Impact of HIV infection and smoking on lung immunity and related disorders

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.

Estimates of prevalence, time-trend, and association of smoking in adults living with HIV, HBV, and HCV (NHANES 1999-2018)

Although the smoking rate of human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV) infected people was much higher than that of the general population, smoking cessation interventions have long been ineffective. We aimed to examine the estimates of prevalence, time-trend, and association of smoking among people living with HIV, HBV, or HCV. This cohort was composed of 32,115 individuals from the NHANES database (1999-2018) and they were collected in the US. The time trend analysis of smoking and quitting rates was conducted using different years of survey follow-up and different infected groups. Multivariable logistic regression analysis was used to identify the risk factors related to smoking behavior of these infected people. Compared to non-infected smokers, infected smokers were more likely to be older (aged 30-39, OR = 9.92, CI 6.07-16.21; aged 40-49,OR = 3.51, CI 2.49-4.94), males (1.99, 1.54-2.55), lower education and economic level (1.78, 1.39-2.29; 2.05, 1.59-2.65), unemployed (1.63, 1.21-2.20), suffering depression (1.35, 1.05-1.72), and drug users (7.65, 5.04-11.59). Taken together, our study showed that these complex psychosocial characteristics and unhealthy behavioral factors might be major independent risk factors for increasing smoking rate and decreasing smoking cessation rate among these infected people.

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.

The influence of smoking and HIV infection on pulmonary function

Background

Prevalence of HIV, smoking, and pulmonary infections in South Africa are high.

Objectives

We investigated the role of smoking and HIV status on lung function.

Methods

This is a secondary analysis of a cross-sectional study conducted in South Africa. Data included demographics, pulmonary risk factors and a spirometry test to obtain the forced expiratory volume in one second (FEV1) and the ratio of FEV1/forced vital capacity (FVC). In the initial multivariable regression analysis, the effect of smoking on pulmonary function in HIV-positive adults was assessed. The analysis was repeated, assessing the influence of HIV status on lung function in both HIV-negative and HIV-positive smokers. The models were adjusted for age, sex, body mass index (BMI), time since HIV diagnosis, antiretroviral treatment (ART) use, occupational hazards, history of tuberculosis or pneumonia, indoor smoking and the presence of an indoor fireplace during childhood.

Results

This study included 524 people living with HIV (PLWH, 66.7% female, mean age 40.9 years [s.d.; 9.4]) and 79 HIV-negative smokers (77.2% male, mean age 34.4 years [s.d.: 12.1]). Of the PLWH, 118 (22.5%) were past or current smokers and 406 (77.5%) were non-smokers. Smoking was not associated with changes in the FEV1 or FEV1/FVC ratio in multivariable regression analysis. In the second analysis, HIV status was also not associated with reduced pulmonary function following adjustment for confounders.

Conclusion

Neither smoking nor being HIV-positive was associated with decreased pulmonary function in this relatively young population. These findings should be confirmed in a longitudinal study, including an older population.

Harm reduction for smokers living with HIV

Tobacco use is now a leading cause of death in people living with HIV in the USA. Increasing cessation rates in this group is a public health priority, yet the results of clinical trials aimed at optimising tobacco treatment strategies have been largely disappointing. Combinations of behavioural and pharmacological cessation therapies in people living with HIV have yielded increases in short-term quit rates, but few have shown long-term efficacy. Even with aggressive therapy combining intensive behavioural treatment with pharmacological agents, most smokers living with HIV continue to smoke. The generalised approach to tobacco treatment that prevails in guidelines and in clinical practices might do a disservice to these individuals, who represent a sizable segment of the population of people living with HIV. Harm reduction is a sensible and needed approach for smokers living with HIV who are unable or unwilling to quit. In this Viewpoint, we take an expansive view of harm reduction to include not only cutting down on cigarette intake for persistent smokers, but also reducing smoking's downstream health effects by increasing lung cancer screening and by controlling concurrent cardiovascular risk factors, especially hypertension and hyperlipidaemia.

