Azathioprine response in patients with fibrotic connective tissue disease-associated interstitial lung disease

Efficacy of disease-modifying antirheumatic drugs in primary Sjögren's syndrome-related interstitial lung disease

OBJECTIVES

To evaluate the treatment modalities and their effects in primary Sjögren's syndrome (pSS) patients with interstitial lung disease (ILD).

METHODS

In this chart review study, patients diagnosed with pSS-related ILD (pSS-ILD) between January 2004 and August 2022 were screened. Glucocorticoid use and administered disease-modifying antirheumatic drugs (DMARDs) were determined. The difference between forced vital capacity (FVC) and diffusion capacity of the lungs for carbon monoxide (DLCO) before and after treatment was evaluated.

RESULTS

ILD was present in 44 of 609 patients (7.2%) diagnosed with pSS. In 27 patients included in the study, steroid usage was 81.5%. There was a statistically insignificant increase in FVC% (from 80.20±22.1 to 81.6±23.0) and a decrease in DLCO% (53.7±15.3-52.2±19.3) with DMARD treatment (p=0.434 and p=0.652, respectively). There was no significant difference between the treatment groups (azathioprine [AZA], mycophenolate mofetil [MMF], and rituximab [RTX]) in terms of the change in FVC% and DLCO% compared with baseline levels. The effect of treatment on FVC and DLCO was similar in UIP and NSIP patterns.

CONCLUSIONS

AZA, MMF, and RTX have similar effects on pulmonary functions in pSS-ILD and provide disease stabilization.

2023 American College of Rheumatology (ACR)/American College of Chest Physicians (CHEST) Guideline for the Treatment of Interstitial Lung Disease in People with Systemic Autoimmune Rheumatic Diseases

OBJECTIVE

We provide evidence-based recommendations regarding the treatment of interstitial lung disease (ILD) in adults with systemic autoimmune rheumatic diseases (SARDs).

METHODS

We developed clinically relevant population, intervention, comparator, and outcomes questions. A systematic literature review was then performed, and the available evidence was rated using the Grading of Recommendations, Assessment, Development, and Evaluation methodology. A panel of clinicians and patients reached consensus on the direction and strength of the recommendations.

RESULTS

Thirty-five recommendations were generated (including two strong recommendations) for first-line SARD-ILD treatment, treatment of SARD-ILD progression despite first-line ILD therapy, and treatment of rapidly progressive ILD. The strong recommendations were against using glucocorticoids in systemic sclerosis-ILD as a first-line ILD therapy and after ILD progression. Otherwise, glucocorticoids are conditionally recommended for first-line ILD treatment in all other SARDs.

CONCLUSION

This clinical practice guideline presents the first recommendations endorsed by the American College of Rheumatology and American College of Chest Physicians for the treatment of ILD in people with SARDs.

Connective Tissue Disease Associated Interstitial Lung Disease

Connective tissue disease associated interstitial lung disease (CTD-ILD) is a heterogenous collection of conditions with a diverse spectrum of interstitial lung disease (ILD) manifestations. Currently, clinical practice of lung-directed immunosuppression in CTD-ILD is supported by several randomized, placebo-controlled trials (RCTs) in patients with scleroderma and several observational, retrospective studies in other autoimmune conditions. However, given the harm of immunosuppression in idiopathic pulmonary fibrosis, there is an urgent need for RCTs of immunosuppression and antifibrotic agents in fibrotic CTD-ILD populations as well as the study of intervention in patients with subclinical CTD-ILD.

2023 American College of Rheumatology (ACR)/American College of Chest Physicians (CHEST) Guideline for the Treatment of Interstitial Lung Disease in People with Systemic Autoimmune Rheumatic Diseases

OBJECTIVE

We provide evidence-based recommendations regarding the treatment of interstitial lung disease (ILD) in adults with systemic autoimmune rheumatic diseases (SARDs).

METHODS

We developed clinically relevant population, intervention, comparator, and outcomes questions. A systematic literature review was then performed, and the available evidence was rated using the Grading of Recommendations, Assessment, Development, and Evaluation methodology. A panel of clinicians and patients reached consensus on the direction and strength of the recommendations.

RESULTS

Thirty-five recommendations were generated (including two strong recommendations) for first-line SARD-ILD treatment, treatment of SARD-ILD progression despite first-line ILD therapy, and treatment of rapidly progressive ILD. The strong recommendations were against using glucocorticoids in systemic sclerosis-ILD as a first-line ILD therapy and after ILD progression. Otherwise, glucocorticoids are conditionally recommended for first-line ILD treatment in all other SARDs.

CONCLUSION

This clinical practice guideline presents the first recommendations endorsed by the American College of Rheumatology and American College of Chest Physicians for the treatment of ILD in people with SARDs.

Clinically Relevant Biomarkers in Connective Tissue Disease-Associated Interstitial Lung Disease

Interstitial lung disease (ILD) complicates connective tissue disease (CTD) with variable incidence and is a leading cause of death in these patients. To improve CTD-ILD outcomes, early recognition and management of ILD is critical. Blood-based and radiologic biomarkers that assist in the diagnosis CTD-ILD have long been studied. Recent studies, including -omic investigations, have also begun to identify biomarkers that may help prognosticate such patients. This review provides an overview of clinically relevant biomarkers in patients with CTD-ILD, highlighting recent advances to assist in the diagnosis and prognostication of CTD-ILD.

Novel Therapeutic Approaches in Connective Tissue Disease-Associated Interstitial Lung Disease

Connective tissue diseases (CTD) comprise a group of autoimmune diseases that can affect multiple organs in the body including the lungs. The most common form of pulmonary involvement is interstitial lung disease (ILD). CTD-associated ILD (CTD-ILD) can take one of several courses including nonprogressive, chronically progressive, or rapidly progressive. Chronically and rapidly progressive patterns are associated with increased mortality. Limited randomized controlled trial data are available for treatment of CTD-ILD, with most data coming from systemic sclerosis-related ILD. The current first-line treatment for all CTD-ILD is immunosuppression with consideration of antifibrotics, stem cell transplant, and lung transplant in progressive disease. In this article, we review data for ILD treatment options in systemic sclerosis, rheumatoid arthritis, myositis, and primary Sjögren's syndrome-related ILDs.

