Obstructive Lung Disease in HIV-Phenotypes and Pathogenesis

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

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

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.

Pathogenesis and management of emphysema in people with HIV

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Magnetic-activated cell sorting identifies a unique lung microbiome community

BACKGROUND

The advent of culture-independent, next-generation DNA sequencing has led to the discovery of distinct lung bacterial communities. Studies of lung microbiome taxonomy often reveal only subtle differences between health and disease, but host recognition and response may distinguish the members of similar bacterial communities in different populations. Magnetic-activated cell sorting has been applied to the gut microbiome to identify the numbers and types of bacteria eliciting a humoral response. We adapted this technique to examine the populations of immunoglobulin-bound bacteria in the lung.

METHODS

Sixty-four individuals underwent bronchoalveolar lavage (BAL). We separated immunoglobulin G-bound bacteria using magnetic-activated cell sorting and sequenced the 16S rRNA gene on the Illumina MiSeq platform. We compared microbial sequencing data in IgG-bound bacterial communities compared to raw BAL then examined the differences in individuals with and without HIV as a representative disease state.

RESULTS

Immunoglobulin G-bound bacteria were identified in all individuals. The community structure differed when compared to raw BAL, and there was a greater abundance of Pseudomonas and fewer oral bacteria in IgG-bound BAL. Examination of IgG-bound communities in individuals with HIV demonstrated the differences in Ig-bound bacteria by HIV status that were not seen in a comparison of raw BAL, and greater numbers of immunoglobulin-bound bacteria were associated with higher pulmonary cytokine levels.

CONCLUSIONS

We report a novel application of magnetic-activated cell sorting to identify immunoglobulin G-bound bacteria in the lung. This technique identified distinct bacterial communities which differed in composition from raw bronchoalveolar lavage, revealing the differences not detected by traditional analyses. Cytokine response was also associated with differential immunoglobulin binding of lung bacteria, suggesting the functional importance of these communities. Video Abstract.

HIV Increases the Risk of Cigarette Smoke-Induced Emphysema Through MMP-9

BACKGROUND

HIV is associated with an increased risk for emphysema. Matrix metalloproteinase 9 (MMP-9) is a lung tissue remodeling enzyme associated with emphysema. We previously found MMP-9 activity increases with increases in oxidative stress and that HIV increases alveolar oxidative stress. We hypothesized that HIV proteins would increase the risk of cigarette smoke-induced emphysema due to MMP-9.

METHODS

HIV-1 transgenic rats and wild-type littermates were exposed to cigarette smoke or sham for 8 weeks. Lung compliance and histology were assessed. Bronchoalveolar lavage (BAL), primary alveolar macrophages (AM), and serum samples were obtained. A rat alveolar macrophage cell line was exposed to the HIV protein Tat, and MMP-9 levels were assessed by Western immunoblotting. MMP-9 protein expression and activity were assessed in AM from the HIV rat model by ELISA and cytoimmunofluoresence, respectively. Serum from human subjects with and without HIV and tobacco dependence was assessed for MMP-9 levels.

RESULTS

MMP-9 expression was significantly increased in rat alveolar macrophages after Tat exposure. HIV-1 transgenic rats developed emphysema while wild-type littermates did not. MMP-9 expression was also increased in the serum, BAL, and AM of HIV-1 transgenic rats after exposure to cigarette smoke compared with wild-type rats. In parallel, serum samples from HIV+ smokers had higher levels of MMP-9 than subjects without HIV and those who did not smoke.

CONCLUSION

The combination of HIV and cigarette smoke increases MMP-9 expression in experimental rat HIV models and human subjects. HIV and cigarette smoke both induce alveolar oxidative stress and thereby increase MMP-9 activity.

Sputum Microbiome and Chronic Obstructive Pulmonary Disease in a Rural Ugandan Cohort of Well-Controlled HIV Infection

