Asthma diagnosis and airway bronchodilator response in HIV-infected patients

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.

Circadian-Coupled Genes Expression and Regulation in HIV-Associated Chronic Obstructive Pulmonary Disease (COPD) and Lung Comorbidities

People living with HIV (PLWH) have an elevated risk of chronic obstructive pulmonary disease (COPD) and are at a higher risk of asthma and worse outcomes. Even though the combination of antiretroviral therapy (cART) has significantly improved the life expectancy of HIV-infected patients, it still shows a higher incidence of COPD in patients as young as 40 years old. Circadian rhythms are endogenous 24 h oscillations that regulate physiological processes, including immune responses. Additionally, they play a significant role in health and diseases by regulating viral replication and its corresponding immune responses. Circadian genes play an essential role in lung pathology, especially in PLWH. The dysregulation of core clock and clock output genes plays an important role in chronic inflammation and aberrant peripheral circadian rhythmicity, particularly in PLWH. In this review, we explained the mechanism underlying circadian clock dysregulation in HIV and its effects on the development and progression of COPD. Furthermore, we discussed potential therapeutic approaches to reset the peripheral molecular clocks and mitigate airway inflammation.

Health conditions in adults with HIV compared with the general population: A population-based cross-sectional analysis

BACKGROUND

Life expectancy in adults with human immunodeficiency virus (HIV) has increased and managing other health conditions is increasingly important for patients and healthcare planning. The aim of this study was to examine the prevalence and association between different health conditions and HIV status.

METHODS

We performed a cross-sectional analysis of adult UK Clinical Practice Research Datalink primary care electronic medical records linked to hospital admissions as of Nov 30, 2015. We examined 47 health condition groups and 304 physical and mental health conditions by HIV status, after adjustment for age, sex, social deprivation status using logistic regression.

FINDINGS

There were 964 patients with HIV (61.7% male; 92.8% aged <65 years) and 941,113 non-HIV patients (49.4% male; 75.2% aged <65 years). Condition groups with the greatest prevalence in HIV that were also highly prevalent in adults without HIV included: lipid disorder (41.4% vs 40.2%), and hypertension (19.1% vs 24.6%). Following adjustment, 18 (37.5%) condition groups were more likely in adults with HIV and ten (20.8%) were less likely. Individual conditions that were less likely in adults with HIV included: atrial fibrillation (odds ratio [OR] 0.37 [95% CI 0.20-0.64]) and hypertension (OR_0.78 [0.65-0.94]); rheumatoid arthritis (OR 0.27 [0.05-0.84]); asthma (OR_0.65 (0.53-0.80]); and certain eye diseases such as macular degeneration (OR_0.30 [0.09-0.70]). Meanwhile individual conditions that were more likely included: liver fibrosis, sclerosis, and cirrhosis (OR_3.23 [1.85-5.20]); pulmonary embolism (OR_2.06 [1.15-3.36]); male infertility (OR_2.23 [1.50-3.16]) and female infertility (OR_2.01 [1.34-2.88]); bipolar disorder (OR_2.93 [1.52-5.05]) and depression (OR_1.49 [1.28-1.71]); cervical malignancy (OR_4.64 [1.15-12.15]); and infections.

INTERPRETATION

Comorbidity is common in adults with HIV, with physical and mental health conditions spanning a wide spectrum. HIV management should consider multidisciplinary care models to provide optimal patient care.

FUNDING

The project was funded by the Bart's Charity; DRM was funded by a Wellcome Trust Clinical Research Career Development Fellowship; DRM and DMM received funding from the HDR-UK Precision therapeutics programme.

The influence of HIV infection and antiretroviral treatment on pulmonary function in individuals in an urban setting in sub-Saharan Africa

Background

With the roll-out of antiretroviral treatment (ART), the life expectancy of people with HIV and, hence, morbidity from non-communicable diseases, including pulmonary diseases, have increased.

Objectives

This research study aims to investigate whether HIV infection and ART use are associated with pulmonary function, given the high frequency of pulmonary infections, including tuberculosis (TB), associated with HIV.

Method

Adults living with HIV (ART-naïve, on first- or second-line ART), and age and sex matched HIV-negative controls were included in a cross-sectional study in Johannesburg, South Africa. Spirometry was performed to determine lung function, measuring the forced expiratory volume in one second (FEV1), the forced vital capacity (FVC) and the FEV1/FVC ratio before (pre), and after (post), short-acting bronchodilator. The association of HIV infection and ART use with pulmonary function was analysed using linear regression models, adjusting for age, gender, body surface area (BSA), employment, education, smoking and TB.

Results

Overall, 548 participants (62% women) were included with a mean age of 38 (standard deviation [s.d.] 9.5) years. No effect of HIV or ART on post-FEV1 was observed in adjusted analysis. Additional adjustment for TB resulted in a higher post-FEV1 in participants on ART compared with HIV-negative participants, whereas TB was associated with a lower FEV1. No effect of HIV and ART on post-FEV1/FVC was observed.

Conclusion

HIV infection and ART use were not associated with reduced pulmonary function in this urban African population. Tuberculosis showed a mediating effect on the association between HIV, ART and pulmonary function.

Gene-specific MicroRNA antagonism protects against HIV Tat and TGF-β-mediated suppression of CFTR mRNA and function

BACKGROUND

MicroRNAs play an important role in health and disease. TGF-β signaling, upregulated by HIV Tat, and in chronic airway diseases and smokers upregulates miR-145-5p to suppress cystic fibrosis transmembrane conductance regulator (CFTR). CFTR suppression in chronic airway diseases like Cystic Fibrosis, COPD and smokers has been associated with suppressed MCC and recurrent lung infections and inflammation. This can explain the emergence of recurrent lung infections and inflammation in people living with HIV.