Overview of Rheumatoid Arthritis-Associated Interstitial Lung Disease and Its Treatment

Interstitial lung disease (ILD) is a common pulmonary complication of rheumatoid arthritis (RA), causing significant morbidity and mortality. Optimal treatment for RA-ILD is not yet well defined. Reliable prognostic indicators are largely byproducts of prior ILD progression, including low or decreasing forced vital capacity and extensive or worsening fibrosis on imaging. In the absence of validated tools to predict treatment response, decisions about whether to initiate or augment treatment are instead based on clinical judgment. In general, treatment should be initiated in patients who are symptomatic, progressing, or at high risk of poor outcomes. Retrospective data suggest that mycophenolate mofetil, azathioprine, and rituximab are likely effective therapies for RA-ILD. Abatacept is also emerging as a potential first-line treatment option for patients with RA-ILD. Further, recent data demonstrate that immunosuppression may be beneficial even in patients with a usual interstitial pneumonia (UIP) pattern on imaging, suggesting that immunosuppression should be considered irrespective of imaging pattern. Recent randomized controlled trials have shown that antifibrotic medications, such as nintedanib and likely pirfenidone, slow forced vital capacity decline in RA-ILD. Consideration can be given to antifibrotic initiation in patients progressing despite immunosuppression, particularly in patients with a UIP pattern. Future research directions include developing tools to predict which patients will remain stable from patients who will progress, discriminating patients who will respond to treatment from nonresponders, and developing algorithms for starting immunosuppression, antifibrotics, or both as first-line therapies.

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.

Interstitial Lung Disease in Rheumatoid Arthritis: A Review

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder. Although the joints are typically the first area affected in RA, it can also involve extra-articular regions. This article provides an overview on rheumatoid arthritis-associated interstitial lung disease (RA-ILD), a component of the disease manifestations leading to significant morbidity and mortality. Managing these pulmonary symptoms in people with RA poses a number of difficulties for medical professionals. In this review article, we shed light on the prevalence of RA-ILD and the common pulmonary manifestations of RA, while focusing on the evolving pathogenesis concepts that link them to RA's autoimmune cascade. We also address the diagnostic challenges and the available screening modalities that aid in the early recognition and effective management of these pulmonary complications. Furthermore, glucocorticoids, disease-modifying antirheumatic medications, immunosuppressive medications, and biological agents are among the pharmacological approaches that have been explored in this review study.

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.

Telomere length and immunosuppression in non-idiopathic pulmonary fibrosis interstitial lung disease

BACKGROUND

Studies suggest a harmful pharmacogenomic interaction exists between short leukocyte telomere length (LTL) and immunosuppressants in idiopathic pulmonary fibrosis (IPF). It remains unknown if a similar interaction exists in non-IPF interstitial lung disease (ILD).

METHODS

A retrospective, multicentre cohort analysis was performed in fibrotic hypersensitivity pneumonitis (fHP), unclassifiable ILD (uILD) and connective tissue disease (CTD)-ILD patients from five centres. LTL was measured by quantitative PCR for discovery and replication cohorts and expressed as age-adjusted percentiles of normal. Inverse probability of treatment weights based on propensity scores were used to assess the association between mycophenolate or azathioprine exposure and age-adjusted LTL on 2-year transplant-free survival using weighted Cox proportional hazards regression incorporating time-dependent immunosuppressant exposure.

RESULTS

The discovery and replication cohorts included 613 and 325 patients, respectively. In total, 40% of patients were exposed to immunosuppression and 22% had LTL <10th percentile of normal. fHP and uILD patients with LTL <10th percentile experienced reduced survival when exposed to either mycophenolate or azathioprine in the discovery cohort (mortality hazard ratio (HR) 4.97, 95% CI 2.26-10.92; p<0.001) and replication cohort (mortality HR 4.90, 95% CI 1.74-13.77; p=0.003). Immunosuppressant exposure was not associated with differential survival in patients with LTL ≥10th percentile. There was a significant interaction between LTL <10th percentile and immunosuppressant exposure (discovery pinteraction=0.013; replication pinteraction=0.011). Low event rate and prevalence of LTL <10th percentile precluded subgroup analyses for CTD-ILD.

CONCLUSION

Similar to IPF, fHP and uILD patients with age-adjusted LTL <10th percentile may experience reduced survival when exposed to immunosuppression.

Targeted Therapy in Rheumatoid-Arthritis-Related Interstitial Lung Disease

Rheumatoid arthritis (RA) is a chronic autoimmune multisystem inflammatory disease in which lung involvement is the most common extra-articular manifestation. Parenchymal lung involvement or interstitial lung disease (ILD) is a significant cause of morbidity and mortality and there is a paucity of evidence-based guidance on how to best treat RA-ILD. This review article aims to evaluate the evidence from cohort studies and best real word data from registries. Extensive discussion of the relative merits and drawbacks of glucocorticoids, various biologics, small molecules and anti-fibrotics is presented. The limited available guidelines in RA-ILD are also discussed and a rational treatment algorithm is offered.

Better Safe than Sorry: Rheumatoid Arthritis, Interstitial Lung Disease, and Medication-A Narrative Review

It is well known that rheumatoid arthritis (RA) patients are at an increased risk of developing non-infectious pulmonary complications, especially interstitial lung disease (ILD); however, the clinician must keep in mind that lung disease could not only be a manifestation of the underlying condition, but also a consequence of using disease-modifying therapies. New-onset ILD or ILD worsening has also been reported as a possible consequence of both conventional disease-modifying antirheumatic drugs (DMARDs) and biologic agents. This study is a narrative review of the current literature regarding the potential risk of developing interstitial lung disease along with the administration of specific drugs used in controlling rheumatoid arthritis. Its purpose is to fill knowledge gaps related to this challenging patient cohort by addressing various aspects of the disease, including prevalence, disease features, treatment strategies, and patient outcomes.

Clinically Relevant Biomarkers in Connective Tissue Disease-Associated Interstitial Lung Disease

Interstitial lung disease (ILD) complicates connective tissue disease (CTD) with variable incidence and is a leading cause of death in these patients. To improve CTD-ILD outcomes, early recognition and management of ILD is critical. Blood-based and radiologic biomarkers that assist in the diagnosis CTD-ILD have long been studied. Recent studies, including -omic investigations, have also begun to identify biomarkers that may help prognosticate such patients. This review provides an overview of clinically relevant biomarkers in patients with CTD-ILD, highlighting recent advances to assist in the diagnosis and prognostication of CTD-ILD.

Connective Tissue Disease Associated Interstitial Lung Disease

Connective tissue disease associated interstitial lung disease (CTD-ILD) is a heterogenous collection of conditions with a diverse spectrum of interstitial lung disease (ILD) manifestations. Currently, clinical practice of lung-directed immunosuppression in CTD-ILD is supported by several randomized, placebo-controlled trials (RCTs) in patients with scleroderma and several observational, retrospective studies in other autoimmune conditions. However, given the harm of immunosuppression in idiopathic pulmonary fibrosis, there is an urgent need for RCTs of immunosuppression and antifibrotic agents in fibrotic CTD-ILD populations as well as the study of intervention in patients with subclinical CTD-ILD.

