Rheumatoid arthritis-associated interstitial lung disease: Current update on prevalence, risk factors, and pharmacologic treatment

Analyzing how SiMiao Wan regulates ferroptosis to prevent RA-ILD using metabolomics and cyberpharmacology

BACKGROUND

Interstitial lung disease (ILD) is a common complication of rheumatoid arthritis (RA) that plays a significant role in the morbidity and mortality of individuals with this condition. In clinical settings, Si Miao Wan (SMW), a traditional Chinese medicine, is often utilized for the management of RA, as it is believed to possess properties that aid in reducing inflammation, eliminating excess moisture, and alleviating joint pain.

PURPOSE

The primary objective of this investigation was to elucidate the potential mechanism of RA-ILD prevention from the perspective of ferroptosis mediated by SMW.

METHODS

UPLC-Q-TOF/MS and network pharmacology were employed to forecast the potential targets of SMW for the early prevention of RA-ILD. Following this, HE staining, metabolomics, and RT-PCR were utilized to investigate the mechanism by which SMW prevents RA-ILD at an early stage.

RESULTS

Following six weeks of continuous administration of SMW extract at a dosage of 2.16 g/kg/day, it was observed that SMW exhibited early preventive effects against RA-ILD. Metabolomics analysis revealed seven potential biomarkers linked to the pharmacological efficacy of SMW in the early prevention of RA-ILD. Additionally, network pharmacology analysis suggested that SMW may exert its therapeutic effects on RA-ILD by modulating signaling pathways associated with lipid metabolism, atherosclerosis, TNF, and IL-17. Ultimately, through the integration of metabolomics and network pharmacology analysis, along with subsequent verification, it was determined that the early prevention of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) by Shenmai injection (SMW) is associated with the ferroptosis pathway.

CONCLUSION

This research offers preliminary insights into the potential mechanism by which traditional Chinese medicine Shen Mai Wan (SMW) may mitigate the early onset of Rheumatoid Arthritis-Interstitial Lung Disease (RA-ILD) via the process of ferroptosis. Furthermore, it establishes a theoretical framework for the development of innovative SMW-based pharmaceuticals for the management of RA-ILD. The signal proteins implicated in this process are anticipated to emerge as crucial targets for the prevention of RA-ILD.

Therapeutic single-cell landscape: methotrexate exacerbates interstitial lung disease by compromising the stemness of alveolar epithelial cells under systemic inflammation

BACKGROUND

Interstitial lung disease (ILD) poses a serious threat in patients with rheumatoid arthritis (RA). However, the impact of cornerstone drugs, including methotrexate (MTX) and TNF inhibitor, on RA-associated ILD (RA-ILD) remains controversial.

METHODS

Using an SKG mouse model and single-cell transcriptomics, we investigated the effects of MTX and TNF blockade on ILD.

FINDINGS

Our study revealed that MTX exacerbates pulmonary inflammation by promoting immune cell infiltration, Th17 activation, and fibrosis. In contrast, TNF inhibitor ameliorates these features and inhibits ILD progression. Analysis of data from a human RA-ILD cohort revealed that patients with ILD progression had persistently higher systemic inflammation than those without progression, particularly among the subgroup undergoing MTX treatment.

INTERPRETATION

These findings highlight the need for personalized therapeutic approaches in RA-ILD, given the divergent outcomes of MTX and TNF inhibitor.

FUNDING

This work was funded by GENINUS Inc., and the National Research Foundation of Korea, and Seoul National University Hospital.

Effect of abatacept versus conventional synthetic disease modifying anti-rheumatic drugs on rheumatoid arthritis-associated interstitial lung disease

BACKGROUND/AIMS

To compare the effects of abatacept and conventional synthetic disease modifying anti-rheumatic drugs (csDMARDs) on the progression and development of rheumatoid arthritis-associated interstitial lung disease (RA-ILD).

METHODS

This multi-center retrospective study included RA patients receiving abatacept or csDMARDs who underwent at least two pulmonary function tests and/or chest high-resolution computed tomography (HRCT). We compared the following outcomes between the groups: progression of RA-ILD, development of new ILD in RA patients without ILD at baseline, 28-joint Disease Activity Score with the erythrocyte sedimentation rate (DAS28-ESR), and safety. Longitudinal changes were compared between the groups by using a generalized estimating equation.

RESULTS

The study included 123 patients who were treated with abatacept (n = 59) or csDMARDs (n = 64). Nineteen (32.2%) and 38 (59.4%) patients treated with abatacept and csDMARDs, respectively, presented with RA-ILD at baseline. Newly developed ILD occurred in one patient receiving triple csDMARDs for 32 months. Among patients with RA-ILD at baseline, ILD progressed in 21.1% of cases treated with abatacept and 34.2% of cases treated with csDMARDs during a median 21-month follow-up. Longitudinal changes in forced vital capacity and diffusing capacity for carbon monoxide were comparable between the two groups. However, the abatacept group showed a more significant decrease in DAS28-ESR and glucocorticoid doses than csDMARDs group during the follow-up. The safety of both regimens was comparable.

CONCLUSION

Abatacept and csDMARDs showed comparable effects on the development and stabilization of RA-ILD. Nevertheless, compared to csDMARDs, abatacept demonstrated a significant improvement in disease activity and led to reduced glucocorticoid use.

A Systematic Review of the Key Predictors of Progression and Mortality of Rheumatoid Arthritis-Associated Interstitial Lung Disease

BACKGROUND

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is an important extra-articular manifestation of rheumatoid arthritis (RA). Identifying patients at risk of progression and death is crucial for improving RA-ILD management and outcomes. This paper explores current evidence on prognostic factors in RA-ILD.

METHODS

We conducted a systematic literature review to examine the impact of clinical, radiological, and histological factors on lung function decline and the survival of RA-ILD patients. We searched electronic databases, including Medline and EMBASE, from inception to date. The incidence and prognosis of predictors were qualitatively analyzed, and univariate results were combined when feasible. Following the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)" guidelines, our systematic literature review involved a five-step algorithm. Out of 2217 records, 48 studies were eligible. These studies reported various prognostic factors, including demographic variables, clinical risk factors, serum markers, and preexisting treatments.