METHODS

Tat-induced aberrant microRNAome was identified by miRNA expression analysis. microRNA mimics and antagomirs were used to validate the identified miRNAs involved in Tat mediated CFTR mRNA suppression. CRISPR-based editing of the miRNA target sites in CFTR 3'UTR was used to determine rescue of CFTR mRNA and function in airway epithelial cell lines and in primary human bronchial epithelial cells exposed to TGF-β and Tat.

FINDINGS

HIV Tat upregulates miR-145-5p and miR-509-3p. The two miRNAs demonstrate co-operative effects in suppressing CFTR. CRISPR-based editing of the miRNA target site preserves CFTR mRNA and function in airway epithelial cells INTERPRETATION: Given the important roles of TGF-β signaling and the multitude of genes regulated by miRNAs, we demonstrate that CRISPR-based gene-specific microRNA antagonism approach can preserve CFTR mRNA and function in the context of HIV Tat and TGF-β signaling without suppressing expression of other genes regulated by miR-145-5p.

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

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

Fraction of Exhaled Nitric Oxide Levels Are Elevated in People Living With Human Immunodeficiency Virus Compared to Uninfected Controls, Suggesting Increased Eosinophilic Airway Inflammation

BACKGROUND

Increased risk of asthma and chronic obstructive pulmonary disease has been reported in people living with human immunodeficiency virus (PLWH). Fraction of exhaled nitric oxide (FeNO) is a marker of eosinophilic airway inflammation. We assessed FeNO levels in PLWH and matched uninfected controls and investigated whether human immunodeficiency virus (HIV) status is independently associated with elevated FeNO.

METHODS

FeNO was quantified by NIOX Vero and pulmonary function was assessed by spirometry in 432 PLWH from the Copenhagen Comorbidity in HIV Infection Study and in 1618 age- and sex-matched uninfected controls from the Copenhagen General Population Study. Elevated FeNO was defined as ≥25 parts per billion. Associations between FeNO and HIV status were adjusted for known potential confounders.

RESULTS

Mean age of PLWH was 50.7 (standard deviation [SD], 11.1) years and 97.4% received combination antiretroviral therapy. PLWH had higher FeNO than uninfected controls (median, 17.0 [interquartile range {IQR}, 11.0-26.0] vs 13.0 [IQR, 9.0-19.0]; P < .001). Also, PLWH had a higher prevalence of elevated FeNO than uninfected controls (27.5% vs 12.3%; P < .001). This association remained after adjusting for age, sex, height, smoking status, use of airway medication, blood eosinophils, and immunoglobulin E (adjusted OR [aOR], 3.56 [95% CI, 2.51-5.04]; P < .001). Elevated FeNO was associated with self-reported asthma (aOR, 2.65 [95% CI, 1.66-4.24]; P < .001) but not with airflow limitation (aOR, 1.07 [95% CI, .71-1.62]; P = .745).

CONCLUSIONS

HIV status was independently associated with elevated FeNO, suggesting increased eosinophilic airway inflammation. The potential impact on chronic lung disease pathogenesis needs further investigation.

Disruption of the cholinergic anti-inflammatory response by R5-tropic HIV-1 protein gp120JRFL

Despite current pharmacological intervention strategies, patients with HIV still suffer from chronic inflammation. The nicotinic acetylcholine receptors (nAChRs) are widely distributed throughout the nervous and immune systems. In macrophages, activation of alpha7-nAChR (α7-nAChR) controls inflammatory processes through the cholinergic anti-inflammatory response (CAR). Given that this innate immune response controls inflammation and α7-nAChR plays a critical role in the regulation of systemic inflammation, we investigated the effects of an R5-tropic HIV soluble component, gp120JRFL, on the CAR functioning. We previously demonstrated that X4-tropic HIV-1 gp120IIIB disrupts the CAR as well as inducing upregulation of the α7-nAChR in vitro in monocyte-derived macrophages (MDMs), which correlates with the upregulation observed in monocytes, T-lymphocytes, and MDMs recovered from HIV-infected people. We demonstrate here using imaging and molecular assays that the R5-tropic HIV-1 glycoprotein gp120JRFL upregulates the α7-nAChR in MDMs dependent on CD4 and/or CCR5 activation. This upregulation was also dependent on MEK1 since its inhibition attenuates the upregulation of α7-nAChR induced by gp120JRFL and was concomitant with an increase in basal calcium levels, which did not result in apoptosis. Moreover, the CAR was determined to be disrupted, since α7-nAChR activation in MDMs did not reduce the production of the proinflammatory cytokines IL-6, GRO-α, or I-309. Furthermore, a partial antagonist of α7-nAChR, bupropion, rescued IL-6 but not GRO-α or I-309 production. Together, these results demonstrate that gp120JRFL disrupts the CAR in MDMs. Other medications targeting the α7-nAChR need to be tested to reactivate the CAR to ameliorate inflammation in HIV-infected subjects.

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.

Bronchoscopy in severe childhood asthma: Irresponsible or irreplaceable?

For children with severe asthma, guideline-based management focuses on the escalation of anti-inflammatory and bronchodilatory medications while addressing comorbid conditions. Bronchoscopy, in this context, has been relegated to ruling out asthma mimickers. More recently, however, there have been questions surrounding the clinical utility of bronchoscopy in severe childhood asthma. In this solicited lecture summary, we discuss the past, present, and potential future applications of bronchoscopy in severe childhood asthma.

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.

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.

The impact of HIV on the prevalence of asthma in Uganda: a general population survey

Background

HIV and asthma are highly prevalent diseases in Africa but few studies have assessed the impact of HIV on asthma prevalence in high HIV burden settings. The objective of this analysis was to compare the prevalence of asthma among persons living with HIV (PLHIV) and those without HIV participating in the Uganda National Asthma Survey (UNAS).

