COPD is associated with production of autoantibodies to a broad spectrum of self-antigens, correlative with disease phenotype

Imbalanced and Unchecked: The Role of Metal Dyshomeostasis in Driving COPD Progression

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory condition characterized by persistent inflammation and oxidative stress, which ultimately leads to progressive restriction of airflow. Extensive research findings have cogently suggested that the dysregulation of essential transition metal ions, notably iron, copper, and zinc, stands as a critical nexus in the perpetuation of inflammatory processes and oxidative damage within the lungs of COPD patients. Unraveling the intricate interplay between metal homeostasis, oxidative stress, and inflammatory signaling is of paramount importance in unraveling the intricacies of COPD pathogenesis. This comprehensive review aims to examine the current literature on the sources, regulation, and mechanisms by which metal dyshomeostasis contributes to COPD progression. We specifically focus on iron, copper, and zinc, given their well-characterized roles in orchestrating cytokine production, immune cell function, antioxidant depletion, and matrix remodeling. Despite the limited number of clinical trials investigating metal modulation in COPD, the advent of emerging methodologies tailored to monitor metal fluxes and gauge responses to chelation and supplementation hold great promise in unlocking the potential of metal-based interventions. We conclude that targeted restoration of metal homeostasis represents a promising frontier for ameliorating pathological processes driving COPD progression.

Does Rheumatoid Arthritis Increase the Risk of COPD?: A Nationwide Retrospective Cohort Study

BACKGROUND

Most reports of pulmonary manifestations in rheumatoid arthritis (RA) have been related to interstitial lung diseases. RA and COPD are both chronic inflammatory systemic diseases.

RESEARCH QUESTION

Does RA increase the risk of developing COPD? Is there a difference between seropositive and seronegative RA in the risk of COPD?

STUDY DESIGN AND METHODS

Using the Korean National Health Insurance Database, we screened individuals diagnosed with RA between 2010 and 2017. We identified 46,030 patients with RA (32,608 with seropositive RA and 13,422 with seronegative RA) and 230,150 matched control individuals; we monitored them until December 2019. We used multivariate Cox proportional hazard models to estimate the adjusted hazard ratio (aHR) of risk factors for the development of COPD.

RESULTS

The incidence of COPD among patients with RA was 5.04 per 1,000 person-years; it was 2.23 per 1,000 person-years in the control group. Patients with RA showed a higher risk of developing COPD (aHR, 2.11; 95% CI, 1.96-2.28) compared with the control group. Although both seropositive RA and seronegative RA were associated with an increased risk of COPD, patients with seropositive RA had a higher risk for the development of COPD (aHR, 1.26; 95% CI, 1.09-1.46) than patients with seronegative RA. In the subgroup analyses, smoking history did not demonstrate significant interactions between RA and COPD development.

INTERPRETATION

RA was shown to be associated with an increased risk of COPD development, augmented by seropositivity. Physicians should monitor respiratory symptoms and pulmonary function carefully in patients with RA.

The association between chronic obstructive pulmonary disease and autoimmune diseases: a bidirectional Mendelian randomization study

Objective

Observational studies have reported that chronic obstructive pulmonary disease (COPD) is often accompanied by autoimmune diseases, but the causal relationships between them remain uncertain. In this Mendelian study, we aimed to investigate the potential causal relationship between COPD and four common autoimmune diseases.

Methods

We conducted an analysis of summary data on COPD and autoimmune disease using publicly available genome-wide association studies (GWAS) summary data. We initially employed the inverse- variance weighted method as the primary approach to establish the causal impact of COPD on autoimmune diseases in the sample and conducted additional sensitivity analyses to examine the robustness of the results. Subsequently, we performed reverse Mendelian randomization (MR) analyses for the four autoimmune diseases. Finally, the potential for bidirectional causal relationships was assessed.

Results

Our MR analysis revealed no significant causal relationship between COPD and any of the studied autoimmune diseases. However, reverse MR results indicated a significant association between rheumatoid arthritis (RA), osteoarthritis (OA) and the risk of developing COPD, with respective odds ratios (OR) of 377.313 (95% CI, 6.625-21487.932, P = 0.004) for RA and 11.097 (95% CI, 1.583-77.796, P = 0.015) for OA. Sensitivity analyses confirmed the robustness of the results.

Conclusion

Our findings support a potential causal relationship between autoimmune diseases and COPD, highlighting the importance of considering comorbidities in clinical management of COPD.

Lymphatic Dysfunction Models an Autoimmune Emphysema Phenotype of Chronic Obstructive Pulmonary Disease

Chronic Obstructive Pulmonary Disease (COPD) is a heterogeneous disease that is characterized by many clinical phenotypes. One such phenotype of COPD is defined by emphysema, pathogenic lung tertiary lymphoid organs (TLOs), and autoantibody production. We have previously shown that lymphatic dysfunction can cause lung TLO formation and lung injury in mice. We now sought to uncover whether underlying lymphatic dysfunction may be a driver of lung injury in cigarette smoke (CS)-induced COPD. We found that lung TLOs in mice with lymphatic dysfunction produce autoantibodies and are associated with a lymphatic endothelial cell subtype that expresses antigen presentation genes. Mice with underlying lymphatic dysfunction develop increased emphysema after CS exposure, with increased size and activation of TLOs. CS further increased autoantibody production in mice with lymphatic dysfunction. B-cell blockade prevented TLO formation and decreased lung injury after CS in mice with lymphatic dysfunction. Using tissue from human COPD patients, we also found evidence of a lymphatic gene signature that was specific to patients with emphysema and prominent TLOs compared to COPD patients without emphysema. Taken together, these data suggest that lymphatic dysfunction may underlie lung injury in a subset of COPD patients with an autoimmune emphysema phenotype.

Causal association of rheumatoid arthritis with obstructive lung disease: Evidence from Mendelian randomization study

BACKGROUND

Observational studies have found an association between rheumatoid arthritis (RA) and risk of obstructive lung disease (ORDs). However, whether RA plays a role in ORDs development remains unclear.

OBJECTIVES

This study aimed to explore the causal association of RA with ORDs.

METHODS

Both univariable and multivariable Mendelian randomization (MR) analyses were employed. Summary statistics for RA were obtained from the genome-wide association study (GWAS) meta-analysis, and the GWAS data source of ORDs, including the chronic obstructive pulmonary disease (COPD) and asthma, was accessed from the FinnGen Biobank. Causal Analysis Using Summary Effect Estimates (CAUSE) method was used to improve statistical power. multivariable and two-step mediation MR was applied to calculate the independent and mediated effects.

RESULTS

The causal estimates by univariable and CAUSE results indicated genetic predisposition to RA had an effect on the increased risk of asthma/COPD (A/C) (ORCAUSE = 1.03; 95% CI: 1.02-1.04), COPD/asthma related infections (ACI) (ORCAUSE = 1.02; 95% CI: 1.01-1.03) and COPD/asthma related pneumonia or pneumonia derived septicemia (ACP) (ORCAUSE = 1.02; 95% CI: 1.01-1.03). Genetic predisposition to RA was significantly associated with early onset COPD (ORCAUSE = 1.02; 95% CI: 1.01-1.03) and asthma (ORCAUSE = 1.02; 95% CI: 1.01-1.03) risk and suggestively associated with non-allergic asthma (nAA) risk. After adjustment for confounders, independent causal effects remained for the associations of RA with risk of A/C, ACI, and ACP, as well as COPD, early-onset COPD, and asthma [total, nAA and allergic asthma (AA)] risk. Mediation analyses revealed no potential mediator.

CONCLUSION

This study indicates a causal effect of increased genetic predisposition to RA on an increased risk of ORDs, including COPD and asthma, especially early-onset COPD and nAA, and on asthma/COPD related infections, pneumonia or pneumonia derived septicemia.

Cystic fibrosis autoantibody signatures associate with Staphylococcus aureus lung infection or cystic fibrosis-related diabetes

Introduction

While cystic fibrosis (CF) lung disease is characterized by persistent inflammation and infections and chronic inflammatory diseases are often accompanied by autoimmunity, autoimmune reactivity in CF has not been studied in depth.

Methods

In this work we undertook an unbiased approach to explore the systemic autoantibody repertoire in CF using autoantibody microarrays.

Results and discussion

Our results show higher levels of several new autoantibodies in the blood of people with CF (PwCF) compared to control subjects. Some of these are IgA autoantibodies targeting neutrophil components or autoantigens linked to neutrophil-mediated tissue damage in CF. We also found that people with CF with higher systemic IgM autoantibody levels have lower prevalence of S. aureus infection. On the other hand, IgM autoantibody levels in S. aureus-infected PwCF correlate with lung disease severity. Diabetic PwCF have significantly higher levels of IgA autoantibodies in their circulation compared to nondiabetic PwCF and several of their IgM autoantibodies associate with worse lung disease. In contrast, in nondiabetic PwCF blood levels of IgA autoantibodies correlate with lung disease. We have also identified other autoantibodies in CF that associate with P. aeruginosa airway infection. In summary, we have identified several new autoantibodies and associations of autoantibody signatures with specific clinical features in CF.