RESULTS

Lung function declined over time in 1225 subjects, with significant variability in smoking history and radiological/pathological UIP patterns. Severe lung fibrosis and abnormal pulmonary function tests (PFTs) were key univariate prognostic indicators, while age at initial presentation, RA disease activity, predicted DLCO percentage, and UIP pattern were the most reliable multivariate risk factors for ILD progression. Age, male gender, disease duration, RA activity, acute phase reactants, and specific serum biomarkers (Krebs vin den Lungen 6, surfactant protein D, and interleukin 6) were significantly associated with all-cause mortality.

CONCLUSIONS

RA-ILD is a severe complication of RA characterized by significant prognostic variability. Key prognostic factors include extensive fibrosis observed on imaging, a marked decline in lung function, high RA disease activity, and specific biomarkers. These factors can guide treatment strategies and improve patient outcomes.

Abatacept versus tumor necrosis factor inhibitors on mortality and medical utilizations in the treatment of rheumatoid arthritis associated interstitial lung disease: a large-scale real-world retrospective cohort study

Rheumatoid arthritis is a chronic inflammatory disease, and interstitial lung disease is one of the important extra-articular manifestations. There is limited evidence comparing abatacept (ABA) and tumor necrosis factor inhibitors (TNFi) regarding the risk of mortality among patients with rheumatoid arthritis associated interstitial lung disease (RA-ILD). The aim of this study is to investigate the risk of mortality in patients with RA-ILD treated with ABA compared to TNFi. This retrospective cohort study utilized TriNetX electronic health record database. We enrolled patients who were diagnosed with RA-ILD and had received a new prescription for either ABA or TNFi. Patients were categorized into two cohorts based on their initial prescription. The primary outcome was all-cause mortality, and secondary outcomes were healthcare utilizations, including hospitalization, critical care services, and mechanical ventilation. Subgroup analyses were performed on age, presence of anti-citrullinated peptide antibodies (ACPA), and cardiovascular risk. Among 34,388 RA-ILD patients, 895 were selected for each group (ABA and TNFi) following propensity score matching. The ABA group exhibited a higher all-cause mortality risk. (HR 1.296, 95% CI 1.006-1.671). Subgroup analysis showed a heightened risk of receiving mechanical ventilation in ABA-treated patients aged 18-64 years old (HR 1.853, 95% CI 1.002-3.426), and those with cardiovascular risk factors (HR 2.015, 95% CI 1.118-3.630). Another subgroup analysis indicated a higher risk of mortality among ABA-treated patients with positive-ACPA. (HR 4.138 95% CI 1.343-12.75). This real-world data research demonstrated a higher risk of all-cause mortality in RA-ILD patients treated with ABA compared to TNFi, particularly those aged 18-64 years, lacking cardiovascular risk factors, and positive-ACPA. ABA was associated with an increased risk of mechanical ventilation in patients aged 18-64 years and those with cardiovascular risk factors.

Exploring rheumatoid arthritis associated interstitial lung disease a retrospective study from two Saudi tertiary care centers

BACKGROUND

Interstitial lung disease (ILD) is an increasingly recognized complication of rheumatoid arthritis (RA) and is associated with significant morbidity and mortality. Many risk factors for RA-related ILD were reported. The current study aims to explore the features and risk factors of Saudi patients with RA-ILD.

METHODS

This is a multicenter, retrospective, observational study of patients with RA-ILD. Clinical and radiological data from patients with RA-ILD were obtained from electronic medical records, including demographics, clinical characteristics, laboratory tests, pulmonary function tests, ECHO, and HRCT images.

RESULT

Out of 732 patients, 57 had RA-ILD. The mean age at the time of ILD diagnosis was 61.9 (± 12.2) years. RA-ILD diagnosis was significantly less among females (p = 0.008). Patients who ever smoked had significantly more RA-ILD (p < 0.001). Patients with RA-ILD were more likely to present with medical comorbidities, namely diabetes (p < 0.001), hypertension (p < 0.001), ischemic heart disease (p < 0.001), and osteoarthritis (p = 0.030). The multivariate analysis revealed that the age (OR: 1.035, 95% CI: 48.45-52.86, p = 0.0001); gender (OR: 2.581, CI: 1.77-1.86, p = 0.001), DM (OR: 2.498, 95% Cl: 1.65-1.76, P = 0.0001), HTN (OR: 1.975, 95% Cl: 1.61-1.74, P = 0.019), IHD (OR: 6.043, 95% Cl: 1.89-1.93, P = 0.0001) have a significant positive association with RA-ILD. No significant differences were observed between seropositive parameters with or without RA-ILD (p > 0.05). The most common symptoms of RA-ILD were cough (55.6%) and dyspnea (30.2%), and the most common ILD pattern was Non-specific Interstitial Pneumonia (NSIP) (55.6%) followed by Usual Interstitial Pneumonia (UIP) (38.9%). Traction bronchiectasis (75.5%) and glass ground opacities (73.6%) were also observed. The mean FVC and DLCO at baseline were 64.6% and 53.3%, respectively.

CONCLUSION

In this cohort of patients, Saudi RA-ILD patients had a predominant NSIP pattern conversely to what is seen globally. These findings could be explained by the lower rates of smoking in our patient population. Future prospective national studies are needed to confirm the current findings and better evaluate RA-ILD epidemiology and risk factors.

Immune response to post-translationally modified proteins in rheumatoid arthritis: what makes it special?

Rheumatoid arthritis (RA) exhibits common characteristics with numerous other autoimmune diseases, including the presence of susceptibility genes and the presence of disease-specific autoantibodies. Anti-citrullinated protein antibodies (ACPA) are the hallmarking autoantibodies in RA and the anti-citrullinated protein immune response has been implicated in disease pathogenesis. Insight into the immunological pathways leading to anti-citrullinated protein immunity will not only aid understanding of RA pathogenesis, but may also contribute to elucidation of similar mechanisms in other autoantibody-positive autoimmune diseases. Similarly, lessons learnt in other human autoimmune diseases might be relevant to understand potential drivers of RA. In this review, we will summarise several novel insights into the biology of the anti-citrullinated protein response and their clinical associations that have been obtained in recent years. These insights include the identification of glycans in the variable domain of ACPA, the realisation that ACPA are polyreactive towards other post-translational modifications on proteins, as well as new awareness of the contributing role of mucosal sites to the development of the ACPA response. These findings will be mirrored to emerging concepts obtained in other human (autoimmune) disease characterised by disease-specific autoantibodies. Together with an updated understanding of genetic and environmental risk factors and fresh perspectives on how the microbiome could contribute to antibody formation, these advancements coalesce to a progressively clearer picture of the B cell reaction to modified antigens in the progression of RA.