Methods

UNAS was a population-based survey of persons aged ≥12 years. Asthma was diagnosed based on either self-reported current wheeze concurrently or within the prior 12 months; physician diagnosis; or use of asthma medication. HIV was defined based on confidential self-report. We used Poisson regression with robust standard errors to estimate asthma prevalence and the prevalence ratio (PR) for HIV and asthma.

Results

Of 3416 participants, 2067 (60.5%) knew their HIV status and 103 (5.0%) were PLHIV. Asthma prevalence was 15.5% among PLHIV and 9.1% among those without HIV, PR 1.72, (95%CI 1.07–2.75, p = 0.025). HIV modified the association of asthma with the following factors, PLHIV vs. not PLHIV: tobacco smoking (12% vs. 8%, p = < 0.001), biomass use (11% vs. 7%, p = < 0.001), allergy (17% vs. 11%, p = < 0.001), family history of asthma (17% vs. 11%, p = < 0.001), and prior TB treatment (15% vs. 10%, p = < 0.001).

Conclusion

In Uganda the prevalence of asthma is higher in PLHIV than in those without HIV, and HIV interacts synergistically with other known asthma risk factors. Additional studies should explore the mechanisms underlying these associations. Clinicians should consider asthma as a possible diagnosis in PLHIV presenting with respiratory symptoms.

Lung function in HIV-infected children and adolescents

Background

The advent of antiretroviral therapy has led to the improved survival of human immunodeficiency virus (HIV)-infected children to adulthood and to HIV becoming a chronic disease in older children and adolescents. Chronic lung disease is common among HIV-infected adolescents. Lung function measurement may help to delineate the spectrum, pathophysiology and guide therapy for HIV-related chronic lung disease.

Aim

The aim of this study was to review the available data on the spectrum and determinants of lung function abnormalities and the impact of antiretroviral therapy on lung function in perinatally HIV-infected children and adolescents.

Methods

Electronic databases “PUBMED”, “African wide” and “CINAHL” via EBSCO Host, using the MeSH terms “Respiratory function” AND “HIV” OR “Acquired Immunodeficiency Syndrome” AND “Children” OR “Adolescents”, were searched for relevant articles on lung function in HIV-infected children and adolescents. The search was limited to English language articles published between January 1984 and September 2017.

Results

Eighteen articles were identified, which included studies from Africa, the United States of America (USA) and Italy, representing 2051 HIV-infected children and adolescents, 68% on antiretroviral therapy, aged from 50 days to 24 years. Lung function abnormalities showed HIV-infected participants had increased irreversible lower airway expiratory obstruction and reduced functional aerobic impairment on exercise, compared to HIV-uninfected participants. Mosaic attenuation, extent of bronchiectasis, history of previous pulmonary tuberculosis or previous lower respiratory tract infection and cough for more than 1 month were associated with low lung function. Pulmonary function tests in children established on antiretroviral therapy did not show aerobic impairment and had less severe airway obstruction.

Conclusion

There is increasing evidence that HIV-infected children and adolescents have high prevalence of lung function impairment, predominantly irreversible lower airway obstruction and reduced aerobic function.

Complex association patterns for inflammatory mediators in induced sputum from subjects with asthma

BACKGROUND

The release of various inflammatory mediators into the bronchial lumen is thought to reflect both the type and degree of airway inflammation, eosinophilic Th2, and Th9, or neutrophilic Th1, and Th17, in patients with asthma.

AIMS

We investigated whether cytokines and chemokines differed in sputum from subjects with more severe compared with milder asthma and whether unbiased factor analysis of cytokine and chemokine groupings indicates specific inflammatory pathways.

METHODS

Cell-free supernatants from induced sputum were obtained from subjects with a broad range of asthma severity (n = 158) and assessed using Milliplex^® Cytokines/Chemokine kits I, II and III, measuring 75 individual proteins. Each cytokine, chemokine or growth factor concentration was examined for differences between asthma severity groups, for association with leucocyte counts, and by factor analysis.

RESULTS

Severe asthma subjects had 9 increased and 4 decreased proteins compared to mild asthma subjects and fewer differences compared to moderate asthma. Twenty-six mediators were significantly associated with an increasing single leucocyte type: 16 with neutrophils (3 interleukins [IL], 3 CC chemokines, 4 CXC chemokines, 4 growth factors, TNF-α and CX3CL1/Fractalkine); 5 with lymphocytes (IL-7, IL-16, IL-23, IFN-α2 and CCL4/MIP1β); IL-15 and CCL15/MIP1δ with macrophages; IL-5 with eosinophils; and IL-4 and TNFSF10/TRAIL with airway epithelial cells. Factor analysis grouped 43 cytokines, chemokines and growth factors which had no missing data onto the first 10 factors, containing mixes of Th1, Th2, Th9 and Th17 inflammatory and anti-inflammatory proteins.

CONCLUSIONS

Sputum cytokines, chemokines and growth factors were increased in severe asthma, primarily with increased neutrophils. Factor analysis identified complex inflammatory protein interactions, suggesting airway inflammation in asthma is characterized by overlapping immune pathways. Thus, focus on a single specific inflammatory mediator or pathway may limit understanding the complexity of inflammation underlying airway changes in asthma and selection of appropriate therapy.

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.

HIV-related chronic lung disease in adolescents: are we prepared for the future?

