Fibrosing alveolitis in patients with rheumatoid arthritis as assessed by high resolution computed tomography, chest radiography, and pulmonary function tests

Rheumatoid arthritis extra-articular lung disease: new insights on pathogenesis and experimental drugs

INTRODUCTION

Pulmonary involvement is one of the most common extra-articular manifestations of rheumatoid arthritis (RA), a systemic inflammatory disease characterized by joint swelling and tenderness. All lung compartments can be interested in the course of RA, including parenchyma, airways, and, more rarely, pleura and vasculature.

AREAS COVERED

The aim of this paper is to review the main RA lung manifestations, focusing on pathogenesis, clinical and therapeutic issues of RA-related interstitial lung disease (ILD). Despite an increasing number of studies in the last years, pathogenesis of RA-ILD remains largely debated and the treatment of RA patients with lung involvement is still challenging in these patients.

EXPERT OPINION

Management of RA-ILD is largely based on expert-opinion. Due to the broad clinical manifestations, including both joints and pulmonary involvement, multidisciplinary discussion, including rheumatologist and pulmonologist, is essential, not only for diagnosis, but also to evaluate the best therapeutic approach and follow-up. In fact, the coexistence of different lung manifestations may influence the treatment response and safety. The identification of biomarkers and risk-factors for an early identification of RA patients at risk of developing ILD remains a need that still needs to be fulfilled, and that will require further investigation in the next years.

Serum alarmins and the risk of incident interstitial lung disease in rheumatoid arthritis

OBJECTIVES

To quantify associations of serum alarmins with risk of rheumatoid arthritis-associated interstitial lung disease (RA-ILD).

METHODS

Using serum collected at enrolment, three alarmins (IL-33, thymic stromal lymphopoietin [TSLP] and IL-25) were measured in a multicentre prospective RA cohort. ILD was classified using systematic medical record review. Cross-sectional associations of log-transformed (IL-33, TSLP) or quartile (IL-25) values with RA-ILD at enrolment (prevalent RA-ILD) were examined using logistic regression, while associations with incident RA-ILD developing after enrolment were examined using Cox proportional hazards. Covariates in multivariate models included age, sex, race, smoking status, RA disease activity score and anti-cyclic citrullinated antibody positivity.

RESULTS

Of 2835 study participants, 115 participants (4.1%) had prevalent RA-ILD at baseline and an additional 146 (5.1%) developed incident ILD. There were no associations between serum alarmin concentrations and prevalent ILD in unadjusted or adjusted logistic regression models. In contrast, there was a significant inverse association between IL-33 concentration and the risk of developing incident RA-ILD in unadjusted (hazard ratio [HR] 0.73 per log-fold increase; 95% CI: 0.57, 0.95; P = 0.018) and adjusted (HR 0.77; 95% CI: 0.59, 1.00; P = 0.047) models. No significant associations of TSLP or IL-25 with incident ILD were observed.

CONCLUSION

In this study, we observed a significant inverse association between serum IL-33 concentration and the risk of developing incident RA-ILD, but no associations with prevalent ILD. Additional investigation is required to better understand the mechanisms driving this relationship and how serum alarmin IL-33 assessment might contribute to clinical risk stratification in patients with RA.

Multidimensional biomarker approach integrating tumor markers, inflammatory indicators, and disease activity indicators may improve prediction of rheumatoid arthritis-associated interstitial lung disease

INTRODUCTION

Rheumatoid arthritis (RA) often leads to interstitial lung disease (ILD), significantly affecting patient outcomes. This study explored the diagnostic accuracy of a multi-biomarker approach to offer a more efficient and accessible diagnostic strategy for RA-associated ILD (RA-ILD).

METHODS

Patients diagnosed with RA, with or without ILD, at Beijing Tiantan Hospital from October 2019 to October 2023 were analyzed. A total of 125 RA patients were included, with 76 diagnosed with RA-ILD. The study focused on three categories of indicators: tumor markers, inflammatory indicators, and disease activity measures. The heatmap correlation analysis was employed to analyze the correlation among these indicators. Logistic regression was used to determine odds ratios (OR) for indicators linked to RA-ILD risk. Receiver-operating characteristic (ROC) curve analysis was employed to evaluate the diagnostic potential of these indicators for RA-ILD.

RESULTS

The results of logistic regression analysis showed that tumor markers (carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 125 (CA125), and cytokeratin 19 fragment (CYFRA21-1)), as well as inflammatory indicators (neutrophil, neutrophil-to-lymphocyte ratio (NLR), platelet, C-reactive protein (CRP)) and disease activity measures (disease activity score-28-CRP (DAS28-CRP), rheumatoid factor (RF), and anti-cyclic peptide containing citrulline (anti-CCP)), were significantly associated with RA-ILD. The correlation coefficients among these indicators were relatively low. Notably, the combination indicator 4, which integrated the aforementioned three categories of biomarkers, demonstrated improved diagnostic accuracy with an AUC of 0.857.