Screening, diagnosis, and monitoring of interstitial lung disease in autoimmune rheumatic diseases: A narrative review

Interstitial lung disease (ILD) is a common and serious manifestation of autoimmune rheumatic diseases. While the prevalence of ILD differs among the individual autoimmune rheumatic diseases, ILD remains an important cause of morbidity and mortality in systemic sclerosis, systemic lupus erythematosus, mixed connective tissue disease, primary Sjögren's disease, rheumatoid arthritis, and idiopathic inflammatory myositis. The present review summarizes recent literature on autoimmune-associated ILD with a focus on screening and monitoring for ILD progression. Reflecting on the currently available evidence, the authors propose a guideline for monitoring for progression in patients with newly diagnosed autoimmune-associated ILD. This review also highlights clinical and biological predictors of progressive pulmonary fibrosis and describes opportunity for further study in the rapidly evolving area of rheumatology and pulmonology.

Potential Rheumatoid Arthritis-Associated Interstitial Lung Disease Treatment and Computational Approach for Future Drug Development

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by swelling in at least one joint. Owing to an overactive immune response, extra-articular manifestations are observed in certain cases, with interstitial lung disease (ILD) being the most common. Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is characterized by chronic inflammation of the interstitial space, which causes fibrosis and the scarring of lung tissue. Controlling inflammation and pulmonary fibrosis in RA-ILD is important because they are associated with high morbidity and mortality. Pirfenidone and nintedanib are specific drugs against idiopathic pulmonary fibrosis and showed efficacy against RA-ILD in several clinical trials. Immunosuppressants and disease-modifying antirheumatic drugs (DMARDs) with anti-fibrotic effects have also been used to treat RA-ILD. Immunosuppressants moderate the overexpression of cytokines and immune cells to reduce pulmonary damage and slow the progression of fibrosis. DMARDs with mild anti-fibrotic effects target specific fibrotic pathways to regulate fibrogenic cellular activity, extracellular matrix homeostasis, and oxidative stress levels. Therefore, specific medications are required to effectively treat RA-ILD. In this review, the commonly used RA-ILD treatments are discussed based on their molecular mechanisms and clinical trial results. In addition, a computational approach is proposed to develop specific drugs for RA-ILD.

Early detection of interstitial lung disease in rheumatic diseases: A joint statement from the Portuguese Pulmonology Society, the Portuguese Rheumatology Society, and the Portuguese Radiology and Nuclear Medicine Society

INTRODUCTION

Interstitial lung disease (ILD) contributes significantly to morbidity and mortality in connective tissue disease (CTD). Early detection and accurate diagnosis are essential for informing treatment decisions and prognosis in this setting. Clear guidance on CTD-ILD screening, however, is lacking.

OBJECTIVE

To establish recommendations for CTD-ILD screening based on the current evidence.

METHOD

Following an extensive literature research and evaluation of articles selected for their recency and relevance to the characterization, screening, and management of CTD-ILD, an expert panel formed by six pulmonologists from the Portuguese Society of Pulmonology, six rheumatologists from the Portuguese Society of Rheumatology, and six radiologists from the Portuguese Society of Radiology and Nuclear Medicine participated in a multidisciplinary discussion to produce a joint statement on screening recommendations for ILD in CTD.

RESULTS

The expert panel achieved consensus on when and how to screen for ILD in patients with systemic sclerosis, rheumatoid arthritis, mixed connective tissue disease, Sjögren syndrome, idiopathic inflammatory myopathies and systemic lupus erythematous.

CONCLUSIONS

Despite the lack of data on screening for CTD-ILD, an expert panel of pulmonologists, rheumatologists and radiologists agreed on a series of screening recommendations to support decision-making and enable early diagnosis of ILD to ultimately improve outcomes and prognosis in patients with CTD.

Identification, Monitoring, and Management of Rheumatoid Arthritis-Associated Interstitial Lung Disease

Interstitial lung disease (ILD) is a frequent complication of rheumatoid arthritis (RA) that is associated with a significant increase in mortality. Several risk factors for the development of ILD in patients with RA have been identified, but ILD can still develop in the absence of these risk factors. Screening tools for RA-ILD are required to facilitate early detection of RA-ILD. Close monitoring of patients with RA-ILD for progression is crucial to enable timely implementation of treatment strategies to improve outcomes. Patients with RA are commonly treated with immunomodulatory therapies, although their efficacy in slowing the progression of RA-ILD remains the subject of debate. Clinical trials have shown that antifibrotic therapies slow decline in lung function in patients with progressive fibrosing ILDs, including patients with RA-ILD. The management of patients with RA-ILD should be based on multidisciplinary evaluation of the severity and progression of their ILD and the activity of their articular disease. Close collaboration between rheumatologists and pulmonologists is essential to optimize patient care.

Prevalence and mortality associations of interstitial lung abnormalities in rheumatoid arthritis within a multicentre prospective cohort of smokers

OBJECTIVE

To investigate the prevalence and mortality impact of interstitial lung abnormalities (ILAs) in RA and non-RA comparators.

METHODS

We analysed associations between ILAs, RA, and mortality in COPDGene, a multicentre prospective cohort study of current and past smokers, excluding known interstitial lung disease (ILD) or bronchiectasis. All participants had research chest high-resolution CT (HRCT) reviewed by a sequential reading method to classify ILA as present, indeterminate or absent. RA cases were identified by self-report RA and DMARD use; non-RA comparators had neither an RA diagnosis nor used DMARDs. We examined the association and mortality risk of RA and ILA using multivariable logistic regression and Cox regression.

