus

BACKGROUND

People with human immunodeficiency virus (PWH) have an increased risk of chronic lung diseases and chronic inflammation. We aimed to investigate if inflammatory markers and monocyte activation are associated with faster lung function decline in PWH.

METHODS

We included 655 PWH from the Copenhagen Comorbidity in HIV Infection (COCOMO) Study. Eligible participants were aged ≥25 years and had 2 spirometries separated by >2 years. Inflammatory markers (interleukin [IL]-1β, IL-2, IL-6, IL-10, tumor necrosis factor-α, and interferon-γ) were measured at baseline by Luminex, and soluble CD14 and soluble CD163 by enzyme-linked immunosorbent assay. Using linear mixed models, we investigated whether elevated cytokine levels were associated with faster lung function decline.

RESULTS

The majority of PWH were males (85.2%) with undetectable viral replication (95.3%). We found a faster decline in forced expiratory volume in 1 second (FEV1) in PWH with elevated IL-1β and IL-10, with an additional decline of 10.3 mL/year (95% confidence interval [CI], 2.1-18.6; P = .014) and 10.0 mL/year (95% CI, 1.8-18.2; P = .017), respectively. We found no interaction between smoking and IL-1β or IL-10 on FEV1 decline.

CONCLUSIONS

Elevated IL-1β and IL-10 were independently associated with faster lung function decline in PWH, suggesting that dysregulated systemic inflammation may play a role in the pathogenesis of chronic lung diseases.

Pulmonary function tests and their associated factors in people living with HIV at Jimma medical center; Ethiopia: a comparative cross-sectional study

Background

People living with HIV (PLHIV) have a greater risk of developing respiratory disorders. The problems are linked to poor socio-economic status, high viral load, low CD4 counts, and antiretroviral therapy. Despite the high prevalence of respiratory disorders, the association between HIV infection and pulmonary function status, as well as the associated factors, is not well established in resource-limited countries.

Methods

A comparative cross-sectional study was conducted from September 24 to October 15 2020 at Jimma Medical Center among people living with HIV who were arranged into an age-sex-matched comparison group. Data were collected using a pretested structured questionnaire administered via face-to-face interviews. The collected data included socio-demographic, respiratory, HIV infection, and substance use variables. Pulmonary function tests were conducted using an SP10 spirometer. The collected data were entered and analyzed using SPSS version 26. Independent t-test and multiple linear regressions were carried out to identify factors associated with the pulmonary function status of the study participants.

Results

A total of 96 PLHIV and 96 matched control individuals participated in the study. The mean of pulmonary function test parameters among the PLHIV respondents was FVC (l) (67.35 ± 19.12, p0.003), FEV1s (l) (61.76 ± 16.04, p0.001), and PEFR (50.14 ± 23.32, p0.001), with a significant lowering in the study group. Female sex, respiratory symptoms, duration of HIV, duration of treatment, and khat chewing were associated with lowered FEV1s (l) (p < 0.05) in HIV-positive respondents.

Conclusion

PLHIV had significantly lower mean lung function parameters than HIV-uninfected participants. As a result, health providers should screen HIV-positive patients with respiratory symptoms, prolonged duration of HIV infection, prolonged treatment, and khat chewing for non-infectious lung disorders while treating them.

HIV-associated lung disease

Lung disease encompasses acute, infectious processes and chronic, non-infectious processes such as chronic obstructive pulmonary disease, asthma and lung cancer. People living with HIV are at increased risk of both acute and chronic lung diseases. Although the use of effective antiretroviral therapy has diminished the burden of infectious lung disease, people living with HIV experience growing morbidity and mortality from chronic lung diseases. A key risk factor for HIV-associated lung disease is cigarette smoking, which is more prevalent in people living with HIV than in uninfected people. Other risk factors include older age, history of bacterial pneumonia, Pneumocystis pneumonia, pulmonary tuberculosis and immunosuppression. Mechanistic investigations support roles for aberrant innate and adaptive immunity, local and systemic inflammation, oxidative stress, altered lung and gut microbiota, and environmental exposures such as biomass fuel burning in the development of HIV-associated lung disease. Assessment, prevention and treatment strategies are largely extrapolated from data from HIV-uninfected people. Smoking cessation is essential. Data on the long-term consequences of HIV-associated lung disease are limited. Efforts to continue quantifying the effects of HIV infection on the lung, especially in low-income and middle-income countries, are essential to advance our knowledge and optimize respiratory care in people living with HIV.

Pneumoproteins and biomarkers of inflammation and coagulation do not predict rapid lung function decline in people living with HIV

Chronic obstructive pulmonary disease (COPD) is among the leading causes of death worldwide and HIV is an independent risk factor for the development of COPD. However, the etiology of this increased risk and means to identify persons with HIV (PWH) at highest risk for COPD have remained elusive. Biomarkers may reveal etiologic pathways and allow better COPD risk stratification. We performed a matched case:control study of PWH in the Strategic Timing of Antiretoviral Treatment (START) pulmonary substudy. Cases had rapid lung function decline (> 40 mL/year FEV₁ decline) and controls had stable lung function (+ 20 to - 20 mL/year). The analysis was performed in two distinct groups: (1) those who were virally suppressed for at least 6 months and (2) those with untreated HIV (from the START deferred treatment arm). We used linear mixed effects models to test the relationship between case:control status and blood concentrations of pneumoproteins (surfactant protein-D and club cell secretory protein), and biomarkers of inflammation (IL-6 and hsCRP) and coagulation (d-dimer and fibrinogen); concentrations were measured within ± 6 months of first included spirometry. We included an interaction with treatment group (untreated HIV vs viral suppression) to test if associations varied by treatment group. This analysis included 77 matched case:control pairs in the virally suppressed batch, and 42 matched case:control pairs in the untreated HIV batch (n = 238 total) who were followed for a median of 3 years. Median (IQR) CD4 + count was lowest in the controls with untreated HIV at 674 (580, 838). We found no significant associations between case:control status and pneumoprotein or biomarker concentrations in either virally suppressed or untreated PWH. In this cohort of relatively young, recently diagnosed PWH, concentrations of pneumoproteins and biomarkers of inflammation and coagulation were not associated with subsequent rapid lung function decline.Trial registration: NCT00867048 and NCT01797367.