"Management of myositis associated interstitial lung disease"

Idiopathic inflammatory myopathies (IIM) are rare disorders characterised by the presence of skeletal muscle inflammation, with interstitial lung disease (ILD) being the most frequent pulmonary manifestation. The spectrum of clinical presentations of myositis related ILD (M-ILD) encompasses a chronic process to a rapidly progressive ILD (RP-ILD); which is associated with a high mortality rate. The most effective treatments remain controversial and poses a unique challenge to both rheumatologists and respiratory physicians to manage. Given the rare heterogenous nature of M-ILD, there is a paucity of data to guide treatment. The cornerstone of existing treatments encompasses combinations of immunosuppressive therapies, as well as non-pharmacological therapies. In this review, we aim to summarize the current pharmacological therapies (including its dosing regimens and side effects profiles) and non-pharmacological therapies. Based on the existing literature to date, we propose a treatment algorithm for both chronic M-ILD and RP-ILD.

Bacterial Infections Associated with Immunosuppressive Agents Commonly Used in Patients with Interstitial Lung Diseases

There are about 200 different types of interstitial lung disease (ILD), and a crucial initial step in the assessment of a patient with suspected ILD is achieving an appropriate diagnosis. Some ILDs respond to immunosuppressive agents, while immunosuppression can be detrimental in others, hence treatment is based on the most confident diagnosis with consideration of a patient's risk factors. Immunosuppressive medications have the potential to result in substantial, and perhaps life-threatening, bacterial infections to a patient. However, data on the risk of bacterial infections from immunosuppressive treatment specifically in patients with interstitial lung disease is lacking. We hereby review the immunosuppressive treatments used in ILD patients excluding sarcoidosis, highlight their risk of bacterial infections, and discuss the potential mechanisms that contribute to the increased risk of infections.

Diagnosis and Pharmacologic Management of Fibrotic Interstitial Lung Disease

Interstitial lung disease is an umbrella term that encompasses a spectrum of parenchymal lung pathologies affecting the gas exchanging part of the lung. While many of these disease entities are not fibrotic in nature, a number can lead to pulmonary fibrosis which may or may not progress over time. Idiopathic pulmonary fibrosis is the prototypical, progressive fibrotic interstitial lung disease, which can lead to worsening hypoxemic respiratory failure and mortality within a number of years from the time of diagnosis. The importance of an accurate and timely diagnosis of interstitial lung diseases, which is needed to inform prognosis and guide clinical management, cannot be overemphasized. Developing a consensus diagnosis requires the incorporation of a variety of factors by a multidisciplinary team, which then may or may not determine a need for tissue sampling. Clinical management can be challenging given the heterogeneity of disease behavior and the paucity of controlled trials to guide decision making. This review addresses current paradigms and recent updates in the diagnosis and pharmacologic management of these fibrotic interstitial lung diseases.

Treatment Outcomes for Rheumatoid Arthritis-Associated Interstitial Lung Disease: A Real-World, Multisite Study of the Impact of Immunosuppression on Pulmonary Function Trajectory

BACKGROUND

Rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) is common in patients with RA and leads to significant morbidity and mortality. No randomized, placebo-controlled data are available that support the role of immunosuppression to treat RA-associated ILD, despite being widely used in clinical practice.

RESEARCH QUESTION

How does immunosuppression impact pulmonary function trajectory in a multisite retrospective cohort of patients with RA-associated ILD?

STUDY DESIGN AND METHODS

Patients with RA who started treatment for ILD with mycophenolate, azathioprine, or rituximab were identified retrospectively from five ILD centers. Change in lung function before and after treatment was analyzed using a linear spline mixed-effect model with random intercept. Prespecified secondary analyses examined the impact of radiologic pattern of ILD (ie, usual interstitial pneumonia [UIP] vs non-UIP) on treatment trajectory.

RESULTS

Two hundred twelve patients were included in the analysis: 92 patients (43.4%) were treated with azathioprine, 77 patients (36.3%) were treated with mycophenolate mofetil, and 43 patients (20.3%) were treated with rituximab. In the combined analysis of all three agents, an improvement in FVC % predicted was found after 12 months of treatment compared with the potential 12-month response without treatment (+3.90%; P ≤ .001; 95% CI, 1.95-5.84). Diffusing capacity of the lungs for carbon monoxide (Dlco) % predicted also improved at 12 months (+4.53%; P ≤ .001; 95% CI, 2.12-6.94). Neither the UIP pattern of ILD nor choice of immunosuppressive agent significantly impacted the pulmonary function trajectory on immunosuppression.

INTERPRETATION

Immunosuppression was associated with an improved trajectory in FVC and Dlco compared with the pretreatment pulmonary function trajectory. Prospective, randomized trials are required to validate these findings.

Hypersensitivity Pneumonitis With and Without Autoimmune Features: A Clinical Comparative Analysis

BACKGROUND

Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) caused by an immunological reaction to repeated inhalational exposure to antigens. The etiology and exact immunopathology are poorly understood. Autoimmunity overlapping with HP has been described but the role of concomitant autoimmunity in the clinical course and outcome of the HP is not clearly established. In this study, we examined patients diagnosed with HP and compare them to patients with concomitant HP and autoimmunity.

METHODS

Patients were retrospectively screened from a single-center ILD registry. Patients > 18 years with an established multidisciplinary diagnosis of HP were included in the study. Patients with HP without autoimmune features and patients with HP with autoimmune features (HPAF) were assessed. We compared the demographics, clinical characteristics, treatment, and outcomes between the two groups. We used a Cox proportional hazards model to compare lung transplant-free survival outcomes of patients with HPAF to those with non-HPAF HP patients.

RESULTS

Of 73 patients with HP, 43 were diagnosed with HPAF. Patients with HPAF had a higher echocardiographic probability of pulmonary hypertension as compared to non-HPAF HP patients [48.8 vs 23.3%, p = 0.028, Crude odds ratio (cOR) = 3.14]. Symptomatically, those with HPAF reported a higher prevalence of arthritis as compared to non-HPAF HP (20.9 vs 3.3%, p = 0.040, cOR = 7.68). No significant differences between pulmonary function tests, oxygen requirements, mortality, and lung transplantation rates were found between the two groups. There was no statistically significant difference in transplant-free survival (p = 0.836).

CONCLUSION

Patients with HPAF had a higher echocardiographic probability of pulmonary hypertension as compared to patients with non-HPAF HP. The clinical characteristics and outcomes did not differ between the two groups and concomitant autoimmunity among the HP group did not portend a poorer prognosis.