CONCLUSION

The study demonstrated that combining tumor markers, inflammatory indicators, and disease activity measures significantly enhanced the prediction of RA-ILD. Key Points • Multidimensional strategy: Integrated tumor markers, inflammatory indicators, and disease activity measures to enhance early detection of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). • Diagnostic accuracy: Employed heatmap correlation and logistic regression, identifying significant associations and improving diagnostic accuracy with a multidimensional biomarker combination. • Superior performance: The combined multidimensional biomarker strategy demonstrated higher diagnostic precision compared to individual or dual-category indicators. • Clinical relevance: Offers a promising, accessible approach for early detection of RA-ILD in clinical settings, potentially improving patient outcomes.

Design of ANCHOR-RA: a multi-national cross-sectional study on screening for interstitial lung disease in patients with rheumatoid arthritis

BACKGROUND

Patients with rheumatoid arthritis (RA) are at risk of developing interstitial lung disease (ILD), which is associated with high mortality. Screening tools based on risk factors are needed to decide which patients with RA should be screened for ILD using high-resolution computed tomography (HRCT). The ANCHOR-RA study is a multi-national cross-sectional study that will develop a multivariable model for prediction of RA-ILD, which can be used to inform screening for RA-ILD in clinical practice.

METHODS

Investigators will enrol consecutive patients with RA who have ≥ 2 of the following risk factors for RA-ILD: male; current or previous smoker; age ≥ 60 years at RA diagnosis; high-positive rheumatoid factor and/or anti-cyclic citrullinated peptide (titre > 3 x upper limit of normal); presence or history of certain extra-articular manifestations of RA (vasculitis, Felty's syndrome, secondary Sjögren's syndrome, cutaneous rheumatoid nodules, serositis, and/or scleritis/uveitis); high RA disease activity in the prior 12 months. Patients previously identified as having ILD, or who have had a CT scan in the prior 2 years, will not be eligible. Participants will undergo an HRCT scan at their local site, which will be assessed centrally by two expert radiologists. Data will be collected prospectively on demographic and RA-related characteristics, patient-reported outcomes, comorbidities and pulmonary function. The primary outcomes will be the development of a probability score for RA-ILD, based on a multivariable model incorporating potential risk factors commonly assessed in clinical practice, and an estimate of the prevalence of RA-ILD in the study population. It is planned that 1200 participants will be enrolled at approximately 30 sites in the USA, UK, Germany, France, Italy, Spain.

DISCUSSION

Data from the ANCHOR-RA study will add to the body of evidence to support recommendations for screening for RA-ILD to improve detection of this important complication of RA and enable early intervention.

TRIAL REGISTRATION

clinicaltrials.gov NCT05855109 (submission date: 3 May 2023).

The diagnosis and management of systemic autoimmune rheumatic disease-related interstitial lung disease: British Society for Rheumatology guideline scope

Interstitial lung disease (ILD) is a significant complication of many systemic autoimmune rheumatic diseases (SARDs), although the clinical presentation, severity and outlook may vary widely between individuals. Despite the prevalence, there are no specific guidelines addressing the issue of screening, diagnosis and management of ILD across this diverse group. Guidelines from the ACR and EULAR are expected, but there is a need for UK-specific guidelines that consider the framework of the UK National Health Service, local licensing and funding strategies. This article outlines the intended scope for the British Society for Rheumatology guideline on the diagnosis and management of SARD-ILD developed by the guideline working group. It specifically identifies the SARDs for consideration, alongside the overarching principles for which systematic review will be conducted. Expert consensus will be produced based on the most up-to-date available evidence for inclusion within the final guideline. Key issues to be addressed include recommendations for screening of ILD, identifying the methodology and frequency of monitoring and pharmacological and non-pharmacological management. The guideline will be developed according to methods and processes outlined in Creating Clinical Guidelines: British Society for Rheumatology Protocol version 5.1.

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.

Association between clinical, serological, functional and radiological findings and ventilatory distribution heterogeneity in patients with rheumatoid arthritis

BACKGROUND

In rheumatoid arthritis (RA), the involvement of the pulmonary interstitium can lead to structural changes in the small airways and alveoli, leading to reduced airflow and maldistribution of ventilation. The single-breath nitrogen washout (SBN2W) test is a measure of the ventilatory distribution heterogeneity and evaluates the small airways. This study aimed to find out which clinical, serological, functional and radiological findings are useful to identify RA patients with pathological values of the phase III slope (SIII) measured by the SBN2W test.

METHODS

This was a cross-sectional study in which RA patients were assessed using the Health Assessment Questionnaire-Disability Index (HAQ-DI) and the Clinical Disease Activity Index (CDAI) and underwent serological analysis of autoantibodies and inflammatory markers. In addition, they underwent pulmonary function tests (including the SBN2W test) and chest computed tomography (CT).