INTRODUCTION

Chronic lung diseases (CLD) are the most chronic disease occurring in adolescents living with human immunodeficiency virus (ALHIV). In ALHIV who received antiretroviral therapy (ART) late in childhood, bronchiectasis, bronchiolitis obliterans and interstitial pneumonitis are common. In adolescents who received ART early in life the spectrum of CLD has changed with asthma and chronic obstructive pulmonary disease being common. Areas covered: The aim of this paper was to review CLD in ALHIV. We conducted a literature review of electronic databases focusing on CLD that were common prior to the introduction of ART (1996-2004), the present situation where ART is widely available (2005 to 2016), and articles which aided us speculating on the impact of HIV-related CLD in adolescents transitioning to adult HIV-clinics. Amongst the approximately 2.1 million adolescents living with HIV, CLD commonly occurs. Awareness of the CLD amongst ALHIV needs to be raised to ensure that disease appropriate treatment is available to these vulnerable adolescents. Expert commentary: As adolescents' transition from pediatric HIV-clinics to adult HIV-clinics the evidence shows that adolescents might not receive optimal care if adult pulmonologists are not aware of the CLD that commonly occur in ALHIV.

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

RATIONALE

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Long-term pulmonary complications in perinatally HIV-infected youth

BACKGROUND

Increased incidence and prevalence of asthma have been documented for perinatally HIV-infected youth 10 to 21 years of age compared with HIV-exposed uninfected (HEU) youth.

OBJECTIVE

We sought to perform objective pulmonary function tests (PFTs) in HIV-infected and HEU youth with and without diagnosed asthma.

METHOD

Asthma was determined in 370 participants (218 HIV-infected and 152 HEU participants) by means of chart review and self-report at 13 sites. Interpretable PFTs (188 HIV-infected and 132 HEU participants) were classified as obstructive, restrictive, or normal, and reversibility was determined after bronchodilator inhalation. Values for HIV-1 RNA, CD4 and CD8 T cells, eosinophils, total IgE, allergen-specific IgE, and urinary cotinine were measured. Adjusted prevalence ratios (PRs) of asthma and PFT outcomes were determined for HIV-infected participants relative to HEU participants, controlling for age, race/ethnicity, and sex.

RESULTS

Current asthma was identified in 75 (34%) of 218 HIV-infected participants and 38 (25%) of 152 HEU participants (adjusted PR, 1.33; P = .11). The prevalence of obstructive disease did not differ by HIV status. Reversibility was less likely in HIV-infected youth than in HEU youth (17/183 [9%] vs 21/126 [17%]; adjusted PR, 0.47; P = .020) overall and among just those with obstructive PFT results (adjusted PR, 0.46; P = .016). Among HIV-infected youth with current asthma, serum IgE levels were inversely correlated with CD8 T-cell counts and positively correlated with eosinophil counts and not associated with CD4 T-cell counts. HIV-infected youth had lower association of specific IgE levels to several inhalant and food allergens compared with HEU participants and significantly lower CD4/CD8 T-cell ratios (suggesting immune imbalance).

CONCLUSION

Compared with HEU youth, HIV-infected youth demonstrated decreased reversibility of obstructive lung disease, which is atypical of asthma. This might indicate an early stage of chronic obstructive pulmonary disease. Follow-up into adulthood is warranted to further define their pulmonary outcomes.

Dectin-1 Plays an Important Role in House Dust Mite-Induced Allergic Airway Inflammation through the Activation of CD11b+ Dendritic Cells

It is well known that sensitization against fungi is closely associated with severity of asthma. Dectin-1 (gene symbol Clec7a), a C-type lectin receptor, recognizes the fungal cell wall component β-glucan, as well as some component(s) in house dust mite (HDM) extract. However, the roles of Dectin-1 in HDM-induced allergic airway inflammation remain unclear. In this study, we used Dectin-1-deficient (Clec7a^-/-) mice to examine whether Dectin-1 is involved in HDM-induced allergic airway inflammation. We found that HDM-induced eosinophil and neutrophil recruitment into the airways was significantly attenuated in Clec7a^-/- mice compared with that in wild-type mice. In addition, HDM-induced IL-5, IL-13, and IL-17 production from mediastinum lymph node cells was reduced in HDM-sensitized Clec7a^-/- mice. Dectin-1 was expressed on CD11b⁺ dendritic cells (DCs), an essential DC subset for the development of allergic inflammation, but not on CD103⁺ DCs, plasmacytoid DCs, or lung epithelial cells. Transcriptome analysis revealed that the expression of chemokine/chemokine receptors, including CCR7, which is indispensable for DC migration to draining lymph nodes, was decreased in Clec7a^-/- DCs. In accordance with these results, the number of HDM-labeled CD11b⁺ DCs in mediastinum lymph nodes was significantly reduced in Clec7a^-/- mice compared with wild-type mice. Taken together, these results suggest that Dectin-1 expressed on CD11b⁺ DCs senses some molecule(s) in HDM extract and plays a critical role in the induction of HDM-induced allergic airway inflammation by inducing the expression of chemokine/chemokine receptors in DCs.

A Novel CD4+ T Cell-Dependent Murine Model of Pneumocystis-driven Asthma-like Pathology

RATIONALE

Infection with Pneumocystis, an opportunistic fungal pathogen, can result in fulminant pneumonia in the clinical setting of patients with immunosuppression. In murine models, Pneumocystis has previously been shown to induce a CD4⁺ T cell-dependent eosinophilic response in the lung capable of providing protection.

OBJECTIVES

We sought to explore the role of Pneumocystis in generating asthma-like lung pathology, given the natural eosinophilic response to infection.

METHODS

Pneumocystis infection or antigen treatment was used to induce asthma-like pathology in wild-type mice. The roles of CD4⁺ T cells and eosinophils were examined using antibody depletion and knockout mice, respectively. The presence of anti-Pneumocystis antibodies in human serum samples was detected by ELISA and Western blotting.