Nicotine self-administration with menthol and audiovisual cue facilitates differential packaging of CYP2A6 and cytokines/chemokines in rat plasma extracellular vesicles

In this study, we investigated whether intravenously self-administered nicotine with menthol and audiovisual cue modulates nicotine-metabolizing CYP2A6, oxidative stress modulators, and cytokines/chemokines in plasma extracellular vesicles (EVs) in rats. We assigned rats to self-administered nicotine with: (a) audiovisual cue (AV), (b) menthol, and (c) menthol and AV cue. We found increased levels of CD9 in plasma EVs after self-administered nicotine with menthol and AV cue. Moreover, expression of CYP2A6 in plasma EVs was significantly increased after self-administered nicotine in response to menthol and AV cue. However, despite an upward trend on SOD1 and catalase, increase was not found to be statistically significant, while total antioxidant capacity was found to be significantly increased in plasma and plasma EVs obtained after self-administered nicotine with menthol and AV cue. Among cytokine and chemokine profiling, we found a significant increase in the levels of MCP-1 after self-administered nicotine with menthol and AV cue and complete packaging of IL-1β in EVs. Taken together, the study provides evidence that nicotine in response to menthol and AV cues can package altered levels of CYP2A6, and cytokines/chemokines in plasma EVs that may contribute to cell–cell communication, nicotine metabolism, and inflammation upon cigarette smoking.

Respiratory virus-associated infections in HIV-infected adults admitted to the intensive care unit for acute respiratory failure: a 6-year bicenter retrospective study (HIV-VIR study)

Introduction

Acute respiratory failure is the main reason for admission to the intensive care unit (ICU) in HIV-infected adults. There is little data about the epidemiology of respiratory viruses in this population.

Methods

HIV-infected adults admitted to two intensive care units over a 6-year period for an acute respiratory failure and explored for respiratory viruses with multiplex polymerase chain reaction (mPCR) were retrospectively selected. Objectives were to describe the prevalence of respiratory viruses, coinfections with non-viral pathogens, and hospital outcome.

Results

A total of 123 episodes were included. An HIV infection was newly diagnosed in 9% of cases and 72% of the population were on antiretroviral therapy. Real-time mPCR tests identified at least one respiratory virus in the respiratory tract of 33 (27%) patients, but with a non-viral copathogen in two-thirds of cases. Rhinovirus was predominant, documented in 15 patients, followed by Influenza and Respiratory Syncytial Viruses (both n = 6). The prevalence of respiratory virus-associated infection did not vary along with the level of the CD4 T-cell deficiency, except for Rhinovirus which was more prevalent in patients with a CD4 lymphocyte count below 200 cells/µL (n = 13 (20%) vs. n = 2 (4%), p < 0.01). In multivariate analysis, respiratory virus-associated infection was not associated with a worse prognosis.

Conclusions

Viruses are frequently identified in the respiratory tract of HIV-infected patients with acute respiratory failure that requires ICU admission, but with a non-viral copathogen in two-thirds of cases. Rhinovirus is the predominant viral specie; its prevalence is highest in patients with a CD4 lymphocyte count below 200 cells/µL.

Smoking increases the risk of infectious diseases: A narrative review

Smoking is relevant to infectious diseases resulting in increased prevalence and mortality. In this article, we aim to provide an overview of the effects of smoking in various infections and to explain the potential mechanisms. We searched PubMed and other relevant databases for scientific studies that explored the relationship between smoking and infection. The mechanisms of susceptibility to infection in smokers may include alteration of the structural, functional and immunologic host defences. Smoking is one of the main risk factors for infections in the respiratory tract, digestive tract, reproductive tract, and other systems in humans, increasing the prevalence of HIV, tuberculosis, SARS-CoV, and the current SARS-CoV-2. Smoking cessation can reduce the risk of infection. Smoking increases the incidence of infections and aggravates the progress and prognosis of infectious diseases in a dose-dependent manner. Smoking cessation promotion and education are the most practical and economical preventive measures to reduce aggravation of disease infection owing to tobacco use.