Sub-Saharan Africa has increased morbidity and mortality related to chronic obstructive pulmonary disease (COPD). COPD among people living with HIV (PLWH) has not been well studied in this region, where HIV/AIDS is endemic. Increasing evidence suggests that respiratory microbial composition plays a role in COPD severity. Therefore, we aimed to investigate microbiome patterns and associations among PLWH with COPD in Sub-Saharan Africa. We conducted a cross-sectional study of 200 adults stratified by HIV and COPD in rural Uganda. Induced sputum samples were collected as an easy-to-obtain proxy for the lower respiratory tract microbiota. We performed 16S rRNA gene sequencing and used PICRUSt2 (version 2.2.3) to infer the functional profiles of the microbial community. We used a statistical tool to detect changes in specific taxa that searches and adjusts for confounding factors such as antiretroviral therapy (ART), age, sex, and other participant characteristics. We could cluster the microbial community into three community types whose distribution was shown to be significantly impacted by HIV. Some genera, e.g., Veillonella, Actinomyces, Atopobium, and Filifactor, were significantly enriched in HIV-infected individuals, while the COPD status was significantly associated with Gammaproteobacteria and Selenomonas abundance. Furthermore, reduced bacterial richness and significant enrichment in Campylobacter were associated with HIV-COPD comorbidity. Functional prediction using PICRUSt2 revealed a significant depletion in glutamate degradation capacity pathways in HIV-positive patients. A comparison of our findings with an HIV cohort from the United Kingdom revealed significant differences in the sputum microbiome composition, irrespective of viral suppression. IMPORTANCE Even with ART available, HIV-infected individuals are at high risk of suffering comorbidities, as shown by the high prevalence of noninfectious lung diseases in the HIV population. Recent studies have suggested a role for the respiratory microbiota in driving chronic lung inflammation. The respiratory microbiota was significantly altered among PLWH, with disease persisting up to 3 years post-ART initiation and HIV suppression. The community structure and diversity of the sputum microbiota in COPD are associated with disease severity and clinical outcomes, both in stable COPD and during exacerbations. Therefore, a better understanding of the sputum microbiome among PLWH could improve COPD prognostic and risk stratification strategies. In this study, we observed that in a virologically suppressed HIV cohort in rural Uganda, we could show differences in sputum microbiota stratified by HIV and COPD, reduced bacterial richness, and significant enrichment in Campylobacter associated with HIV-COPD comorbidity.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pulmonary Immune Dysregulation and Viral Persistence During HIV Infection

Despite the success of antiretroviral therapy (ART), people living with HIV continue to suffer from high burdens of respiratory infections, lung cancers and chronic lung disease at a higher rate than the general population. The lung mucosa, a previously neglected HIV reservoir site, is of particular importance in this phenomenon. Because ART does not eliminate the virus, residual levels of HIV that remain in deep tissues lead to chronic immune activation and pulmonary inflammatory pathologies. In turn, continuous pulmonary and systemic inflammation cause immune cell exhaustion and pulmonary immune dysregulation, creating a pro-inflammatory environment ideal for HIV reservoir persistence. Moreover, smoking, gut and lung dysbiosis and co-infections further fuel the vicious cycle of residual viral replication which, in turn, contributes to inflammation and immune cell proliferation, further maintaining the HIV reservoir. Herein, we discuss the recent evidence supporting the notion that the lungs serve as an HIV viral reservoir. We will explore how smoking, changes in the microbiome, and common co-infections seen in PLWH contribute to HIV persistence, pulmonary immune dysregulation, and high rates of infectious and non-infectious lung disease among these individuals.

Predictors of Transition to Frailty in Middle-Aged and Older People With HIV: A Prospective Cohort Study

BACKGROUND

People with HIV (PWH) have increased frailty risk at younger ages compared with the general population. Multimorbidity is associated with frailty, yet effects of specific comorbidities on transition to frailty in PWH are unknown.

SETTING

Prospective study of 219 PWH age 45 years or older in the National NeuroAIDS Tissue Consortium.

METHODS

Frailty status was categorized using Fried frailty phenotype criteria. Comorbidities [bone disease, cardiovascular disease, cerebrovascular disease, liver disease, renal disease, diabetes, chronic obstructive pulmonary disease (COPD), hypertension, obesity, cancers, neuropsychiatric conditions] were assessed from longitudinal data. Associations between baseline comorbidities and transition to frailty within 30 months were analyzed using Kaplan-Meier and Cox regression models. Grip strength was assessed using mixed-effects models.

RESULTS

At baseline, the median age was 61 years, 73% were male 98% were on antiretroviral therapy, 29% had ≥3 comorbidities, 27% were robust, and 73% were pre-frail. Cerebrovascular disease, diabetes, and COPD were independent predictors of transition to frailty within 30 months in models adjusted for age, sex, and multimorbidity (≥3 additional comorbidities) [hazard ratios (95% confidence intervals) 2.52 (1.29 to 4.93), 2.31 (1.12 to 4.76), and 1.82 (0.95 to 3.48), respectively]. Furthermore, cerebrovascular disease, diabetes, COPD, or liver disease co-occurring with multimorbidity was associated with substantially increased frailty hazards compared with multimorbidity alone (hazard ratios 4.75-7.46). Cerebrovascular disease was associated with decreased baseline grip strength (P = 0.0001), whereas multimorbidity, diabetes, and COPD were associated with declining grip strength (P < 0.10).