SER-SEPAR recommendations for the management of rheumatoid arthritis-related interstitial lung disease. Part 2: Treatment

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 safety and effectiveness of glucocorticoids, classical synthetic disease-modifying anti-rheumatic drugs (DMARDs) and other immunosuppressants, biological agents, targeted synthetic DMARDs, and antifibrotic therapies in the treatment of this complication. A total of 12 recommendations 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, reduce clinical healthcare variability, and facilitate decision-making for patients.

[Latest news on RA-ILD]

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is of high clinical relevance. It not only affects the quality of life but also makes a significant contribution to the mortality rate of patients with rheumatoid arthritis. RA-ILD can present with all known radiological and histopathological patterns seen in other interstitial pneumonias. Among these pneumonias, diffuse alveolar damage (DAD), followed by usual interstitial pneumonia (UIP) has the worst prognosis. In addition, acute exacerbation of RA-ILD, which can occur at any time during the disease, is highly lethal. An algorithm for the diagnosis and treatment of RA-ILD is pending and will be addressed in the following article. In addition to immunosuppressants and disease-modifying antirheumatic drugs (DMARD), antifibrotics have recently gained importance in the therapy of RA-ILD.

Safety and Effectiveness of Abatacept in a Prospective Cohort of Patients with Rheumatoid Arthritis–Associated Interstitial Lung Disease

Objective: To prospectively evaluate the safety and efficacy profile of abatacept in patients with rheumatoid arthritis–associated interstitial lung disease (RA-ILD). Methods: We performed a prospective observational multicenter study of a cohort of patients with RA-ILD treated with abatacept between 2015 and 2021. Patients were evaluated using high-resolution computed tomography and pulmonary function tests at initiation, 12 months, and the end of follow-up. The effectiveness of abatacept was evaluated based on whether ILD improved, stabilized, progressed, or was fatal. We also evaluated factors such as infection, hospitalization, and inflammatory activity using the 28-joint Disease Activity Score with the erythrocyte sedimentation rate (DAS28-ESR). Cox regression analysis was performed to identify factors associated with progression of lung disease. Results: The study population comprised 57 patients with RA-ILD treated with abatacept for a median (IQR) of 27.3 (12.2–42.8) months. Lung disease had progressed before starting abatacept in 45.6% of patients. At the end of follow-up, lung disease had improved or stabilized in 41 patients (71.9%) and worsened in 13 (22.8%); 3 patients (5.3%) died. No significant decreases were observed in forced vital capacity (FVC) or in the diffusing capacity of the lung for carbon monoxide (DLCO).The factors associated with progression of RA-ILD were baseline DAS28-ESR (OR [95% CI], 2.52 [1.03–3.12]; p = 0.041), FVC (OR [95% CI], 0.82 [0.70–0.96]; p = 0.019), and DLCO (OR [95% CI], 0.83 [0.72–0.96]; p = 0.018). Only 10.5% of patients experienced severe adverse effects. Conclusion: Pulmonary function and joint inflammation stabilized in 71% of patients with RA-ILD treated with abatacept. Abatacept had a favorable safety profile.

Effect size of rituximab on pulmonary function in the treatment of connective-tissue disease-related interstitial lung disease: a systematic review and meta-analysis

Background

Rituximab (RTX) has been previously reported as directed treatment in patients with connective-tissue disease-related interstitial lung diseases (CTD-ILD). A systematic assessment of treatment effect size on pulmonary function outcomes and related adverse effects in patients with CTD-ILD has not been previously reported.

Methods

We performed a systematic review and meta-analysis of published reports from PubMed, Embase, and Cochrane Libraries. Randomized and non-randomized controlled trials, case–control, cohort, and case series (with five or more cases) containing individual pulmonary function data and adverse effects were included. Study endpoints were pre- and post-treatment change in percent predicted forced vital capacity (FVC %) and diffusion capacity for carbon monoxide (DLCO%), along with reported drug-related adverse events.

Results

Twenty studies totaling 411 patients were identified with 14 included in the meta-analysis of pulmonary function and six in the descriptive review. Random effects meta-analysis of pre- and post-treatment pulmonary function findings demonstrated increases in FVC% (n = 296) (mean difference (MD) 4.57%, [95% CI 2.63–6.51]) and DLCO% (n = 246) (MD 5.0% [95% CI 2.71–7.29]) after RTX treatment. RTX treatment-related adverse effects were reported in 13.6% of the pooled cohort.

Conclusions

A systematic assessment of post-treatment effect size suggests a potential role for RTX in stabilizing or improving lung function in patients with CTD-ILD, with a modest but not insignificant adverse effect profile.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02082-x.

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.

Lung function trajectory in progressive fibrosing interstitial lung disease

BACKGROUND

Proposed criteria for progressive fibrosing interstitial lung disease (PF-ILD) have been linked to increased mortality risk, but lung function trajectory after satisfying individual criteria remains unknown. Because survival is rarely employed as the primary end-point in therapeutic trials, identifying PF-ILD criteria that best predict subsequent change in forced vital capacity (FVC) could improve clinical trial design.

METHODS

A retrospective, multicentre longitudinal cohort analysis was performed in consecutive patients with fibrotic connective tissue disease-associated ILD (CTD-ILD), chronic hypersensitivity pneumonitis and idiopathic interstitial pneumonia at three US centres (test cohort) and one UK centre (validation cohort). 1-year change in FVC after satisfying proposed PF-ILD criteria was estimated using joint modelling. Subgroup analyses were performed to determine whether results varied across key subgroups.

RESULTS

1227 patients were included, with CTD-ILD predominating. Six out of nine PF-ILD criteria were associated with differential 1-year change in FVC, with radiological progression of fibrosis, alone and in combination with other features, associated with the largest subsequent decline in FVC. Findings varied significantly by ILD subtype, with CTD-ILD demonstrating little change in FVC after satisfying most PF-ILD criteria, while other ILDs showed significantly larger changes. Findings did not vary after stratification by radiological pattern or exposure to immunosuppressant therapy. Near-term change in FVC after satisfying proposed PF-ILD criteria was heterogeneous depending on the criterion assessed and was strongly influenced by ILD subtype.

CONCLUSIONS

These findings may inform future clinical trial design and suggest ILD subtype should be taken into consideration when applying PF-ILD criteria.