Extracellular Vesicles in Smoking-Mediated HIV Pathogenesis and their Potential Role in Biomarker Discovery and Therapeutic Interventions

In the last two decades, the mortality rate in people living with HIV/AIDS (PLWHA) has decreased significantly, resulting in an almost normal longevity in this population. However, a large portion of this population still endures a poor quality of life, mostly due to an increased inclination for substance abuse, including tobacco smoking. The prevalence of smoking in PLWHA is consistently higher than in HIV negative persons. A predisposition to cigarette smoking in the setting of HIV potentially leads to exacerbated HIV replication and a higher risk for developing neurocognitive and other CNS disorders. Oxidative stress and inflammation have been identified as mechanistic pathways in smoking-mediated HIV pathogenesis and HIV-associated neuropathogenesis. Extracellular vesicles (EVs), packaged with oxidative stress and inflammatory agents, show promise in understanding the underlying mechanisms of smoking-induced HIV pathogenesis via cell-cell interactions. This review focuses on recent advances in the field of EVs with an emphasis on smoking-mediated HIV pathogenesis and HIV-associated neuropathogenesis. This review also provides an overview of the potential applications of EVs in developing novel therapeutic carriers for the treatment of HIV-infected individuals who smoke, and in the discovery of novel biomarkers that are associated with HIV-smoking interactions in the CNS.

Lung Cancer (LC) in HIV Positive Patients: Pathogenic Features and Implications for Treatment

: The human immunodeficiency virus (HIV) infection continues to be a social and public health problem. Thanks to more and more effective antiretroviral therapy (ART), nowadays HIV-positive patients live longer, thus increasing their probability to acquire other diseases, malignancies primarily. Senescence along with immune-system impairment, HIV-related habits and other oncogenic virus co-infections increase the cancer risk of people living with HIV (PLWH); in the next future non-AIDS-defining cancers will prevail, lung cancer (LC) in particular. Tumor in PLWH might own peculiar predictive and/or prognostic features, and antineoplastic agents' activity might be subverted by drug-drug interactions (DDIs) due to concurrent ART. Moreover, PLWH immune properties and comorbidities might influence both the response and tolerability of oncologic treatments. The therapeutic algorithm of LC, rapidly and continuously changed in the last years, should be fitted in the context of a special patient population like PLWH. This is quite challenging, also because HIV-positive patients have been often excluded from participation to clinical trials, so that levels of evidence about systemic treatments are lower than evidence in HIV-uninfected individuals. With this review, we depicted the epidemiology, pathogenesis, clinical-pathological characteristics and implications for LC care in PLWH, offering a valid focus about this topic to clinicians.

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

Background

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

Methods

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

Results

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

Conclusions

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

Effects of Tobacco Usage and Antiretroviral Therapy on Biomarkers of Systemic Immune Activation in HIV-Infected Participants

Like HIV infection, smoking, which is common among HIV-infected persons, is associated with chronic, systemic inflammation. However, the possible augmentative effects of HIV infection and smoking and other types of tobacco usage on indices of systemic inflammation and the impact of combination antiretroviral therapy (cART) thereon remain largely unexplored and represent the focus of the current study. Of the total number of HIV-infected persons recruited to the study (n = 199), 100 were categorised as pre-cART and 99 as virally suppressed (HIV viral load < 40 copies/mL). According to serum cotinine levels, 144 and 55 participants were categorised as nonusers and users of tobacco, respectively. In addition to cytokines (IL-6, IL-8, and TNF-α) and chemokines (IP-10, MIG, IL-8, MCP-1, and RANTES), other biomarkers of systemic inflammation included C-reactive protein (CRP), β2-microglobulin, and those of neutrophil activation [ICAM-1, L-selectin, matrix metalloproteinase-9 (MMP-9)], microbial translocation (soluble CD14, LPS-binding protein), and oxidative stress (cyclophilin A, surfactant D). These were measured using multiplex bead array, ELISA, and immunonephelometric procedures. Viral suppression was associated with significant decreases in the levels of most of the biomarkers tested (P < 0.0037-0.0008), with the exceptions of CRP, cyclophilin A, and MMP-9. With respect to tobacco usage, irrespective of cART status, circulating levels of β2-microglobulin, cyclophilin A, and RANTES were significantly elevated (P < 0.042-0.012) in users vs nonusers. Additional analysis of the groups of tobacco users and nonusers according to cART status revealed high levels of RANTES in pre-cART/tobacco users relative to the three other subgroups (P < 0.004-0.0001), while more modest increases in cyclophilin A and MMP-9 (P < 0.019-0.027) were observed in comparison with the cART/tobacco user subgroup. Notwithstanding the efficacy of cART in attenuating HIV-associated, chronic systemic inflammation, the current study has identified RANTES as being significantly and seemingly selectively increased in those with active HIV infection who use tobacco, a mechanism which may underpin augmentative proinflammatory activity.