RESULTS

Of the 60 RA patients evaluated, 39 (65%) had an SIII >120% of the predicted value. There were significant correlations between SIII and age (r = 0.56, p<0.0001), HAQ-DI (r = 0.34, p = 0.008), forced vital capacity (FVC, r = -0.67, p<0.0001), total lung capacity (r = -0.46, p = 0.0002), residual volume/total lung capacity (TLC) (r = 0.44, p = 0.0004), and diffusing capacity of the lungs for carbon monoxide (r = -0.45, p = 0.0003). On CT scans, the subgroup with moderate/severe disease had a significantly higher SIII than the normal/minimal/mild subgroup (662 (267-970) vs. 152 (88-283)% predicted, p = 0.0004). In the final multiple regression model, FVC, extent of moderate/severe involvement and age were associated with SIII, explaining 59% of its variability.

CONCLUSIONS

In patients with RA, FVC, extent of lung involvement and age, all of which are easily obtained variables in clinical practice, identify poorly distributed ventilation. In addition, the presence of respiratory symptoms and deteriorated physical function are closely related to the distribution of ventilation in these patients.

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.

Childhood-onset rheumatoid arthritis at a tertiary hospital in Senegal, West Africa

BACKGROUND

Childhood-onset rheumatoid arthritis (CORA), known as rheumatoid factor (RF)-positive juvenile idiopathic arthritis is a type of juvenile idiopathic arthritis that shares the same genetic factors and clinical features as adult-onset rheumatoid arthritis. In Africa, CORA hasn't been the subject of a specific study.

OBJECTIVES

The aim of this study is to describe the clinical features, disease activity, functional disability, and treatment of CORA at diagnosis in Senegal and compare the findings to other CORA populations.

METHODS

We conducted a mixed cohort study by reviewing the medical records of patients diagnosed with CORA with an age of symptom onset < 18 years according to the 2019 PRINTO provisional criteria for RF-positive JIA from January 2020 to December 2022 at rheumatology department of Aristide Le Dantec Hospital in Dakar, Senegal. We collected demographic, clinical, paraclinical and therapeutic data. Disease activity score was assessed by DAS28-ESR and DAS28-CRP. Functional disability was assessed using Health Assessment Questionnaire (HAQ) or Childhood HAQ.

RESULTS

A total of 21 patients were included. Eighteen (85.7%) were Females. The mean age at symptom onset was 13.0 ± 3.0 years, and at diagnosis was 16.4 ± 4.2 years. Morning stiffness, joint swelling, and joint deformities were found in 20, 18 and 13 patients respectively. Four patients had a family history of rheumatoid arthritis. Five patients had extra-articular involvement such as rheumatoid nodules. Two patients had interstitial lung disease. The biological inflammatory syndrome was found in 90% of cases. 16 of 21 (76.2%) patients had positive RF, and 18 of 20 (90%) patients had positive Anti-CCP. Seven of 12 (58.3%) patients had positive anti-nuclear antibodies. The mean DAS28-ESR was 5.7 ± 1.0. Fifteen (71.4%) patients had high disease activity (DAS28-ESR > 5.1). The mean DAS28-CRP was 5.4 ± 1.1. The median HAQ was 2.12 with a mean HAQ of 1.9. Nineteen (90.5%) patients were treated with methotrexate, while 17 (81%) had a combination of methotrexate and hydroxychloroquine. Oral prednisone was used in 17 (81%) cases. Non-steroidal anti-inflammatory drugs were used in 4 cases (19%). After 6 months of treatment, mean DAS28-CRP was 2.9.

CONCLUSION

In our study, CORA mainly affects 13-year-old girls, characterised by high disease activity with joint deformity and significant functional impairment. Treatment is mainly based on methotrexate, prednisone and hydroxychloroquine. Further studies are needed to determine the exact clinical phenotype of this disease.

Serum CHI3L1 as a biomarker of interstitial lung disease in rheumatoid arthritis

Background

Interstitial lung disease (ILD) is a relatively prevalent extra-articular manifestation of rheumatoid arthritis (RA) and contributes to significant morbidity and mortality. This study aimed to analyze the association between chitinase-3 like-protein-1(CHI3L1) and the presence of RA-ILD.

Methods

A total of 239 RA patients fulfilling the American Rheumatism Association (ACR) 1987 revised criteria were enrolled and subclassified as RA-ILD and RA-nILD based on the results of high-resolution computed tomography scans (HRCT) of the chest. The disease activity of RA was assessed by Disease Activity Score for 28 joints (DAS28) and categorized as high, moderate, low, and remission. Chemiluminescence immunoassays were applied to determine the serum levels of CHI3L1. Univariate analysis was performed and the receiver operating characteristics (ROC) curves were plotted to evaluate the correlation between RA-ILD and CHI3L1.

Results

Among the eligible RA patients studied, 60 (25.1%) patients were diagnosed with RA-ILD. Compared with RA-nILD, RA patients with ILD had significantly higher median age (median [IQR], 68.00 [62.00-71.75] vs 53.00 [40.00-63.00], p<0.001) and a higher proportion of males (21 (35.0%) vs 30 (16.8%), p=0.003). Notably, differences in DAS28 scores between the two groups were not observed. The serum level of CHI3L1 was significantly higher in RA-ILD patients (median [IQR], 69.69 [44.51-128.66] ng/ml vs 32.19 [21.63-56.99] ng/ml, p<0.001). Furthermore, the areas under the curve (AUC) of CHI3L1 attained 0.74 (95% confidence interval [CI], 0.68-0.81, p<0.001) in terms of identifying patients with RA-ILD from those without ILD. Similar trends were seen across the spectrum of disease activity based on DAS28-ESR.

