Interstitial lung disease in rheumatoid arthritis: response to IL-6R blockade

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.

Rheumatoid arthritis related interstitial lung disease - improving outcomes over 25 years: a large multicentre UK study

OBJECTIVE

This study explores whether the prognosis of interstitial lung disease in rheumatoid arthritis (RA-ILD) has improved over time and assesses the potential influence of drug therapy in a large multicentre UK network.

METHODS

We analysed data from 18 UK centres on patients meeting criteria for both RA and ILD diagnosed over a 25-year period. Data included age, disease duration, outcome and cause of death. We compared all cause and respiratory mortality between RA controls and RA-ILD patients, assessing the influence of specific drugs on mortality in four quartiles based on year of diagnosis.

RESULTS

A total of 290 RA-ILD patients were identified. All cause (respiratory) mortality was increased at 30% (18%) compared with controls 21% (7%) (P =0.02). Overall, prognosis improved over quartiles with median age at death rising from 63 years to 78 years (P =0.01). No effect on mortality was detected as a result of DMARD use in RA-ILD. Relative risk (RR) of death from any cause was increased among patients who had received anti-TNF therapy [2.09 (1.1-4.0)] P =0.03, while RR was lower in those treated with rituximab [0.52(0.1-2.1)] or mycophenolate [0.65 (0.2-2.0)]. Patients receiving rituximab as their first biologic had longer three (92%), five (82%) and seven year (80%) survival than those whose first biologic was an anti-TNF agent (82%, 76% and 64%, respectively) (P =0.037).

DISCUSSION

This large retrospective multicentre study demonstrates survival of patients with RA-ILD has improved. This may relate to the increasing use of specific immunosuppressive and biologic agents.

Targeted therapies in interstitial lung disease secondary to systemic autoimmune rheumatic disease. Current status and future development

Autoimmune rheumatic diseases (ARD) are characterized by systemic manifestations and multiple organ involvement, including the lung. Interstitial Lung Disease (ILD) is a cardinal manifestation of lung involvement in patients with ARD and is associated with significant morbidity and mortality. Corticosteroids and immunosuppressive drugs are used as first -line treatment. Targeted therapies, such as biological disease modifying antirheumatic drugs (DMARDS) and anti- fibrotic agents are new treatment options. In this review we discuss the role of targeted therapies in patients with ILD secondary to ARD.

Understanding the Role of Interleukin-6 (IL-6) in the Joint and Beyond: A Comprehensive Review of IL-6 Inhibition for the Management of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, debilitating autoimmune disorder involving inflammation and progressive destruction of the joints, affecting up to 1% of the population. The majority of patients with RA have one or more comorbid conditions, the most common being cardiovascular disease, osteoporosis, and depression, the presence of which are associated with poorer clinical outcomes and lower health-related quality of life. RA pathogenesis is driven by a complex network of proinflammatory cells and cytokines, and of these, interleukin-6 (IL-6) plays a key role in the chronic inflammation associated with RA. Through cell signaling that can be initiated by both membrane-bound and soluble forms of its receptor, IL-6 acts both locally to promote joint inflammation and destruction, and in the circulation to mediate extra-articular manifestations of RA, including pain, fatigue, morning stiffness, anemia, and weight loss. This narrative review describes the role of IL-6 in the pathogenesis of RA, its comorbidities, and extra-articular systemic manifestations, and examines the effects of the IL-6 receptor inhibitors sarilumab and tocilizumab on clinical endpoints of RA, patient-reported outcomes, and common comorbidities and extra-articular manifestations.

Treatment of Rheumatoid Arthritis-Associated Interstitial Lung Disease: Lights and Shadows

Rheumatoid arthritis (RA) is a chronic and systemic inflammatory disease affecting 0.5–1% of the population worldwide. Interstitial lung disease (ILD) is a serious pulmonary complication of RA and it is responsible for 10–20% of mortality, with a mean survival of 5–8 years. However, nowadays there are no therapeutic recommendations for the treatment of RA-ILD. Therapeutic options for RA-ILD are complicated by the possible pulmonary toxicity of many disease modifying anti-rheumatic drugs (DMARDs) and by their unclear efficacy on pulmonary disease. Therefore, joint and lung involvement should be evaluated independently of each other for treatment purposes. On the other hand, some similarities between RA-ILD and idiopathic pulmonary fibrosis and the results of the recent INBIULD trial suggest a possible future role for antifibrotic agents. From this perspective, we review the current literature describing the pulmonary effects of drugs (immunosuppressants, conventional, biological and target synthetic DMARDs and antifibrotic agents) in patients with RA and ILD. In addition, we suggest a framework for the management of RA-ILD patients and outline a research agenda to fill the gaps in knowledge about this challenging patient cohort.