MEASUREMENTS AND MAIN RESULTS

Pneumocystis infection generates a strong type II response in the lung that requires CD4⁺ T cells. Pneumocystis infection was capable of priming a Th2 response similar to that of a commonly studied airway allergen, the house dust mite. Pneumocystis antigen treatment was also capable of inducing allergic inflammation in the lung, resulting in anti-Pneumocystis IgE production, goblet cell hyperplasia, and increased airway resistance. In the human population, patients with severe asthma had increased levels of anti-Pneumocystis IgG and IgE compared with healthy control subjects. Patients with severe asthma with elevated anti-Pneumocystis IgG levels had worsened symptom scores and lung parameters such as decreased forced expiratory volume and increased residual volume compared with patients with severe asthma who had low anti-Pneumocystis IgG.

CONCLUSIONS

The present study demonstrates for the first time, to our knowledge, that Pneumocystis is an airway allergen capable of inducing asthma-like lung pathology.

Adiposity influences airway wall thickness and the asthma phenotype of HIV-associated obstructive lung disease: a cross-sectional study

Background

Airflow obstruction, which encompasses several phenotypes, is common among HIV-infected individuals. Obesity and adipose-related inflammation are associated with both COPD (fixed airflow obstruction) and asthma (reversible airflow obstruction) in HIV-uninfected persons, but the relationship to airway inflammation and airflow obstruction in HIV-infected persons is unknown. The objective of this study was to determine if adiposity and adipose-associated inflammation are associated with airway obstruction phenotypes in HIV-infected persons.

Methods

We performed a cross-sectional analysis of 121 HIV-infected individuals assessed with pulmonary function testing, chest CT scans for measures of airway wall thickness (wall area percent [WA%]) and adipose tissue volumes (mediastinal and subcutaneous), as well as HIV- and adipose-related inflammatory markers. Participants were defined as COPD phenotype (post-bronchodilator FEV₁/FVC < lower limit of normal) or asthma phenotype (doctor-diagnosed asthma or bronchodilator response). Pearson correlation coefficients were calculated between adipose measurements, WA%, and pulmonary function. Multivariable logistic and linear regression models were used to determine associations of airflow obstruction and airway remodeling (WA%) with adipose measurements and participant characteristics.

Results

Twenty-three (19 %) participants were classified as the COPD phenotype and 33 (27 %) were classified as the asthma phenotype. Body mass index (BMI) was similar between those with and without COPD, but higher in those with asthma compared to those without (mean [SD] 30.7 kg/m² [8.1] vs. 26.5 kg/m² [5.3], p = 0.008). WA% correlated with greater BMI (r = 0.55, p < 0.001) and volume of adipose tissue (subcutaneous, r = 0.40; p < 0.001; mediastinal, r = 0.25; p = 0.005). Multivariable regression found the COPD phenotype associated with greater age and pack-years smoking; the asthma phenotype with younger age, female gender, smoking history, and lower adiponectin levels; and greater WA% with greater BMI, younger age, higher soluble CD163, and higher CD4 counts.

Conclusions

Adiposity and adipose-related inflammation are associated with an asthma phenotype, but not a COPD phenotype, of obstructive lung disease in HIV-infected persons. Airway wall thickness is associated with adiposity and inflammation. Adipose-related inflammation may play a role in HIV-associated asthma.

A cross-sectional, facility based study of comorbid non-communicable diseases among adults living with HIV infection in Zimbabwe

BACKGROUND

Increased antiretroviral therapy uptake in sub-Saharan Africa has resulted in improved survival of the infected. Opportunistic infections are declining as leading causes of morbidity and mortality. Though comprehensive data are lacking, concern has been raised about the rapid emergence of non-communicable diseases (NCDs) in the African HIV care setting. We therefore set out to characterise the NCD/HIV burden among adults living and ageing with HIV infection in Zimbabwe.

METHODS

We conducted a cross-sectional study among patients receiving care in a public sector facility. We reviewed patient records and determined the prevalence of comorbid and multi-morbid NCDs. Associations with patient characteristics were evaluated using univariate and multi-variate logistic regression modelling. Significance testing was done using 2-sided p values and 95 % confidence intervals calculated.

RESULTS

We recruited 1033 participants. 31 % were men. Significant gender differences included: older median age, more advanced disease at baseline, and greater use of stavudine and protease inhibitor containing regimens in men compared to women. The prevalence of comorbidity and multi-morbidity were, respectively, 15.3 % (95 % CI 13.3-17.7 %) and 4.5 % (95 % CI 3.4-6.0 %). Women had higher rates than men of both co-morbidity and multi-morbid ity: 21.8 vs. 14.9 %; p = 0.010 and 5.3 vs. 2.9 %; p = 0.025 respectively. The commonly observed individual NCDs were hypertension [10.2 %; (95 % CI 8.4-12.2 %)], asthma [4.3 % (95 % CI 3.1-5.8 %)], type 2 diabetes mellitus [2.1 % (95 % CI 1.3-3.2 %)], cancer [1.8 % (95 % CI 1.1-2.8 %)], and congestive cardiac failure [1.5 % (95 % CI 0.9-2.5 %)]. After adjusting for confounding, only age categories 45-≤55 years (AOR 2.25; 95 % CI 1.37-3.69) and >55 years (AOR 5.42; 95 % CI 3.17-9.26), and female gender (AOR 2.12; 95 % CI 1.45-3.11) remained significantly and strongly associated with comorbidity risk.

CONCLUSIONS

We found a substantial burden of comorbid non-communicable diseases among HIV infected patients in a high HIV and low-income setting. Integrating non-communicable diseases care, including active screening, with HIV care is recommended.

Clinical Characteristics and Lung Function in Older Children Vertically Infected With Human Immunodeficiency Virus in Malawi

BACKGROUND

Antiretroviral therapy (ART) has led to increased survival of children with vertically acquired human immunodeficiency virus infection. Significant morbidity arises from respiratory symptoms, but aetiology and pulmonary function abnormalities have not been systematically studied.