Interstitial Lung Disease in Rheumatoid Arthritis: A Practical Review

Rheumatoid arthritis (RA) is a systemic inflammatory disease, which primarily causes symmetric polyarthritis. An extrarticolar involvement is common, and the commonly involved organ is lungs. Although cardiac disease is responsible for most RA-related deaths, pulmonary disease is also a major contributor, accounting for ~10-20% of all mortality. Pulmonary disease is a common (60-80% of patients with RA) extra-articular complication of RA. Optimal screening, diagnostic, and treatment strategies of pulmonary disease remain uncertain, which have been the focus of an ongoing investigation. Clinicians should regularly assess patients with RA for the signs and symptoms of pulmonary disease and, reciprocally, consider RA and other connective tissue diseases when evaluating a patient with pulmonary disease of an unknown etiology. RA directly affects all anatomic compartments of the thorax, including the lung parenchyma, large and small airways, pleura, and less commonly vessels. In addition, pulmonary infection and drug-induced lung disease associated with immunosuppressive agents used for the treatment of RA may occur.

Clinical characteristics and prognostic factors of fibrotic nonspecific interstitial pneumonia

Aim:

Several studies have reported favorable outcomes of nonspecific interstitial pneumonia (NSIP); however, its prognosis and prognostic factors remain unclear. This study aimed to determine the outcomes of fibrotic NSIP and the prognostic factors for progression, relapse, and survival.

Methods:

In this retrospective study, we reviewed the clinical data of 204 patients diagnosed with fibrotic NSIP by surgical lung biopsy at Samsung Medical Center. The factors associated with survival and disease progression or relapse were determined using Cox proportional hazard analysis.

Results:

The median age of patients was 54 years and 67 (33%) patients were male. Also, 47 patients (23%) were current or ex-smokers. In all, 141 (69%) patients were diagnosed with idiopathic NSIP, while 63 (31%) patients were associated with connective tissue diseases. Progression or relapse was observed in 100 (49%) patients. The 5-year and 10-year survival rates were 94.6% and 90.4%, respectively. The factors associated with disease progression and relapse were diffusing capacity for carbon monoxide (DLco) <60% [adjusted hazard ratio (HR), 1.739; 95% confidence interval (CI), 1.036–2.921; p = 0.036], bronchoalveolar lavage (BAL) lymphocyte >15% (adjusted HR, 0.592; 95% CI, 0.352–0.994; p = 0.047), and treatment with corticosteroid and azathioprine (adjusted HR, 0.556; 95% CI, 0.311–0.955; p = 0.048). Disease progression or relapse was associated with mortality (adjusted HR, 7.135; 95% CI, 1.499–33.971; p = 0.014).

Conclusion:

Preserved lung function, BAL lymphocytosis, and treatment with corticosteroids and azathioprine were associated with lower risks of disease progression and relapse, which were risk factors for mortality.

Efficacy and Safety of Rituximab in Autoimmune Disease-Associated Interstitial Lung Disease: A Prospective Cohort Study

OBJECTIVES

To analyze the efficacy and safety of rituximab (RTX) in connective tissue disease associated with interstitial lung disease (CTD-ILD).

METHODS

We performed a multicenter, prospective, observational study of patients with CTD-ILD receiving rituximab between 2015 and 2020. The patients were assessed using high-resolution computed tomography and pulmonary function tests at baseline, at 12 months, and at the end of follow-up. The main outcome measure at the end of follow-up was forced vital capacity (FVC) > 10% or diffusing capacity of the lungs for carbon monoxide (DLCO) > 15% and radiological progression or death. We recorded clinical characteristics, time to initiation of RTX, concomitant treatment, infections, and hospitalization. A Cox regression analysis was performed to identify factors associated with worsening ILD.

RESULTS

We included 37 patients with CTD-ILD treated with RTX for a median (IQR) of 38.2 (17.7-69.0) months. At the end of the follow-up, disease had improved or stabilized in 23 patients (62.1%) and worsened in seven (18.9%); seven patients (18.9%) died. No significant decline was observed in median FVC (72.2 vs. 70.8; p = 0.530) or DLCO (55.9 vs. 52.2; p = 0.100). The multivariate analysis showed the independent predictors for worsening of CTD-ILD to be baseline DLCO (OR (95% CI), 0.904 (0.8-0.9); p = 0.015), time to initiation of RTX (1.01 (1.001-1.02); p = 0.029), and mycophenolate (0.202 (0.04-0.8); p = 0.034). Only 28 of the 37 patients (75.6%) were still undergoing treatment with RTX: two patients (5.4%) stopped treatment due to adverse events and seven patients (18.9%) died owing to progression of ILD and superinfection.

CONCLUSION

Lung function improved or stabilized in more than half of patients with CTD-ILD treated with RTX. Early treatment and combination with mycophenolate could reduce the risk of progression of ILD.

Interstitial pneumonia with autoimmune features: challenges and controversies

The presence of clinical, serological and/or radiological features suggestive, but not confirmatory, of a defined connective tissue disease in patients with interstitial lung disease is a relatively frequent occurrence. In 2015, the European Respiratory Society and the American Thoracic Society proposed classification criteria for the interstitial pneumonia with autoimmune features (IPAF) research entity to capture such patients in a standardised manner, with the intention of nurturing clinical research. This initiative resulted in the publication of several series of IPAF patients, with significant variation between cohorts in clinical characteristics, outcome and the application of IPAF criteria in patient selection. From this increasing body of published work, it has become apparent that revision of IPAF criteria is now required in order to justify the eventual designation of IPAF as a standalone diagnostic term, as opposed to a provisional entity put forward as a basis for clinical research. This review covers the current state of IPAF, conclusions that can and cannot be drawn from the IPAF evidence base, and ongoing uncertainties that require further expert group consideration.

Advances with pharmacotherapy for the treatment of interstitial lung disease

INTRODUCTION

In recent decades, the primary focus of pharmaceutical research in interstitial lung diseases (ILD) has been on idiopathic pulmonary fibrosis (IPF). Recently, pharmaceutical development has also focused on other forms of ILDs, including connective tissue diseases associated ILD, fibrotic hypersensitivity pneumonitis, and sarcoidosis.

AREAS COVERED

The authors summarize the advances in pharmacotherapy for the treatment of ILD. Specifically, the authors review the most recent studies and discuss the most recent research findings and future prospects.

EXPERT OPINION

Data collected over the past years have confirmed the efficacy of antifibrotic drugs on slowing disease progression in IPF. The usual strategy for CTD-ILD management is represented by the combined use of corticosteroids and immunosuppressive agents. There is an urgent need for new target therapies. The concept of progressive fibrosing ILD has emerged in the ILD community in recent years, which has led to grouping several diseases with a common disease behavior to find an effective treatment . At present, selecting the best therapy in ILDs should be reasonably performed on a case-by-case basis through a multidisciplinary team discussion in tertiary ILD centers, taking into consideration patients' symptoms, lung functional trends, and radiological changes.