Current and Emerging Drug Therapies for Connective Tissue Disease-Interstitial Lung Disease (CTD-ILD)

Interstitial lung disease (ILD) can be associated with all connective tissue diseases and is an important cause of morbidity and mortality. The management of connective tissue disease-interstitial lung disease (CTD-ILD) is challenging due substantial heterogeneity in disease behaviour and paucity of controlled clinical trials to guide treating clinicians. Not all patients require treatment, and the decision to treat needs to be individualised based on a patient's observed disease behaviour, baseline and longitudinal lung function measurements, extent of lung involvement on radiology and patient factors including age, co-morbidities and personal preference. If indicated, treatment of the CTD-ILD is largely with immunomodulation, with the aim to prevent progression of the ILD before further irreversible lung injury and disability occurs. Corticosteroids, cyclophosphamide, mycophenolate mofetil and azathioprine are the most common immunosuppressive agents currently used to treat CTD-ILD, demonstrating stability of lung function in case series and a small number of randomised controlled trials in ILD associated with systemic sclerosis. Biological and non-biological disease-modifying anti-rheumatic drugs, and the anti-fibrotics nintedanib and pirfenidone, have revolutionised the treatment of connective tissue diseases and idiopathic ILD, respectively. Furthermore, anti-fibrotics have recently demonstrated safety and efficacy in ILD associated with systemic sclerosis. There remains a critical unmet need to clarify when and in whom to initiate treatment, and which agent(s) to utilise to achieve optimal outcomes for CTD-ILD patients whilst minimising harms through prospective multicentre trials. This review highlights the challenges faced when treating patients with CTD-ILD and summarises available evidence for current, emerging and novel therapies.

Korean Guidelines for Diagnosis and Management of Interstitial Lung Diseases: Part 5. Connective Tissue Disease Associated Interstitial Lung Disease

Connective tissue disease (CTD) is a collection of disorders characterized by various signs and symptoms such as circulation of autoantibodies in the entire system causing damage to internal organs. Interstitial lung disease (ILD) which is associated with CTD is referred to as CTD-ILD. Patients diagnosed with ILD should be thoroughly examined for the co-occurrence of CTD, since the treatment procedures and prognosis of CTD-ILD are vary from those of idiopathic interstitial pneumonia. The representative types of CTD which may accompany ILD include rheumatoid arthritis, systemic sclerosis (SSc), Sjögren's syndrome, mixed CTD, idiopathic inflammatory myopathies, and systemic lupus erythematous. Of these, ILD most frequently co-exists with SSc. If an ILD is observed in the chest, high resolution computed tomography and specific diagnostic criteria for any type of CTD are met, then a diagnosis of CTD-ILD is made. It is challenging to conduct a properly designed randomized study on CTD-ILD, due to low incidence. Therefore, CTD-ILD treatment approach is yet to been established in absence of randomized controlled clinical trials, with the exception of SSc-ILD. When a patient is presented with acute CTD-ILD or if symptoms occur due to progression of the disease, steroid and immunosuppressive therapy are generally considered.

Biologic Treatments in Interstitial Lung Diseases

Interstitial lung diseases (ILD) represent a group of heterogeneous parenchymal lung disorders with complex pathophysiology, characterized by different clinical and radiological patterns, ultimately leading to pulmonary fibrosis. A considerable proportion of these disease entities present with no effective treatment, as current therapeutic regimens only slow down disease progression, thus leaving patients, at best case, with considerable functional disability. Biologic therapies have emerged and are being investigated in patients with different forms of ILD. Unfortunately, their safety profile has raised many concerns, as evidence shows that they might cause or exacerbate ILD status in a subgroup of patients. This review article aims to summarize the current state of knowledge on their role in patients with ILD and highlight future perspectives.