METHODS

Human immunodeficiency virus-positive children aged 8-16 years were systematically recruited within clinics in Blantyre, Malawi. Clinical review, quality of life assessment, spirometry, and chest radiography were performed.

RESULTS

One hundred sixty participants had a mean of age 11.1 (range, 8-16) years and 50.0% were female. Cough was present in 60 (37.5%) participants, and 55 (34.4%) had moderate or severe dyspnoea. Thirty-four (22.1%) participants had digital clubbing. Thirty-three (20.6%) participants were hypoxic at rest. One hundred eighteen (73.8%) of the children were receiving ART; median CD4 count was 698 cells/µL in these compared with 406 cells/µL in ART-naive individuals (P < .001). From 145 spirometry traces (90.6%), mean forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were 1.06 and 0.89 standard deviations below predicted mean, respectively. Twenty-one (14.5%) traces demonstrated obstructive defects and 26 (17.9%) reduced FVC. Lung function abnormality was not associated with any clinical findings. Of the 51 individuals with abnormal lung function, the mean increase in FEV1 after salbutamol was 3.8% (95% confidence interval, 0.02-7.53). "Tramlines" and ring shadows were seen on chest radiographs in over half of cases.

CONCLUSIONS

Symptoms of chronic lung disease were highly prevalent with 2 main clinical phenotypes: "cough" and "hypoxia". Lung function abnormalities are common, poorly responsive to bronchodilators, and apparent throughout the age range of our cohort. Pathological causes remain to be elucidated. Cough and hypoxic phenotypes could be a useful part of diagnostic algorithms if further validated.

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

OBJECTIVE

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

DESIGN

Longitudinal observational study.

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Risk factors associated with acute exacerbation of chronic obstructive pulmonary disease in HIV-infected and uninfected patients

OBJECTIVE

To determine the association between HIV infection and other risk factors for acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

DESIGN

Longitudinal, national Veterans Aging Cohort Study including 43 618 HIV-infected and 86 492 uninfected veterans.

METHODS

AECOPD was defined as an inpatient or outpatient COPD ICD-9 diagnosis accompanied by steroid and/or antibiotic prescription within 5 days. We calculated incidence rate ratios (IRR) and 95% confidence intervals (CI) for first AECOPD over 2 years and used Poisson regression models to adjust for risk factors.

RESULTS

Over 234 099 person-years of follow-up, 1428 HIV-infected and 2104 uninfected patients had at least one AECOPD. HIV-infected patients had an increased rate of AECOPD compared with uninfected (18.8 vs. 13.3 per 1000 person-years, P < 0.001). In adjusted models, AECOPD risk was greater in HIV-infected individuals overall (IRR 1.54; 95% CI 1.44-1.65), particularly in those with more severe immune suppression when stratified by CD4 cell count (cells/μl) compared with uninfected (HIV-infected CD4 < 200: IRR 2.30, 95% CI 2.10-2.53, HIV-infected CD4 ≥ 200-349: IRR 1.32, 95% CI 1.15-1.51, HIV-infected CD4 ≥ 350: IRR 0.99, 95% CI 0.88-1.10). HIV infection also modified the association between current smoking and alcohol-related diagnoses with risk for AECOPD such that interaction terms for HIV and current smoking or HIV and alcohol-related diagnoses were each significantly associated with AECOPD.

CONCLUSION

HIV infection, especially with lower CD4 cell count, is an independent risk factor for AECOPD. Enhanced susceptibility to harm from current smoking or unhealthy alcohol use in HIV-infected patients may also contribute to the greater rate of AECOPD.

Factors associated with abnormal spirometry among HIV-infected individuals

OBJECTIVE

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

DESIGN

Cross-sectional cohort study.

METHODS

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

RESULTS

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

CONCLUSIONS

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

Eosinophils Contribute to Early Clearance of Pneumocystis murina Infection

Pneumocystis pneumonia remains a common opportunistic infection in the diverse immunosuppressed population. One clear risk factor for susceptibility to Pneumocystis is a declining CD4(+) T cell count in the setting of HIV/AIDS or primary immunodeficiency. Non-HIV-infected individuals taking immunosuppressive drug regimens targeting T cell activation are also susceptible. Given the crucial role of CD4(+) T cells in host defense against Pneumocystis, we used RNA sequencing of whole lung early in infection in wild-type and CD4-depleted animals as an unbiased approach to examine mechanisms of fungal clearance. In wild-type mice, a strong eosinophil signature was observed at day 14 post Pneumocystis challenge, and eosinophils were increased in the bronchoalveolar lavage fluid of wild-type mice. Furthermore, eosinophilopoiesis-deficient Gata1(tm6Sho)/J mice were more susceptible to Pneumocystis infection when compared with BALB/c controls, and bone marrow-derived eosinophils had in vitro Pneumocystis killing activity. To drive eosinophilia in vivo, Rag1(-/-) mice were treated with a plasmid expressing IL-5 (pIL5) or an empty plasmid control via hydrodynamic injection. The pIL5-treated mice had increased serum IL-5 and eosinophilia in the lung, as well as reduced Pneumocystis burden, compared with mice treated with control plasmid. In addition, pIL5 treatment could induce eosinophilia and reduce Pneumocystis burden in CD4-depleted C57BL/6 and BALB/c mice, but not eosinophilopoiesis-deficient Gata1(tm6Sho)/J mice. Taken together, these results demonstrate that an early role of CD4(+) T cells is to recruit eosinophils to the lung and that eosinophils are a novel candidate for future therapeutic development in the treatment of Pneumocystis pneumonia in the immunosuppressed population.