Belimumab in the Treatment of Connective Tissue Disease-Associated Interstitial Lung Disease: Case Report and Literature Review

Interstitial lung disease or ILD can be described as inflammation, fibrosis, or scarring of the lung’s interstitial, resulting in dyspnea. ILD represents a group of heterogeneous parenchymal lung disorders with complex pathophysiology, differentiated by the clinical and radiological patterns. ILD is one of the most serious pulmonary complications associated with connective tissue diseases (CTDs), resulting in significant morbidity and mortality. Nonspecific interstitial pneumonia is the most common morphological and pathological pattern of ILD seen in CTDs. There are limitations in the therapeutic options resulting in significant morbidity. Certain biologic therapies are being evaluated for the various forms of ILD. The ILD, in this case, is associated with systemic lupus erythematosus (SLE) and scleroderma overlap that was effectively treated with belimumab, a recombinant monoclonal antibody against the B-cell activating factor (B-lymphocyte stimulator).

The emerging role of mycophenolate mofetil in interstitial lung diseases

INTRODUCTION

Mycophenolate mofetil (MMF), initially approved to prevent rejection in solid organ allograft, is now being increasingly used for other conditions. Over the last decade, MMF has emerged as a useful therapy for a variety of immune-mediated diseases.

AREAS COVERED

There has been a growing interest in the clinical use of MMF in the treatment of ILDs due to its versatile anti-inflammatory, immunomodulatory, anti-fibrotic and anti-proliferative properties. In this focussed review, we summarize the available literature using the Pubmed, Science Direct and EMBASE databases published until June 2021 on the efficacy and tolerability of MMF in various ILDs.

EXPERT OPINION

Other than idiopathic pulmonary fibrosis (IPF) and its broader category of progressive fibrosing ILD, there have been no drugs approved by relevant regulatory agencies for the treatment of the multiple other forms of ILD. Though results are limited, immunosuppressants such as MMF have shown promise as an effective and well-tolerated steroid-sparing agent, providing hope that the limited treatment armamentarium for ILDs can be expanded.

Idiopathic Interstitial Pneumonias: A Review of the Past and Emerging Therapies

PURPOSE

This article is an in-depth review of the complex classification, diagnosis, and treatment of idiopathic interstitial pneumonias (IIP), as well as emergence of new treatment options.

SUMMARY

Idiopathic interstitial pneumonias consist of various subgroup classifications that require expert analysis of imaging and histology to accurately diagnose this broad group of patients. Timely and accurate assessment of these patients is key in developing an appropriate pharmacological plan. The pathophysiology of IIP is not well understood but has been linked to an immune response resulting in inflammation, fibrosis, or proliferation of lung tissue which reduces lung function. Lung transplantation is currently the only curative option for treatment, but many new antiproliferative and immunosuppressive agents are being used to effectively slow the progression of lung dysfunction.

CONCLUSION

An often mixed radiological and histological pattern along with the invasive nature of biopsy for gold standard diagnosis create a challenge for the accurate identification of IIP. Further understanding of these idiopathic interstitial pneumonias will pave the way forward to the emergence of new treatment options and updates to standards of care.

Interstitial pneumonia with autoimmune features: from research classification to diagnosis

PURPOSE OF REVIEW

The term interstitial pneumonia with autoimmune features (IPAF) was first proposed by an international task force in 2015 as a research classification to standardise nomenclature regarding patients with idiopathic interstitial pneumonia and features of connective tissue disease. However, how the use of this term and its proposed definition translates to clinical practice remains uncertain. This review will provide a comprehensive overview of studies of IPAF cohorts to date, discuss the consideration of IPAF as a distinct diagnostic entity and outline a suggested approach to patient management.

RECENT FINDINGS

Considerable heterogeneity exists between published IPAF cohorts, with some cohorts exhibiting similarities to those with connective tissue disease-associated interstitial lung disease (CTD-ILD), and others more similar to idiopathic interstitial pneumonias including idiopathic pulmonary fibrosis (IPF). Little data exist to inform the management of patients who fulfil the IPAF criteria. Preliminary data supports pragmatic management of these patients as having a working clinical diagnosis of either idiopathic interstitial pneumonia or CTD-ILD. Future research studies into this approach are required.

SUMMARY

The term IPAF, and its definition, have been of fundamental benefit to facilitating research in this diverse patient group. However, to date, there remain many unanswered questions regarding their natural histories and response to treatment.

Interstitial Lung Disease in Connective Tissue Disease: A Common Lesion With Heterogeneous Mechanisms and Treatment Considerations

Connective tissue disease (CTD) related interstitial lung disease (CTD-ILD) is one of the leading causes of morbidity and mortality of CTD. Clinically, CTD-ILD is highly heterogenous and involves rheumatic immunity and multiple manifestations of respiratory complications affecting the airways, vessels, lung parenchyma, pleura, and respiratory muscles. The major pathological features of CTD are chronic inflammation of blood vessels and connective tissues, which can affect any organ leading to multi-system damage. The human lung is particularly vulnerable to such damage because anatomically it is abundant with collagen and blood vessels. The complex etiology of CTD-ILD includes genetic risks, epigenetic changes, and dysregulated immunity, which interact leading to disease under various ill-defined environmental triggers. CTD-ILD exhibits a broad spectra of clinical manifestations: from asymptomatic to severe dyspnea; from single-organ respiratory system involvement to multi-organ involvement. The disease course is also featured by remissions and relapses. It can range from stability or slow progression over several years to rapid deterioration. It can also present clinically as highly progressive from the initial onset of disease. Currently, the diagnosis of CTD-ILD is primarily based on distinct pathology subtype(s), imaging, as well as related CTD and autoantibodies profiles. Meticulous comprehensive clinical and laboratory assessment to improve the diagnostic process and management strategies are much needed. In this review, we focus on examining the pathogenesis of CTD-ILD with respect to genetics, environmental factors, and immunological factors. We also discuss the current state of knowledge and elaborate on the clinical characteristics of CTD-ILD, distinct pathohistological subtypes, imaging features, and related autoantibodies. Furthermore, we comment on the identification of high-risk patients and address how to stratify patients for precision medicine management approaches.

Progressive fibrosing interstitial lung disease: treatable traits and therapeutic strategies

PURPOSE OF REVIEW

In this review, the authors describe therapeutic strategies for a disease group called progressive fibrosing interstitial lung disease (PF-ILD) and highlight the importance of the definition of progression, prognosis, and treatment response.