RESULTS

We identified 83 RA cases and 8725 non-RA comparators with HRCT performed for research purposes. ILA prevalence was 16.9% in RA cases and 5.0% in non-RA comparators. After adjusting for potential confounders, including genetics, current/past smoking and other lifestyle factors, ILAs were more common among those with RA compared with non-RA [odds ratio 4.76 (95% CI 2.54, 8.92)]. RA with ILAs or indeterminate for ILAs was associated with higher all-cause mortality compared with non-RA without ILAs [hazard ratio (HR) 3.16 (95% CI 2.11, 4.74)] and RA cases without ILA [HR 3.02 (95% CI 1.36, 6.75)].

CONCLUSIONS

In this cohort of smokers, RA was associated with ILAs and this persisted after adjustment for current/past smoking and genetic/lifestyle risk factors. RA with ILAs in smokers had a 3-fold increased all-cause mortality, emphasizing the importance of further screening and treatment strategies for preclinical ILD in RA.

Etiology and Pathogenesis of Rheumatoid Arthritis-Interstitial Lung Disease

Interstitial lung disease (ILD) is one of the most serious extra-articular complications of rheumatoid arthritis (RA), which increases the mortality of RA. Because the pathogenesis of RA-ILD remains poorly understood, appropriate therapeutic strategies and biomarkers have not yet been identified. Thus, the goal of this review was to summarize and analyze the reported data on the etiology and pathogenesis of RA-ILD. The incidence of RA-ILD increases with age, and is also generally higher in men than in women and in patients with specific genetic variations and ethnicity. Lifestyle factors associated with an increased risk of RA-ILD include smoking and exposure to pollutants. The presence of an anti-cyclic citrullinated peptide antibody, high RA disease activity, and rheumatoid factor positivity also increase the risk of RA-ILD. We also explored the roles of biological processes (e.g., fibroblast-myofibroblast transition, epithelial-mesenchymal transition, and immunological processes), signaling pathways (e.g., JAK/STAT and PI3K/Akt), and the histopathology of RA involved in RA-ILD pathogenesis based on published preclinical and clinical models of RA-ILD in animal and human studies.

Acute and postacute COVID-19 outcomes for patients with rheumatoid arthritis: lessons learned and emerging directions 3 years into the pandemic

PURPOSE OF REVIEW

To summarize the findings of studies investigating patients with rheumatoid arthritis (RA) and risk of acute and postacute COVID-19 outcomes 3 years into the pandemic.

RECENT FINDINGS

Most studies early in the pandemic included all patients with systemic autoimmune rheumatic diseases (SARDs), not only those with RA, due to limited sample size. Many of these studies found that patients with SARDs were at higher risk of COVID-19 infection and severe outcomes, including hospitalization, hyperinflammation, mechanical ventilation, and death. Studies performed later were able to focus on RA and found similar associations, while also identifying RA-specific factors such as immunosuppressive medications, disease activity/severity, and interstitial lung disease as risk factors for severe COVID-19. After COVID-19 vaccination, the risks for COVID-19 infection and severity were reduced for patients with RA, but a gap between the general population persisted, and some patients with RA are susceptible to breakthrough infection after vaccination. Preexposure prophylaxis, effective treatments, and changes in viral variants have also contributed to improved COVID-19 outcomes throughout the pandemic. Emerging data suggest that patients with RA may be at risk for postacute sequelae of COVID-19 (PASC).

SUMMARY

Although COVID-19 outcomes have improved over the pandemic for patients with RA, some experience poor acute and postacute outcomes after COVID-19. Clinicians and patients should remain vigilant about risk mitigation for infection and consider early treatment for RA patients with COVID-19. Future studies are needed to investigate clinical outcomes and mechanisms of PASC among patients with RA.

Diffuse lung involvement in rheumatoid arthritis: a respiratory physician's perspective

ABSTRACT

The lungs are one of the most common extra-articular organs involved in rheumatoid arthritis (RA), which is reported to occur in up to 60% to 80% of RA patients. Respiratory complications are the second leading cause of death due to RA. Although there is a wide spectrum of RA-associated respiratory diseases, interstitial lung disease is the most common manifestation and it impacts the prognosis of RA. There has been progress in understanding the management and progression of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) and RA-associated respiratory diseases recently, for example, opportunistic pulmonary infectious diseases and toxicity from RA therapies. From a chest physicians' perspective, we will update the diagnosis and treatment of RA-associated ILD, methotrexate-associated lung disease, and the complication of Pneumocystis jiroveci pneumonia in RA in this review.

Radiomics to predict the mortality of patients with rheumatoid arthritis-associated interstitial lung disease: A proof-of-concept study

Objectives

Patients with rheumatoid arthritis (RA) and interstitial lung disease (ILD) have increased mortality compared to the general population and factors capable of predicting RA-ILD long-term clinical outcomes are lacking. In oncology, radiomics allows the quantification of tumour phenotype by analysing the characteristics of medical images. Using specific software, it is possible to segment organs on high-resolution computed tomography (HRCT) images and extract many features that may uncover disease characteristics that are not detected by the naked eye. We aimed to investigate whether features from whole lung radiomic analysis of HRCT may alone predict mortality in RA-ILD patients.

Methods

High-resolution computed tomographies of RA patients from January 2012 to March 2022 were analyzed. The time between the first available HRCT and the last follow-up visit or ILD-related death was recorded. We performed a volumetric analysis in 3D Slicer, automatically segmenting the whole lungs and trachea via the Lung CT Analyzer. A LASSO-Cox model was carried out by considering ILD-related death as the outcome variable and extracting radiomic features as exposure variables.

Results

We retrieved the HRCTs of 30 RA-ILD patients. The median survival time (interquartile range) was 48 months (36-120 months). Thirteen out of 30 (43.33%) patients died during the observation period. Whole line segmentation was fast and reliable. The model included either the median grey level intensity within the whole lung segmentation [high-resolution (HR) 9.35, 95% CI 1.56-55.86] as a positive predictor of death and the 10th percentile of the number of included voxels (HR 0.20, 95% CI 0.05-0.84), the voxel-based pre-processing information (HR 0.23, 95% CI 0.06-0.82) and the flatness (HR 0.42, 95% CI 0.18-0.98), negatively correlating to mortality. The correlation of grey level values to their respective voxels (HR 1.52 95% CI 0.82-2.83) was also retained as a confounder.

Conclusion

Radiomic analysis may predict RA-ILD patients' mortality and may promote HRCT as a digital biomarker regardless of the clinical characteristics of the disease.