Infections in "noninfectious" lung diseases

Many chronic pulmonary diseases, including those that are not primarily infectious in etiology, have some aspects of their pathogenesis that are influenced by infectious organisms. Microorganisms may contribute to chronic lung diseases, either directly (i.e., overt infection) or indirectly, via the amplification of inflammatory pathways that are critical to host defense. As techniques for detecting and characterizing microorganisms have advanced, investigations of both infecting and colonizing organisms have yielded new insights into mechanisms of pulmonary disease. In addition, changes in patterns of infection and microbial resistance have important implications for treatment. Examples of these infectious-pulmonary associations, including Haemophilus influenzae infection and chronic obstructive pulmonary disease, nontuberculous mycobacteria and bronchiectasis, and human immunodeficiency virus and obstructive lung disease, are reviewed.

Noninfectious pulmonary complications of human immunodeficiency virus infection

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

Chest computed tomography findings in HIV-infected individuals in the era of antiretroviral therapy

BACKGROUND

Chest radiographic abnormalities were common in HIV-infected individuals in the pre-combination antiretroviral therapy era, but findings may differ now due to a changing spectrum of pulmonary complications.

METHODS

Cross-sectional study of radiographic abnormalities in an HIV-infected outpatient population during the antiretroviral therapy era. Demographics, chest computed tomography, and pulmonary function tests were obtained in HIV-infected volunteers without acute respiratory illness from the University of Pittsburgh HIV/AIDS clinic. Overall prevalence of radiographic abnormalities and potential risk factors for having any abnormality, nodules, or emphysema were evaluated using univariate and multivariable analyses.

RESULTS

A majority of the 121 participants (55.4%) had a radiographic abnormality with the most common being emphysema (26.4%), nodules (17.4%), and bronchiectasis (10.7%). In multivariate models, age (odds ratio [OR] per year  = 1.07, 95% confidence interval [CI] 1.04-1.14, p<0.001), pneumonia history (OR  = 3.60, 95% CI  = 1.27-10.20, p = 0.016), and having ever smoked (OR  = 3.66, p = 0.013, 95% CI  = 1.31-10.12) were significant predictors of having any radiographic abnormality. Use of antiretroviral therapy, CD4 cell count, and HIV viral load were not associated with presence of abnormalities. Individuals with radiographic emphysema were more likely to have airway obstruction on pulmonary function tests. Only 85.8% participants with nodules had follow-up imaging resulting in 52.4% having stable nodules, 23.8% resolution of their nodules, 4.8% development of a new nodule, and 4.8% primary lung cancer.

CONCLUSIONS

Radiographic abnormalities remain common in HIV-infected individuals with emphysema, nodules, and bronchiectasis being the most common. Age, smoking, and pneumonia were associated with radiographic abnormalities, but HIV-associated factors did not seem to predict risk.

Lung function abnormalities in HIV-infected adults and children

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

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

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

Clinical view on the importance of dendritic cells in asthma

Allergic asthma is characterized by airway hyperresponsiveness and inflammation and may lead to airway remodeling in uncontrolled cases. Genetic predisposition to an atopic phenotype plays a major component in the pathophysiology of asthma. However, with tremendous role of epigenetic factors and environmental stimuli in precipitating an immune response, the underlying pathophysiological mechanisms are complicated. Dendritic cells are principal antigen-presenting cells and initiators of the immune response in allergic asthma. Their phenotype, guided by multiple factors may dictate the immune reaction to an allergic or tolerogenic response. Involvement of the local cytokine milieu, microbiome and interplay between immune cells add dimension to the fate of immune response. In addition to allergen exposure, these factors modulate DC phenotype and function. In this article, integration of many factors and pathways associated with the recruitment and activation of DCs in the pathophysiology of allergic asthma is presented in a clinical and translational manner.

HIV-associated obstructive lung diseases: insights and implications for the clinician

The effectiveness of antiretroviral therapy to control HIV infection has led to the emergence of an older HIV population who are at risk of chronic diseases. Through a comprehensive search of major databases, this Review summarises information about the associations between chronic obstructive pulmonary disease (COPD), asthma, and HIV infection. Asthma and COPD are more prevalent in HIV-infected populations; 16-20% of individuals with HIV infection have asthma or COPD, and poorly controlled HIV infection worsens spirometric and diffusing capacity measurements, and accelerates lung function decline by about 55-75 mL/year. Up to 21% of HIV-infected individuals have obstructive ventilatory defects and reduced diffusing capacity is seen in more than 50% of HIV-infected populations. Specific pharmacotherapy considerations are needed to care for HIV-infected populations with asthma or COPD-protease inhibitor regimens to treat HIV (such as ritonavir) can result in systemic accumulation of inhaled corticosteroids and might increase pneumonia risk, exacerbating the toxicity of this therapy. Therefore, it is essential for clinicians to have a heightened awareness of the increased risk and manifestations of obstructive lung diseases in HIV-infected patients and specific therapeutic considerations to care for this population. Screening spirometry and tests of diffusing capacity might be beneficial in HIV-infected people with a history of smoking or respiratory symptoms.

Pulmonary symptoms and diagnoses are associated with HIV in the MACS and WIHS cohorts

Background

Several lung diseases are increasingly recognized as comorbidities with HIV; however, few data exist related to the spectrum of respiratory symptoms, diagnostic testing, and diagnoses in the current HIV era. The objective of the study is to determine the impact of HIV on prevalence and incidence of respiratory disease in the current era of effective antiretroviral treatment.

Methods

A pulmonary-specific questionnaire was administered yearly for three years to participants in the Multicenter AIDS Cohort Study (MACS) and Women’s Interagency HIV Study (WIHS). Adjusted prevalence ratios for respiratory symptoms, testing, or diagnoses and adjusted incidence rate ratios for diagnoses in HIV-infected compared to HIV-uninfected participants were determined. Risk factors for outcomes in HIV-infected individuals were modeled.