Interstitial lung abnormality in COPD is associated with higher prevalence of antinuclear antibody

OBJECT

To investigate whether the prevalence of positive ANA was increased in COPD with interstitial lung abnormality (ILA).

METHODS

Patients with COPD from 1 September, 2019 to 31 August, 2022 were consecutively enrolled in this cross-sectional study. The characteristics, PFTs, visual assessment of ILA and emphysema on chest CT, and tests for ANA and CRP were recorded for analysis.

RESULTS

In the study period, 100 patients with COPD were enrolled, with 90 (90.0%) males, aging 69.4 ± 8.3 years. ILA was present in 42% (n = 42) of the patients, with subpleural non-fibrotic ILA being the most common pattern. In patients with ILA, the prevalence of positive ANA was higher (45.2%) as compared to those without ILA (13.3%); between whom the difference in DLCO was also significant. In patients with positive ANA, the scores of ILA were higher, while FEV1, DLCO, DLCO % predicted, FVC, total lung capacity (TLC), and TLC % predicted were significantly lower, as compared to those with negative ANA.

CONCLUSION

The presence of ILA in patients with COPD was associated with a higher prevalence of positive ANA. Patients with positive ANA tended to have lower FEV1, DLCO and lung volume.

Contribution of adaptive immunity to human COPD and experimental models of emphysema

The pathophysiology of chronic obstructive pulmonary disease (COPD) and the undisputed role of innate immune cells in this condition have dominated the field in the basic research arena for many years. Recently, however, compelling data suggesting that adaptive immune cells may also contribute to the progressive nature of lung destruction associated with COPD in smokers have gained considerable attention. The histopathological changes in the lungs of smokers can be limited to the large or small airways, but alveolar loss leading to emphysema, which occurs in some individuals, remains its most significant and irreversible outcome. Critically, however, the question of why emphysema progresses in a subset of former smokers remained a mystery for many years. The recognition of activated and organized tertiary T- and B-lymphoid aggregates in emphysematous lungs provided the first clue that adaptive immune cells may play a crucial role in COPD pathophysiology. Based on these findings from human translational studies, experimental animal models of emphysema were used to determine the mechanisms through which smoke exposure initiates and orchestrates adaptive autoreactive inflammation in the lungs. These models have revealed that T helper (Th)1 and Th17 subsets promote a positive feedback loop that activates innate immune cells, confirming their role in emphysema pathogenesis. Results from genetic studies and immune-based discoveries have further provided strong evidence for autoimmunity induction in smokers with emphysema. These new findings offer a novel opportunity to explore the mechanisms underlying the inflammatory landscape in the COPD lung and offer insights for development of precision-based treatment to halt lung destruction.

Airway microbiome-immune crosstalk in chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) has significantly contributed to global mortality, with three million deaths reported annually. This impact is expected to increase over the next 40 years, with approximately 5 million people predicted to succumb to COPD-related deaths annually. Immune mechanisms driving disease progression have not been fully elucidated. Airway microbiota have been implicated. However, it is still unclear how changes in the airway microbiome drive persistent immune activation and consequent lung damage. Mechanisms mediating microbiome-immune crosstalk in the airways remain unclear. In this review, we examine how dysbiosis mediates airway inflammation in COPD. We give a detailed account of how airway commensal bacteria interact with the mucosal innate and adaptive immune system to regulate immune responses in healthy or diseased airways. Immune-phenotyping airway microbiota could advance COPD immunotherapeutics and identify key open questions that future research must address to further such translation.

Diagnostic value of tumor-associated autoantibodies panel in combination with traditional tumor markers for lung cancer

Introduction

The diagnostic value of 7 tumor-associated autoantibodies (AABs) including p53, PGP9.5, SOX2, GAGE7, GBU4-5, MEGEA1, and CAGE for the detection of lung cancer has shown inconsistency in several studies. This study aimed to confirm the diagnostic value of 7AABs and to explore whether the diagnostic value would be improved by combining them with 7 traditional tumor-associated antigens (CEA, NSE, CA125, SCC, CA15-3, pro-GRP, and CYFRA21-1) in clinical settings.

Methods

The plasma levels of 7-AABs were detected by enzyme-linked immunosorbent assay (ELISA) in 533 lung cancer cases and 454 controls. The 7 tumor antigens (7-TAs) were measured by Electrochemiluminescence immunoassay with Cobas 6000 (Roche, Basel, Switzerland).

Results

The positive rate of 7-AABs in the lung cancer group (64.00%) was significantly higher than that of healthy controls (47.90%). The 7-AABs panel was able to discriminate lung cancer from controls with a specificity of 51.50%. After combining the 7-AABs with 7-TAs, the sensitivity showed a significantly enhancement compared with 7AABs panel alone (92.09% vs 63.21%). In patients with resectable lung cancer, the combination of 7-AABs and 7-TAs improved the sensitivity from 63.52% to 97.42.

Discussion

In conclusion, our study found that the diagnostic value of 7-AABs was enhanced when combined with 7-TAs. This combined panel could be used as promising biomarker to detect resectable lung cancer in clinical settings.

Autoantibody profile in sarcoidosis, analysis from the GRADS sarcoidosis cohort

BACKGROUND

Sarcoidosis, a multi-systemic granulomatous disease, is a predominantly T-cell disease but evidence for a role for humoral immunity in disease pathogenesis is growing. Utilizing samples from the Genomic Research in Alpha-1 anti-trypsin Deficiency and Sarcoidosis (GRADS) study, we examined the prevalence of autoantibodies in sarcoidosis patients with pulmonary-only and extra-pulmonary organ involvement compared to normal controls.

STUDY DESIGN AND METHODS

We analyzed serum samples from sarcoidosis patients who participated in the GRADS study utilizing an autoantigen microarray platform for both IgM and IgG antibodies. The cohort included sarcoidosis patients with pulmonary-only disease (POS, n = 106), sarcoidosis patients with extra-pulmonary disease (EPS, n = 120) and a normal control cohort (NC, n = 101). Organ involvement was assessed following a standardized format across all GRADS participating centers.

RESULTS

Sarcoidosis patients overall had increased levels of IgM and IgG autoantibodies compared to normal controls. In addition, several autoantibodies were elevated in the POS and EPS cohorts compared to the NC cohort. Differences in autoantibody levels were also noted between the POS and the EPS cohorts. When comparing organ involvement with sarcoidosis, bone, spleen and ear, nose and throat involvement had higher IgM expression than other organs.

CONCLUSION

Sarcoidosis patients have elevated IgM and IgG autoantibody levels compared to normal controls. In addition, individuals with pulmonary as well as additional organ involvement had higher IgM expression. Further research is needed focusing on specific organ-autoantibody pairs and role of autoantibodies in disease pathogenesis.

Risk of Ankylosing Spondylitis in Patients With Endometriosis: A Population-Based Retrospective Cohort Study

Objectives

Previous research has shown a possible relationship between endometriosis and autoimmune diseases. However, the relationship between endometriosis and ankylosing spondylitis (AS) is lacking. Therefore, we intended to find possible associations between endometriosis and AS using ICD-9 coding data in a population-based retrospective cohort study in Taiwan.

Method

Data for this retrospective cohort study were collected from the Taiwan National Health Insurance Research Database (NHIRD) between 2000–2012. We collected 13,145 patients with endometriosis and a 78,870 non-endometriosis comparison cohort. Diagnoses of endometriosis and AS were defined by the International Classification of Diseases-9 (ICD-9-CM) code for at least 3 outpatients or 1 hospitalization. Propensity score matching by comorbidities, corticosteroids, and non-steroidal anti-inflammatory drugs (NSAIDs) usage were done for baseline comparability. Cox proportional hazard models were used to evaluate crude and adjusted hazard ratios.

Results

The cumulative incidence of AS was higher in patients with endometriosis compared to the non-endometriosis comparison cohort (log-rank test, p = 0.015). The adjusted hazard ratio (aHR) of incidental AS in patients with endometriosis was 1.61 (95% CI = 1.11 to 2.35) in comparison to the non-endometriosis comparison cohort. An increased risk of AS was also observed in subjects with major depressive disorder (aHR = 5.05, 95% CI = 1.85 to 13.78). Stratified analyses of age subgroups showed consistent results. NSAID users had a lower risk of AS than NSAID non-users (aHR 4.57 vs 1.35, p for interaction = 0.031).

Conclusions

In this retrospective population-based cohort study, we found a higher risk of AS in patients with endometriosis. We suggest that clinicians should pay attention to the occurrence of AS in patients with endometriosis.