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.

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

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

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Altered polarization and impaired phagocytic activity of lung macrophages in people with HIV and COPD

BACKGROUND

People with HIV (PWH) have an increased risk of developing Chronic Obstructive Pulmonary Disease (COPD).

METHODS

We phenotyped lung macrophages in four subgroups: M1 (CD40+CD163-), M2 (CD40-CD163+), Double Positives (CD40+CD163+), Double Negatives (CD40-CD163-) and determined their phagocytic capacity in PWH with and without COPD.

RESULTS

PWH with COPD have more double negative macrophages (84.1%) vs PWH without (54.3%) vs controls (23.9%) (p=0.004) and reduced phagocytosis (p=0.012). Double negative macrophages had the worst phagocytic capacity (p<0.001).

CONCLUSIONS

PWH with COPD have an abundance of non-polarized macrophages which have poor phagocytic capacity therefore predispose them to increased risk of disease progression.

Predictors of impaired pulmonary function in people living with HIV in an urban African setting

Background

Studies have associated HIV with an increased risk of obstructive lung disease (OLD).

Objectives

We aimed to identify the predictive factors for impaired lung function in an urban, African, HIV-positive population.

Method

A cross-sectional study was performed in Johannesburg, South Africa, from July 2016 to November 2017. A questionnaire was administered and pre- and post-bronchodilator spirometry conducted. The predictors investigated included age, sex, antiretroviral treatment (ART) duration, body mass index, history of tuberculosis (TB) or pneumonia, occupational exposure, environmental exposure, smoking and symptoms of OLD (cough, wheeze, mucus and dyspnoea). Impaired lung function was defined as a forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio of < 0.70, or below the 20th percentile of normal.

Results

The 98 ART-naïve participants (mean age = 34.0, standard deviation [s.d.] = 8.2), 85 participants on first-line ART (mean age = 36.9, s.d. = 6.6) and 189 participants on second-line ART (mean age = 43.5, s.d. = 7.9) were predominantly female (65.6%). Of the participants, 64 (17.2%) had impaired lung function and 308 had normal lung function. Linear regression identified age (β = –0.003, P < 0.01), male sex (β = –0.016, P = 0.03) and history of TB or pneumonia (β = –0.024, P < 0.01) as independent predictors of a lower FEV1/FVC ratio. Following logistic regression, only a history of TB or pneumonia (odds ratio = 2.58, 95% confidence interval = 1.47–4.52) was significantly related to impaired lung function (area under the receiver operating characteristic curve = 0.64).

Conclusion

Our data show that a history of TB or pneumonia predicts impaired lung function. In order to improve timely access to spirometry, clinicians should be alert to the possibility of impaired lung function in people with a history of TB or pneumonia.

Soluble biomarkers associated with chronic lung disease in older children and adolescents with perinatal HIV infection

OBJECTIVE

HIV-associated chronic lung disease (HCLD) is a common comorbidity in children and adolescents in sub-Saharan Africa (SSA). The pathogenesis of HCLD is unclear and may be driven by underlying dysregulated systemic immune activation and inflammation. We investigated the association between 26 plasma soluble biomarkers and HCLD.

DESIGN

Case--control analysis of baseline biomarker data from 336 children and adolescents (6-19 years old) with perinatal HIV infection (PHIV) and HCLD (cases) and 74 age-matched and sex-matched controls with PHIV but no CLD. HCLD was defined as having a forced expiratory volume in one second (FEV1) z score less than -1 with no reversibility.

METHODS

Cryopreserved plasma collected at recruitment was used in a multiplex bead assay (Luminex) to measure baseline levels of soluble biomarkers. Logistic regression alongside data-reduction and techniques quantifying the interconnectedness of biomarkers were used to identify biomarkers associated with odds of HCLD.

RESULTS

Biomarkers of general immune activation and inflammation (β2M, CRP, sCCL5, GCSF, IFN-γ, IP-10), T-cell activation (sCD25, sCD27), platelet activation (sCD40-L), monocyte activation (sCD14), coagulation (D-Dimer), cellular adhesion (E-selectin), and extracellular matrix degradation (MMP-1, MMP-7, MMP-10) were associated with increased odds of HCLD. Exploratory PCA and assessment of biomarker interconnectedness identified T-cell and platelet activation as centrally important to this association.

CONCLUSION

HCLD was associated with a large number of soluble biomarkers representing a range of different pathways. Our findings suggest a prominent role for T-cell and platelet activation in HCLD.

Inflammatory biomarkers in the pathogenesis of respiratory dysfunction in people living with HIV

BACKGROUND

Although the association between HIV infection and airway obstruction is well known, its etiopathogenesis is not clear.

OBJECTIVES

Our aim was to analyze the association between biomarkers of systemic inflammation and bacterial translocation and pulmonary function tests in HIV-infected patients and compare the results between smokers and non-smokers.

METHOD

It was a cross-sectional, observational study. The inclusion criterion of the study was people living with HIV with undetectable plasma viral load. The exclusion criterion was other comorbidities associated with systemic inflammation. Outcome variables were spirometry and diffusing capacity for carbon monoxide; explanatory variables were inflammatory biomarkers (interleukin-6, tumor necrosis factor-alpha), bacterial translocation (soluble CD14 [sCD14] and bacterial 16S rDNA), and variables related to HIV infection. Associations were tested using the Pearson/Spearman correlation tests, the Student t-test, and multivariable linear regression.

RESULTS

We included 71 patients (54.9% smokers). We did not observe significant differences in pulmonary function tests according to biomarkers of inflammation or bacterial translocation. In non-smokers (n=32), sCD14 was negatively correlated with forced expiratory volume in 1 second (R = -0.35, P = 0.048) and forced vital capacity (R= -0.40, P=0.023). Age, time since HIV diagnosis, and CD4+ nadir were associated with alterations in PFTs. In smokers, the only association observed was between the pack-years and pulmonary obstruction.