Management of the Rheumatoid Arthritis Patient with Interstitial Lung Disease

The treatment of rheumatoid arthritis (RA) has undergone considerable changes over the last 15–20 years. With an expansion in the armamentarium of therapies available for RA comes a wider choice in selecting the best treatment in terms of comparative safety in the presence of comorbidities. Clinicians frequently encounter patients with RA-associated interstitial lung disease with uncontrolled joint disease and have to make decisions about the safest treatments in this context with the eventual goal of joint remission. In this chapter, available evidence is reviewed on the comparative pulmonary safety of non-biologic disease-modifying antirheumatic drugs (nbDMARDs), biologic DMARDs, biosimilars and targeted synthetic DMARDs in RA-ILD. In addition, the potential role for additional immunosuppression in RA-ILD is reviewed as well as overarching recommendations proposed for patient assessment to guide treatment decisions and management.

Treatment of connective tissue disease-associated interstitial lung disease: the pulmonologist's point of view

Interstitial lung disease (ILD) occurs in 15% of patients with collagen vascular disease (CVD), referred to as connective tissue disease (CTD). Despite advances in management strategies, ILD continues to be a significant cause of mortality in patients with CVD-associated ILD (CTD-ILD). There is a lack of randomized, clinical trials assessing pharmacological agents for CTD-ILD, except in cases of ILD-associated systemic sclerosis (SSc). This may be due to the lack of CTD cases available, the difficulty of histological confirmation of ILD, and the various types of CTD and ILD. As a result, evidence-based pharmacological treatment of CTD-ILD is not yet well established. CTD-ILD presents with varying degrees of histology, from inflammation to fibrosis, and a wide spectrum of clinical manifestations, from minimal symptoms to respiratory failure. This renders it difficult for clinicians to make decisions regarding treatment options, observational strategies, optimal timing for interventions, and the appropriateness of pharmacological agents for treatment. There is no specific treatment for reversing fibrosis-like idiopathic pulmonary fibrosis in a clinical setting. This review describes pharmacological interventions for SSc-ILD described in randomized control trials, and presents an overview of recent advances of CTD-ILD-dependent treatments based on the types of CTD.

Biologics-induced interstitial lung diseases in rheumatic patients: facts and controversies

INTRODUCTION

Interstitial lung disease (ILD) is a common, devastating pulmonary complication. An increased number of reports suggesting that biological disease modifying antirheumatic drugs (DMARDs) induced or exacerbated ILDs in rheumatoid arthritis (RA) patients has garnered increased attention. Areas covered: This article discusses ILDs induced by or exacerbated during biological therapy in RA patients. The article summarizes the efficacy and safety of a variety of licensed and off-label biologics clinically used for rheumatic diseases, focusing on the onset or exacerbation of RA-associated ILDs (RA-ILDs) in RA patients treated with biologics targeting tumor necrosis factor, CD20, interleukin 1 (IL-1) and IL-6 receptors. Additionally, the pathogenesis of RA-ILDs is discussed. Expert opinion: To some extent, the possibility of biologic-induced RA-ILDs increases the difficulty in choosing an optimal regimen for RA treatment with biological agents, as the relationship between biological therapy safety and the induction or exacerbation of RA-ILDs has not been established. A framework to assess baseline disease severity, particularly standardizing the evaluation of the pulmonary condition stage in RA patients and monitoring the outcome during the biological therapy treatment, is highly needed and may substantially help guide treatment decisions and predict the treatment benefits.

Therapeutic management of patients with rheumatoid arthritis and associated interstitial lung disease: case report and literature review

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease that can present different extrarticular manifestations involving heart, lungs and kidneys. In recent years there has been a growing awareness of the central role played by the lungs in the onset and progression of RA. In particular interstitial lung disease (ILD) is a common pulmonary manifestation that may be related to the inflammatory process itself, infectious complications and to the treatments used. Management of patients with ILD/RA is still a challenge for clinicians, both synthetic [mainly methotrexate (MTX), leflunomide] and biologic immunosuppressors [mainly anti-tumor necrosis factor (TNF)α] have in fact been related to the onset or worsening of lung diseases with conflicting data. Here we report the case of a 61-year-old male patient with severely active early RA, previously treated with MTX, who developed subacute ILD, along with a review of ILD/RA topic. Tocilizumab (humanized monoclonal antibody against the interleukin-6 receptor) was introduced on the basis of its effectiveness in RA without concomitant MTX and the ability to overcome the profibrotic effects of interleukin (IL)-6. After 3 months of treatment the clinical condition of the patient strongly improved until it reached low disease activity. He no longer complained of cough and dyspnea and bilateral basal crackles were no more present. Considering its distinctive features, tocilizumab, in such a challenging clinical condition, appears to be a safe and effective therapy, thus it enables RA remission without deteriorating ILD, at 1-year follow up, as confirmed by ultrasonography of the affected joints and chest high-resolution computed tomography (HRCT).