Suppressed paraoxonase-1 activity associates with elevated oxylipins and the presence of small airways disease in patients with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA)-associated lung disease (LD) associates with significantly increased morbidity and mortality. Although oxidative stress plays an important role in the inflammatory responses in other forms of lung disease, minimal work has evaluated its role in RA-LD. The current work examines the relationship between the anti-oxidant HDL-associated enzyme paraoxonase-1 (PON1), the PON1 Q192R polymorphism, and a targeted oxylipin panel with RA-LD.

METHODS

This study was conducted as a retrospective chart review of a longitudinal single-center cohort of 250 RA patients. CT scans of the chest were reviewed by the interpreting radiologist and classified as small airways disease (SAD), interstitial lung disease (ILD), and bronchiectasis. PON1 activity was measured by its lactonase, arylesterase, and paraoxonase functions. The PON1 Q192R polymorphism and a targeted lipidomics panel were performed as previously reported.

RESULTS

43.2% of the 250 RA patient cohort (n = 108) had available CT scans, including 48 patients (44.4%) with SAD, 27 patients (25.0%) with bronchiectasis, and 16 patients (14.8%) with ILD. Patients with SAD had significantly lower baseline PON1 activity by its arylesterase, and lactonase functions, as well as higher 15-HETE, LTB4, and PGE2 levels compared to those without SAD. These predictors of SAD remained significant after multivariate analysis including known risk factors for RA-LD. Suppressed PON1 activity also correlated with higher levels of 15-HETE and 12-HETE.

CONCLUSION

In a single-center RA cohort, suppressed baseline PON1 activity and elevation in the oxylipins 15-HETE, LTB4, and PGE2 predicted the presence of RA-SAD in longitudinal follow-up. Key Points • Small airways disease (SAD) was present in 44.4% of this rheumatoid arthritis (RA) cohort. • Patients with SAD had significantly lower baseline PON1 activity, as well as higher levels of the oxylipins 15-HETE, LTB4, and PGE2 levels compared to those without SAD. • Further work is warranted to confirm these findings and further define the role of PON1 and lipid oxidation in RA lung disease.

Systemic complications of rheumatoid arthritis: Focus on pathogenesis and treatment

As a systemic autoimmune disease, rheumatoid arthritis (RA) usually causes damage not only to joints, but also to other tissues and organs including the heart, kidneys, lungs, digestive system, eyes, skin, and nervous system. Excessive complications are closely related to the prognosis of RA patients and even lead to increased mortality. This article summarizes the serious complications of RA, focusing on its incidence, pathogenesis, clinical features, and treatment methods, aiming to provide a reference for clinicians to better manage the complications of RA.

Assessment of risk factors in patients with rheumatoid arthritis-associated interstitial lung disease

OBJECTIVE

To assess the risk factors for interstitial lung disease (ILD) in patients with rheumatoid arthritis (RA) and to evaluate the association of ILD with the use of methotrexate as well as with joint disease activity.

METHODS

A retrospective, cross-sectional study conducted between March and December 2019 at a tertiary healthcare center, in a follow-up of RA patients who had undergone pulmonary function tests (PFT) and chest computed tomography. We evaluated the tomographic characteristics, such as the presence of ILD and its extension, as well as joint disease activity. Functional measurements, such as forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO), were also assessed. After this, a multivariate logistic regression analysis was applied in order to identify risk factors associated with ILD.

RESULTS

We evaluated 1.233 patients, of which 134 were eligible for this study. The majority were female (89.6%), with a mean age of 61 years old and with a positive rheumatoid factor (86.2%). RA-associated ILD (RA-ILD) was detected in 49 patients (36.6%). We found an association of RA-ILD with age ≥= 62 year, male sex, smoking history and fine crackles in lung auscultation and a decreased DLCO. The indicators of being aged ≥ 62 years old and having moderate or high RA disease activity were both independent factors associated with RA-ILD, with an odds ratio of 4.36 and 3.03, respectively. The use of methotrexate was not associated with a higher prevalence of ILD.

CONCLUSION

Age and RA disease activity are important risk factors associated with RA-ILD. Methotrexate was not associated with the development of RA-ILD in the present study.

Risk of lung cancer in rheumatoid arthritis and in relation to autoantibody positivity and smoking

OBJECTIVE

Lung cancer is a common malignancy in rheumatoid arthritis (RA). Since smoking is a risk factor for both (seropositive) RA and lung cancer, it remains unclear whether RA, in itself, increases lung cancer risk.

METHODS

We performed a population-based cohort study of patients with RA and individually matched general population reference individuals identified in Swedish registers and from the Epidemiological Investigation of RA early RA study, prospectively followed for lung cancer occurrence 1995-2018. We calculated incidence rates and performed Cox regression to estimate HRs including 95% CIs of lung cancer, taking smoking and RA serostatus into account.

RESULTS

Overall, we included 44 101 patients with RA (590 incident lung cancers, 56 per 100 000), and 216 495 matched general population individuals (1691 incident lung cancers, 33 per 100 000), corresponding to a crude HR (95% CI) of 1.76 (1.60 to 1.93). In subset analyses, this increased risk remained after adjustment for smoking (HR 1.77, 95% CI 1.06 to 2.97). Compared with general population subjects who were never smokers, patients with RA who were ever smokers had almost seven times higher risk of lung cancer. In RA, seropositivity was a significant lung cancer risk factor, even when adjusted for smoking, increasing the incidence 2-6 times. At 20 years, the risk in patients with RA was almost 3%, overall and over 4% for patients who were ever smokers and had at least one RA autoantibody.

CONCLUSIONS

Seropositive RA is a risk factor for lung cancer over and above what can be explained by smoking, although residual confounding by smoking or other airway exposures cannot be formally excluded. There is a need for increased awareness and potentially for regular lung cancer screening, at least in a subset of patients with RA.

Demographic, Lifestyle, and Serologic Risk Factors for Rheumatoid Arthritis (RA)-associated Bronchiectasis: Role of RA-related Autoantibodies

OBJECTIVE

To investigate demographic, lifestyle, and serologic risk factors for isolated rheumatoid arthritis (RA)-associated bronchiectasis (RA-BR) that is not a result of interstitial lung disease (ILD).