The Prevalence of HIV Load Suppression and Related Factors Among Patients on ART at Phedisong 4 Clinic, Pretoria, South Africa

Background:

Globally, the benefits of viral load suppression in improving the lives of people living with HIV/AIDS have been established. In 2010, the South African Government decentralised ART to the primary care level. This study intended to determine the effect of this decentralisation in achieving viral load suppression among patients.

Objective:

To determine the prevalence of HIV viral load suppression and factors related to the suppression among patients initiated on ART at Pedisong 4 clinic, Tshwane District in Pretoria.

Methods:

A prospective cohort study was conducted on 98 patients initiated on ART between 01 November 2012 and 30 April 2013. Based on the viral load results, they were divided into those who achieved Viral Load Suppression (VLS), and those who did not (NVLS). Analyses were done using SAS® (version 9.2) for Microsoft software. A p < 0.05 was considered significant.

Results:

Ninety patients (91.8%; 95%CI, 84.7% – 95.8%) achieved viral load suppression while eight (8.2%; 95%CI, 4.2% – 15.3%), did not. Of the 98 patients, 63 (64%) were female. In the NVLS group, the female to male ratio was 7:1 (p = 0.038). There was no relationship between viral load suppression and patients’ baseline characteristics, behavioural characteristics and clinical characteristics (p > 0.05). ART adherence reported in both patient groups was ≥ 87.0%.

Conclusion:

There was good viral load suppression in patients initiated on ART at Pedisong 4 clinic. Patients’ baseline, behavioural and clinical characteristics were not related to viral load suppression, necessitating further large sample size studies in various health facilities.

New therapies for the prevention and treatment of exacerbations of bronchiectasis

PURPOSE OF REVIEW

Exacerbations of bronchiectasis have a major impact on quality of life, healthcare costs, and long-term risk of complications. Preventing exacerbations is one of the major goals of treatment. Bronchiectasis is increasingly recognized and the impact of bronchiectasis exacerbations on daily clinical practice is also increasing.

RECENT FINDINGS

Preventing bronchiectasis exacerbations are dependent on appropriate risk assessment, identifying the patients at highest risk to rationally target preventive therapies. Inhaled and oral antibiotic treatments can target chronic bacterial infection which is one of the major risk factors for exacerbation. Although the data is weak, airway clearance is an important part of long-term management including in patients with frequent exacerbations. Anti-inflammatory therapies such as inhaled corticosteroids do not currently have a major role outside comorbid chronic obstructive pulmonary disease and asthma, but further studies are required.

SUMMARY

Treatment of acute exacerbations involves prompt administration of antibiotic therapy with usually 14 days of oral, or for severe exacerbations, intravenous antibiotics. The role of corticosteroids is not established and there is little data on the optimal management approach for acute exacerbations. Home intravenous therapy can reduce healthcare costs and improve patient satisfaction with care. A number of large randomized controlled trials are currently enrolling or have recently completed raising the possibility that the treatment paradigm may change in the near future.

Human immunodeficiency virus infection and mortality risk among lung cancer patients: A systematic review and meta-analysis

BACKGROUND

Previous studies have suggested that patients with human immunodeficiency virus (HIV) infection are at higher risk of lung cancer, but the impact of HIV infection on the risk of mortality among lung cancer patients is still unclear. We conducted a systematic review and meta-analysis to clarify the association between HIV infection and mortality risk among lung cancer patients.

METHODS

PubMed and Embase databases were searched to identify studies assessing the association between HIV infection and mortality risk among lung cancer patients. Only studies reporting adjusted relative risk (RR) of mortality among lung cancer patients with HIV infection were included. Meta-analysis of random-effect model was utilized to calculate the pooled RR with 95% confidence interval (CI).