Treatment of rheumatoid arthritis-associated interstitial lung disease: a perspective review

Rheumatoid arthritis (RA) is a systemic autoimmune disease affecting 0.5-1% of the worldwide population. Whilst predominantly causing chronic pain and inflammation in synovial joints, it is also associated with significant extra-articular manifestations in a large proportion of patients. Among the various pulmonary manifestations, interstitial lung disease (ILD), a progressive fibrotic disease of the lung parenchyma, is the commonest and most important, contributing significantly to increased morbidity and mortality. The most frequent patterns of RA-associated ILD (RA-ILD) are usual interstitial pneumonia and nonspecific interstitial pneumonia. New insights during the past several years have highlighted the epidemiological impact of RA-ILD and have begun to identify factors contributing to its pathogenesis. Risk factors include smoking, male sex, human leukocyte antigen haplotype, rheumatoid factor and anticyclic citrullinated protein antibodies (ACPAs). Combined with clinical information, chest examination and pulmonary function testing, high-resolution computed tomography of the chest forms the basis of investigation and allows assessment of subtype and disease extent. The management of RA-ILD is a challenge. Several therapeutic agents have been suggested in the literature but as yet no large randomized controlled trials have been undertaken to guide clinical management. Therapy is further complicated by commonly prescribed drugs of proven articular benefit such as methotrexate, leflunomide (LEF) and anti-tumour necrosis factor α agents having been implicated in both ex novo occurrence and acceleration of existing ILD. Agents that offer promise include immunomodulators such as mycophenolate and rituximab as well as newly studied antifibrotic agents. In this review, we discuss the current literature to evaluate recommendations for the management of RA-ILD and discuss key gaps in our knowledge of this important disease.

Management of Rheumatoid Arthritis Patients with Interstitial Lung Disease: Safety of Biological Antirheumatic Drugs and Assessment of Pulmonary Fibrosis

Interstitial lung disease (ILD) is one of the major causes of morbidity and mortality of patients with rheumatoid arthritis (RA). Accompanying the increased number of reports on the development or exacerbation of ILD in RA patients following therapy with biological disease-modifying antirheumatic drugs (DMARDs), RA-associated ILD (RA-ILD) has aroused renewed interest. Although such cases have been reported mainly in association with the use of tumor necrosis factor inhibitors, the use of other biological DMARDs has also become a matter of concern. Nevertheless, it is difficult to establish a causative relationship between the use of biological DMARDs and either the development or exacerbation of ILD. Such pulmonary complications may occur in the natural course of RA regardless of the use of biological DMARDs. Since rheumatologists currently aim to achieve remission in RA patients, the administration of biological DMARDs is increasing, even for those with RA-ILD. However, there are no reliable, evidence-based guidelines for deciding whether biological DMARDs can be safely introduced and continued in RA-ILD patients. A standardized staging system for pulmonary conditions of RA-ILD patients is needed when making therapeutic decisions at baseline and monitoring during biological DMARD therapy. Based on the available information regarding the safety of biological DMARDs and the predictive factors for a worse prognosis, this review discusses candidate parameters for risk evaluation of ILD in RA patients who are scheduled to receive biological antirheumatic therapy.

Interstitial lung disease in patients with rheumatoid arthritis: spontaneous and drug induced

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease characterized by the destruction of articular joint structures. RA is a systemic condition that often affects multiple organs, including the heart, lungs, and kidneys. Pulmonary complications of RA are relatively common and include pleural effusion, rheumatoid nodules, bronchiectasis, obliterative bronchiolitis, and opportunistic infections. Interstitial lung disease (ILD) is a common occurrence in patients with RA, and can range in severity from an asymptomatic incidental finding to a rapidly progressing life-threatening event. Usual interstitial pneumonia and non-specific interstitial pneumonia are the two most common patterns, though others have been reported. Various disease-modifying anti-rheumatic drugs-in particular, methotrexate and the tumor necrosis factor-alpha inhibitors-have been associated with RA-ILD in numerous case reports and case series, though it is often difficult to distinguish association from causality. Treatment for RA-ILD typically involves the use of high-dose corticosteroids, often in conjunction with alternative immunosuppressant agents such as azathioprine or mycophenolate mofetil, and outcomes vary widely depending on the initial pattern of lung disease. Additional research into the mechanisms driving RA-ILD is needed to guide future therapy.