Results

Baseline pulmonary questionnaires were completed by 907 HIV-infected and 989 HIV-uninfected participants in the MACS cohort and by 1405 HIV-infected and 571 HIV-uninfected participants in the WIHS cohort. In MACS, dyspnea, cough, wheezing, sleep apnea, and incident chronic obstructive pulmonary disease (COPD) were more common in HIV-infected participants. In WIHS, wheezing and sleep apnea were more common in HIV-infected participants. Smoking (MACS and WIHS) and greater body mass index (WIHS) were associated with more respiratory symptoms and diagnoses. While sputum studies, bronchoscopies, and chest computed tomography scans were more likely to be performed in HIV-infected participants, pulmonary function tests were no more common in HIV-infected individuals. Respiratory symptoms in HIV-infected individuals were associated with history of pneumonia, cardiovascular disease, or use of HAART. A diagnosis of asthma or COPD was associated with previous pneumonia.

Conclusions

In these two cohorts, HIV is an independent risk factor for several respiratory symptoms and pulmonary diseases including COPD and sleep apnea. Despite a higher prevalence of chronic respiratory symptoms, testing for non-infectious respiratory diseases may be underutilized in the HIV-infected population.

Human immunodeficiency virus-associated obstructive lung diseases

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

Human immunodeficiency virus-1 transgene expression increases pulmonary vascular resistance and exacerbates hypoxia-induced pulmonary hypertension development

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary arterial resistance and vessel remodeling. Patients living with human immunodeficiency virus-1 (HIV-1) have an increased susceptibility to develop severe pulmonary hypertension (PH) irrespective of their CD4+ lymphocyte counts. While the underlying cause of HIV-PAH remains unknown, the interaction of HIV-1 proteins with the vascular endothelium may play a critical role in HIV-PAH development. Hypoxia promotes PH in experimental models and in humans, but the impact of HIV-1 proteins on hypoxia-induced pulmonary vascular dysfunction and PAH has not been examined. Therefore, we hypothesize that the presence of HIV-1 proteins and hypoxia synergistically augment the development of pulmonary vascular dysfunction and PH. We examined the effect of HIV-1 proteins on pulmonary vascular resistance by measuring pressure-volume relationships in isolated lungs from wild-type (WT) and HIV-1 Transgenic (Tg) rats. WT and HIV-1 Tg rats were exposed to 10% O₂ for four weeks to induce experimental pulmonary hypertension to assess whether HIV-1 protein expression would impact the development of hypoxia-induced PH. Our results demonstrate that HIV-1 protein expression significantly increased pulmonary vascular resistance (PVR). HIV-1 Tg mice demonstrated exaggerated pulmonary vascular responses to hypoxia as evidenced by greater increases in right ventricular systolic pressures, right ventricular hypertrophy and vessel muscularization when compared to wild-type controls. This enhanced PH was associated with enhanced expression of HIF-1α and PCNA. In addition, in vitro studies reveal that medium from HIV-infected monocyte derived macrophages (MDM) potentiates hypoxia-induced pulmonary artery endothelial proliferation. These results indicate that the presence of HIV-1 proteins likely impact pulmonary vascular resistance and exacerbate hypoxia-induced PH.

The impact of HAART on the respiratory complications of HIV infection: longitudinal trends in the MACS and WIHS cohorts

OBJECTIVE

To review the incidence of respiratory conditions and their effect on mortality in HIV-infected and uninfected individuals prior to and during the era of highly active antiretroviral therapy (HAART).

DESIGN

Two large observational cohorts of HIV-infected and HIV-uninfected men (Multicenter AIDS Cohort Study [MACS]) and women (Women's Interagency HIV Study [WIHS]), followed since 1984 and 1994, respectively.

METHODS

Adjusted odds or hazards ratios for incident respiratory infections or non-infectious respiratory diagnoses, respectively, in HIV-infected compared to HIV-uninfected individuals in both the pre-HAART (MACS only) and HAART eras; and adjusted Cox proportional hazard ratios for mortality in HIV-infected persons with lung disease during the HAART era.

RESULTS

Compared to HIV-uninfected participants, HIV-infected individuals had more incident respiratory infections both pre-HAART (MACS, odds ratio [adjusted-OR], 2.4; 95% confidence interval [CI], 2.2-2.7; p<0.001) and after HAART availability (MACS, adjusted-OR, 1.5; 95%CI 1.3-1.7; p<0.001; WIHS adjusted-OR, 2.2; 95%CI 1.8-2.7; p<0.001). Chronic obstructive pulmonary disease was more common in MACS HIV-infected vs. HIV-uninfected participants pre-HAART (hazard ratio [adjusted-HR] 2.9; 95%CI, 1.02-8.4; p = 0.046). After HAART availability, non-infectious lung diseases were not significantly more common in HIV-infected participants in either MACS or WIHS participants. HIV-infected participants in the HAART era with respiratory infections had an increased risk of death compared to those without infections (MACS adjusted-HR, 1.5; 95%CI, 1.3-1.7; p<0.001; WIHS adjusted-HR, 1.9; 95%CI, 1.5-2.4; p<0.001).

CONCLUSION

HIV infection remained a significant risk for infectious respiratory diseases after the introduction of HAART, and infectious respiratory diseases were associated with an increased risk of mortality.

Advances in adult asthma diagnosis and treatment in 2012: potential therapeutics and gene-environment interactions

In the Journal of Allergy and Clinical Immunology in 2012, research reports related to asthma in adults clustered around mechanisms of disease, with a special focus on their potential for informing new therapies. There was also consideration of the effect of the environment on health from pollution, climate change, and epigenetic influences, underlining the importance of understanding gene-environment interactions in the pathogenesis of asthma and response to treatment.

Pathogenesis of HIV and the lung

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