Airway Disease in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a common condition affecting approximately 1% of the general population. RA is a multisystem disorder that causes progressive articular destruction through synovial inflammation. One of the most common extraarticular manifestations of RA is pulmonary involvement, where all compartments of the pulmonary system can be impacted (e.g., pulmonary vasculature, pleura, parenchyma, and the airways). Although it has been known for decades that a portion of patients with RA develop interstitial lung disease, and recent advancements in understanding the genetic risk and treatment for RA-interstitial lung disease have drawn attention, more recent data have begun to highlight the significance of airway disease in patients with RA. Yet, little is known about the underlying pathogenesis, clinical impact, or optimal treatment strategies for airway disease in RA. This review will focus on airway disease involvement in patients with RA by highlighting areas of clinical inquiry for pulmonologists and rheumatologists and discuss areas for future research. Finally, we discuss a potential screening algorithm for providers when approaching patients with RA with respiratory complaints.

Autoantibodies are present in the bronchoalveolar lavage but not circulation in patients with fibrotic interstitial lung disease

Background

Fibrotic interstitial lung disease (fILD) has previously been associated with the presence of autoantibody. While studies have focused on systemic autoimmunity, the role of local autoantibodies in the airways remains unknown. We therefore extensively characterised the airway and peripheral autoantibody profiles in patients with fILD, and assessed association with disease severity and outcome.

Methods

Bronchoalveolar lavage (BAL) fluid was collected from a cohort of fILD patients and total BAL antibody concentrations were quantified. An autoantigen microarray was used to measure IgG and IgA autoantibodies against 122 autoantigens in BAL from 40 idiopathic pulmonary fibrosis (IPF), 20 chronic hypersensitivity pneumonitis (CHP), 20 connective tissue disease-associated ILD (CTD-ILD) patients and 20 controls.

Results

A subset of patients with fILD but not healthy controls had a local autoimmune signature in their BAL that was not present systemically, regardless of disease. The proportion of patients with IPF with a local autoantibody signature was comparable to that of CTD-ILD, which has a known autoimmune pathology, identifying a potentially novel subset of patients. The presence of an airway autoimmune signature was not associated with reduced survival probability or changes in lung function in the cohort as a whole. Patients with IPF had increased BAL total IgA and IgG₁ while subjects with CHP had increased BAL IgA, IgG₁ and IgG₄. In patients with CHP, increased BAL total IgA was associated with reduced survival probability.

Conclusion

Airway autoantibodies that are not present systemically identify a group of patients with fILD and the mechanisms by which these autoantibodies contribute to disease requires further investigation.

Autoantibodies are present in the bronchoalveolar lavage but not circulation in patients with fibrotic interstitial lung diseasehttps://bit.ly/3CNvKjj

Pro-inflammatory IgG1 N-glycan signature correlates with primary graft dysfunction onset in COPD patients

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide. The pathogenesis of COPD is complex; however, recent studies suggest autoimmune changes, characterized by the presence of autoantibodies to elastin and collagen, may contribute to disease status. COPD patients make up approximately 30% of all lung transplants (LTx) annually, however, little is known regarding the relationship between COPD-related autoantibodies and LTx outcomes. We hypothesized that COPD patients that undergo LTx and develop primary graft dysfunction (PGD) have altered circulating autoantibody levels and phenotypic changes as compared those COPD-LTx recipients that do not develop PGD. We measured total immunoglobulin and circulating elastin and collagen autoantibody levels in a cohort of COPD lung transplant recipients pre- and post-LTx. No significant differences were seen in total, elastin, or collagen IgM, IgG, IgG1, IgG2, IgG3, and IgG4 antibodies between PGD+ and PGD- recipients. Antibody function can be greatly altered by glycosylation changes to the antibody Fc region and recent studies have reported altered IgG glycosylation profiles in COPD patients. We therefore utilized a novel mass spectrometry-based multiplexed N-glycoprotein imaging approach and measured changes in IgG-specific antibody N-glycan structures. COPD-LTx recipients who developed PGD had significantly increased IgG1 N-glycan signatures as compared PGD- recipients. In conclusion, we show that immunoglobulin and autoreactive antibody levels are not significantly different in COPD LTx recipients that develop PGD. However, using a novel IgG glycomic analysis we were able to demonstrate multiple significant increases in IgG1 specific N-glycan signatures that were predictive of PGD development. Taken together, these data represent a potential novel method for identifying COPD patients at risk for PGD development and may provide clues to mechanisms by which antibody N-glycan signatures could contribute to antibody-mediated PGD pathogenesis.

Musculoskeletal Disorders in Chronic Obstructive Airway Diseases: A Neglected Clinical Entity

Chronic obstructive pulmonary disease (COPD) is a lung disease that can affect various extra-pulmonary organs; one being the musculoskeletal system. Skeletal muscle dysfunction and osteoporosis are two important musculoskeletal disorders that have an impact on the quality of life in COPD patients in terms of morbidity and mortality. Treatment related adverse effects of COPD such as steroid-induced myopathy and osteoporosis are well recognised. Other comorbidities like sarcopenia, cardiovascular disease, metabolic diseases (diabetes mellitus, obesity, and thyroid diseases), chronic kidney disease, sleep apnoea, anaemia, and depression are also noted, which can contribute to impaired health status, increased healthcare utilisation, and even mortality. As well, it has been shown that autoimmunity and autoimmune rheumatic diseases (AIRDs) are linked to COPD. In this mini-review, we intend to give an overview of different types of musculoskeletal disorders associated with COPD.

In Vitro Models for Studying Respiratory Host-Pathogen Interactions

Respiratory diseases and lower respiratory tract infections are among the leading cause of death worldwide and, especially given the recent severe acute respiratory syndrome coronavirus-2 pandemic, are of high and prevalent socio-economic importance. In vitro models, which accurately represent the lung microenvironment, are of increasing significance given the ethical concerns around animal work and the lack of translation to human disease, as well as the lengthy time to market and the attrition rates associated with clinical trials. This review gives an overview of the biological and immunological components involved in regulating the respiratory epithelium system in health, disease, and infection. The evolution from 2D to 3D cell biology and to more advanced technological integrated models for studying respiratory host-pathogen interactions are reviewed and provide a reference point for understanding the in vitro modeling requirements. Finally, the current limitations and future perspectives for advancing this field are presented.

Differential expression of sputum and serum autoantibodies in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a complex and progressive respiratory disease. Autoimmune processes have been hypothesized to contribute to disease progression; however, the presence of autoantibodies in the serum has been variable. Given that COPD is a lung disease, we sought to investigate whether autoantibodies in sputum supernatant would better define pulmonary autoimmune processes. Matched sputum and serum samples were obtained from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study and at the Guangzhou Institute of Respiratory Health (GIRH). Samples were collected from patients with varying severity of COPD, asymptomatic smokers, and healthy control subjects. IgG and IgM autoantibodies were detected in sputum and serum of all subjects in both cohorts using a broad-spectrum autoantigen array. No differences were observed in sputum autoantibodies between COPD and asymptomatic smokers in either cohort. In contrast, 16% of detectable sputum IgG autoantibodies were decreased in subjects with COPD compared to healthy controls in the ADEPT cohort. Compared to asymptomatic smokers, approximately 13% of detectable serum IgG and 40% of detectable serum IgM autoantibodies were differentially expressed in GIRH COPD subjects. Of the differentially expressed specificities, anti-nuclear autoantibodies were predominately decreased. A weak correlation between increased serum IgM anti-tissue autoantibodies and a measure of airspace enlargement was observed. The differential expression of specificities varied between the cohorts. In closing, using a comprehensive autoantibody array, we demonstrate that autoantibodies are present in subjects with COPD, asymptomatic smokers, and healthy controls. Cohorts displayed high levels of heterogeneity, precluding the utilization of autoantibodies for diagnostic purposes.

Vascular Ehlers-Danlos syndrome (vEDS): CT and histologic findings of pleural and lung parenchymal damage

OBJECTIVES

To describe CT features of lung involvement in patients with vascular Ehlers-Danlos syndrome (vEDS), a rare genetic condition caused by pathogenic variants within the COL3A1 gene, characterized by recurrent arterial, digestive, and pulmonary events.

MATERIAL AND METHODS

All consecutive vEDS patients referred to the national tertiary referral center for vEDS, between 2004 and 2016, were included. Chest CT scans obtained during the initial vascular work-up were reviewed retrospectively by two chest radiologists for lung involvement. Five surgical samples underwent histologic examination.

RESULTS

Among 136 enrolled patients (83 women, 53 men; mean age 37 years) with molecularly confirmed vEDS, 24 (17.6%) had a history of respiratory events: 17 with pneumothorax, 4 with hemothorax, and 3 with hemoptysis that required thoracic surgery in 11. CT scans detected lung parenchymal abnormalities in 78 (57.3%) patients: emphysema (mostly centrilobular and paraseptal) in 44 (32.3%), comparable for smokers and non-smokers; clusters of calcified small pulmonary nodules in 9 (6.6%); and cavitated nodules in 4 (2.9%). Histologic examination of surgical samples found arterial abnormalities, emphysema with alveolar ruptures in 3, accompanied by diffuse hemorrhage and increased hemosiderin resorption.