CONCLUSION

In non-smokers, HIV patients' lung dysfunction can be, at least partially, related to bacterial translocation (sCD14), CD4+ nadir, and time since HIV diagnosis.

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

OBJECTIVES

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

DESIGN

Cross-sectional, observational study.

METHODS

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

RESULTS

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

CONCLUSION

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

Abnormal Levels of Some Biomarkers of Immune Activation Despite Very Early Treatment of Human Immunodeficiency Virus

BACKGROUND

Despite early antiretroviral therapy (ART), ART-suppressed people with human immunodeficiency virus (HIV) (PWH) remain at higher risk for infections and infection-related cancers than the general population. The immunologic pathways that remain abnormal in this setting, potentially contributing to these complications, are unclear.

METHODS

ART-suppressed PWH and HIV-negative controls, all cytomegalovirus seropositive and enriched for HIV risk factors, were sampled from an influenza vaccine responsiveness study. PWH were stratified by timing of ART initiation (within 6 months of infection [early ART] vs later) and nadir CD4+ T-cell count among later initiators. Between-group differences in kynurenine-tryptophan (KT) ratio, interferon-inducible protein 10, soluble CD14 and CD163, soluble tumor necrosis factor receptor 2, interleukin 6, and soluble urokinase plasminogen activator receptor were assessed after confounder adjustment.

RESULTS

Most participants (92%) were male, reflecting the demographics of early-ART initiators in San Francisco. Most biomarkers were higher among later-ART initiators. Participants in the early-ART group achieved near-normal soluble tumor necrosis factor receptor 2, interleukin 6, and soluble urokinase plasminogen activator receptor levels, but substantially higher KT ratio than those without HIV after confounder adjustment (P = .008). Soluble CD14, soluble CD163, and interferon-inducible protein 10 trended similarly.

CONCLUSIONS

While early-ART initiators restore near-normal levels of many inflammatory markers, the kynurenine pathway of tryptophan catabolism remains abnormally high. Because this pathway confers adaptive immune defects and predicts tuberculosis and cancer progression, this it may contribute to persistent risks of these complications in this setting.

T cell responses in respiratory viral infections and chronic obstructive pulmonary disease

ABSTRACT

Respiratory viruses are major human pathogens that cause approximately 200 million pneumonia cases annually and induce various comorbidities with chronic obstructive pulmonary disease (COPD), resulting in significant health concerns and economic burdens. Clinical manifestations in respiratory viral infections and inflammations vary from asymptomatic, mild, to severe, depending on host immune cell responses to pathogens and interactions with airway epithelia. We critically review the activation, effector, and regulation of T cells in respiratory virus infections and chronic inflammations associated with COPD. Crosstalk among T cells, innate immune cells, and airway epithelial cells is discussed as essential parts of pathogenesis and protection in viral infections and COPD. We emphasize the specificity of peptide antigens and the functional heterogeneity of conventional CD4+ and CD8+ T cells to shed some light on potential cellular and molecular candidates for the future development of therapeutics and intervention against respiratory viral infections and inflammations.

Association of Monocyte Migration Marker CD11b With Pulmonary Function in People Living With HIV

BACKGROUND

Maladaptive immune responses contribute to the pathogenesis of many chronic lung diseases. Here, we tested hypotheses that CD4 and CD8 T-cell and monocyte phenotypes are associated with lung function in people living with HIV and those without HIV.

METHODS

Markers of T cell differentiation, activation, exhaustion and senescence, and markers of monocyte recruitment and migration were quantified in 142 HIV-positive and 73 HIV-negative participants of the Pittsburgh HIV Lung Cohort. All participants underwent lung function testing.

RESULTS

CD4 or CD8 T-cell phenotypes were not associated with measures of lung function in HIV-positive or HIV-negative participants after adjustment for multiple comparisons. In HIV-positive participants, however, the percentage of classical monocytes that were CD11b+ had positive associations at the Bonferroni-adjusted significance threshold of P = 0.05/63 with prebronchodilator and postbronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio (β = 0.36; P = 0.00003 and β = 0.31; P = 0.0003, respectively). In stratified analyses of n = 87 participants with CD4 ≥ 500 cells/µL, associations of percentage of classical monocytes that were CD11b+ with prebronchodilator and postbronchodilator FEV1/FVC ratio were stronger (β = 0.48 and β = 0.41, for pre- and post-, respectively) than in the entire HIV-positive study population. Significant associations of monocyte phenotypes were not observed in HIV-negative participants after adjustment for multiple comparisons.

CONCLUSIONS

CD11b+ expression on classical monocytes is positively associated with FEV1/FVC ratio in people living with HIV including in those with CD4 T-cell recovery. Given the normal surveillance activity of monocytes, such association suggests this monocyte subset may play a role in preservation of pulmonary function in PLWH.

Prevalence and antimicrobial resistance profiles of respiratory microbial flora in African children with HIV-associated chronic lung disease

BACKGROUND

HIV-associated chronic lung disease (CLD) is common among children living with HIV (CLWH) in sub-Saharan Africa, including those on antiretroviral therapy (ART). However, the pathogenesis of CLD and its possible association with microbial determinants remain poorly understood. We investigated the prevalence, and antibiotic susceptibility of Streptococcus pneumoniae (SP), Staphylococcus aureus (SA), Haemophilus influenzae (HI), and Moraxella catarrhalis (MC) among CLWH (established on ART) who had CLD (CLD+), or not (CLD-) in Zimbabwe and Malawi.

METHODS

Nasopharyngeal swabs (NP) and sputa were collected from CLD+ CLWH (defined as forced-expiratory volume per second z-score < - 1 without reversibility post-bronchodilation with salbutamol), at enrolment as part of a randomised, placebo-controlled trial of azithromycin (BREATHE trial - NCT02426112 ), and from age- and sex-matched CLD- CLWH. Samples were cultured, and antibiotic susceptibility testing was conducted using disk diffusion. Risk factors for bacterial carriage were identified using questionnaires and analysed using multivariate logistic regression.

