Effective treatment of rheumatoid arthritis-associated interstitial lung disease by B-cell targeted therapy with rituximab

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.

Efficacy and safety of rituximab in the treatment of connective tissue disease-related interstitial lung disease

Interstitial lung disease (ILD) represents a severe pulmonary complication of connective tissue diseases, rheumatoid arthritis (RA), and antineutrophil cytoplasmic antibody-associated vasculitis. Treatment of ILD, mainly based on immunosuppression, remains challenging. Rituximab (RTX), a monoclonal antibody binding to CD20, is considered a valuable therapeutic choice in cases of refractory ILD. Here, we review the available efficacy and safety data on the use of RTX in the treatment of rheumatic disease-related ILD. Despite controversial efficacy data, RTX seems to be able to stabilize or improve ILD related to RA and antisynthetase syndrome and in established and severe ILD complicating systemic sclerosis. Fewer data are available regarding ILD related to Sjögren syndrome, systemic lupus erythematosus, and antineutrophil cytoplasmic antibody-associated vasculitis. To date, few prospective studies are available and randomized trials are still ongoing with the purpose of exploring the role of RTX in this condition, including the supposed relationship between efficacy and ILD radiologic patterns and safety data, up to now derived mainly from RA studies. Despite an overall acceptable safety profile, concerns remain regarding an increased infectious disease risk in patients with ILD as well as possible lung toxicity and the increased rate of immune-mediated reactions in patients with connective tissue diseases. In conclusion, RTX is a relevant therapeutic option for rheumatic disease-related ILD despite the existing uncertainties; ongoing trials are expected to clarify its use.

Rituximab in the Treatment of Interstitial Lung Disease Associated with Autoimmune Diseases: Experience from a Single Referral Center and Literature Review

In the present study, we aimed to report our experience with rituximab (RTX) in the treatment of patients with ILD associated with AD (AD-ILD) at a single center. For this purpose, clinical characteristics, radiological findings, and pulmonary function tests (PFTs) of RTX-treated AD-ILD-patients seen from May 2016 until March 2020 at a referral center for individuals with ILD were retrospectively reviewed. Additionally, an updated literature review was conducted. A total of 26 patients (mean age 58.3 ± 11.1 years at ILD diagnosis) was included. The most common ADs related to ILD were systemic sclerosis, idiopathic inflammatory myositis (including anti-synthetase syndrome) and rheumatoid arthritis. Non-specific interstitial pneumonia (n = 12) and usual interstitial pneumonia (n = 11) were the predominant radiological patterns. The sustained improvement in PFTs was observed from the start of RTX, with a statistically significant increase in DLCO from basal to one year after RTX (mean + 4.2%, p = 0.024). Overall, there were no differences when comparing PFT outcome according to the radiological pattern or the specific type of AD. In conclusion, RTX constitutes a good therapeutic option to preserve lung function in patients with AD-ILD, regardless of the radiological pattern or the underlying AD.

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.

TNF-Induced Interstitial Lung Disease in a Murine Arthritis Model: Accumulation of Activated Monocytes, Conventional Dendritic Cells, and CD21+/CD23- B Cell Follicles Is Prevented with Anti-TNF Therapy

Interstitial lung disease (ILD) is a well-known extra-articular manifestation of rheumatoid arthritis (RA). RA-associated ILD (RA-ILD) exists on a wide spectrum, with variable levels of inflammatory and fibrotic activity, although all subtypes are regarded as irreversible pathologic conditions. In both articular and pulmonary manifestations, TNF is a significant pathogenic factor. Whereas anti-TNF therapy alleviates joint pathologic conditions, it exacerbates fibrotic RA-ILD. The TNF-transgenic (TNF-Tg) murine model of RA develops both inflammatory arthritis and an ILD that mimics a cellular nonspecific interstitial pneumonia pattern dominated by an interstitial accumulation of inflammatory cells with minimal-to-absent fibrosis. Given the model's potential to elucidate the genesis of inflammatory RA-ILD, we aim to achieve the following: 1) characterize the cellular accumulations in TNF-Tg lungs, and 2) assess the reversibility of inflammatory ILD following anti-TNF therapy known to resolve TNF-Tg inflammatory arthritis. TNF-Tg mice with established disease were randomized to anti-TNF or placebo therapy and evaluated with imaging, histology, and flow cytometric analyses, together with wild-type controls. Flow cytometry of TNF-Tg versus wild-type lungs revealed significant increases in activated monocytes, conventional dendritic cells, and CD21+/CD23- B cells that are phenotypically distinct from the B cells in inflamed nodes, which are known to accumulate in joint-draining lymph nodes. In contrast to human RA-ILD, anti-TNF treatment significantly alleviated both joint and lung inflammation. These results identify a potential role for activated monocytes, conventional dendritic cells, and CD21+/CD23- B cells in the genesis of RA-ILD, which exist in a previously unknown, reversible, prefibrotic stage of the disease.

Rituximab in connective tissue disease-associated interstitial lung disease

INTRODUCTION/OBJECTIVES

To evaluate rituximab (RTX) effectiveness and safety in patients with interstitial lung disease (ILD) related to connective tissue diseases (CTD).