RESULTS

Twelve cohort studies were finally included. Compared with lung cancer patients without HIV infection, the pooled RR of mortality among lung cancer patients with HIV infection was 1.48 (95% CI, 1.22-1.78, P < .001; I = 88.6%). After excluding 2 studies with low quality, HIV infection was still significantly associated with an elevated risk of mortality among lung cancer patients (RR = 1.51, 95% CI, 1.25-1.82, P < .001; I = 89.8%). Sensitivity analysis showed that the statistical significance of the pooled RR was not changed by excluding any one study.

CONCLUSION

The outcomes from the meta-analysis provide strong evidence for the elevated risk of mortality among lung cancer patients with HIV infection, and HIV infection is an important prognostic factor in lung cancer patients.

Non-infectious Pulmonary Diseases and HIV

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

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.

Lung Cancer Mortality Associated With Smoking and Smoking Cessation Among People Living With HIV in the United States

Importance

Lung cancer has become a leading cause of death among people living with human immunodeficiency virus (HIV) (PLWH). Over 40% of PLWH in the United States smoke cigarettes; HIV independently increases the risk of lung cancer.

Objective

To project cumulative lung cancer mortality by smoking exposure among PLWH in care.

Design

Using a validated microsimulation model of HIV, we applied standard demographic data and recent HIV/AIDS epidemiology statistics with specific details on smoking exposure, combining smoking status (current, former, or never) and intensity (heavy, moderate, or light). We stratified reported mortality rates attributable to lung cancer and other non-AIDS-related causes by smoking exposure and accounted for an HIV-conferred independent risk of lung cancer. Lung cancer mortality risk ratios (vs never smokers) for male and female current moderate smokers were 23.6 and 24.2, respectively, and for those who quit smoking at age 40 years were 4.3 and 4.5. In sensitivity analyses, we accounted for nonadherence to antiretroviral therapy (ART) and for a range of HIV-conferred risks of death from lung cancer and from other non-AIDS-related diseases (eg, cardiovascular disease).

Main Outcomes and Measures

Cumulative lung cancer mortality by age 80 years (stratified by sex, age at entry to HIV care, and smoking exposure); total expected lung cancer deaths, accounting for nonadherence to ART.

Results

Among 40-year-old men with HIV, estimated cumulative lung cancer mortality for heavy, moderate, and light smokers who continued to smoke was 28.9%, 23.0%, and 18.8%, respectively; for those who quit smoking at age 40 years, it was 7.9%, 6.1%, and 4.3%; and for never smokers, it was 1.6%. Among women, the corresponding mortality for current smokers was 27.8%, 20.9%, and 16.6%; for former smokers, it was 7.5%, 5.2%, and 3.7%; and for never smokers, it was 1.2%. ART-adherent individuals who continued to smoke were 6 to 13 times more likely to die from lung cancer than from traditional AIDS-related causes, depending on sex and smoking intensity. Due to greater AIDS-related mortality risks, individuals with incomplete ART adherence had higher overall mortality but lower lung cancer mortality. Applying model projections to the approximately 644 200 PLWH aged 20 to 64 in care in the United States, 59 900 (9.3%) are expected to die from lung cancer if smoking habits do not change.

Conclusions and Relevance

Those PLWH who adhere to ART but smoke are substantially more likely to die from lung cancer than from AIDS-related causes.

The respiratory microbiome of HIV-infected individuals

INTRODUCTION

The respiratory tract is constantly exposed to various environmental and endogenous microbes; however, unlike other similar mucosal surfaces, there has been limited investigation of the microbiome of the respiratory tract.

AREAS COVERED

In this review, we summarize the current state of knowledge of the bacterial, fungal, and viral respiratory microbiomes during HIV infection and how the microbiome might relate to HIV-associated lung disease. Expert commentary: HIV infection is associated with alterations in the respiratory microbiome. The clinical implications of lung microbial dysbiosis are however currently unknown. Mechanistic studies are needed to establish causality between shifts in the respiratory microbiome and pulmonary complications in HIV-infected individuals.

Emphysema and soluble CD14 are associated with pulmonary nodules in HIV-infected patients: implications for lung cancer screening

OBJECTIVE

Lung cancer screening may benefit HIV-infected (HIV) smokers because of an elevated risk of lung cancer, but may have unique harms because of HIV-specific risk factors for false-positive screens. This study seeks to understand whether inflammatory biomarkers and markers of chronic lung disease are associated with noncalcified nodules at least 4 mm (NCN) in HIV compared with uninfected patients.