Conclusion

Our findings of elevated serum CHI3L1 levels in RA-ILD patients suggest its possible role as a biomarker to detect RA-ILD noninvasively.

Rheumatoid arthritis associated interstitial lung disease: Trends in epidemiology and mortality in Ontario from 2000-2018

BACKGROUND

The epidemiology and mortality of rheumatoid arthritis related interstitial lung disease (RA-ILD) have not been described in Canada. Our aim was to describe recent trends in RA-ILD prevalence, incidence, and mortality in Ontario, Canada.

METHODS

This was a retrospective population-based study using repeated cross-sections from 2000 to 2018. We estimated annual age- and sex-standardized rates for RA-ILD prevalence, incidence and mortality.

RESULTS

Among 184,400 RA patients identified between 2000 and 2018, 5722 (3.1%) were diagnosed with RA-ILD. Most RA-ILD patients were women (63.9%) and ≥60 years old (76.9%) at the time of RA-ILD diagnosis. RA-ILD incidence rose from 1.6 (95% confidence interval (CI) 1.3-2.0) to 3.3 (95% CI 3.0-3.6) per 1000 RA patients (204% relative increase, p < 0.0001) during this time. RA-ILD incidence increased in both sexes and all age groups over time. The cumulative prevalence of RA-ILD increased from 8.4 (95% CI 7.6-9.2) to 21.1 (95% CI 20.3-21.8) per 1000 RA patients (250% relative increase, p < 0.0001), increasing in both sexes and all age groups. All-cause and RA-ILD related mortality declined in patients with RA-ILD over time [55.1% relative reduction, (p < 0.0001) and 70.9% relative reduction, (p < 0.0001), respectively]. In RA-ILD patients, RA-ILD contributed to the cause of death in approximately 29% of cases. Men and older patients had higher all-cause and RA-ILD related mortality.

CONCLUSION

In a large, diverse Canadian population, the incidence and prevalence of RA-ILD are increasing. RA-ILD related mortality is declining, but remains an important cause of death in this population.

Unmet needs and perspectives in rheumatoid arthritis-associated interstitial lung disease: A critical review

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by synovitis as the most common clinical manifestation, and interstitial lung disease (RA-ILD) represents one of the most common and potentially severe extra-articular features. Our current understanding of the mechanisms and predictors of RA-ILD is limited despite the demonstration that an early identification of progressive fibrosing forms is crucial to provide timely treatment with antifibrotic therapies. While high resolution computed tomography is the gold standard technique for the diagnosis and follow-up of RA-ILD, it has been hypothesized that serum biomarkers (including novel and rare autoantibodies), new imaging techniques such as ultrasound of the lung, or the application of innovative radiologic algorithms may help towards predicting and detecting early forms of diseases. Further, while new treatments are becoming available for idiopathic and connective tissue disease-associated forms of lung fibrosis, the treatment of RA-ILD remains anecdotal and largely unexplored. We are convinced that a better understanding of the mechanisms connecting RA with ILD in a subgroup of patients as well as the creation of adequate diagnostic pathways will be mandatory steps for a more effective management of this clinically challenging entity.

Lung Damage in Rheumatoid Arthritis-A Retrospective Study

The current study aimed to evaluate rheumatoid arthritis (RA) patients with interstitial lung disease (ILD) in clinical practice and whether disease characteristics are associated with X-ray and high-resolution computed tomography (HR-CT) findings. Medical history of RA patients from a tertiary rheumatology clinic was retrieved from its electronic database starting from 1 January 2019 until the study date (8 August 2022) using International Classification of Disease version 10 codes for RA, ILD and exclusion criteria. The study included 78 RA patients (75.6% women, 15.4% active smokers), with average time from RA to ILD of 5.6 years. Regarding chest X-ray findings, men had a higher prevalence of nodules, combined fibrosis and nodules and combined bronchiectasis and nodules, rheumatoid factor (RF)-positive patients had a higher prevalence of fibrosis and anti-cyclic citrullinated peptide antibodies (ACPA)-positive patients had a higher prevalence of bronchiectasis. Regarding HR-CT findings, patients actively treated with methotrexate had a higher prevalence of nodules; a combination of fibrosis and nodules; combination of emphysema and nodules; and combination of fibrosis, emphysema and nodules. ILD develops within approximately 5 years from RA diagnosis, and ILD-associated imaging findings on chest X-rays and HR-CT are more prevalent among men with RA, among patients with positive RA serology (RF and/or ACPA) and RA patients on methotrexate.

Screening of interstitial lung disease in patients with rheumatoid arthritis: A systematic review

AIMS

Interstitial lung disease (ILD) is frequent in patients with rheumatoid arthritis (RA) and is associated with significant morbidity and mortality. The aim of this review was to identify the different screening methods for ILD in patients with RA.