Interstitial lung disease in rheumatoid arthritis: Current concepts in pathogenesis, diagnosis and therapeutics

Rheumatoid arthritis (RA) is the most common chronic autoimmune inflammatory joint disease. RA-associated interstitial lung disease (RA-ILD) is a major extra-articular complication and causes symptoms that lead to a deterioration in the quality of life, high utilization of health resources, and an increased risk of earlier mortality. Early in the course of RA-ILD, symptoms are highly variable, making the diagnosis difficult. Therefore, a rational diagnostic strategy that combines an adequate clinical assessment with the appropriate use of clinical tests, including pulmonary function tests and high-resolution computed tomography, should be used. In special cases, lung biopsy or bronchioalveolar lavage should be performed to achieve an early diagnosis. Several distinct histopathological subtypes of RA-ILD are currently recognized. These subtypes also have different clinical presentations, which vary in therapeutic response and prognosis. This article reviews current evidence about the epidemiology of RA-ILD and discusses the varying prevalence rates observed in different studies. Additionally, aspects of RA-ILD pathogenesis, including the role of cytokines and other molecules such as autoantibodies, as well as the evidence linking several drugs used to treat RA with lung damage will be discussed. Some aspects of the clinical characteristics of RA-ILD are noted, and diagnostic strategies are reviewed. Finally, this article analyzes current treatments for RA-ILD, including immunosuppressive therapies and biologic agents, as well as other therapeutic modalities. The prognosis of this severe complication of RA is discussed. Additionally, this paper examines updated evidence from studies identifying an association between drugs used for the treatment of RA and the development of ILD.

Lung involvement and drug-induced lung disease in patients with rheumatoid arthritis

Interstitial lung disease (ILD) is a common extra-articular manifestation of rheumatoid arthritis (RA) and a significant cause of morbidity and mortality. Usual interstitial pneumonia and nonspecific interstitial pneumonia seem to be the most frequent patterns in RA patients with ILD, although the proportion of patients with usual interstitial pneumonia is higher than among patients with other systemic rheumatic autoimmune diseases. RA patients with ILD most frequently present with chronic symptoms of cough and dyspnea when climbing stairs or walking uphill. A physical examination may reveal inhalatory crackles and a pulmonary function test demonstrates restrictive physiology, often with reduced diffusing capacity. High-resolution computed tomography is generally sufficient to confirm a diagnosis of ILD, although a minority of cases may require a surgical lung biopsy. Conventional disease-modifying antirheumatic drugs such as methotrexate (MTX) or leflunomide (LEF) and biological agents such as TNF-blocking agents or rituximab may trigger or aggravate ILD in RA patients, and infections may contribute to increased mortality in such patients. LEF should not be used in patients with a history of MTX pneumonitis. The prevalence of interstitial pneumonia among RA patients treated with anti-TNF agents ranges from 0.5 to 3%; however, as the evidence that anti-TNF increases or decreases the risk of ILD is controversial, it is not clear whether this indicates more severe RA requiring biological therapy or the effect of exposure to potentially toxic drugs such as MTX or LEF. The development of treatment-related ILD is a paradoxical adverse event, and patients should be warned about this rare but serious complication of biological or disease-modifying antirheumatic drug therapy.

The safety of biologic therapies in RA-associated interstitial lung disease

Interstitial lung disease (ILD) is a common extra-articular manifestation associated with increased morbidity and mortality in patients with rheumatoid arthritis (RA). Early case reports of serious respiratory adverse events (SRAEs) following treatment with anti-TNF agents have led to concerns about biologic therapy in patients with RA-associated ILD (RA-ILD), and a tendency for biologic agents targeting factors other than TNF to be prescribed in such patients. At present, the appropriateness of such decisions is not clear. Given that the therapeutic goal for RA is remission, clinicians increasingly face the challenge of choosing the optimal biologic agent in patients with RA-ILD and uncontrolled joint disease. However, no evidence-based guidelines exist to guide physicians in deciding whether to commence biologic therapy in this setting, or in selecting which drug is most appropriate. Herein, we review the evidence for the comparative pulmonary safety of anti-TNF agents and non-TNF-targeting biologic agents in RA-ILD. In addition, we propose a framework for assessment of baseline disease severity to guide treatment decisions, and for monitoring during therapy. Because of substantial gaps in the available evidence, we also describe a research agenda aimed at obtaining data that will help inform future clinical practice.