RECENT FINDINGS

Although it is a relatively new concept, the term PF-ILD has been increasingly applied in clinical research and practice. Three domains commonly used to detect the disease progression include clinical symptoms, rate of forced vital capacity (FVC) decline and the extent of fibrosis on imaging. Although details of the pathogenesis of PF-ILD are still unclear, it has become apparent that genetic predisposition and an abnormal tissue microenvironment and host response are involved in the nature of the disease. Antifibrotic agents recently showed their efficacy on the treatment of PF-ILD. Both nintedanib and pirfenidone can slow the disease progression, as defined by a decline of FVC from baseline, of PF-ILD whenever compared with placebo, similar to the results in idiopathic pulmonary fibrosis (IPF) trials. This effect seems consistent irrespective of the underlying ILD diagnosis.

SUMMARY

Recent evidence supports the use of antifibrotic therapy in the management of the phenotype progressive non-IPF ILD. Ongoing studies exploring genetic and other molecular biomarkers could identify at-risk individuals or predict treatment response and prognosis (endotypes). This would support the concept of 'treatable traits' in the field of ILD.

Management of Myositis-Associated Interstitial Lung Disease

Idiopathic inflammatory myopathies, including polymyositis (PM), dermatomyositis (DM), and clinically amyopathic DM (CADM), are a diverse group of autoimmune diseases characterized by muscular involvement and extramuscular manifestations. Interstitial lung disease (ILD) has major pulmonary involvement and is associated with increased mortality in PM/DM/CADM. The management of PM-/DM-/CADM-associated ILD (PM/DM/CADM-ILD) requires careful evaluation of the disease severity and clinical subtype, including the ILD forms (acute/subacute or chronic), because of the substantial heterogeneity of their clinical courses. Recent studies have highlighted the importance of myositis-specific autoantibodies’ status, especially anti-melanoma differentiation-associated gene 5 (MDA5) and anti-aminoacyl tRNA synthetase (ARS) antibodies, in order to evaluate the clinical phenotypes and treatment of choice for PM/DM/CADM-ILD. Because the presence of the anti-MDA5 antibody is a strong predictor of a worse prognosis, combination treatment with glucocorticoids (GCs) and calcineurin inhibitors (CNIs; tacrolimus (TAC) or cyclosporin A (CsA)) is recommended for patients with anti-MDA5 antibody-positive DM/CADM-ILD. Rapidly progressive DM/CADM-ILD with the anti-MDA5 antibody is the most intractable condition, which requires immediate combined immunosuppressive therapy with GCs, CNIs, and intravenous cyclophosphamide. Additional salvage therapies (rituximab, tofacitinib, and plasma exchange) should be considered for patients with refractory ILD. Patients with anti-ARS antibody-positive ILD respond better to GC treatment, but with frequent recurrence; thus, GCs plus immunosuppressants (TAC, CsA, azathioprine, and mycophenolate mofetil) are often needed in order to achieve favorable long-term disease control. PM/DM/CADM-ILD management is still a therapeutic challenge for clinicians, as evidence-based guidelines do not exist to help with management decisions. A few prospective clinical trials have been recently reported regarding the treatment of PM/DM/CADM-ILD. Here, the current knowledge on the pharmacologic managements of PM/DM/CADM-ILD was mainly reviewed.

Progression in the Management of Non-Idiopathic Pulmonary Fibrosis Interstitial Lung Diseases, Where Are We Now and Where We Would Like to Be

A significant proportion of patients with interstitial lung disease (ILD) may develop a progressive fibrosing phenotype characterized by worsening of symptoms and pulmonary function, progressive fibrosis on chest computed tomography and increased mortality. The clinical course in these patients mimics the relentless progressiveness of idiopathic pulmonary fibrosis (IPF). Common pathophysiological mechanisms such as a shared genetic susceptibility and a common downstream pathway—self-sustaining fibroproliferation—support the concept of a progressive fibrosing phenotype, which is applicable to a broad range of non-IPF ILDs. While antifibrotic drugs became the standard of care in IPF, immunosuppressive agents are still the mainstay of treatment in non-IPF fibrosing ILD (F-ILD). However, recently, randomized placebo-controlled trials have demonstrated the efficacy and safety of antifibrotic treatment in systemic sclerosis-associated F-ILD and a broad range of F-ILDs with a progressive phenotype. This review summarizes the current pharmacological management and highlights the unmet needs in patients with non-IPF ILD.

Predictors of Progression and Mortality in Patients with Prevalent Rheumatoid Arthritis and Interstitial Lung Disease: A Prospective Cohort Study

OBJECTIVES

To describe a prospective cohort of patients with rheumatoid arthritis associated with interstitial lung disease (RA-ILD) and identify risk factors associated with disease progression and mortality in this cohort.

PATIENTS AND METHODS

We performed a multicenter, prospective, observational study of patients with RA-ILD receiving disease-modifying antirheumatic drugs (DMARDs) between 2015 and 2020. The patients were assessed using high-resolution computed tomography and pulmonary function tests at baseline and at 60 months. The main endpoint was "Progression to ILD at the end of follow-up" in terms of the following outcomes: (1) improvement (i.e., improvement in forced vital capacity (FVC) ≥10% or diffusing capacity of the lungs for carbon monoxide (DLCO) ≥15% and absence of radiological progression); (2) nonprogression (stabilization or improvement in FVC ≤10% or diffusing capacity of the lungs for carbon monoxide (DLCO) <15% and absence of radiological progression); (3) progression (worsening of FVC >10% or DLCO >15% and radiological progression); or (4) death. We recorded demographic and clinical characteristics, lung function, and the incidence of adverse events. A Cox regression analysis was performed to identify factors associated with the worsening of ILD.

RESULTS

After 60 months, lung disease had stabilized in 66 patients (56.9%), improved in 9 (7.8%), and worsened in 23 (19.8%). Eighteen patients (15.5%) died, with a mean survival of 71.8 (1.9) months after diagnosis of ILD. The Cox multivariate analysis revealed the independent predictors of worsening of RA-ILD to be usual interstitial pneumonia (hazard ratio (HR), 2.6 (95%CI, 1.0-6.7)), FVC <80% (HR, 3.8 (95%CI, 1.5-6.7)), anticitrullinated protein antibody titers (HR, 2.8 (95%CI, 1.1-6.8)), smoking (HR, 2.5 (95%CI, 1.1-6.2)), and treatment with abatacept, tocilizumab, or rituximab (HR, 0.4 (95%CI, 0.2-0.8)). During follow-up, 79 patients (68%) experienced an adverse event, mostly infection (61%). Infection was fatal in 10/18 patients (55.5%) during follow-up.

CONCLUSIONS

Lung function is stable in most patients with RA-ILD receiving treatment with disease-modifying anti-rheumatic drugs (DMARDs), although one-third worsened or died. Identifying factors associated with worsening in RA-ILD is important for clinical management.