METHODS

We ran a systematic search in Pubmed, Embase and Cochrane Library up to April 2020 and did a hand search of the references of the retrieved articles. The search was limited to humans and articles published in English, Spanish or French. We selected studies with any design where: (a) the population included adult patients with RA; (b) the intervention was any screening method for ILD; and (c) validity or reliability of the screening method were evaluated, or a screening method was described. Two reviewers independently screened the articles by title and abstract and subsequently extracted the information using a specific data extraction form.

RESULTS

25 studies were included with a total of 2593 patients. The most frequently used tool for ILD screening was high resolution computed tomography (HRCT) of the lung. Electronic auscultation, biochemical markers, bronchoalveolar lavage (BAL), pulmonary function tests (PFTs) and lung ultrasonography were also evaluated. Across the different studies, electronic auscultation and lung ultrasonography achieved higher accuracy than PFTs, BAL and biochemical markers.

CONCLUSIONS

HRCT resulted as the most sensitive tool for ILD screening in patients with RA. Given its harmlessness and high sensitivity, lung ultrasonography may become the first-choice tool in the future.

Rationale and the Protocol for the Rheumatoid Arthritis-Associated ILD: Screening and Evaluation in High-Risk Patients (RAISE) Study

Rheumatoid arthritis (RA) is chronic inflammatory joint disease with a prevalence of up to 1%. Various extra-articular manifestations have been reported, including rheumatoid arthritis-associated interstitial lung disease (RA-ILD). RA-ILD contributes to significant morbidity and is a leading cause of death in patients with RA. Detection of lung involvement is therefore important. However, the prevalence of RA-ILD is not well known and varies among different studies depending on the methods of detection. Multiple clinical risk factors and novel biomarkers have been explored. To evaluate the usefulness of these predictors and to evaluate the burden of interstitial lung disease (ILD) among patients with RA, we designed a study (RAISE, Rheumatoid Arthritis-associated ILD: Screening and Evaluation in high-risk patients) to assess the prevalence of RA-ILD among RA patients with high risk, and to identify potential clinical and biochemical markers associated with the condition.

Imaging of Lung Disease Associated with Connective Tissue Disease

There is a well-known association between the connective tissue disorders (CTDs) and lung disease. In addition to interstitial lung disease, the CTDs may affect the air spaces and pulmonary vasculature. Imaging tests are important not only in diagnosis but also in management of these complex disorders. In the present review, key aspects of the imaging of CTD-reated diseases are discussed.

SER-SEPAR recommendations for the management of rheumatoid arthritis-related interstitial lung disease. Part 1: Epidemiology, risk factors and prognosis

OBJECTIVE

To develop multidisciplinary recommendations to improve the management of rheumatoid arthritis-related interstitial lung disease (RA-ILD).

METHODS

Clinical research questions relevant to the objective of the document were identified by a panel of rheumatologists and pneumologists selected based on their experience in the field. Systematic reviews of the available evidence were conducted, and evidence was graded according to the Scottish Intercollegiate Guidelines Network (SIGN) criteria. Specific recommendations were made.

RESULTS

Six PICO questions were selected, three of which analysed the incidence and prevalence of RA-ILD, associated risk factors, and predictors of progression and mortality. A total of 6 specific recommendations on these topics, structured by question, were formulated based on the evidence found and/or expert consensus.

CONCLUSIONS

We present the first official SER-SEPAR document with specific recommendations for RA-ILD management developed to resolve some common clinical questions and facilitate decision-making for patients.

Syndrome of Combined Pulmonary Fibrosis and Emphysema: An Official ATS/ERS/JRS/ALAT Research Statement

Background: The presence of emphysema is relatively common in patients with fibrotic interstitial lung disease. This has been designated combined pulmonary fibrosis and emphysema (CPFE). The lack of consensus over definitions and diagnostic criteria has limited CPFE research. Goals: The objectives of this task force were to review the terminology, definition, characteristics, pathophysiology, and research priorities of CPFE and to explore whether CPFE is a syndrome. Methods: This research statement was developed by a committee including 19 pulmonologists, 5 radiologists, 3 pathologists, 2 methodologists, and 2 patient representatives. The final document was supported by a focused systematic review that identified and summarized all recent publications related to CPFE. Results: This task force identified that patients with CPFE are predominantly male, with a history of smoking, severe dyspnea, relatively preserved airflow rates and lung volumes on spirometry, severely impaired DlCO, exertional hypoxemia, frequent pulmonary hypertension, and a dismal prognosis. The committee proposes to identify CPFE as a syndrome, given the clustering of pulmonary fibrosis and emphysema, shared pathogenetic pathways, unique considerations related to disease progression, increased risk of complications (pulmonary hypertension, lung cancer, and/or mortality), and implications for clinical trial design. There are varying features of interstitial lung disease and emphysema in CPFE. The committee offers a research definition and classification criteria and proposes that studies on CPFE include a comprehensive description of radiologic and, when available, pathological patterns, including some recently described patterns such as smoking-related interstitial fibrosis. Conclusions: This statement delineates the syndrome of CPFE and highlights research priorities.