METHODS

We performed a case-control study using patients with RA from the Mass General Brigham Biobank. We reviewed the records of all patients with RA meeting the 2010 American College of Rheumatology/European Alliance of Associations for Rheumatology criteria with computed tomography (CT) chest imaging to identify RA-BR cases and controls with RA and RA-related lung disease. For each patient, the CT chest imaging that was performed closest to enrollment was independently reviewed by 2 radiologists for the presence of RA-related lung diseases. Cases had clinical and radiologic evidence of RA-BR without interstitial lung abnormalities on imaging. Controls had RA and no evidence of bronchiectasis or ILD. We examined the associations between demographic, lifestyle, and serologic factors with RA-BR using multivariable logistic regression.

RESULTS

We identified 57 cases of isolated RA-BR and 360 RA controls without RA-related lung disease. In multivariable models, RA-BR was associated with older age at RA onset (OR 1.37 per 10 years, 95% CI 1.02-1.82), lower BMI at RA diagnosis (OR 0.94 per kg/m2, 95% CI 0.89-0.99), seropositive RA (OR 3.96, 95% CI 1.84-8.53), positive rheumatoid factor (OR 4.40, 95% CI 2.14-9.07), and positive anticyclic citrullinated peptide (OR 3.47, 95% CI 1.65-7.31). Higher titers of RA-related autoantibodies were associated with higher odds of RA-BR.

CONCLUSION

Seropositivity, older age at RA diagnosis, and lower BMI at RA onset were associated with isolated bronchiectasis in RA that was not a result of ILD. These findings expand the list of potential risk factors for RA-BR and suggest a pathogenic link between airway inflammation and RA-related autoantibodies.

Novel Biomarkers, Diagnostic and Therapeutic Approach in Rheumatoid Arthritis Interstitial Lung Disease-A Narrative Review

Rheumatoid arthritis (RA) is considered a systemic inflammatory disease marked by polyarthritis which affects the joints symmetrically, leading to progressive damage of the bone structure and eventually joint deformity. Lung involvement is the most prevalent extra-articular feature of RA, affecting 10-60% of patients with this disease. In this review, we aim to discuss the patterns of RA interstitial lung disease (ILD), the molecular mechanisms involved in the pathogenesis of ILD in RA, and also the therapeutic challenges in this particular extra-articular manifestation. The pathophysiology of RA-ILD has been linked to biomarkers such as anti-citrullinated protein antibodies (ACPAs), MUC5B mutation, Krebs von den Lungen 6 (KL-6), and other environmental factors such as smoking. Patients at the highest risk for RA-ILD and those most likely to advance will be identified using biomarkers. The hope is that finding biomarkers with good performance characteristics would help researchers better understand the pathophysiology of RA-ILD and, in turn, lead to the development of tailored therapeutics for this severe RA manifestation.

Sphingosine 1-phosphate receptor-targeted therapeutics in rheumatic diseases

Sphingosine 1-phosphate (S1P), which acts via G protein-coupled S1P receptors (S1PRs), is a bioactive lipid essential for vascular integrity and lymphocyte trafficking. The S1P-S1PR signalling axis is a key component of the inflammatory response in autoimmune rheumatic diseases. Several drugs that target S1PRs have been approved for the treatment of multiple sclerosis and inflammatory bowel disease and are under clinical testing for patients with systemic lupus erythematosus (SLE). Preclinical studies support the hypothesis that targeting the S1P-S1PR axis would be beneficial to patients with SLE, rheumatoid arthritis (RA) and systemic sclerosis (SSc) by reducing pathological inflammation. Whereas most preclinical research and development efforts are focused on reducing lymphocyte trafficking, protective effects of circulating S1P on endothelial S1PRs, which maintain the vascular barrier and enable blood circulation while dampening leukocyte extravasation, have been largely overlooked. In this Review, we take a holistic view of S1P-S1PR signalling in lymphocyte and vascular pathobiology. We focus on the potential of S1PR modulators for the treatment of SLE, RA and SSc and summarize the rationale, pathobiology and evidence from preclinical models and clinical studies. Improved understanding of S1P pathobiology in autoimmune rheumatic diseases and S1PR therapeutic modulation is anticipated to lead to efficacious and safer management of these diseases.

Management of Connective Tissue Disease-related Interstitial Lung Disease

Purpose of Review

This review aims to collate current evidence on the screening, diagnosis, and treatment of various connective tissue disease (CTD)-associated interstitial lung diseases (CTD-ILD) and present a contemporary framework for the management of such patients. It also seeks to summarize treatment outcomes including efficacy and safety of immunosuppressants, anti-fibrotics, and stem cell transplantation in CTD-ILD.

Recent Findings

Screening for ILD has been augmented by the use of artificial intelligence, ultra-low dose computerized tomography (CT) of the chest, and the use of chest ultrasound. Serum biomarkers have not found their way into clinical practice as yet. Identifying patients who need treatment and choosing the appropriate therapy is important to minimize the risk of therapy-related toxicity. The first-line drugs for systemic sclerosis (SSc) ILD include mycophenolate and cyclophosphamide. Nintedanib, an anti-fibrotic tyrosine kinase inhibitor, is approved for use in SSc-ILD. The US Food and Drug Administration (FDA) has recently approved tocilizumab subcutaneous injection for slowing the rate of decline in pulmonary function in adult patients with SSc-ILD. Autologous stem cell transplantation may have a role in select cases of SSc-ILD.

Summary

CTD-ILD is a challenging area with diverse entities and variable outcomes. High-resolution CT is the investigative modality of choice. Treatment decisions need to be individualized and are based on patient symptoms, lung function, radiologic abnormalities, and the risk of disease progression. Precision medicine may play an important role in determining the optimal therapy for an individual patient in the future.