METHODS

Retrospective multicenter cohort study, including patients with CTD-ILD, followed in six Portuguese rheumatology departments until November 2018. ILD diagnosis was based on high-resolution CT (HRCT) and/or lung biopsy. Results of HRCT, pulmonary function tests, and 6-min walking test before and after RTX were compared using the Wilcoxon matched pair test. Safety, including adverse events during treatment and reasons for RTX discontinuation, was also analyzed.

RESULTS

A total of 49 patients were included, with rheumatoid arthritis being the commonest CTD (61.2%). The median interval between CTD onset and ILD diagnosis was 4 years (IQR 1-9.5) and median ILD duration at first RTX administration was 1 year (IQR 0-4). The median RTX treatment duration until the last follow-up was 3 years (IQR 1-6). Usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP) were the commonest patterns, occurring in 20 and 18 patients, respectively. One year after RTX first administration, there was a stabilization in carbon monoxide diffusing capacity (DLCO; mean + 5.4%, p = 0.12) and improvement in forced vital capacity (FVC; mean + 4.3%, p = 0.03), particularly in patients with NSIP. Patients with UIP had less promising results, but at 1 year, pulmonary function tests remained stable (DLCO + 2.5%, p = 0.77; FVC + 4.2%, p = 0.16). Infection was the main reason for RTX discontinuation and led to two deaths.

CONCLUSIONS

RTX seems to be a promising treatment for CTD-ILD patients, particularly when NSIP pattern is present. Key points • The use of rituximab in patients with interstitial lung disease related to connective tissue disease is associated with long-standing disease stability in a wide range of systemic rheumatic diseases. • Efficacy results were particularly impressive in patients with non-specific interstitial pneumonia pattern, although in a subgroup of patients with usual interstitial pneumonia pattern, disease progression was also hold with this treatment. • In a large number of patients, rituximab was used in monotherapy and as first-line treatment.

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.

Up-to-Date Information on Rheumatoid Arthritis-Associated Interstitial Lung Disease

Pulmonary involvement is common in rheumatoid arthritis (RA) and affects all the components of the lung. Interstitial lung disease (ILD) is the most predominant pulmonary manifestation and has been identified as the main cause of morbidity and mortality in RA. Clinically significant RA-ILD occurs in approximately 10% of RA patients. Several risk factors, such as old age, male gender, and smoking, have been reported to date. Histologically, the proportion of the usual interstitial pneumonia (UIP) pattern is higher in RA-ILD than in ILD associated with other connective tissue diseases, and RA-ILD also shows nonspecific interstitial pneumonia and organizing pneumonia patterns. High-resolution computed tomography scans are highly predictive of the histological UIP pattern with a specificity of 96%–100%. Acute exacerbation, which is the acute deterioration of the respiratory status characterized by newly developed bilateral infiltrates with unknown etiologies, has been reported in RA-ILD. Although acute exacerbation of RA-ILD has high mortality, similar to that of idiopathic pulmonary fibrosis, its incidence is lower in RA-ILD than in idiopathic pulmonary fibrosis. A consensus treatment has not yet been established. Current therapeutic regimens typically include corticosteroids with or without cytotoxic agents. Recent large longitudinal studies reported that the prognosis of RA-ILD was poor with a median survival of 2.6–3.0 years. Furthermore, histological and/or radiological patterns, such as UIP or non-UIP, have significant prognostic implications. RA-ILD patients with histological or radiological UIP patterns have poorer prognoses than those with non-UIP patterns. This review assessed the characteristics of RA-ILD by overviewing recent studies in the field and focused on the clinical significance of histological and/or radiological patterns in RA-ILD.

Efficacy of intensive immunosuppression in exacerbated rheumatoid arthritis-associated interstitial lung disease

OBJECTIVES

Acute or subacute exacerbations are recognized as a severe complication of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Nevertheless, the role of intensive immunosuppression in RA-ILD remains elusive. We attempted to evaluate the clinical characteristics and efficacy of immunosuppressive treatment in exacerbated RA-ILD.

METHODS

Clinical data, including respiratory function, imaging, treatment, and prognosis, were retrospectively collected for 17 patients with RA-ILD who required hospitalization at the University of Tokyo Hospital due to an acute exacerbation (12 patients) or subacute exacerbation (5 patients).

RESULTS

Patients with RA-ILD demonstrated a significantly higher titers of anticyclic citrullinated peptide antibodies compared with RA patients in Japanese Ninja registry, suggesting the role of adaptive immunity. Immunosuppressive treatment suppressed the deterioration of pulmonary functions with improved ground grass opacity and consolidation. In particular, in patients with less fibrosis on computed tomography (CT) images showed a better response to treatment. Although five patients treated with combination therapy, including cyclophosphamide, showed a severely decreased lung volume, these intensive therapies provided a good prognosis without fatalities for the average observation period of 474 days.

CONCLUSIONS

Immunosuppressive therapy is effective for exacerbations of RA-ILD. For severe cases with low respiratory function, intensive therapy, including cyclophosphamide, has a potential to improve the prognosis.

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.