Assessing predictors of rheumatoid arthritis-associated interstitial lung disease using quantitative lung densitometry

OBJECTIVE

To assess predictors of subclinical RA-associated interstitial lung disease (RA-ILD) using quantitative lung densitometry (qLD).

METHODS

RA patients underwent multi-detector row CT scanning at baseline and after an average of 39 months. Scans were analysed with qLD for the percentage of lung parenchyma with high attenuation areas (%HAA: the percentage of voxels of -600 to -250 Hounsfield units). Additionally, a pulmonary radiologist calculated an expert radiologist scoring (ERS) for RA-ILD features. Generalized linear models were used to identify indicators of baseline %HAA and predictors of %HAA change.

RESULTS

Baseline %HAA was assessed in 193 RA patients and 106 had repeat qLD assessment. %HAA was correlated with ERS (Spearman's rho = 0.261; P < 0.001). Significant indicators of high baseline %HAA (>10% of lung parenchyma with high attenuation) included female sex, higher pack-years of smoking, higher BMI and anti-CCP ≥200 units, collectively contributing an area under the receiver operator curve of 0.88 (95% CI 0.81, 0.95). Predictors of %HAA increase, occurring in 49% with repeat qLD, included higher baseline %HAA, presence of mucin 5B (MUC5B) minor allele and absence of HLA-DRB1 shared epitope (area under the receiver operator curve = 0.69; 95% CI 0.58, 0.79). The association of the MUC5B minor allele with %HAA change was higher among men and those with higher cumulative smoking. Within the group with increased %HAA, anti-CCP level was significantly associated with a greater increase in %HAA.

CONCLUSIONS

%HAA, assessed with qLD, was linked to several known risk factors for RA-ILD and may represent a more quantitative method to identify RA-ILD and track progression than expert radiologist interpretation.

Pulmonary fibrosis associated with rheumatoid arthritis: from pathophysiology to treatment strategies

INTRODUCTION

Rheumatoid arthritis (RA) is the most common inflammatory autoimmune disease, characterised by symmetric destructive arthritis and synovitis. Lung involvement is frequent, including in the form of interstitial lung disease (ILD). RA-ILD often presents with a radiologic and pathologic pattern of usual interstitial pneumonia, similar to idiopathic pulmonary fibrosis, highlighting the similarities between the two diseases, but other patterns and pathological associations are described.

AREAS COVERED

This article reviews the pathogenesis of pulmonary fibrosis in the setting of rheumatoid arthritis as well as the current and future therapeutic options.

EXPERT OPINION

Pulmonary fibrosis in the setting of RA-ILD is an example of genotype-environment interaction and involves multiple mechanisms including autoimmunity, inflammation and fibrogenesis. Despite that ILD conveys most of the exceeding mortality in RA patients, there are no official guidelines for the management of RA-ILD. Attention should be paid to potential lung toxicity of RA treatment even though some of them might help stabilise the ILD. Current standard of care is often composed of glucocorticoids that may be associated with immunosuppressive therapy. Following the approval of antifibrotic therapy for ILDs with a progressive fibrosing phenotype, current works are evaluating the benefit of such treatment in RA-ILD.

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.

Rheumatoid Arthritis and Associated Lung Diseases: A Comprehensive Review

Rheumatoid arthritis (RA) is a prevalent autoimmune disorder affecting 0.5-1% of the population in North America and Europe. Pulmonary manifestations in rheumatoid arthritis patients result in significant morbidity and mortality. Management of these pulmonary manifestations in RA patients causes various challenges for the physicians. This review article has discussed the current state of knowledge of these pulmonary manifestations, including interstitial lung diseases, airway-related diseases, pulmonary vasculature, and pleural involvement in RA patients. This review article has also explored various pharmacological options, including steroids, disease-modifying antirheumatic drugs (DMARDs), immunosuppressive drugs, and biologic agents. Non-pharmacological options include conservative treatment, supplemental oxygen, pulmonary rehabilitation, smoking cessation, and lung transplantation.

Prevalence and risk factors of bronchiectasis in rheumatoid arthritis: A systematic review and meta-analysis

OBJECTIVES

We performed a systematic review and meta-analysis for the prevalence and risk factors of rheumatoid arthritis-related bronchiectasis (RA-BR).

METHODS

We queried PubMed and EMBASE databases to identify published literature related to prevalence and risk factors for RA-BR among patients with RA. Data extraction included study design, country, year, method of RA-BR detection, RA characteristics, numerator of RA-BR cases and denominator of patients with RA, and associations with RA-BR presence. We performed a meta-analysis using random or fixed effects models to estimate the prevalence of RA-BR among RA.