Efficacy and safety of mycophenolate mofetil in the treatment of rheumatic disease-related interstitial lung disease: a narrative review

Mycophenolate mofetil (MMF) is an antimetabolite with a potent inhibitory effect on proliferation of T and B lymphocytes used since the early 1990s for the prevention of acute allograft rejection after organ transplant. MMF is also widely used for the treatment of a variety of rheumatic diseases (RDs) and their pulmonary involvement. Interstitial lung disease (ILD) is a heterogeneous group of progressive fibrotic diseases of the lung, which is often secondary to RD and represents a major cause of morbidity and mortality. MMF is considered the main alternative to cyclophosphamide as a first-line agent to treat RD-related ILD or as possible maintenance therapy after cyclophosphamide, with a lower rate of side-effects. However, as for other immunosuppressive agents, the use of MMF in RD-ILD is supported by poor scientific evidence. In this narrative review, we describe the available data and recent advances on the effectiveness and safety of MMF for the treatment of ILD related to RD, including rheumatoid arthritis, systemic sclerosis, primary Sjögren syndrome, systemic lupus erythematosus, idiopathic inflammatory myopathies, undifferentiated connective tissue disease, interstitial pneumonia with autoimmune features and antineutrophil cytoplasmic antibody-associated vasculitis.

TPMT and HLA-DQA1-HLA-DRB genetic profiling to guide the use of azathioprine in the treatment of interstitial lung disease: First experience

BACKGROUND

The choice of immunosuppressive therapy in interstitial lung disease (ILD) other than idiopathic pulmonary fibrosis (IPF) is based on safety profile and expected efficacy. Azathioprine is one of the most commonly used agents to treat ILD. The immunosuppressive effect and pancreatitis risk of azathioprine are influenced by the activity of the enzyme thiopurine methyltransferase (TPMT) and by the genetic mutations in HLA-DQA1-HLA-DRB locus, respectively. We hypothesized that systematic genotyping prior to starting azathioprine improves the rate of discontinuation of immunosuppressive therapy and the total incidence of adverse drug reactions (ADRs).

METHODS

Eighty-two patients with ILD other than IPF were included in the study. The rate of immunosuppressive therapy discontinuation due to major ADRs and the total incidence of ADRs were compared between a cohort of genotyped patients (n = 49) and an untested cohort of patients (n = 33).

RESULTS

Thirty-seven out of 49 patients in the genotyped cohort and 27 out of 33 patients in the untested cohort were started on azathioprine. The rate of immunosuppressive therapy discontinuation due to major ADRs was significantly lower (6/49) in the genotyped cohort compared to the untested cohort (11/33; p = 0.0276). All but one discontinuation due to severe ADRs occurred within a month of therapy. However, the total incidence rate of ADRs was very similar in the 2 cohorts (0.025 in the genotyped cohort vs. 0.023 in the untested cohort).

CONCLUSION

In patients with ILD other than IPF, genotyping for azathioprine metabolism prior to starting therapy is associated with a significantly reduced rate of immunosuppressive therapy discontinuation due to major ADRs, with prevention of bone marrow suppression and pancreatitis, but without a reduction of the total incidence of ADRs. While these data support the use of genetic profiling prior to starting azathioprine to treat ILD, its cost effectiveness remains to be established.

Use of nintedanib in interstitial lung disease other than idiopathic pulmonary fibrosis: much caution is warranted

Interstitial lung disease (ILD) other than idiopathic pulmonary fibrosis (IPF) is currently treated with immunosuppressive therapy, with a dynamic algorithm based on continued clinical surveillance. Published results on mycophenolate mofetil, cyclophosphamide and azathioprine showed either stabilization or improvement of lung function with these therapies. However, despite treatment optimization, progression of disease in ILD other than IPF is often observed, and a role for antifibrotic drug nintedanib has been hypothesized. The present article first reviews relevant aspects when considering anti-fibrotic therapy in progressing ILD other than IPF, including accuracy of the diagnosis, optimization of disease-modifying, immunosuppressive therapy and optimal timing. Next, a critical appraisal of published results on nintedanib in ILD other than IPF considers the design of the studies, inclusion criteria, used definition of "progression" of disease, frequency and severity of side effects observed and cost of the therapy. There currently is a strong and legitimate interest in additional therapies that can help controlling progressing ILD other than IPF. When the studies on the use of nintedanib are carefully considered, however, caution should be exercised before prematurely endorsing and applying this therapy. The conduction of studies that will clarify and justify its potential role as switch vs. add-on therapy and, at the same time, a more rigorous definition of disease progression are both strongly encouraged.

Immunomodulation in Autoimmune Interstitial Lung Disease

Interstitial lung diseases (ILDs) associated with autoimmune or systemic disease are increasingly recognized and our pathophysiological understanding rapidly expanding. Treatment modalities, however, are still mainly driven by established disease-modifying antirheumatic drugs (DMARDs) where, despite decades of experience of their use in the underlying diseases such as rheumatoid arthritis, mostly ret-rospective data exist informing their effect on the course of interstitial lung disease (ILD). In recent years, randomized trials investigating the effects of biological DMARDs (bDMARDs) have been completed or are currently running, generating new treatment options for often relentlessly progressive diseases. Herein, we summarize the evidence and current use of both synthetic DMARDs and bDMARDs in the context of ILDs associated with autoimmune/systemic disease.

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

Purpose of review

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is one of the most serious extra-articular RA manifestations. RA-ILD is associated with worse physical function, lower quality of life, and increased mortality. RA-ILD is comprised of heterogeneous subtypes characterized by inflammation and fibrosis. Diagnosis can be difficult since the presentation of RA-ILD is characterized by non-specific symptoms and imaging findings. Management of RA-ILD is also challenging due to difficulty in precisely measuring pulmonary disease activity and response to treatment in patients who may also have articular inflammation. We provide a current overview of RA-ILD focusing on prevalence, risk factors, and treatment.

Recent findings

Research interest in RA-ILD has increased in recent years. Some studies suggest that RA-ILD prevalence may be increasing; this may be due to underlying biologic drivers or increases in imaging and recognition. Novel RA-ILD risk factors include the MUC5B promotor variant, articular disease activity, autoantibodies, and biomarkers of damaged pulmonary parenchyma. Treatment should focus on controlling RA disease activity, which emerging data suggest may reduce RA-ILD risk. Immunomodulatory and antifibrotic drugs may also treat RA-ILD.

Summary

RA-ILD is an underrecognized and serious manifestation of RA, but important progress is being made in identifying risk factors and treatment.