CONCLUSION

In vEDS patients, identification of lung parenchymal abnormalities is common on CT. The most frequently observed CT finding was emphysema suggesting alveolar wall rupture which might facilitate the diagnostic screening of the disease in asymptomatic carriers of a genetic COL3A1 gene mutation. The prognostic value and evolution of these parenchymal abnormalities remain to be evaluated.

KEY POINTS

• Patients with vEDS can have lung parenchymal changes on top of or next to thoracal vascular abnormalities and that these changes can be present in asymptomatic cases. • The presence of these parenchymal changes is associated with a slightly higher incidence of respiratory events (although not statistically significant). • Identification of the described CT pattern by radiologists and chest physicians may facilitate diagnostic screening.

Omega-3 fatty acid intake suppresses induction of diverse autoantibody repertoire by crystalline silica in lupus-prone mice

Inhalation of crystalline silica (cSiO2) in the workplace is etiologically linked to lupus and other autoimmune diseases. Exposing lupus-prone NZBWF1 mice to respirable cSiO2 unleashes a vicious cycle of inflammation and cell death in the lung that triggers interferon-regulated gene expression, ectopic lymphoid structure (ELS) development, elevation of local and systemic autoantibodies (AAbs), and glomerulonephritis. However, cSiO2-induced inflammation and onset of autoimmunity can be prevented by inclusion of the ω-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) into the diet of these mice. Since cSiO2 both causes cell death and interferes with efferocytosis, secondary necrosis of residual cell corpses might provide a rich and varied autoantigen (AAg) source in the lung. While it is known that the particle induces anti-nuclear and anti-dsDNA AAbs in NZBWF1 mice, the full extent of the cSiO2-induced AAb response relative to specificity and isotype is not yet understood. The purpose of this study was to test the hypotheses that cSiO2 exposure induces a wide spectrum of AAbs in the pulmonary and systemic compartments, and that dietary DHA intervention prevents these changes. Archived tissue fluid samples were obtained from a prior study in which NZBWF1 mice were fed purified isocaloric diets containing no DHA (control) or DHA corresponding calorically to human doses of 2 and 5 g/day. Mice were intranasally instilled with 1 mg cSiO2 or saline vehicle weekly for 4 weeks, then groups euthanized 1, 5, 9, or 13 weeks post-instillation (PI) of the last cSiO2 dose. Bronchoalveolar lavage fluid (BALF) and plasma from each time point were subjected to AAb profiling using a microarray containing 122 AAgs. cSiO2 triggered robust IgG and IgM AAb responses against lupus-associated AAgs, including DNA, histones, ribonucleoprotein, Smith antigen, Ro/SSA, La/SSB, and complement as early as 1 week PI in BALF and 5 weeks PI in plasma, peaking at 9 and 13 weeks PI, respectively. Importantly, cSiO2 also induced AAbs to AAgs associated with rheumatoid arthritis (collagen II, fibrinogen IV, fibrinogen S, fibronectin, and vimentin), Sjögren's syndrome (α-fodrin), systemic sclerosis (topoisomerase I), vasculitis (MPO and PR3), myositis (Mi-2, TIF1-γ, MDA5), autoimmune hepatitis (LC-1), and celiac disease (TTG). cSiO2 elicited comparable but more modest IgA AAb responses in BALF and plasma. cSiO2-induced AAb production was strongly associated with time dependent inflammatory/autoimmune gene expression, ELS development, and glomerulonephritis. AAb responses were dose-dependently suppressed by DHA supplementation and negatively correlated with the ω-3 index, an erythrocyte biomarker of ω-3 content in tissue phospholipids. Taken together, these findings suggest that cSiO2 exposure elicits a diverse multi-isotype repertoire of AAbs, many of which have been reported in individuals with lupus and other autoimmune diseases. Furthermore, induction of this broad AAb spectrum could be impeded by increasing ω-3 tissue content via dietary DHA supplementation.

HLA-DRB1 Alleles are Associated With COPD in a Latin American Admixed Population

INTRODUCTION

While the molecular mechanisms of COPD pathogenesis remain obscure, there is mounting evidence supporting a key role for autoimmunity. Although human leukocyte antigens (HLA) alleles have been repeatedly associated with autoimmune processes, the relation between HLA and COPD remains largely unexplored, especially in Latin American (LA) populations. Consequently, this study aimed to investigate the presence of HLA class I and II alleles in COPD patients and healthy controls in a LA population with admixed ancestry.

METHODS

COPD patients (n=214) and age-matched controls (n=193) were genotyped using the Illumina Infinium Global Screening Array. The classic HLA alleles were imputed using HLA Genotype Imputation with Attribute Bagging (HIBAG) and the Hispanic reference panel. Finally, the distribution of HLA-DRB1 alleles was reexamined in 510 randomly recruited unrelated volunteers.

RESULTS

CODP patients showed a higher HLA-DRB1*01:02 allele frequency (6.54%) than healthy controls (3.27%, p=0.04, OR=2.07). HLA-DRB1*01:02 was also significantly associated with FEV₁ (p=0.04) and oxygen saturation (p=0.02), and the FEV₁/FVC ratio was higher in HLA-DRB1*15:01-positive patients (p=9×10^-3).

CONCLUSION

We report an association among HLA-DRB1 alleles, COPD risk and pulmonary function parameters for the first time in Latin Americans. Since HLA-DRB1 genetic variability relates to the individual autoimmune response, these results support a role of autoimmunity in the pathogenesis of COPD.

Dissociation between airway and systemic autoantibody responses in chronic obstructive pulmonary disease

Background

Autoimmune processes have been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the relationship between airway and systemic autoantibody responses remains unclear. The aim of this study was to elucidate this relationship in patients with stable COPD by investigating the correlation patterns between sputum and serum autoantibodies.

Methods

In this cross-sectional study, sputum supernatant and serum obtained from 47 patients with stable COPD were assayed for the presence of IgG antibodies against ten autoantigens: Smith antigen (Sm), ribosomal phosphoprotein P0 (P0), Ro/Sjögren syndrome type A antigen (Ro/SSA), La/Sjögren syndrome type B antigen (La/SSB), DNA topoisomerase I (Scl-70), histidyl-tRNA synthetase (Jo-1), U1 small nuclear ribonucleoprotein (U1-SnRNP), thyroid peroxidase (TPO), proteinase-3 (PR3), and myeloperoxidase (MPO). A second cohort of 55 stable COPD patients was recruited for validation, and a group of 59 non-COPD controls and a group of 20 connective-tissue disease-associated interstitial lung disease (CTD-ILD) patients were also recruited for comparison. Hierarchical clustering and network analysis were used to evaluate the correlation patterns between sputum and serum autoantibody profiles.

Results

Both hierarchical clustering and network analysis showed that sputum and serum autoantibody profiles were distinct in either analytic COPD cohort or validation cohort. In contrast, the autoantibodies of the two compartments in non-COPD controls and CTD-ILD patients were inadequately distinguished using either hierarchical clustering or network analysis. Many autoantibodies in the sputum were found to have significant correlations with lung function, symptom score and frequency of prior exacerbations in COPD patients, but the antibodies in the serum were not.

Conclusions

We observed a dissociation between sputum autoantibodies and serum autoantibodies in patients with stable COPD, suggesting that airway and systemic immune status may play very different roles in the disease. Sputum autoantibodies are more clinically relevant than serum autoantibodies. Focusing on airway autoimmunity may help improve understanding of the immunopathological mechanism of COPD.

Sputum and serum autoantibody profiles and their clinical correlation patterns in COPD patients with and without eosinophilic airway inflammation

Background

Autoimmunity plays a role in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the autoantibody responses and their clinical correlation patterns in COPD patients with and without airway eosinophilic inflammation are unknown. The aim of this study was to compare the autoantibody profiles and their clinical associations in stable COPD patients, stratified by airway inflammatory phenotypes.

Methods

Matched sputum and serum, obtained from 62 stable COPD patients and 14 age-matched controls, were assayed for the presence of IgG and IgM antibodies against 13 autoantigens using protein array. A sputum eosinophil count ≥3% was used as cut-off value to stratify COPD patients into eosinophilic and non-eosinophilic groups. Correlation network analysis was used to evaluate the correlation patterns among autoantibody and clinical variables in each group.