RESULTS

Out of a total of 253 studies, we identified 41 total studies that reported on prevalence (n = 34), risk factors (n = 5), or both (n = 2). The included studies had heterogeneous methods to identify RA-BR. Among the 36 studies reporting prevalence, 608 RA-BR cases were identified from a total of 8569 patients with RA. In the meta-analysis, the pooled overall prevalence of RA-BR among RA was 18.7% (95%CI 13.7-24.3%) using random effects and 3.8% (95%CI 3.3-4.2%) using fixed effects. Among studies that used high-resolution chest computed tomography (HRCT) imaging, the prevalence of RA-BR was 22.6% (95%CI 16.8-29.0%) using random effects. When only considering retrospective studies (n = 12), the pooled prevalence of RA-BR among RA was 15.5% (95%CI 7.5-25.5%); among prospective studies (n = 24), the pooled prevalence was 20.7% (95% CI 14.7-27.4%). Risk factors for RA-BR included older age, longer RA duration, genetics (CFTR and HLA), and undetectable circulating mannose binding lectin (MBL) as a biomarker.

CONCLUSION

In this systematic review and meta-analysis, the prevalence of RA-BR was nearly 20% among studies with HRCT imaging, suggesting that bronchiectasis may be a common extra-articular feature of RA. Relatively few factors have been associated with RA-BR. Future studies should standardize methods to identify RA-BR cases and investigate the natural history and clinical course given the relatively high prevalence among RA.

Lifetime risk of rheumatoid arthritis-associated interstitial lung disease in MUC5B mutation carriers

Objectives

To estimate lifetime risk of developing rheumatoid arthritis-associated interstitial lung disease (RA-ILD) with respect to the strongest known risk factor for pulmonary fibrosis, a MUC5B promoter variant.

Methods

FinnGen is a collection of epidemiological cohorts and hospital biobank samples, integrating genetic data with up to 50 years of follow-up within nationwide registries in Finland. Patients with RA and ILD were identified from the Finnish national hospital discharge, medication reimbursement and cause-of-death registries. We estimated lifetime risks of ILD by age 80 with respect to the common variant rs35705950, a MUC5B promoter variant.

Results

Out of 293 972 individuals, 1965 (0.7%) developed ILD by age 80. Among all individuals in the dataset, MUC5B increased the risk of ILD with a HR of 2.44 (95% CI: 2.22 to 2.68). Out of 6869 patients diagnosed with RA, 247 (3.6%) developed ILD. In patients with RA, MUC5B was a strong risk factor of ILD with a HR similar to the full dataset (HR: 2.27, 95% CI: 1.75 to 2.95). In patients with RA, lifetime risks of ILD were 16.8% (95% CI: 13.1% to 20.2%) for MUC5B carriers and 6.1% (95% CI: 5.0% to 7.2%) for MUC5B non-carriers. The difference between risks started to emerge at age 65, with a higher risk among men.

Conclusion

Our findings provide estimates of lifetime risk of RA-ILD based on MUC5B mutation carrier status, demonstrating the potential of genomics for risk stratification of RA-ILD.

The Attitudes and Practices of Physicians Caring for Patients with Rheumatoid Arthritis-Interstitial Lung Disease: An International Survey

OBJECTIVES

This study sought to determine the level of understanding and opinion amongst rheumatologist and pulmonologists regarding risk factors, diagnostic approach and treatment of rheumatoid arthritis-associated interstitial lung disease (RA-ILD).

METHODS

We conducted an international electronic survey of rheumatologists and pulmonologists utilizing two separate Redcap-based surveys with questions on the epidemiology, workup and management of RA-ILD as well as ILD screening questions using case-based scenarios directed at rheumatologists. The survey also collected demographic data on participants including their practice setting, years in practice and country of practice.

RESULTS

We received a total of 616 responses (354 rheumatologists and 262 pulmonologists) from 6 continents. There were significant differences in responses between pulmonologists and rheumatologists in estimated prevalence and mortality, risk factors for the development of ILD in RA and medications that are effective or should be avoided. Rheumatologists were much less likely to consider assessment for ILD in high risk, asymptomatic patients compared with high-risk patients with either symptoms or exam findings suggestive of ILD.

CONCLUSION

Our study brought to light the variability in disease assessment and clinical practice amongst providers caring for patients with RA-ILD and indicate that greater education is needed to optimize clinical decision making in the risk assessment, screening and treatment of RA-ILD. Research questions that address appropriate screening and treatment strategies for RA-ILD will be valuable for rheumatologists given their central role in the overall health and lung health of patients with RA.

Rheumatoid arthritis-associated interstitial lung disease: an overview of epidemiology, pathogenesis and management

Interstitial lung disease (ILD) accounts for the major cause of morbidity and mortality in rheumatoid arthritis (RA). However, little is known of the pathogenesis, diagnosis and treatment of RA-associated ILD. In this review, we describe our present understanding and ongoing research in RA-ILD. Its aetiology does appear to associate with anti-cyclic citrullinated peptide antibodies, MUC5B mutation and smoking. Another focus of this article is on recent diagnostic methods in RA-ILD. Compared with other methods, high-resolution computed tomography (HRCT) imaging is a main method for the evaluation of ILD in RA patients. Pulmonary function is better suited for assessing progression. An important topic relates to therapeutic intervention. Disease-modifying anti-rheumatic drugs (DMARDs) in RA lack strong evidence in the onset or worsening of ILD. The available literature support that methotrexate, leflunomide, abatacept and rituximab play beneficial roles in the prevention and treatment of RA-ILD.