The multifaceted aspects of interstitial lung disease in rheumatoid arthritis

Interstitial lung disease (ILD) is a relevant extra-articular manifestation of rheumatoid arthritis (RA) that may occur either in early stages or as a complication of long-standing disease. RA related ILD (RA-ILD) significantly influences the quoad vitam prognosis of these patients. Several histopathological patterns of RA-ILD have been described: usual interstitial pneumonia (UIP) is the most frequent one, followed by nonspecific interstitial pneumonia (NSIP); other patterns are less commonly observed. Several factors have been associated with an increased risk of developing RA-ILD. The genetic background plays a fundamental but not sufficient role; smoking is an independent predictor of ILD, and a correlation with the presence of rheumatoid factor and anti-cyclic citrullinated peptide antibodies has also been reported. Moreover, both exnovo occurrence and progression of ILD have been related to drug therapies that are commonly prescribed in RA, such as methotrexate, leflunomide, anti-TNF alpha agents, and rituximab. A greater understanding of the disease process is necessary in order to improve the therapeutic approach to ILD and RA itself and to reduce the burden of this severe extra-articular manifestation.

Diagnosis and treatment of connective tissue disease-associated interstitial lung disease

Interstitial lung disease (ILD) is one of the most serious pulmonary complications associated with connective tissue diseases (CTDs), resulting in significant morbidity and mortality. Although the various CTDs associated with ILD often are considered together because of their shared autoimmune nature, there are substantial differences in the clinical presentations and management of ILD in each specific CTD. This heterogeneity and the cross-disciplinary nature of care have complicated the conduct of prospective multicenter treatment trials and hindered our understanding of the development of ILD in patients with CTD. In this update, we present new information regarding the diagnosis and treatment of patients with ILD secondary to systemic sclerosis, rheumatoid arthritis, dermatomyositis and polymyositis, and Sjögren syndrome. We review information on risk factors for the development of ILD in the setting of CTD. Diagnostic criteria for CTD are presented as well as elements of the clinical evaluation that increase suspicion for CTD-ILD. We review the use of medications in the treatment of CTD-ILD. Although a large, randomized study has examined the impact of immunosuppressive therapy for ILD secondary to systemic sclerosis, additional studies are needed to determine optimal treatment strategies for each distinct form of CTD-ILD. Finally, we review new information regarding the subgroup of patients with ILD who meet some, but not all, diagnostic criteria for a CTD. A careful and systematic approach to diagnosis in patients with ILD may reveal an unrecognized CTD or evidence of autoimmunity in those previously believed to have idiopathic ILD.

Lung involvement in connective tissue diseases: a comprehensive review and a focus on rheumatoid arthritis

The lungs are frequently involved in Connective Tissue Diseases (CTDs). Interstitial lung disease (ILD) is one of the most common pleuropulmonary manifestations that affects prognosis significantly. In practice, rheumatologists and other physicians tend to underestimate the impact of CTD-ILDs and diagnose respiratory impairment when it has reached an irreversible fibrotic stage. Early investigation, through clinical evidence, imaging and - in certain cases - lung biopsy, is therefore warranted in order to detect a possible ILD at a reversible initial inflammatory stage. In this review, we focus on lung injury during CTDs, with particular attention to ILDs, and examine their prevalence, clinical manifestations and histological patterns, as well as therapeutic approaches and known complications till date. Although several therapeutic agents have been approved, the best treatment is still not certain and additional trials are required, which demand more knowledge of pulmonary involvement in CTDs. Our central aim is therefore to document the impact that lung damage has on CTDs. We will mainly focus on Rheumatoid Arthritis (RA), which - unlike other rheumatic disorders - resembles Idiopathic Pulmonary Fibrosis (IPF) in numerous aspects.