Results

There were no significant differences of clinical parameters and autoantibody levels between the two COPD groups. In non-eosinophilic COPD, sputum anti-CytochromeC_IgG and anti-Aggrecan_IgM were significantly higher than those in healthy controls, and prior exacerbation was positively associated with lung function and sputum anti-Collagen-IV_IgG. While in eosinophilic COPD, sputum/serum anti-heat shock protein (HSP)47_IgG, serum anti-HSP70_IgG and serum anti-Amyloid-beta_IgG were significantly lower than those in healthy controls, and no significant correlation between prior exacerbations and lung function was found. Differences were also observed in network hubs, with the network for non-eosinophilic COPD possessing 9 hubs comprising two lung function parameters and seven autoantibodies, compared with eosinophilic COPD possessing 12 hubs all comprising autoantibodies.

Conclusions

Autoantibody responses were heterogeneous and differentially correlated with the exacerbation risk and other clinical parameters in COPD patients of different inflammatory phenotypes. These findings provide useful insight into the need for personalized management for preventing COPD exacerbations.

Glucose-Regulated Protein 78 Autoantibodies Are Associated with Carotid Atherosclerosis in Chronic Obstructive Pulmonary Disease Patients

Atherosclerosis prevalence is increased in chronic obstructive pulmonary disease (COPD) patients, independent of other risk factors. The etiology of the excess vascular disease in COPD is unknown, although it is presumably related to an underlying (if cryptic) systemic immune response. Autoantibodies with specificity for glucose-regulated protein 78 (GRP78), a multifunctional component of the unfolded protein response, are common in COPD patients and linked to comorbidities of this lung disease. We hypothesized anti-GRP78 autoreactivity might also be a risk factor for atherosclerosis in COPD patients. Carotid intima-medial thickness (cIMT) was measured in 144 current and former smokers by ultrasound. Concentrations of circulating IgG autoantibodies against full-length GRP78, determined by ELISA, were greater among subjects with abnormally increased cIMT (p <, 0.01). Plasma levels of autoantibodies against a singular GRP78 peptide segment, amino acids 246–260 (anti-GRP78_{aa 246–260}), were even more highly correlated with cIMT, especially among males with greater than or equal to moderate COPD (r_s = 0.62, p = 0.001). Anti-GRP78_{aa 246–260} concentrations were independent of CRP, IL-6, and TNF-α levels. GRP78 autoantigen expression was upregulated among human aortic endothelial cells (HAECs) stressed by incubation with tunicamycin (an unfolded protein response inducer) or exposure to culture media flow disturbances. Autoantibodies against GRP78_{aa 246–260}, isolated from patient plasma by immunoprecipitation, induced HAEC production of proatherosclerotic mediators, including IL-8. In conclusion, anti-GRP78 autoantibodies are highly associated with carotid atherosclerosis in COPD patients and exert atherogenic effects on HAECs. These data implicate Ag-specific autoimmunity in the pathogenesis of atherosclerosis among COPD patients and raise possibilities that directed autoantibody reduction might ameliorate vascular disease in this high-risk population.

Pre-existing self-reactive IgA antibodies associated with primary graft dysfunction after lung transplantation

BACKGROUND

Primary graft Dysfunction (PGD) results in significant mortality and morbidity after lung transplantation (LT). The objective of this study was to evaluate if pre-existing antibodies to self-antigens in sera of LT recipients are associated with PGD.

METHODS

The serum profiles of IgG and IgA autoantibodies were analyzed using a customized proteomic microarray bearing 124 autoantigens. Autoantibodies were analyzed using Mann-Whitney U test or Fisher exact test. The association of the autoantibodies with clinical phenotypes and survival was analyzed by Kaplan-Meier Survival Analysis. Receiver operating curve characteristics (ROC) were calculated to evaluate the predictive value of the autoantibodies for PGD.

RESULTS

51 patients were included in this study. Autoantigen microarray analysis on the pre-transplantation samples identified 17 IgA and 3 IgG autoantibodies which were significantly higher in recipients who developed PGD compared to those who did not (adjusted p < .05 and fold change>1.5). 6 IgA Abs were significantly associated with survival. Taken as a panel, an elevation of 6 IgA Abs had significant predictive value for PGD. Area under the curve value for the panel was 0.9413 for PGD with ROC analysis. Notably, 6 of the 17 IgA autoantigen targets are belong to proteoglycan family of extracellular matrix proteins.

CONCLUSION

Pre-existing IgG and IgA autoantibodies in LT patients correlate with PGD and with survival in a single center, small cohort of lung transplant recipients. Further validation is needed to confirm the findings in the study.

Serum Levels of Autoantibodies Against Extracellular Antigens and Neutrophil Granule Proteins Increase in Patients with COPD Compared to Non-COPD Smokers

Background

Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease leading to irreversible airflow limitation and is characterized by chronic pulmonary inflammation, obstructive bronchiolitis and emphysema. Etiologically, COPD is mediated by toxic gases and particles, eg, cigarette smoke, while the pathogenesis of the disease is largely unknown. Several lines of evidence indicate a link between COPD and autoimmunity but comprehensive studies are lacking.

Methods

By using a protein microarray assaying more than 19,000 human proteins we determined in this study the autoantibody profiles of COPD and non-COPD smokers. The discovery cohort included 5 COPD patients under acute exacerbation (AECOPD) and 5 age- and gender-matched non-COPD smokers. One putative candidate autoantibody, anti-lactoferrin IgG, was further investigated by using immunoblotting with a large validation cohort containing 124 healthy controls, 92 patients with AECOPD and 52 patients with stable COPD.

Results

We show that i) autoantigens targeted by autoantibodies with higher titers in COPD patients were enriched in extracellular regions, while those with lower titers in COPD patients were enriched in intracellular compartments. ii) levels of IgG autoantibodies against many neutrophil granule proteins were significantly higher in COPD patients than in non-COPD smokers. Furthermore, increased levels of anti-lactoferrin antibodies in COPD patients were confirmed in a cohort with a large number of samples.

Conclusion

The comprehensive autoantibody profiles from COPD patients established in this study demonstrated for the first time a shift in the cellular localization of antigens targeted by autoantibodies in COPD.

Obstructive lung diseases and risk of rheumatoid arthritis

Introduction: Smoking is an established risk factor for both lung diseases and rheumatoid arthritis (RA). Chronic mucosal airway inflammation may result in immune tolerance loss, neoantigen formation, and production of RA-related autoantibodies that increase the subsequent risk of RA. In this review, we aimed to summarize the current evidence supporting the role of obstructive lung diseases and subsequent risk of RA.Areas covered: We identified scientific articles discussing the biologic mechanisms linking mucosal airway inflammation and RA risk. We also identified studies investigating asthma, chronic obstructive pulmonary disease, bronchiectasis, cystic fibrosis, chronic tuberculous and nontuberculous mycobacterial infections, and interstitial lung disease with subsequent risk for RA.Expert opinion: The current evidence supports the hypothesis that mucosal airway inflammation may increase the risk of developing RA. However, most studies investigating this relationship have been retrospective and may not have adequately addressed the role of smoking. Larger prospective studies may provide stronger evidence for obstructive lung disease and RA risk. Determining the role of obstructive lung disease in RA pathogenesis may provide opportunity for RA prevention and screening strategies, while identifying novel biologic mechanisms that could offer targets to improve treatment and outcomes.

Chronic obstructive pulmonary disease in rheumatoid arthritis: a systematic review and meta-analysis

BACKGROUND

The risk and prevalence of chronic obstructive pulmonary disease (COPD) in rheumatoid arthritis (RA) is still obscure. The current study was aimed to systematically review and meta-analyse the risk ratio (RR) and prevalence of COPD in RA.

METHODS

A comprehensive systematic review was conducted based on PubMed, Web of Science and Cochrane Library from inception to April 30, 2018. The primary outcome of our study was the RR of COPD in RA patients compared with controls, and secondary was the prevalence of COPD in RA patients. Pooled effect sizes were calculated according to fixed effect model or random effects model depending on heterogeneity.

RESULTS

Six and eight studies reported the RR and prevalence of COPD in RA respectively. Compared with controls, RA patients have significant increased risk of incident COPD with pooled RR 1.82 (95% CI = 1.55 to 2.10, P <  0.001). The pooled prevalence of COPD in RA patients was 6.2% (95% CI = 4.1 to 8.3%). Meta-regression identified that publication year was an independent covariate negatively associated with the RR of COPD, and smoker proportion of RA population was also positively associated with the prevalence of COPD significantly in RA patients.

CONCLUSIONS

The present meta-analysis has demonstrated the significant increased risk and high prevalence of COPD in RA patients. Patients with RA had better cease tobacco use and rheumatologists should pay attention to the monitoring of COPD for the prevention and control of COPD.