RESULTS

A total of 410 participants (336 CLD+, 74 CLD-) were enrolled (median age, 15 years [IQR = 13-18]). SP and MC carriage in NP were higher in CLD+ than in CLD- children: 46% (154/336) vs. 26% (19/74), p = 0.008; and 14% (49/336) vs. 3% (2/74), p = 0.012, respectively. SP isolates from the NP of CLD+ children were more likely to be non-susceptible to penicillin than those from CLD- children (36% [53/144] vs 11% [2/18], p = 0.036). Methicillin-resistant SA was uncommon [4% (7/195)]. In multivariate analysis, key factors associated with NP bacterial carriage included having CLD (SP: adjusted odds ratio (aOR) 2 [95% CI 1.1-3.9]), younger age (SP: aOR 3.2 [1.8-5.8]), viral load suppression (SP: aOR 0.6 [0.4-1.0], SA: 0.5 [0.3-0.9]), stunting (SP: aOR 1.6 [1.1-2.6]) and male sex (SA: aOR 1.7 [1.0-2.9]). Sputum bacterial carriage was similar in both groups (50%) and was associated with Zimbabwean site (SP: aOR 3.1 [1.4-7.3], SA: 2.1 [1.1-4.2]), being on ART for a longer period (SP: aOR 0.3 [0.1-0.8]), and hot compared to rainy season (SP: aOR 2.3 [1.2-4.4]).

CONCLUSIONS

CLD+ CLWH were more likely to be colonised by MC and SP, including penicillin-non-susceptible SP strains, than CLD- CLWH. The role of these bacteria in CLD pathogenesis, including the risk of acute exacerbations, should be further studied.

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.

Independent Association of Interleukin 6 With Low Dynamic Lung Function and Airflow Limitation in Well-Treated People With Human Immunodeficiency Virus

BACKGROUND

Human immunodeficiency virus (HIV) infection is associated with an increased risk of chronic pulmonary diseases. We compared cytokine concentrations (interleukin 6 [IL-6], interleukin 1β, 2, 4, 10, and 17A, tumor necrosis factor α, interferon γ, soluble CD14 [sCD14] and soluble CD163 [sCD163]) in people with HIV (PWH) and uninfected controls and investigated whether elevated cytokine concentrations were independently associated with lung function indices in PWH.

METHODS

We performed spirometry and measured cytokine concentrations by Luminex immunoassays or enzyme-linked immunoassay in 951 PWH and 79 uninfected controls from the Copenhagen Comorbidity in HIV Infection study. Regression analyses were used to explore associations between elevated cytokine concentrations and lung function indices.

RESULTS

PWH were predominantly male (84.6%) and 94.2% had undetectable viral replication. In PWH, elevated IL-6 was associated with lower forced expiratory volume in 1 second (-212 mL [95% confidence interval, -308 to -116 mL]), lower forced vital capacity (-208 mL [-322 to -93 mL]), and airflow limitation (aOR, 2.62 [1.58-4.36]) (all P < .001) in models adjusted for age, sex, ethnicity, smoking status, body mass index, and CD4 T-cell nadir. The association between IL-6 and dynamic lung function was modified by smoking (P for interaction = .005).

CONCLUSION

IL-6 levels were elevated and independently associated with low dynamic lung function and airflow limitation in well-treated PWH, suggesting that systemic inflammation may contribute to the pathogenesis of chronic pulmonary diseases.

Lung function in men with and without HIV

OBJECTIVES

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

DESIGN

Cross-sectional, observational study.

METHODS

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

RESULTS

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

CONCLUSION

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

Association Between Inflammatory Pathways and Phenotypes of Pulmonary Dysfunction Using Cluster Analysis in Persons Living With HIV and HIV-Uninfected Individuals

BACKGROUND

Persons living with HIV (PLWH) are at risk of developing different phenotypes of chronic lung disease, including chronic obstructive pulmonary disease. Mechanisms underlying these phenotypes are unclear.

OBJECTIVE

To identify clusters of peripheral inflammatory mediators associated with pulmonary function to determine inflammatory pathways and phenotypes of chronic obstructive pulmonary disease in PLWH and HIV-uninfected individuals.

METHODS

Study participants were PLWH and HIV-uninfected individuals enrolled in the Pittsburgh HIV Lung Cohort. Pulmonary function tests were performed for all participants. Chest computed tomographic scans were performed in a subset of PLWH. Plasma levels of 19 inflammatory mediators were measured by Luminex or ELISA. Clusters were identified based on the expression pattern of inflammatory mediators in PLWH and HIV-uninfected individuals, and the relationships among clinical parameters were evaluated within clusters by using cluster and network analyses.

RESULTS

In PLWH, we identified a distinct cluster with higher levels of Th1, Th2, and Th17 inflammatory mediators with increased complexity of these mediators and inferred presence of pathogenic Th17 cell types. Individuals in this cluster had worse airway obstruction and more radiographic emphysema. In HIV-uninfected individuals, a cluster with high-grade systemic inflammation also had worse diffusing capacity for carbon monoxide.

CONCLUSIONS

Inflammatory pathways associated with pulmonary dysfunction in PLWH suggest multifaceted immune dysregulation involved in different phenotypes of pulmonary dysfunction with a potential specific contribution of the Th17 pathway to airway obstruction in PLWH. Identification of these associations may help in development of treatments that could alter the course of the disease.

ET-traps offer a potential therapeutic tool for use in different autoimmune diseases

Research shows that endothelin (ET)-traps are a potential therapy for diabetes. Given that type 1 diabetes mellitus (T1DM) is an autoimmune disorder, ET-traps could also have an efficacious, therapeutic effect on other autoimmune diseases associated with pathologically elevated ET-1. Here, we describe those different autoimmune diseases that might benefit from a tool such as ET-traps, which potently sequester these elevated levels of ET-1. We also discuss the current use of ET receptor (ETR) antagonists and the associated adverse effects, and how ET-traps are associated with no toxicity and potentially offer a superior alternative. ET-traps could be used against different autoimmune diseases and, therefore, are a novel therapeutic tool for such conditions.