Baseline Characteristics and Progression of a Spectrum of Interstitial Lung Abnormalities and Disease in Rheumatoid Arthritis

BACKGROUND

Interstitial lung abnormalities (ILA) and interstitial lung disease (ILD) are seen in up to 60% of individuals with rheumatoid arthritis (RA), some of which will progress to have a significant impact on morbidity and mortality rates. Better characterization of progressive interstitial changes and identification of risk factors that are associated with progression may enable earlier intervention and improved outcomes.

RESEARCH QUESTION

What are baseline characteristics associated with RA-ILD progression?

STUDY DESIGN AND METHODS

We performed a retrospective study in which all clinically indicated CT chest scans in adult individuals with RA from 2014 to 2016 were evaluated for interstitial changes, and the data were further subdivided into ILA and ILD based on clinical record review. Progression was determined visually and subsequently semiquantified.

RESULTS

Those individuals with a spectrum of interstitial changes (64 of 293) were older male smokers and less likely to be receiving biologics/small molecule disease-modifying antirheumatic drugs. Of 44% of the individuals with ILA, 46% had had chest CT scans performed for nonpulmonary indications. Of the 56 individuals with ILA/ILD with sequential CT scans, 38% had evidence of radiologic progression over 4.4 years; 29% of of individuals with ILA progressed. Risk factors for progressive ILA/ILD included a subpleural distribution and higher baseline involvement.

INTERPRETATION

Of 293 individuals with RA with clinically indicated CT scans, interstitial changes were observed in 22%, one-half of whom had had a respiratory complaint at the time of imaging; radiologic progression was seen in 38%. Of individuals with progressive ILA, one-half had had baseline CT scans performed for nonpulmonary indications. Subpleural distribution and higher baseline ILA/ILD extent were risk factors associated with progression. Prospective longitudinal studies of RA-ILA are necessary.

Progressive fibrosing interstitial lung disease associated with systemic autoimmune diseases

Interstitial lung disease (ILD) is a common manifestation of systemic autoimmune diseases and a leading cause of death in these patients. A proportion of patients with autoimmune ILDs develop a progressive fibrosing form of ILD, characterized by increasing fibrosis on high-resolution computed tomography, worsening of lung function, and early mortality. Autoimmune disease-related ILDs have a variable clinical course and not all patients will require treatment, but all patients should be monitored for signs of progression. Apart from systemic sclerosis-associated ILD, the limited evidence to support the efficacy of immunosuppression as a treatment for ILDs is based mainly on small retrospective series and expert opinion. Non-clinical data suggest that there are commonalities in the mechanisms that drive progressive fibrosis in ILDs with an immunological trigger as in other forms of progressive fibrosing ILD. This suggests that nintedanib and pirfenidone, drugs known to slow disease progression in patients with idiopathic pulmonary fibrosis, may also slow the progression of ILD associated with systemic autoimmune diseases. In the SENSCIS® trial, nintedanib reduced the rate of ILD progression in patients with systemic sclerosis-associated ILD. The results of other large clinical trials will provide further insights into the role of anti-fibrotic therapies in the treatment of autoimmune disease-related ILDs.

Computed tomographic characterization of the pulmonary system in clinically normal alpacas

OBJECTIVE

To characterize and quantitatively assess the typical pulmonary anatomy of healthy adult alpacas with multidetector row CT.

ANIMALS

10 clinically normal adult female alpacas.

PROCEDURES

CT examination of the thorax was performed before and after IV administration of iodinated contrast medium in sedated alpacas in sternal recumbency. Measurements of the trachea, bronchi and related blood vessels, and selected vertebrae as well as the extent and density of lung parenchyma were performed with a Digital Imaging and Communications in Medicine (DICOM) viewer. Morphometric and quantitative data were summarized.

RESULTS

Separation of individual lung lobes could not be identified, except for the accessory lung lobe. In all alpacas, both lungs extended farther caudally at the medial aspect than at the lateral aspect. The right lung extended farther in both cranial and caudal directions than did the left lung. The branching pattern of the bronchial tree varied only slightly among alpacas and consisted of 1 cranial bronchus and 3 caudal bronchi bilaterally, with a right accessory bronchus. Luminal diameters of first-generation bronchi ranged from 3 to 9 mm. Mean ± SD parenchymal lung density was -869 ± 40 Hounsfield units (HU) before contrast injection and -825 ± 51 HU after contrast injection. Mean difference in diameter between bronchi and associated arteries or veins was 0.8 ± 0.9 mm.

CONCLUSIONS AND CLINICAL RELEVANCE

Knowledge of the typical anatomy of the lungs and bronchial tree in healthy alpacas as determined via CT will aid veterinarians in clinical assessment and bronchoscopic evaluation of alpacas.