Type I interferon induced by DNA of nontypeable Haemophilus influenza modulates inflammatory cytokine profile to promote susceptibility to this bacterium

Type I interferon (IFN) is indispensable for antiviral immunity, but its role in bacterial infections is controversial and not fully described. Nontypeable Haemophilus influenzae (NTHi) is one of the most common bacterial pathogens in patients with chronic obstructive pulmonary disease (COPD). NTHi-DNA activates type I IFN production in macrophages, but the function of type I IFN in host-pathogen interactions, in the context of NTHi infection, is still unclear. Here, we showed that type I IFN, induced by NTHi-DNA, restrained bacterial killing in vitro and promoted COPD development in vivo in response to NTHi. Mice deficient for type I IFN receptor (IFNAR) exhibited improved resistance to NTHi infection. Moreover, similar to exogenous IFN-β, NTHi-DNA-induced type I IFN increased the production of IL-6, IL-1β, IL-12 and CXCL10 via p38 MAPK activation. Our findings demonstrated that NTHi-DNA-induced type I IFN signaling played a negative role in host defense against NTHi infection and identified potential targets for future therapeutic management of COPD.

Cigarette smoke-induced reduction of C1q promotes emphysema

Alteration of innate immune cells in the lungs can promote loss of peripheral tolerance that leads to autoimmune responses in cigarette smokers. Development of autoimmunity in smokers with emphysema is also strongly linked to the expansion of autoreactive T helper (Th) cells expressing interferon gamma (Th1), and interleukin 17A (Th17). However, the mechanisms responsible for enhanced self-recognition and reduced immune tolerance in smoker with emphysema remain less clear. Here we show that C1q, a component of the complement protein 1 complex (C1), is downregulated in lung CD1a+ antigen presenting cells (APCs) isolated from emphysematous human, and mouse lung APCs after chronic cigarette smoke exposure. C1q potentiated the function of APCs to differentiate CD4+ T cells to Tregs, while it inhibited Th17 cell development and proliferation. Mice deficient in C1q that were exposed to chronic smoke exhibited exaggerated lung inflammation marked by increased Th17 cells, while reconstitution of C1q in the lungs enhanced Tregs abundance, dampened smoke-induced lung inflammation, and reversed established emphysema. Our findings demonstrate that cigarette smoke-mediated loss of C1q could play a key role in reduced peripheral tolerance, which could be explored to treat emphysema.

Reproducibility of fluid-phase measurements in PBS-treated sputum supernatant of healthy and stable COPD subjects

Purpose

The purpose of this study was to investigate the reproducibility of fluid-phase measurements in PBS-treated sputum supernatant, processed using the two-step method, of healthy and stable COPD individuals.

Methods

Nine healthy subjects and 23 stable COPD patients provided sputum twice within 6 days. A two-step sputum processing method was used to obtain PBS-treated supernatant and sputum cells. Soluble protein markers and IgG and IgM autoantibody profiles in PBS supernatant were analyzed using customized microarrays. Repeatability of measurements was assessed by paired-sample testing and an intraclass correlation coefficient, then graphically reported by Bland–Altman plot.

Results

There was no significant difference between the repeated detection of 8/10 types of soluble protein markers, all 13 types of IgG autoantibodies, and 12/13 types of corresponding IgM autoantibodies in PBS supernatant. The repeatability of measurements in PBS supernatant was substantial to very good for interleukin 6 (IL6), IL8, IL13, IL10, IL33, vascular endothelial growth factor, soluble receptor for advanced glycation end-products, and tumor necrosis factor-α; for IgG autoantibodies against aggrecan, centromere protein B (CENP-B), collagen II, collagen IV, cytochrome C, elastin, heat shock protein 47 (HSP47), HSP70, and La/Sjögren syndrome type B antigen; for IgM autoantibodies against CENP-B, collagen I, collagen II, collagen IV, cytokeratin 18, and HSP70; and for sputum neutrophils, macrophages and eosinophils count. Bland–Altman plots suggested good consistency within repeated measurements. Stable COPD patients differed from healthy subjects in the proportion of neutrophils and eosinophils; relative fluorescence intensity of anti-cytochrome C IgG, anti-aggrecan IgM, and anti-cytochrome C IgM. There was a significant positive correlation for stable COPD patients between sputum anti-collagen II IgG and post-bronchodilator FEV₁%.

Conclusion

We confirmed fluid-phase measurements in PBS-treated sputum supernatant by high-throughput techniques with good repeatability. We demonstrated the presence of IgG and IgM autoantibodies to multiple antigens in the airways of COPD patients.

IL-33 induces production of autoantibody against autologous respiratory epithelial cells: a potential mechanism for the pathogenesis of COPD

The mechanisms underlying the chronic, progressive airways inflammation, remodelling and alveolar structural damage characteristic of human chronic obstructive pulmonary disease (COPD) remain unclear. In the present study, we address the hypothesis that these changes are at least in part mediated by respiratory epithelial alarmin (IL-33)-induced production of autoantibodies against airways epithelial cells. Mice immunized with homologous, syngeneic lung tissue lysate along with IL-33 administered directly to the respiratory tract or systemically produced IgG autoantibodies binding predominantly to their own alveolar type II epithelial cells, along with increased percentages of Tfh cells and B2 B-cells in their local, mediastinal lymph nodes. Consistent with its specificity for respiratory epithelial cells, this autoimmune inflammation was confined principally to the lung and not other organs such as the liver and kidney. Furthermore, the serum autoantibodies produced by the mice bound not only to murine, but also to human alveolar type II epithelial cells, suggesting specificity for common, cross-species determinants. Finally, concentrations of antibodies against both human and murine alveolar epithelial cells were significantly elevated in the serum of patients with COPD compared with those of control subjects. These data are consistent with the hypothesis that IL-33 contributes to the chronic, progressive airways obstruction, inflammation and alveolar destruction characteristic of phenotypes of COPD/emphysema through induction of autoantibodies against lung tissue, and particularly alveolar type II epithelial cells.

Risk of systemic lupus erythematosus in patients with human papillomavirus infection: a population-based retrospective cohort study

Background: Viral infection contributing to systemic lupus erythematosus (SLE) development has been largely reported. However, the SLE risk in patients with human papillomavirus (HPV) infection is unknown. Methods: Data were retrieved from the Longitudinal Health Insurance Database (2000) in Taiwan. We identified 43,567 patients with HPV infection and 174,268 age- and sex-matched uninfected controls from 2002 to 2012. Individuals were followed up from index date (first date of diagnosis with HPV) until the occurrence of SLE, at the end of the study (December 2013), or when they were withdrawn from the insurance program. The incidence rate ratio (IRR) was calculated using the univariate Poisson regression. The adjusted hazard ratios (aHRs) were calculated, and sensitive and subgroups analyses were also conducted. Results: Compared with the non-HPV controls, the IRR of SLE in HPV patients was 1.52 (95% confidence interval (CI): 1.09–2.12). The risk of SLE in HPV-infected individuals was significantly high (aHR: 1.48, 95% CI: 1.06–2.06) after adjusting for age, sex, and comorbidities. Men aged between 16 and 45 years were more susceptible to developing SLE (aHR: 21.57, 95% CI: 2.52–184.60, p = 0.0051). Conclusion: Our study showed a significantly higher risk of SLE among HPV-infected patients, especially in men aged between 16 and 45 years.

Prevalence of chronic obstructive pulmonary disease (COPD) among rheumatoid arthritis: results from national inpatient database

Rheumatoid arthritis (RA) is being increasingly recognized as an important contributor to chronic obstructive pulmonary disease (COPD). Although smoking is a major risk factor, other factors may play a role. We used National Inpatient Sample (NIS) from 2013 to explore this relationship. We used propensity matching with a 1:3 nearest-neighbor-matching algorithm to match 1 RA hospitalization to 3 age- and-sex-matched comparators. In the age- and-sex-matched population, RA had a higher odds of COPD (OR 1.20, 95% CI: 1.17-1.22, p < 0.0001). RA is associated with increased COPD prevalence, independent of smoking. COPD might fall within the spectrum of RA complications, likely due to autoimmune and inflammatory mechanisms.

Risk of Incident Chronic Obstructive Pulmonary Disease in Rheumatoid Arthritis: A Population-Based Cohort Study

OBJECTIVE

Studies have demonstrated a link between chronic obstructive pulmonary disease (COPD) and inflammation, raising the question whether chronic inflammatory conditions, such as rheumatoid arthritis (RA), predispose to COPD. Our objective was to evaluate the risk of incident COPD hospitalization in RA compared to the general population.

METHODS

We studied a population-based incident RA cohort with matched general population controls, using administrative health data. All incident RA cases in British Columbia who first met RA definition between January 1996 and December 2006 were selected using previously published criteria. General population controls were randomly selected, matched 1:1 to RA cases on birth year, sex, and index year. COPD outcome was defined as hospitalization with a primary COPD code. Incidence rates, 95% confidence intervals (95% CIs), and incidence rate ratios (IRRs) were calculated for RA and controls. Multivariable Cox proportional hazards models estimated the risk of COPD in RA compared to the general population after adjusting for potential confounders. Sensitivity analyses were performed to test the robustness of the results to the possible confounding effect of smoking, unavailable in administrative data, and to COPD outcome definitions.