CONCLUSIONS

In older PWH, cerebrovascular disease, diabetes, COPD, or liver disease co-occurring with multimorbidity is associated with substantially increased risk of becoming frail within 30 months. Interventions targeting these comorbidities may ameliorate frailty and age-related functional decline in PWH.

Human Immunodeficiency Virus/AIDS in the Era of Coronavirus Disease 2019: A Juxtaposition of 2 Pandemics

The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted persons with human immunodeficiency virus (HIV), interfering with critical health services for HIV prevention, treatment, and care. While there are multiple profiles of persons living with HIV and the impact of COVID-19 may differ for each, the severity of COVID-19 in persons with HIV is related strongly to the presence of comorbidities that increase the risk of severe disease in COVID-19 patients in the absence of HIV. An effective response to the juxtaposition of the HIV and COVID-19 pandemics requires a novel coordinated and collaborative global effort of scientists, industry, and community partners to accelerate basic and clinical research, as well as implementation science to operationalize evidence-based interventions expeditiously in real-world settings. Accelerated development and clinical evaluation of prevention and treatment countermeasures are urgently needed to mitigate the juxtaposition of the HIV and COVID-19 pandemics.

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.

Responses of Mast Cells to Pathogens: Beneficial and Detrimental Roles

Mast cells (MCs) are strategically located in tissues close to the external environment, being one of the first immune cells to interact with invading pathogens. They are long living effector cells equipped with different receptors that allow microbial recognition. Once activated, MCs release numerous biologically active mediators in the site of pathogen contact, which induce vascular endothelium modification, inflammation development and extracellular matrix remodeling. Efficient and direct antimicrobial mechanisms of MCs involve phagocytosis with oxidative and non-oxidative microbial destruction, extracellular trap formation, and the release of antimicrobial substances. MCs also contribute to host defense through the attraction and activation of phagocytic and inflammatory cells, shaping the innate and adaptive immune responses. However, as part of their response to pathogens and under an impaired, sustained, or systemic activation, MCs may contribute to tissue damage. This review will focus on the current knowledge about direct and indirect contribution of MCs to pathogen clearance. Antimicrobial mechanisms of MCs are addressed with special attention to signaling pathways involved and molecular weapons implicated. The role of MCs in a dysregulated host response that can increase morbidity and mortality is also reviewed and discussed, highlighting the complexity of MCs biology in the context of host-pathogen interactions.

The burden of non-communicable diseases and mortality in people living with HIV (PLHIV) in the pre-, early- and late-HAART era

Objectives

To estimate the burden of non‐communicable diseases (NCDs) and mortality among PLHIV in the pre‐, early‐ and late‐HAART (highly active antiretroviral therapy) era.

Methods

We conducted a cohort study using population‐based Danish medical registries including all adult HIV‐infected residents of the Central Denmark Region during 1985–2017. For each HIV patient, we selected 10 comparisons from the background population matched by age, sex and municipality of residence. Based on hospital‐related diagnoses we estimated the prevalence and incidence of specific NCD at diagnosis and at 5 and 10 years.

Results

We identified 1043 PLHIV and 10 430 matched comparisons. PLHIV had lower socioeconomic status and more were born outside western Europe. At HIV diagnosis, 21.9% of PHLIV vs. 18.2% of non‐HIV individuals had at least one NCD, increasing to 42.2% vs. 25.9% after 10 years. PLHIV had higher prevalence and cumulative incidence of alcohol abuse, chronic obstructive pulmonary disease (COPD), ischaemic heart disease, mental disorders, renal and liver disease, but no increased risk of diabetes mellitus. Only PLHIV in the age groups 41–50 and > 51 years had an increased incidence of osteoporosis. From the pre‐ to the late‐HAART era, 10‐year mortality among PLHIV decreased from 45.5% to 9.4% but continued at more than twice that of uninfected comparisons. However, in the late‐HAART era, the mortality of PLHIV who were alive 2 years after HIV diagnosis was approaching that of comparisons.

Conclusions

Even in the late‐HAART era, PLHIV have an excess mortality, which may be attributable to several NCDs being more prevalent among PLHIV. The prevalence rates of ischaemic heart disease, diabetes, osteoporosis and renal disease tend to increase over calendar time. Therefore, improvement of survival and quality of life of PLHIV neets strategies to reduce the risk of developing NCDs, including avoiding toxic antiretroviral therapy and lifestyle changes.

HIV-1 Productively Infects and Integrates in Bronchial Epithelial Cells

BACKGROUND

The role of lung epithelial cells in HIV-1-related lung comorbidities remains unclear, and the major hurdle in curing HIV is the persistence of latent HIV reservoirs in people living with HIV (PLWH). The advent of combined antiretroviral therapy has considerably increased the life span; however, the incidence of chronic lung diseases is significantly higher among PLWH. Lung epithelial cells orchestrate the respiratory immune responses and whether these cells are productively infected by HIV-1 is debatable.