Endothelial Activation, Innate Immune Activation, and Inflammation Are Associated With Postbronchodilator Airflow Limitation and Obstruction Among Adolescents Living With HIV

BACKGROUND

Chronic inflammation, innate immune activation, T-cell imbalance and endothelial activation have been linked with lung diseases. We sought to determine whether markers of these pathophysiologic pathways were associated with spirometry and chest computed tomography (CT) abnormalities among adolescents living with HIV (ALWH).

SETTING

Coptic Hope Center for Infectious Diseases in Nairobi, Kenya.

METHODS

We performed a cross-sectional study of ALWH (10-19 years old). Participants underwent chest CT, spirometry, and venipuncture for serum biomarkers. We also collected demographic, anthropometric, T-cell subset, antiretroviral therapy, and exposure data. We compared characteristics and biomarkers by airflow obstruction [postbronchodilator FEV1/FVC z-score (zFEV1/FVC) < -1.64]. We used multivariable linear regression to determine associations of log10-transformed biomarkers and chest CT abnormalities with lower postbronchodilator zFEV1/FVC (airflow limitation). We performed exploratory principal components analysis on biomarkers, and determined associations of factors with postbronchodilator zFEV1/FVC and chest CT abnormalities.

RESULTS

Of 47 participants with acceptable quality spirometry, 21 (45%) were female, median age was 13 years and 96% had perinatally-acquired HIV. Median CD4 was 672 cells/µL. Overall, 28% had airflow obstruction and 78% had a chest CT abnormality; airflow obstruction was associated with mosaic attenuation (P = 0.001). Higher endothelial activation (sVCAM-1, sICAM-1), inflammation and innate immune activation (serum amyloid-A, sTREM-1, sCD163), and T-cell imbalance (lower CD4/CD8) markers were associated with airflow limitation. Factors comprising endothelial and innate immune activation were associated with airflow limitation.

CONCLUSIONS

Endothelial activation, innate immune activation, T-cell imbalance, and chronic inflammation are associated with airflow limitation and obstruction, providing insights into chronic lung disease pathophysiology among ALWH.

Alterations in Oral Microbiota in HIV Are Related to Decreased Pulmonary Function

Rationale: Mechanisms of HIV-associated chronic obstructive pulmonary disease (COPD) are poorly understood. The oral microbiome shapes the lung microbiome, and gut dysbiosis can affect lung diseases; however, relationships of the oral and gut microbiome to COPD in HIV have not been explored.Objectives: To examine alterations in the oral and gut microbiome associated with pulmonary disease in persons with HIV (PWH).Methods: Seventy-five PWH and 93 HIV-uninfected men from the MACS (Multicenter AIDS Cohort Study) performed pulmonary function testing. Sequencing of bacterial 16S ribosomal RNA in saliva and stool was performed. We used nonmetric multidimensional scaling, permutational multivariate ANOVA, and linear discriminant analysis to analyze communities by HIV and lung function.Measurements and Main Results: Oral microbiome composition differed by HIV and smoking status. Alterations of oral microbial communities were observed in PWH with abnormal lung function with increases in relative abundance of Veillonella, Streptococcus, and Lactobacillus. There were no significant associations between the oral microbiome and lung function in HIV-uninfected individuals. No associations with HIV status or lung function were seen with the gut microbiome.Conclusions: Alterations of oral microbiota in PWH were related to impaired pulmonary function and to systemic inflammation. These results suggest that the oral microbiome may serve as a biomarker of lung function in HIV and that its disruption may contribute to COPD pathogenesis.

Chronic lung disease in children and adolescents with HIV: a case-control study

OBJECTIVE

To describe the features of HIV-associated chronic lung disease (CLD) in older children and adolescents living with HIV and to examine the clinical factors associated with CLD. This is a post hoc analysis of baseline data from the BREATHE clinical trial (ClinicalTrials.gov, NCT02426112).

METHODS

Children and adolescents aged 6-19 years were screened for CLD (defined as a FEV1 z-score <-1 with no reversibility post-bronchodilation with salbutamol) at two HIV clinics in Harare, Zimbabwe, and Blantyre, Malawi. Eligible participants with CLD (cases) were enrolled, together with a control group without CLD [frequency-matched by age group and duration on antiretroviral therapy (ART)] in a 4:1 allocation ratio. A clinical history and examination were undertaken. The association between CLD and a priori-defined demographic and clinical covariates was investigated using multivariable logistic regression.

RESULTS

Of the 1585 participants screened, 419 (32%) had a FEV1 z-score <-1, of whom 347 were enrolled as cases [median age 15.3 years (IQR 12.7-17.7); 48.9% female] and 74 with FEV1 z-score >0 as controls [median age 15.6 years (IQR 12.1-18.2); 62.2% female]. Among cases, current respiratory symptoms including cough and shortness of breath were reported infrequently (9.3% and 1.8%, respectively). However, 152 (43.8%) of cases had a respiratory rate above the 90th centile for their age. Wasting and taking second-line ART were independently associated with CLD.

CONCLUSIONS

The presence of CLD indicates the need to address additional treatment support for youth living with HIV, alongside ART provision, to ensure a healthier adulthood.