Clinical Features of Anti-Synthetase Syndrome Associated with Prognosis in Patients with Dermatomyositis and Polymyositis

We evaluated whether the clinical features of anti-synthetase syndrome (ASA)—myositis, fever, arthritis, mechanic’s hand, Raynaud’s phenomenon and interstitial lung disease—are relevant to prognosis in patients with dermatomyositis/polymyositis (DM/PM). A retrospective analysis was performed to identify patients diagnosed with DM/PM according to Bohan and Peter criteria. Clinical information, laboratory data and the presence of ASA clinical features at disease diagnosis were searched, and the outcomes of all-cause mortality, intensive care unit admission and disease remission at 1 year were assessed. Among the 86 patients included, fever (36.0%) and interstitial lung disease (26.7%) were the most common ASA clinical features. During the follow-up, 12 patients experienced death, and 7 of the 12 deaths (58.3%) occurred within 3 months of DM/PM diagnosis. Mortality was more frequently observed in those presenting with fever than in those without (25.8% versus 7.3%, p = 0.024). Multivariable Cox proportional analysis revealed that male sex (hazard ratio [HR] 5.53, 95% confidence interval [CI] 1.65, 18.49, p < 0.01) and fever (HR 4.20, 95% CI 1.26, 14.01, p = 0.02) independently predicted mortality. The clinical impact of fever was consistent in both sexes. Fever could be a warning signal heralding the poor outcome of mortality in patients with DM/PM, especially in early disease phases.

Recent Advances in Basic and Clinical Aspects of Rheumatoid Arthritis-associated Interstitial Lung Diseases

Rheumatoid arthritis (RA) is a common autoimmune disease that mainly affects the joints and systemic organs, such as the skin, eyes, heart, gastrointestinal tract, and lungs. In particular, among various pulmonary involvements, interstitial lung disease (ILD) is closely related to the selection of anti-rheumatic drugs and the long-term prognosis of patients with RA. Although the exact pathogenesis of RA-ILD is not well defined, several mechanistic pathways, similar to those of idiopathic pulmonary fibrosis, have been elucidated recently. Conversely, RA-related autoantibodies, including anti-cyclic citrullinated peptide antibody, are detectable in circulation and in the lungs, even in the absence of articular symptoms. RA-ILD can also predate years before the occurrence of joint symptoms. This evidence supports the fact that local dysregulated mucosal immunity in the lung causes systemic autoimmunity, resulting in clinically evident polyarthritis of RA. Because the early diagnosis of RA-ILD is important, imaging tests, such as computed tomography and pulmonary function tests, are being used for early diagnosis, but there is no clear guideline for the early diagnosis of RA-ILD and selection of optimal disease-modifying anti-rheumatic drugs for the treatment of patients with RA with ILD. In addition, the efficacy of nintedanib, a new anti-fibrotic agent, for RA-ILD treatment, has been investigated recently. This review collectively discusses the basic and clinical aspects, such as pathogenesis, animal models, diagnosis, and treatment, of RA-ILD.

Decision-Making Strategy for the Treatment of Rheumatoid Arthritis-Associated Interstitial Lung Disease (RA-ILD)

Rheumatoid arthritis (RA) is a common type of autoimmune arthritis. Patient clinical outcomes might be influenced by numerous respiratory diseases, but interstitial lung disease (ILD) is the most important comorbidity. RA-associated ILD (RA-ILD) is divided into acute/subacute and chronic forms. In the acute/subacute course, if the disease is severe as indicated by a diffuse alveolar damage pattern, high-dose corticosteroids combined with antimicrobial agents should be promptly initiated while considering the differential diagnoses, primarily acute exacerbation (AE) of RA-ILD, drug-induced pneumonitis, and Pneumocystis pneumonia. As initial therapeutic management in the chronic course, the RA itself should be stabilized without delay; thereafter, the activity of ILD itself can be stabilized, considering the safety of each anti-rheumatic drug. The formation of the usual interstitial pneumonia (UIP) pattern is the most important determinant because lung function can worsen more quickly with this pattern. However, because clinicians can fail to identify specific radiological patterns, it is important to determine whether each patient with RA-ILD has UIP-like lesions such as subpleural reticulation, traction bronchiectasis, and honeycombing especially progressively enlarged cysts. In patients with progressive RA-ILD and high risk for infection or AE of ILD in whom fibrosis is dominant, clinicians should consider starting an anti-fibrotic agent.

Prevalence, incidence and cause-specific mortality of rheumatoid arthritis-associated interstitial lung disease among older rheumatoid arthritis patients

OBJECTIVE

We aimed to investigate the prevalence, incidence and cause-specific mortality of RA-associated interstitial lung disease (RA-ILD) among older US patients with RA.

METHODS

We performed a nationwide cohort study using Medicare claims data (parts A, B and D for 2008-2017). RA was identified with a validated algorithm using RA diagnosis codes and DMARD prescription. RA-ILD was identified with a validated algorithm using ILD diagnosis codes by a rheumatologist/pulmonologist. RA-ILD was categorized as prevalent or incident relative to the initial RA observation (baseline/index date). We compared the total mortality of RA-ILD to RA without ILD using multivariable Cox regression, adjusting for baseline covariates. For cause-specific mortality, Fine and Gray subdistribution hazard ratios (sdHRs) were estimated to handle competing risks of alternative mortality causes.

RESULTS

Among 509 787 RA patients (mean age 72.6 years, 76.2% female), 10 306 (2.0%) had prevalent RA-ILD at baseline. After baseline, 13 372 (2.6%) developed RA-ILD during 1 873 127 person-years of follow-up (median 3.0 years/person). During follow-up, 38.7% of RA-ILD patients died compared with 20.7% of RA patients without ILD. After multivariable adjustment, RA-ILD had an HR of 1.66 (95% CI 1.60, 1.72) for total mortality. Accounting for competing risk of other causes of death, RA-ILD had an sdHR of 4.39 (95% CI 4.13, 4.67) for respiratory mortality and an sdHR of 1.56 (95% CI 1.43, 1.71) for cancer mortality compared with RA without ILD.

CONCLUSIONS

RA-ILD was present or developed in nearly 5% of patients in this nationwide study of older patients with RA. Compared with RA without ILD, RA-ILD was associated with excess total, respiratory and cancer mortality that was not explained by measured factors.

Multimorbidity Accrual After Incident Rheumatoid Arthritis: A Wolf at the Door

Rheumatoid arthritis (RA) has long been recognized to have serious extraarticular manifestations such as interstitial lung disease (ILD).¹ Consequences of immunosuppressive medications used to treat RA include serious infections, liver toxicity, and osteoporosis leading to fracture.^2,3.