METHODS

Normal human bronchial epithelial cells (NHBEs) grown on air-liquid interface were infected with X4-tropic HIV-1LAV and examined for latency using latency-reversing agents (LRAs). The role of CD4 and CXCR4 HIV coreceptors in NHBEs were tested, and DNA sequencing analysis was used to analyze the genomic integration of HIV proviral genes, Alu-HIVgag-pol, HIV-nef, and HIV-LTR. Lung epithelial sections from HIV-infected humans and SHIV-infected macaques were analyzed by FISH for HIV-gag-pol RNA and epithelial cell-specific immunostaining.

RESULTS AND DISCUSSION

NHBEs express CD4 and CXCR4 at higher levels than A549 cells. NHBEs are infected with HIV-1 basolaterally, but not apically, by X4-tropic HIV-1LAV in a CXCR4/CD4-dependent manner leading to HIV-p24 antigen production; however, NHBEs are induced to express CCR5 by IL-13 treatment. In the presence of cART, HIV-1 induces latency and integration of HIV provirus in the cellular DNA, which is rescued by the LRAs (endotoxin/vorinostat). Furthermore, lung epithelial cells from HIV-infected humans and SHIV-infected macaques contain HIV-specific RNA transcripts. Thus, lung epithelial cells are targeted by HIV-1 and could serve as potential HIV reservoirs that may contribute to the respiratory comorbidities in PLWH.

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.

Deconstructing Syndemics: The Many Layers of Clustering Multi-Comorbidities in People Living with HIV

The HIV epidemic has dramatically changed over the past 30 years; there are now fewer newly infected people (especially children), fewer AIDS-related deaths, and more people with HIV (PWH) receiving treatment. However, the HIV epidemic is far from over. Despite the tremendous advances in anti-retroviral therapies (ART) and the implementation of ART regimens, HIV incidence (number of new infections over a defined period of time) and prevalence (the burden of HIV infection) in certain regions of the world and socio-economic groups are still on the rise. HIV continues to disproportionally affect highly marginalized populations that constitute higher-risk and stigmatized groups, underserved and/or neglected populations. In addition, it is not uncommon for PWH to suffer enhanced debilitating conditions resulting from the synergistic interactions of both communicable diseases (CDs) and non-communicable diseases (NCDs). While research utilizing only a comorbidities framework has advanced our understanding of the biological settings of the co-occurring conditions from a molecular and mechanistic view, harmful interactions between comorbidities are often overlooked, particularly under adverse socio-economical and behavioral circumstances, likely prompting disease clustering in PWH. Synergistic epidemics (syndemics) research aims to capture these understudied interactions: the mainly non-biological aspects that are central to interpret disease clustering in the comorbidities/multi-morbidities only framework. Connecting population-level clustering of social and health problems through syndemic interventions has proved to be a critical knowledge gap that will need to be addressed in order to improve prevention and care strategies and bring us a step closer to ending the HIV epidemic.

HIV gp120 Induces the Release of Proinflammatory, Angiogenic, and Lymphangiogenic Factors from Human Lung Mast Cells

Human lung mast cells (HLMCs) express the high-affinity receptor FcεRI for IgE and are involved in chronic pulmonary diseases occurring at high frequency among HIV-infected individuals. Immunoglobulin superantigens bind to the variable regions of either the heavy or light chain of immunoglobulins (Igs). Glycoprotein 120 (gp120) of HIV-1 is a typical immunoglobulin superantigen interacting with the heavy chain, variable 3 (V_H3) region of human Igs. The present study investigated whether immunoglobulin superantigen gp120 caused the release of different classes of proinflammatory and immunoregulatory mediators from HLMCs. The results show that gp120 from different clades induced the rapid (30 min) release of preformed mediators (histamine and tryptase) from HLMCs. gp120 also caused the de novo synthesis of cysteinyl leukotriene C₄ (LTC₄) and prostaglandin D₂ (PGD₂) from HLMCs. Incubation (6 h) of HLMC with gp120 induced the release of angiogenic (VEGF-A) and lymphangiogenic (VEGF-C) factors from HLMCs. The activating property of gp120 was mediated through the interaction with IgE V_H3⁺ bound to FcεRI. Our data indicate that HIV gp120 is a viral superantigen, which induces the release of different proinflammatory, angiogenic, and lymphangiogenic factors from HLMCs. These observations could contribute to understanding, at least in part, the pathophysiology of chronic pulmonary diseases in HIV-infected individuals.