Inflammatory mediators and lung abnormalities in HIV: A systematic review

HIV and pneumonia infections have both been shown to negatively impact lung function. However, evidence of the role of inflammation on lung dysfunction in HIV and pneumonia co-infected individuals remains limited. We aimed to systematically review the association of inflammatory markers and lung abnormalities in HIV and pneumonia co-infected individuals. This systematic review was registered with the International Prospective Register of Systematic Reviews on August 15, 2017 (registration number CRD42017069254) and used 4 databases (Cochrane Central Register of Controlled Trials, PubMed Central, Clinical Trials.gov and Google Scholar). All clinical trial, observational, and comparative studies targeting adult (> 18 years old) populations with HIV, pneumonia, or both, that report on immune response (cytokine, chemokine, or biomarker), and lung abnormality as an outcome were eligible. Data selection, risk of bias and extraction were performed independently by 2 blinded reviewers. Due to heterogeneity among the articles, a qualitative synthesis was performed. Our search strategy identified 4454 articles of which, 7 met our inclusion criteria. All of the studies investigated the ability of circulating biomarkers to predict lung damage in HIV. None of the articles included patients with both HIV and pneumonia, nor pneumonia alone. Markers of inflammation (IL-6, TNF-α, CRP), innate defense (cathelicidin), monocyte and macrophage activation (sCD14, sCD163 and, IL-2sRα), endothelial dysfunction (ET-1) and general immune health (CD4/CD8 ratio) were associated with lung abnormalities in HIV. This review highlights the lack of available information regarding the impact of inflammatory mediators on lung function in HIV and pneumonia populations, therefore opportunities to prevent lung damage with available anti-inflammatory treatment or to investigate new ones still remain.

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

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

Pneumoproteins are associated with pulmonary function in HIV-infected persons

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Brief Report: Systemic Inflammation, Immune Activation, and Impaired Lung Function Among People Living With HIV in Rural Uganda

BACKGROUND

Although both chronic lung disease and HIV are inflammatory diseases common in sub-Saharan Africa, the relationship between systemic inflammation and lung function among people living with HIV (PLWH) in sub-Saharan Africa is not well described.

METHODS

We measured lung function (using spirometry) and serum high sensitivity C-reactive protein, interleukin 6 (IL-6), soluble CD14 (sCD14), and soluble CD163 (sCD163) in 125 PLWH on stable antiretroviral therapy (ART) and 109 age- and sex-similar HIV-uninfected control subjects in rural Uganda. We modeled the relationship between lung function and systemic inflammation using linear regression, stratified by HIV serostatus, controlled for age, sex, height, tobacco, and biomass exposure.

RESULTS

Half of subjects [46% (107/234)] were women, and the median age was 52 years (interquartile range: 48-55). Most PLWH [92% (115/125)] were virologically suppressed on first-line ART. Median CD4 count was 472 cells/mm. In multivariable linear regression models stratified by HIV serostatus, an interquartile range increase in IL-6 and sCD163 were each inversely associated with lung function (mL, 95% confidence interval) among PLWH [IL-6: forced expiratory volume in 1 second (FEV1) -18.1 (-29.1 to -7.1), forced vital capacity (FVC) -17.1 (-28.2 to -5.9); sCD163: FVC -14.3 (-26.9 to -1.7)]. High sensitivity C-reactive protein (>3 vs. <1 mg/L) was inversely associated with lung function among both PLWH and HIV-uninfected control subjects [PLWH: FEV1 -39.3 (-61.7 to -16.9), FVC -44.0 (-48.4 to -6.4); HIV-uninfected: FEV1 -37.9 (-63.2 to -12.6), FVC -58.0 (-88.4 to -27.5)]. sCD14 was not associated with lung function, and all interaction terms were insignificant.

CONCLUSIONS

Macrophage activation and systemic inflammation are associated with lower lung function among PLWH on stable ART in rural Uganda. Future work should focus on underlying mechanisms and public health implications.

Prevalence and correlates of chronic obstructive pulmonary disease and chronic respiratory symptoms in rural southwestern Uganda: a cross-sectional, population-based study

Background

The global burden of chronic obstructive pulmonary disease (COPD) disproportionately affects resource-limited settings such as sub-Saharan Africa (SSA), but population-based prevalence estimates in SSA are rare. We aimed to estimate the population prevalence of COPD and chronic respiratory symptoms in rural southwestern Uganda.

Methods

Adults at least 18 years of age who participated in a population-wide census in rural southwestern Uganda completed respiratory questionnaires and lung function testing with bronchodilator challenge at health screening events in June 2015. We defined COPD as post-bronchodilator forced expiratory volume in one second to forced vital capacity ratio less than the lower limit of normal. We fit multivariable linear and log binomial regression models to estimate correlates of abnormal lung function and respiratory symptoms, respectively. We included inverse probability of sampling weights in models to facilitate population-level estimates.

Results

Forty-six percent of census participants (843/1814) completed respiratory questionnaires and spirometry, of which 565 (67%) met acceptability standards. COPD and respiratory symptom population prevalence were 2% (95% confidence interval (CI)  = 1%-3%) and 30% (95% CI = 25%-36%), respectively. Respiratory symptoms were more prevalent and lung function was lower among women and ever-smokers (P < 0.05). HIV serostatus was associated with neither respiratory symptoms nor lung function.

Conclusions

COPD population prevalence was low despite prevalent respiratory symptoms. This work adds to the growing body of literature depicting lower-than-expected COPD prevalence estimates in SSA and raises questions about whether the high respiratory symptom burden in rural southwestern Uganda represents underlying structural lung disease not identified by screening spirometry.

Lung Function, Coronary Artery Disease, and Mortality in HIV

Rationale: Impaired lung function is a potent independent predictor of coronary artery disease (CAD) in individuals without human immunodeficiency virus (HIV) infection; however, the relationship between lung function and CAD in HIV remains undefined. Objectives: To examine the relationship between lung function, CAD, mortality, and circulating biomarkers in HIV. Methods: Spirometry, diffusing capacity of the lung for carbon monoxide (DlCO), emphysema, coronary artery calcium, mortality, cause of death, and biomarkers were examined in HIV-infected and uninfected individuals enrolled in a cohort study at the University of Pittsburgh. Results were then validated in the Multicenter AIDS Cohort Study (MACS) cohort. Results: We examined data on 234 participants in the Pittsburgh cohort. The mean ± standard deviation age was 49.5 ± 10.2 years old, 82.1% were male, and 67.5% were ever smokers. Among the 177 of 234 individuals with HIV infection, lower DlCO (not forced expiratory volume in 1 second or emphysema) was independently associated with greater coronary artery calcium (odds ratio, 1.43 per 10% lower DlCO; 95% confidence interval, 1.14-1.81). HIV-infected individuals with both reduced DlCO and coronary artery calcium had a much higher mortality than those with either low DlCO or coronary calcium alone or with neither condition. Endothelin-1, a circulating biomarker of endothelial dysfunction, was associated with both lower DlCO and greater coronary artery calcium in those with HIV infection. Results were reproducible in 144 individuals enrolled in the MACS cohort; intercellular adhesion molecule 1 was the biomarker of endothelial dysfunction assessed in the MACS cohort. Conclusions: Impaired DlCO and CAD were associated with each other and with higher mortality in individuals with HIV infection.