Interstitial lung disease throughout the rheumatoid arthritis disease course

PURPOSE OF REVIEW

To summarize the current understanding of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) throughout the rheumatoid arthritis (RA) disease course from preclinical to established disease.

RECENT FINDINGS

ILD is a serious extra-articular manifestation of RA. Multiple studies have demonstrated a high prevalence of both subclinical and clinical ILD throughout the RA disease course. Investigations of patients without RA have demonstrated an association between RA-related autoantibodies like anticitrullinated protein antibodies (ACPA) and interstitial abnormalities on lung imaging. A significant proportion of RA-ILD patients develop ILD prior to articular manifestations, suggesting that the lung plays a central role in RA development, perhaps through ACPA production. RA-ILD also occurs in early RA, when exuberant autoantibody production and systemic inflammation may propagate pulmonary disease activity. In patients with established RA, a high burden of subclinical and clinical ILD results in significant morbidity, mortality, and healthcare expenditure. Multiple epidemiologic and genetic risk factors, as well as serum biomarkers, have been associated with RA-ILD.

SUMMARY

Subclinical and clinical ILD occur frequently in preclinical, early, and established RA and may play a key role in RA-related autoantibody production and disease progression. Further studies are needed to better understand the risk factors, prognosis, and potential therapies for RA-ILD.

Serum Krebs von den Lungen-6 and lung ultrasound B lines as potential diagnostic and prognostic factors for rheumatoid arthritis-associated interstitial lung disease

INTRODUCTION

Rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) (RA-ILD) is a serious systemic RA manifestation with high mortality that needs proper, accurate, and sensitive assessment tools.

OBJECTIVES

Firstly, evaluate serum Krebs von den Lungen-6 (KL-6) levels and lung ultrasound B lines (LUS B lines) score in RA-ILD correlating them with the severity of ILD assessed by high-resolution computed tomography (HRCT) and pulmonary function tests (PFTs). Secondly, determine cut-off values for LUS and KL-6 in RA-ILD assessment and outcome prediction.

METHODS

A case-control study included seventy-five RA-ILD patients with an equal number of matched RA patients without ILD. Clinical assessment includes DAS-28 and PFTs, laboratory assessment of serum KL-6 by latex-enhanced immunoturbidimetric assay, and radiological evaluation of ILD using semiquantitative CT grade and LUS B lines.

RESULTS

RA-ILD patients had significantly higher serum KL6 compared to those without ILD (1025.5 ± 419.6 vs. 237.5 ± 51.9, p ≤ 0.001). Serum KL6 was positively correlated with HRCT and LUS scores (r = 0.93, r = 0.97, respectively) with negative correlation with FVC% and FEV1% (r = - 0.93, r = - 0.91, respectively). LUS was positively correlated with KL6 and HRCT (r = 0.97, r = 0.944, respectively) while, negatively correlated with PFTs. Cut-off values of KL6 and LUS were 277.5 U/ml and < 5.5, with AUC 0.878 and 1, sensitivity 86.7% and 100%, and specificity 88% and 100%, respectively.

CONCLUSIONS

The non-invasive, radiation-free LUS with a score < 5.5 combined with serum KL6 could be helpful for RA-ILD assessment correlating with HRCT and disease severity. Serum KL6 combined with LUS is important new and potential prognostic factor predicting poor outcomes in RA-ILD. Further large-scale, multi-center, and prospective studies are needed to confirm these findings.

KEY POINTS

• Combination of the non-invasive, radiation-free LUS with a score < 5.5 and serum KL6 levels of 277.5 U/ml is recommended as prognostic tools for RA-ILD. • Easily obtainable tests such as serum KL-6, inflammatory markers, and LUS are sensitive for assessing RA-ILD and the risk of poor outcomes in patients with RA-ILD. • RA-ILD patients with higher KL6 levels, higher LUS scores had a poor prognosis with short survival. • LUS B lines could be used as the first imaging tool for the evaluation of RA-ILD decreasing the risk of HRCT radiation exposure in asymptomatic or mild RA-ILD patients.

Monitoring and management of fibrosing interstitial lung diseases: a narrative review for practicing clinicians

Close monitoring of patients with fibrosing interstitial lung diseases (ILDs) is important to enable prompt identification and management of progressive disease. Monitoring should involve regular assessment of physiology (including pulmonary function tests), symptoms, and, when appropriate, high-resolution computed tomography. The management of patients with fibrosing ILDs requires a multidisciplinary approach and should be individualized based on factors such as disease severity, evidence of progression, risk factors for progression, comorbidities, and the preferences of the patient. In this narrative review, we discuss how patients with fibrosing ILDs can be effectively monitored and managed in clinical practice.

Zinc and Cadmium in the Aetiology and Pathogenesis of Osteoarthritis and Rheumatoid Arthritis

Osteoarthritis (OA) and rheumatoid arthritis (RA) are inflammatory articular conditions with different aetiology, but both result in joint damage. The nutritionally essential metal zinc (Zn²⁺) and the non-essential metal cadmium (Cd²⁺) have roles in these arthritic diseases as effectors of the immune system, inflammation, and metabolism. Despite both metal ions being redox-inert in biology, they affect the redox balance. It has been known for decades that zinc decreases in the blood of RA patients. It is largely unknown, however, whether this change is only a manifestation of an acute phase response in inflammation or relates to altered availability of zinc in tissues and consequently requires changes of zinc in the diet. As a cofactor in over 3000 human proteins and as a signaling ion, zinc affects many pathways relevant for arthritic disease. How it affects the diseases is not just a question of zinc status, but also an issue of mutations in the many proteins that maintain cellular zinc homoeostasis, such as zinc transporters of the ZIP (Zrt-/Irt-like protein) and ZnT families and metallothioneins, and the multiple pathways that change the expression of these proteins. Cadmium interferes with zinc's functions and there is increased uptake under zinc deficiency. Remarkably, cadmium exposure through inhalation is now recognized in the activation of macrophages to a pro-inflammatory state and suggested as a trigger of a specific form of nodular RA. Here, we discuss how these metal ions participate in the genetic, metabolic, and environmental factors that lead to joint destruction. We conclude that both metal ions should be monitored routinely in arthritic disease and that there is untapped potential for prognosis and treatment.