RESULTS

The cohorts included 24,625 RA individuals and 25,396 controls. The incidence of COPD hospitalization was greater in RA than controls (IRR 1.58, 95% CI 1.34-1.87). After adjusting for potential confounders, RA cases had a 47% greater risk of COPD hospitalization than controls. The increased risk remained significant after modeling for smoking and with varying COPD definitions.

CONCLUSION

In our population-based cohort, individuals with RA had a 47% greater risk of COPD hospitalization compared to the general population.

Prevalence and Effects of Emphysema in Never-Smokers with Rheumatoid Arthritis Interstitial Lung Disease

AIMS

Autoimmune conditions such as rheumatoid arthritis-related interstitial lung disease (RA-ILD) have been linked to the existence of emphysema in never-smokers. We aimed to quantify emphysema prevalence in RA-ILD never-smokers and investigate whether combined pulmonary fibrosis and emphysema (CPFE) results in a worsened prognosis independent of baseline disease extent.

METHODS

RA-ILD patients presenting to the Royal Brompton Hospital (n=90) and Asan Medical Center (n=155) had CT's evaluated for a definite usual interstitial pneumonia (UIP) pattern, and visual extents of emphysema and ILD.

RESULTS

Emphysema, identified in 31/116 (27%) RA-ILD never-smokers, was associated with obstructive functional indices and conformed to a CPFE phenotype: disproportionate reduction in gas transfer (DLco), relative preservation of lung volumes. Using multivariate logistic regression, adjusted for patient age, gender and ILD extent, emphysema presence independently associated with a CT-UIP pattern in never-smokers (0.009) and smokers (0.02). On multivariate Cox analysis, following adjustment for patient age, gender, DLco, and a CT-UIP pattern, emphysema presence (representing the CPFE phenotype) independently associated with mortality in never-smokers (p=0.04) and smokers (p<0.05).

CONCLUSION

27% of RA-ILD never-smokers demonstrate emphysema on CT. Emphysema presence in never-smokers independently associates with a definite CT-UIP pattern and a worsened outcome following adjustment for baseline disease severity.

Autoantibodies in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD), the fourth leading cause of death worldwide, is characterized by irreversible airflow limitation based on obstructive bronchiolitis, emphysema, and chronic pulmonary inflammation. Inhaled toxic gases and particles, e.g., cigarette smoke, are major etiologic factors for COPD, while the pathogenesis of the disease is only partially understood. Over the past decade, an increasing body of evidence has been accumulated for a link between COPD and autoimmunity. Studies with clinical samples have demonstrated that autoantibodies are present in sera of COPD patients and some of these antibodies correlate with specific disease phenotypes. Furthermore, evidence from animal models of COPD has shown that autoimmunity against pulmonary antigens occur during disease development and is capable of mediating COPD-like symptoms. The idea that autoimmunity could contribute to the development of COPD provides a new angle to understand the pathogenesis of the disease. In this review article, we provide an advanced overview in this field and critically discuss the role of autoantibodies in the pathogenesis of COPD.

Increased Circulating Autoantibodies Levels of IgG, IgA, IgM Against Cytokeratin 18 and Cytokeratin 19 in Chronic Obstructive Pulmonary Disease

BACKGROUND AND AIMS

Autoimmune processes are involved in the progression of chronic obstructive pulmonary disease (COPD). Autoantibodies against cytokeratin 18 (CK18) and cytokeratin 19 (CK19) could be associated with lung injury. We undertook this study to investigate the role of these autoantibodies against CK18 and CK19 in the development of COPD.

METHODS AND RESULTS

We used blood samples from 228 COPD patients or 136 healthy controls and male C57BL/6j mice as experimental subjects to analyze the serum autoantibody levels against CK18 or CK19 autoantigen by enzyme-linked immunosorbent assay (ELISA). We found that the circulating autoantibody levels of IgG, IgA, IgM against CK18 and CK19 were elevated in patients with COPD compared with healthy controls, which were increased gradually as the severity of the disease increases, especially in GOLD III and GOLD IV with the exception of anti-CK19 IgG and anti-CK18 IgA autoantibodies. Moreover, we observed that the serum levels of anti-CK18 and anti-CK19 IgG autoantibodies were higher in mice exposed to cigarette smoke compared with mice exposed to room air for 6 months and 9 months. Additionally, we identified the distribution of antibodies and the presence of autoantibodies (IgG) against CK18 and CK19 in the damaged lung tissues of mice.

CONCLUSIONS

Increased circulating autoantibodies against CK18 and CK19 are closely related to the progression of COPD, which play an important role in the process of lung injury in COPD, suggesting that it is promising for anti-CK18 and anti-CK19 autoantibodies to serve as a tool to monitor lung damage and guide treatment.

Gut bacterial peptides with autoimmunity potential as environmental trigger for late onset complex diseases: In-silico study

Recent evidences suggest that human gut microbiota with major component as bacteria can induce immunity. It is also known that gut lining depletes with ageing and that there is increased risk of autoimmune and inflammatory disorders with ageing. It is therefore likely that both may be correlated as depletion of gut lining exposes the gut bacterial antigens to host immune mechanisms, which may induce immunity to certain bacterial proteins, but at the same time such immunity may also be auto-immunogenic to host. This autoimmunity may make a protein molecule nonfunctional and thereby may be involved in late onset metabolic, autoimmune and inflammatory disorders such as, Diabetes, Rheumatoid Arthritis, Hyperlipidemias and Cancer. In this in-silico study we found a large number of peptides identical between human and gut bacteria which were binding to HLA-II alleles, and hence, likely to be auto-immunogenic. Further we observed that such autoimmune candidates were enriched in bacterial species belonging to Firmicutes and Proteobacteria phyla, which lead us to conclude that these phyla may have higher disease impact in genetically predisposed individuals. Functional annotation of human proteins homologous to candidate gut-bacterial peptides showed significant enrichment in metabolic processes and pathways. Cognitive trait, Ageing, Alzheimer, Type 2 diabetes, Chronic Kidney Failure (CKF), Chronic Obstructive Pulmonary Disease (COPD) and various Cancers were the major diseases represented in the dataset. This dataset provides us with gut bacterial autoimmune candidates which can be studied for their clinical significance in late onset diseases.

Increased circulating β2-adrenergic receptor autoantibodies are associated with smoking-related emphysema

Smoking is a dominant risk factor for chronic obstructive pulmonary disease (COPD) and emphysema, but not every smoker develops emphysema. Immune responses in smokers vary. Some autoantibodies have been shown to contribute to the development of emphysema in smokers. β₂-adrenergic receptors (β₂-ARs) are important targets in COPD therapy. β₂-adrenergic receptor autoantibodies (β₂-AAbs), which may directly affect β₂-ARs, were shown to be increased in rats with passive-smoking-induced emphysema in our current preliminary studies. Using cigarette-smoke exposure (CS-exposure) and active-immune (via injections of β₂-AR second extracellular loop peptides) rat models, we found that CS-exposed rats showed higher serum β₂-AAb levels than control rats before alveolar airspaces became enlarged. Active-immune rats showed increased serum β₂-AAb levels, and exhibited alveolar airspace destruction. CS-exposed-active-immune treated rats showed more extensive alveolar airspace destruction than rats undergoing CS-exposure alone. In our current clinical studies, we showed that plasma β₂-AAb levels were positively correlated with the RV/TLC (residual volume/total lung capacity) ratio (r = 0.455, p < 0.001) and RV%pred (residual volume/residual volume predicted percentage, r = 0.454, p < 0.001) in 50 smokers; smokers with higher plasma β₂-AAb levels exhibited worse alveolar airspace destruction. We suggest that increased circulating β₂-AAbs are associated with smoking-related emphysema.

Gender differences in the T-cell profiles of the airways in COPD patients associated with clinical phenotypes

T lymphocytes are believed to play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). How T cells are recruited to the lungs and contribute to the inflammatory process is largely unknown. COPD is a heterogeneous disease, and discriminating disease phenotypes based on distinct molecular and cellular pathways may provide new approaches for individualized diagnosis and therapies. Bronchoalveolar lavage (BAL) and blood samples were obtained from 40 never-smokers, 40 smokers with normal lung function, and 38 COPD patients. T-cell chemokine receptor expression was analyzed with flow cytometry, and soluble BAL cytokines and chemokines were measured using a cytokine multiplex assay. Correlations with gender and clinical characteristics including lung imaging were investigated using multivariate modeling. Th1/Tc1- and Th2/Tc2-associated soluble analytes and T-cell chemokine receptors were analyzed as cumulative Th1/Tc1 and Th2/Tc2 immune responses. A higher expression of chemokine receptor CCR5 on CD8⁺ T cells in BAL and higher percentage of CXCR3⁺CD8⁺ T cells in blood was found in female smokers with COPD compared to those without COPD. CCR5 expression on CD4⁺ and CD8⁺ T cells was lower in BAL from male smokers with COPD compared to those without COPD. Among female smokers with COPD, Th1/Tc1 immune response was linked to BAL macrophage numbers and goblet cell density, and Th2/Tc2 response was associated with the measures of emphysema on high-resolution computed tomography. The highly gender-dependent T-cell profile in COPD indicates different links between cellular events and clinical manifestations in females compared to males. Our findings may reveal mechanisms of importance for the difference in clinical course in female COPD patients compared to males.