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

RATIONALE

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Associations between baseline biomarkers and lung function in HIV-positive individuals

OBJECTIVE

The aim of this study was to analyse the association of baseline biomarker data with cross-sectional lung function and subsequent decline in lung function in HIV-positive persons.

DESIGN

Lung function was modelled in all START pulmonary substudy participants who had baseline biomarker data and good-quality spirometry. In longitudinal analyses, we restricted to those participants with at least one good-quality follow-up spirometry test.

METHODS

We performed linear regression of baseline forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC and their longitudinal slopes on log2-transformed baseline biomarkers with adjustment for age, sex, race, region, smoking status, baseline CD4+ T-cell counts and baseline HIV-RNA. Biomarkers included D-dimer, high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, IL-27, serum amyloid A, soluble intercellular adhesion molecule (sICAM)-1, soluble vascular cell adhesion molecule (sVCAM)-1, albumin and total bilirubin.

RESULTS

Among 903 included participants, baseline median age was 36 years, CD4+ cell count was 647 cells/μl, and 28.5% were current smokers. In adjusted analyses, elevated markers of systemic inflammation (hsCRP, IL-6 and serum amyloid A) were associated with lower baseline FEV1 and FVC. Elevated D-dimer and IL-6 were associated with worse airflow obstruction (lower FEV1/FVC). Despite these cross-sectional associations at baseline, no associations were found between baseline biomarkers and subsequent longitudinal lung function decline over a median follow-up time of 3.9 years (3293 spirometry-years of follow-up).

CONCLUSION

Commonly available biomarkers, in particular markers of systemic inflammation, are associated with worse cross-sectional lung function, but do not associate with subsequent lung function decline among HIV-positive persons with early HIV infection and baseline CD4 T-cell counts more than 500 cells/μl.

Effect of marijuana smoking on pulmonary disease in HIV-infected and uninfected men: a longitudinal cohort study

BACKGROUND

Lung disease is a common comorbidity in people with HIV/AIDS, independent of smoking status. The effects of marijuana smoking on risk of lung disease in HIV-infected individuals are unclear.

METHODS

In this prospective cohort study, we quantified lung disease risk among men enrolled in the Multicenter AIDS Cohort Study (MACS), a long-term observational cohort of HIV-infected and uninfected men who have sex with men. Eligible participants were aged ≥30 years with self-reported marijuana and tobacco smoking data from biannual study visits between 1996 and 2014. Pulmonary diagnoses were obtained from self-report and medical records. Analyses were performed using Cox models and Generalized Estimating Equations adjusted for tobacco smoking, CD4 T cell count, and other risk factors.

FINDINGS

1,630 incident pulmonary diagnoses were reported among 1,352 HIV-seropositive and 1,352 HIV-seronegative eligible participants matched for race and baseline age (53,794 total person-visits, median follow-up 10.5 years). 27% of HIV-infected participants reported daily or weekly marijuana smoking for one or more years in follow-up, compared to 18% of uninfected participants (median 4·0 and 4·5 years daily/weekly use, respectively). HIV-infected participants had an increased likelihood of infectious or non-infectious pulmonary diagnoses compared to uninfected participants (33·2% vs. 21·5%, and 20·6% vs. 17·2%, respectively). Among HIV-infected participants, recent marijuana smoking was associated with increased risk of infectious pulmonary diagnoses and chronic bronchitis independent of tobacco smoking and other risk factors for lung disease (hazard ratio [95% confidence interval] 1·43 [1·09-1·86], and 1·54 [1·11-2·13], respectively); these risks were additive in participants smoking both substances. There was no association between marijuana smoking and pulmonary diagnoses in HIV-uninfected participants.

INTERPRETATION

In this longitudinal study, long-term marijuana smoking was associated with lung disease independent of tobacco smoking and other risk factors in HIV-infected individuals. These findings could be used to reduce modifiable risks of lung disease in high-risk populations.

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

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

Endothelins in inflammatory neurological diseases

Endothelins were discovered more than thirty years ago as potent vasoactive compounds. Beyond their well-documented cardiovascular properties, however, the contributions of the endothelin pathway have been demonstrated in several neuroinflammatory processes and the peptides have been reported as clinically relevant biomarkers in neurodegenerative diseases. Several studies report that endothelin-1 significantly contributes to the progression of neuroinflammatory processes, particularly during infections in the central nervous system (CNS), and is associated with a loss of endothelial integrity at the blood brain barrier level. Because of the paucity of clinical trials with endothelin-1 antagonists in several infectious and non-infectious neuroinflammatory diseases, it remains an open question whether the 21 amino acid peptide is a mediator/modulator rather than a biomarker of the progression of neurodegeneration. This review focuses on the potential roles of endothelins in the pathology of neuroinflammatory processes, including infectious diseases of viral, bacterial or parasitic origin in which the synthesis of endothelins or its pharmacology have been investigated from the cell to the bedside in several cases, as well as in non-infectious inflammatory processes such as neurodegenerative disorders like Alzheimers Disease or central nervous system vasculitis.

HIV Infection, Pulmonary Tuberculosis, and COPD in Rural Uganda: A Cross-Sectional Study

PURPOSE

HIV is associated with chronic obstructive pulmonary disease (COPD) in high resource settings. Similar relationships are less understood in low resource settings. We aimed to estimate the association between HIV infection, tuberculosis, and COPD in rural Uganda.

METHODS

The Uganda Non-communicable Diseases and Aging Cohort study observes people 40 years and older living with HIV (PLWH) on antiretroviral therapy, and population-based HIV-uninfected controls in rural Uganda. Participants completed respiratory questionnaires and post-bronchodilator spirometry.