DESIGN

This is a cohort study of Examinations of HIV-Associated Lung Emphysema (EXHALE), including 158 HIV and 133 HIV-uninfected participants.

METHODS

Participants underwent a laboratory assessment [including measurement of D-dimer, interleukin 6, and soluble CD14 (sCD14)], chest computed tomography (CT), and pulmonary function testing. We created multivariable logistic regression models to determine predictors of NCN in the participants stratified by HIV status, with attention to semiqualitative scoring of radiographic emphysema, markers of pulmonary function, and inflammatory biomarkers.

RESULTS

Of the 291 participants, 69 had NCN on chest CT. As previously reported, there was no difference in prevalence of these nodules by HIV status. Emphysema and elevated sCD14 demonstrated an association with NCN in HIV participants independent of smoking status, CD4 cell count, HIV viral load, and pulmonary function.

CONCLUSION

Emphysema and sCD14, a marker of immune activation, was associated with a higher prevalence of NCN on chest CT in HIV participants. Patients with chronic immune activation and emphysema may be at higher risk for both false-positive findings and incident lung cancer, thus screening in this group requires further study to understand the balance of benefits and harms.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical and computed tomography findings in Chinese lung cancer patients with HIV infection: A multi-center study

BACKGROUND

The study was conducted to investigate clinical and computed tomography (CT) features in Chinese lung cancer patients with human immunodeficiency virus (HIV).

METHODS

Forty consecutive lung cancer patients with HIV were included. Clinical data were collected, and CT features were reviewed and measured. The factors associated with stages of cancer and the CT features with opportunistic pulmonary infections (OPIs) were also analyzed.

RESULTS

Thirty-four of the patients were men (85%), and the mean age was 57.5 years. The mean CD4 count was 288 cells/μL, and 23 patients received highly active antiretroviral therapy. OPIs were common (50%). The major histological type (85%) was non-small cell lung cancer (NSCLC), and 15 NSCLC patients (44%) were in stages IIIb and IV. NSCLC patients with an OPI were more common in the advanced stages compared with those without an OPI (P = 0.04). There were no significant differences in advanced and non-advanced stages in terms of CD4 level, highly active antiretroviral therapy, and smoking (P = 0.31, P = 1.00; P = 0.49, respectively). The average size of tumors was 4.5 cm. Irregularly shaped or larger sized tumors were associated with OPIs (P = 0.03, P = 0.04, respectively).

CONCLUSIONS

The persistence of locally irregular and large lesions in middle-aged men with HIV and a history of OPIs should be an alert for lung cancer, and clinical management is needed.

HIV-related pneumococcal disease prevention in adults

INTRODUCTION

HIV-infected persons are particularly susceptible to the development of severe pneumococcal disease, even in the setting of combination antiretroviral therapy (cART), due to slow, incomplete recovery of anti-pneumococcal host defenses. This risk is increased by avoidable aspects of lifestyle, particularly smoking, which intensify immunosuppression. Clearly, more effective preventive measures are needed to counter this threat. Areas covered: This is a detailed review of the published literature focusing on currently available strategies for prevention of pneumococcal infection in HIV-infected patients, including cotrimoxazole prophylaxis, cART, pneumococcal vaccination, and smoking cessation strategies. This is preceded by a consideration of the epidemiology, clinical presentation, risk factors, and outcome of pneumococcal disease. Expert commentary: Cotrimoxazole prophylaxis has been shown to reduce morbidity and mortality in HIV-infected patients, although there is inconsistent data on the preventive efficacy against pneumococcal infections. Some recent studies have documented unchanged incidences of IPD in adult patients in the cART era. With regard to pneumococcal vaccination, routine acceptance of the efficacy of the PCV13/PPV23 sequential administration prime-boost strategy awaits the outcome of clinical trials in those with HIV infection. Smoking cessation, and discontinuation of excessive alcohol consumption and intravenous drug abuse, are priority strategies to prevent severe pneumococcal infection.