The formation and function of tertiary lymphoid follicles in chronic pulmonary inflammation

Tertiary lymphoid follicles (TLFs) can develop in the respiratory tract in response to infections or chronic inflammation. However, their functional relevance remains unclear because they are implicated in both protective and pathological responses. In contrast to homeostatic conditions, external antigens and damage to the lung tissue may drive TLF formation in inflamed lungs, and once established, the presence of pulmonary TLFs may signal the progression of chronic lung disease. This novel concept will be discussed in light of recent work in chronic obstructive pulmonary disease and how changes in the pulmonary microbiota may drive and direct TLF formation and function. We will also discuss the cellularity of TLFs at the pulmonary mucosa, with emphasis on the potential roles of lymphoid tissue inducer cells, and B- and T-cell aggregates, and will examine the function of key chemokines and cytokines including CXCL13 and interleukin-17, in the formation and maintenance of pulmonary TLFs.

Autoantibodies against CD80 in patients with COPD

Chronic obstructive pulmonary disease (COPD) is an inflammation disorder and possibly an autoimmune disease. The components of the autoimmune response in the circulatory system are of considerable interest to clinicians. Because aberrations of costimulation status have been noted in COPD, the presence of autoantibodies to B7 costimulatory factor CD80 were investigated in a cohort of patients. Recombinant rs1CD80 (lacking the transmembrane domain of CD80) was used for Western blot analysis and ELISA to investigate the presence of autoantibodies in sera of patients with stable COPD and in controls without COPD. Cytokines IL-6 and IL-8 were detected using ELISA. Western blot revealed a specific band reacting to rs1CD80 by diluting sera pool of patients, which indicated the existence of autoantibodies to CD80. The serum level of anti-rs1CD80 was higher in patients with COPD than in controls(P=0.0185) and was positively correlated to the serum level of IL-6 (r=0.797, P<0.001) and IL-8 (r=0.608, P<0.001). There was a tendency that more higher level of anti-rs1CD80, more severe COPD stage. The existence of autoantibodies to costimulatory factor CD80 may suggest a pathogenic role of costimulatory factors in COPD.

Loss of Peripheral Tolerance in Emphysema. Phenotypes, Exacerbations, and Disease Progression

Heterogeneity in the development and progression of cigarette smoke-induced lung diseases strongly argues for a need to improve the clinical and phenotypic characterization of patients with chronic obstructive lung disease and emphysema. Smokers with emphysema are at a much higher risk for accelerated loss of lung function, increased cardiovascular morbidity, and development of lung cancer. Recent evidence in human translational studies and animal models suggests that emphysema is associated with activation of specialized antigen-presenting cells and that cigarette smoke can disrupt the induction of immune tolerance in the lungs. Quantitative assessment of cytokines expressed by autoreactive T lymphocytes in response to human lung elastin fragments has shown a strong positive correlation between T helper Type 1 (Th1) and Th17 cells' immune responses and emphysema. In search of factors that could reduce the threshold for induction of autoimmune inflammation, we have discovered that cleavage of complement protein 3 (C3) generates bioactive molecules (e.g., C3a) and activates lung antigen-presenting cells. The autocrine and paracrine function of C3a and its receptor are required in T cell-mediated inflammatory responses to cigarette smoke in both human and preclinical models of emphysema. Targeting upstream molecules that reduce the potential for generation of autoreactive T cells could lead to the development of novel therapeutics to prevent progression of emphysema in smokers.

Risk of Chronic Obstructive Pulmonary Disease in Female Adults With Primary Sjögren Syndrome: A Nationwide Population-Based Cohort Study

No large-scale population-based cohort study has ever investigated the risk of developing chronic obstructive pulmonary disease (COPD) in patients with Sjögren syndrome (SS). This study evaluated the risk of COPD in women with primary SS (pSS) in a nationwide population.We used the data of the National Health Insurance Research Database of Taiwan to establish a pSS group consisting of 3013 female adults diagnosed between 2000 and 2005, and a non-SS group consisting of 12,052 women without SS matched by a propensity score. Incident COPD cases were identified to the end of 2011. The pSS group to non-SS group adjusted hazard ratios (aHRs) of COPD were estimated using multivariable Cox proportional hazards regression analysis.After a mean follow-up period of 7.99 years, the incidence of COPD was 1.4-fold greater in the pSS group than in the non-SS group (3.87 vs 2.77 per 1000 person-years) with an aHR of 1.39 (95% confidence interval [CI] = 1.10-1.75, P = 0.007). The COPD incidence was 7-fold greater for women aged 50 years and above than women aged 20 to 49, with the aHR of 4.24 (95% CI = 3.06-5.88, P < 0.001). Comorbidity increased the COPD risk further for women with pSS. Women with both pSS and comorbidity had an aHR of 3.11 (95% CI = 2.23-4.33, P < 0.001) for COPD, compared to those free of both pSS and comorbidity.Women with pSS are at a greater risk of developing COPD than those without SS. Patients with SS require close monitoring to prevent COPD development, particularly for those with comorbidity.

B Cell-Activating Factor. An Orchestrator of Lymphoid Follicles in Severe Chronic Obstructive Pulmonary Disease

RATIONALE

Patients with chronic obstructive pulmonary disease (COPD) have increased pulmonary lymphoid follicle (LF) counts. B cell-activating factor of tumor necrosis factor family (BAFF) regulates B cells in health, but its role in COPD pathogenesis is unclear.

OBJECTIVES

To determine whether BAFF expression in pulmonary LFs correlates with COPD severity, LF size or number, and/or readouts of B-cell function in LFs.

METHODS

We correlated BAFF immunostaining in LFs in lung explants or biopsies from nonsmoking control subjects (NSC), smokers without COPD (SC), and patients with COPD with the number and size of LFs, and LF B-cell apoptosis, activation, and proliferation. We analyzed serum BAFF levels and BAFF expression in B cells in blood and bronchoalveolar lavage samples from the same subject groups. We assessed whether: (1) cigarette smoke extract (CSE) increases B-cell BAFF expression and (2) recombinant BAFF (rBAFF) rescues B cells from CSE-induced apoptosis by inhibiting activation of nuclear factor-κB (NF-κB).

MEASUREMENTS AND MAIN RESULTS

Patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage IV COPD had increased numbers and larger pulmonary LFs than patients with GOLD stages I-II COPD and SC. We identified two main types of pulmonary LFs: (1) type A, the predominant type in GOLD stages I-II COPD and SC, characterized by abundant apoptotic but few BAFF-positive cells (mostly B cells); and (2) type B, the main type in GOLD stage IV COPD, characterized by abundant BAFF-positive cells but few apoptotic cells (mostly B cells). BAFF levels were also higher in blood and bronchoalveolar lavage B cells in patients with COPD versus NSC and SC. Surprisingly, rBAFF blocked CSE-induced B-cell apoptosis by inhibiting CSE-induced NF-κB activation.

CONCLUSIONS

Our data support the hypothesis that B-cell BAFF expression creates a self-perpetuating loop contributing to COPD progression by promoting pulmonary B-cell survival and LF expansion.

Role of Sphingolipids in the Pathobiology of Lung Inflammation

Sphingolipid bioactivities in the respiratory airways and the roles of the proteins that handle them have been extensively investigated. Gas or inhaled particles or microorganisms come into contact with mucus components, epithelial cells, blood barrier, and immune surveillance within the airways. Lung structure and functionality rely on a complex interplay of polar and hydrophobic structures forming the surfactant layer and governing external-internal exchanges, such as glycerol-phospholipids sphingolipids and proteins. Sphingolipids act as important signaling mediators involved in the control of cell survival and stress response, as well as secreted molecules endowed with inflammation-regulatory activities. Most successful respiratory infection and injuries evolve in the alveolar compartment, the critical lung functional unit involved in gas exchange. Sphingolipid altered metabolism in this compartment is closely related to inflammatory reaction and ceramide increase, in particular, favors the switch to pathological hyperinflammation. This short review explores a few mechanisms underlying sphingolipid involvement in the healthy lung (surfactant production and endothelial barrier maintenance) and in a selection of lung pathologies in which the impact of sphingolipid synthesis and metabolism is most apparent, such as acute lung injury, or chronic pathologies such as cystic fibrosis and chronic obstructive pulmonary disease.