RESULTS

Among 269 participants with spirometry, median age was 52 (IQR 48-55), 48% (n = 130) were ever-smokers, and few (3%, n = 9) reported a history of COPD or asthma. All participants with prior tuberculosis (7%, n = 18) were PLWH. Among 143 (53%) PLWH, median CD4 count was 477 cells/mm3 and 131 (92%) were virologically suppressed. FEV1 was lower among older individuals (- 0.5%pred/year, 95% CI 0.2-0.8, p < 0.01) and those with a history of tuberculosis (- 14.4%pred, 95% CI - 23.5 to - 5.3, p < 0.01). COPD was diagnosed in 9 (4%) participants, eight of whom (89%) were PLWH, six of whom (67%) had a history of tuberculosis, and all of whom (100%) were men. Among 287 participants with complete symptom questionnaires, respiratory symptoms were more likely among women (AOR 3.9, 95% CI 2.0-7.7, p < 0.001) and those in homes cooking with charcoal (AOR 3.2, 95% CI 1.4-7.4, p = 0.008).

CONCLUSION

In rural Uganda, COPD may be more prevalent among PLWH, men, and those with prior tuberculosis. Future research is needed to confirm these findings and evaluate their broader impacts on health.

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.

Bronchiectasis and other chronic lung diseases in adolescents living with HIV

PURPOSE OF REVIEW

The incidence of pulmonary infections has declined dramatically with improved access to antiretroviral therapy (ART) and cotrimoxazole prophylaxis, but chronic lung disease (CLD) is an increasingly recognized but poorly understood complication in adolescents with perinatally acquired HIV.

RECENT FINDINGS

There is a high prevalence of chronic respiratory symptoms, abnormal spirometry and chest radiographic abnormalities among HIV-infected adolescents in sub-Saharan Africa, wherein 90% of the world's HIV-infected children live. The incidence of lymphocytic interstitial pneumonitis, the most common cause of CLD in the pre-ART era, has declined with increased ART access. Small airways disease, particularly constrictive obliterative bronchiolitis and bronchiectasis, are emerging as leading causes of CLD among HIV-infected adolescents in low-income and middle-income countries. Asthma may be more common in high-income settings. Likely risk factors for CLD include recurrent pulmonary infections, air pollution, HIV-related immune dysfunction, and untreated HIV infection, particularly during critical stages of lung development.

SUMMARY

Globally, the importance of HIV-associated CLD as a cause of morbidity and mortality is increasing, especially as survival has improved dramatically with ART and growing numbers of children living with HIV enter adolescence. Further research is urgently needed to elucidate the natural history and pathogenesis of CLD, and to determine optimal screening, diagnostic and treatment strategies.

The Role of Transforming Growth Factor Beta-1 in the Progression of HIV/AIDS and Development of Non-AIDS-Defining Fibrotic Disorders

Even after attainment of sustained viral suppression following implementation of highly active antiretroviral therapy, HIV-infected persons continue to experience persistent, low-grade, systemic inflammation. Among other mechanisms, this appears to result from ongoing microbial translocation from a damaged gastrointestinal tract. This HIV-related chronic inflammatory response is paralleled by counteracting, but only partially effective, biological anti-inflammatory processes. Paradoxically, however, this anti-inflammatory response not only exacerbates immunosuppression but also predisposes for development of non-AIDS-related, non-communicable disorders. With respect to the pathogenesis of both sustained immunosuppression and the increased frequency of non-AIDS-related disorders, the anti-inflammatory/profibrotic cytokine, transforming growth factor-β1 (TGF-β1), which remains persistently elevated in both untreated and virally suppressed HIV-infected persons, may provide a common link. In this context, the current review is focused on two different, albeit related, harmful activities of TGF-β1 in HIV infection. First, on the spectrum of anti-inflammatory/immunosuppressive activities of TGF-β1 and the involvement of this cytokine, derived predominantly from T regulatory cells, in driving disease progression in HIV-infected persons via both non-fibrotic and profibrotic mechanisms. Second, the possible involvement of sustained elevations in circulating and tissue TGF-β1 in the pathogenesis of non-AIDS-defining cardiovascular, hepatic, pulmonary and renal disorders, together with a brief comment on potential TGF-β1-targeted therapeutic strategies.

Emphysema is associated with thoracic vertebral bone attenuation on chest CT scan in HIV-infected individuals

BACKGROUND

Age-related chronic diseases are prevalent in HIV-infected persons in the antiretroviral therapy (ART) era. Bone mineral density (BMD) loss and emphysema have separately been shown to occur at a younger age and with lesser risk exposure in HIV-infected compared to HIV-uninfected individuals. In non-HIV infected smokers, emphysema has been shown to independently predict low BMD. We hypothesized that emphysema would independently associate with thoracic vertebral bone attenuation, a surrogate for bone mineral density, in HIV-infected individuals.

METHODS

Clinical, pulmonary function, and radiographic data were analyzed for 164 individuals from the University of Pittsburgh's HIV Lung Research Center cohort. Chest CT scans were used to quantify emphysema and compute Hounsfield Unit (HU) attenuation of the 4th, 7th, and 10th thoracic vertebrae. The association between mean HU attenuation values across the three vertebrae and radiographic emphysema, age, sex, body mass index (BMI), steroid use, viral load, CD4 count, and forced expiratory volume in the first second (FEV1) was assessed by univariate and multivariate analyses.

RESULTS

In univariate analysis, mean HU attenuation decreased with increasing age (p<0.001), pack years (p = 0.047), and percent emphysema (p<0.001). In a multivariable model, including pack years, age, sex, ART and steroid use, greater emphysema was independently associated with this surrogate marker of BMD in HIV-infected individuals (p = 0.034).

CONCLUSIONS

The association of emphysema with thoracic bone attenuation in HIV-infected individuals is consistent with previous reports in non-HIV infected smokers. These findings suggest that emphysema should be considered a potential marker of osteoporosis risk in HIV-infected individuals.