Global impact of bronchiectasis and cystic fibrosis

EDUCATIONAL AIMS

To recognise the clinical and radiological presentation of the spectrum of diseases associated with bronchiectasis.To understand variation in the aetiology, microbiology and burden of bronchiectasis and cystic fibrosis across different global healthcare systems.

Bronchiectasis is the term used to refer to dilatation of the bronchi that is usually permanent and is associated with a clinical syndrome of cough, sputum production and recurrent respiratory infections. It can be caused by a range of inherited and acquired disorders, or may be idiopathic in nature. The most well recognised inherited disorder in Western countries is cystic fibrosis (CF), an autosomal recessive condition that leads to progressive bronchiectasis, bacterial infection and premature mortality. Both bronchiectasis due to CF and bronchiectasis due to other conditions are placing an increasing burden on healthcare systems internationally. Treatments for CF are becoming more effective leading to more adult patients with complex healthcare needs. Bronchiectasis not due to CF is becoming increasingly recognised, particularly in the elderly population. Recognition is important and can lead to identification of the underlying cause, appropriate treatment and improved quality of life. The disease is highly diverse in its presentation, requiring all respiratory physicians to have knowledge of the different "bronchiectasis syndromes". The most common aetiologies and presenting syndromes vary depending on geography, with nontuberculous mycobacterial disease predominating in some parts of North America, post-infectious and idiopathic disease predominating in Western Europe, and post-tuberculosis bronchiectasis dominating in South Asia and Eastern Europe. Ongoing global collaborative studies will greatly advance our understanding of the international impact of bronchiectasis and CF.

HIV and COPD: a conspiracy of risk factors

Chronic obstructive pulmonary disease (COPD) is an under recognized complication of HIV infection. It is estimated that up to 25% of HIV infected people may have COPD. HIV is associated with COPD as a result of a complex interplay of multiple factors such as pulmonary inflammation, recurrent pulmonary infections especially tuberculosis (TB), increased cigarette smoking, socio-economic status, childhood respiratory illnesses and industrial and environmental exposures; each of which are risk factors for COPD in their own right. COPD presents at an earlier age in people with HIV infection. There are over 35 million people living with HIV, and most people infected with HIV live in developing regions of the world where they are faced with multiple risk factors for COPD and suboptimal access to health care. TB is the commonest infectious complication of HIV, and HIV infected persons often experience multiple episodes of TB. Cigarette smoking is increasing in developing countries where the greatest burden of TB and HIV is experienced. Cigarette smoking is associated with increased risk of TB and may be associated with acquisition of HIV infection and progression. It is not clear whether non-infectious pulmonary inflammation persists in the lung when immune reconstitution occurs. Prevention and control of HIV infection must be part of the multiple interventions to reduce the global burden of COPD. A multidisciplinary approach, including behavioural science is required to address this challenge. It presents research opportunities that should be driven by the pulmonology community.

Systemic Immune Activation Profiles of HIV-1 Subtype C-Infected Children and Their Mothers

Little is known about immune activation profiles of children infected with HIV-1 subtype C. The current study compared levels of selected circulating biomarkers of immune activation in HIV-1 subtype C-infected untreated mothers and their children with those of healthy controls. Multiplex bead array, ELISA, and immunonephelometric procedures were used to measure soluble CD14 (sCD14), beta-2 microglobulin (β2M), CRP, MIG, IP-10, and transforming growth factor beta 1 (TGF-β1). Levels of all 6 biomarkers were significantly elevated in the HIV-infected mothers and, with the exception of MIG, in their children (P < 0.01–P < 0.0001). The effects of antiretroviral therapy (ART) and maternal smoking on these biomarkers were also assessed. With the exception of TGF-β1, which was unchanged in the children 12 months after therapy, initiation of ART was accompanied by decreases in the other biomarkers. Regression analysis revealed that although most biomarkers were apparently unaffected by smoking, exposure of children to maternal smoking was associated with a significant increase in IP-10. These findings demonstrate that biomarkers of immune activation are elevated in HIV-infected children pre-ART and decline, with the exception of TGF-β1, after therapy. Although preliminary, elevation of IP-10 in smoke-exposed infants is consistent with a higher level of immune activation in this group.