Decline in Incidence of Extra-Articular Manifestations of Rheumatoid Arthritis: A Population-Based Cohort Study

A review on the epidemiology of rheumatoid arthritis: An update and trends from current literature

Rheumatoid arthritis (RA) is a systemic, chronic autoimmune disease affecting mainly the joints, often with extra articular manifestations. This review provides an update on RA epidemiological trends and management. PubMed and EMBASE were searched from 2014 to 2024 using rheumatoid arthritis as keyword, combined with incidence, prevalence, diagnosis, classification, and management. Emphasis was on papers published in the past 5 years. Globally, the age-standardised prevalence and incidence rate (ASPR and ASIR) of RA increased with varying figures. The ASPR increased by 0.37%, 14.1%, and 6.4% from 1990 to 2019, 2020 and 2017 respectively; and 9% from 1980 to 2019. The ASIR increased by 0.3% and 8.2% from 1990 to 2019 and 2017 respectively; the disability-adjusted life years (DALY) figures increased 0.12% and decreased 0.36% in the same period from different authors. Reduction in ASIR were reported while ASPR varies. Disease modifying anti-rheumatic drugs (DMARDs) remain the cornerstone of treatment.

Mortality and Predictive Factors for Death Following the Diagnosis of Interstitial Lung Disease in Patients with Rheumatoid Arthritis: A Retrospective, Long-Term Follow-Up Study

Objective: The aim of this study was to determine mortality and predictive factors for death in patients with rheumatoid arthritis (RA) diagnosed with and without interstitial lung disease (ILD). Methods: We retrospectively performed a long-term follow-up study of patients diagnosed with RA at our medical center between April 2001 and June 2023. The diagnosis and classification of ILD were made based on pulmonary high-resolution computed tomography (HRCT), taken at RA diagnosis and during follow-up. Results: Among 781 patients with RA, 78 were diagnosed with ILD; all cases except one were subclinical. The most common HRCT pattern was definite usual interstitial pneumonia (UIP) followed by nonspecific interstitial pneumonia (NSIP)/UIP, probable UIP, NSIP, and early UIP. During follow-up (mean of 10.0 years), the crude incidence rate of death (95% confidence interval [CI]) was 7.1 (5.2-10.0) and 1.5 (1.0-1.9) per 100 person-years in RA patients with and without ILD. Poor control of RA activity was associated with increased incidence rates of death. The standardized mortality ratio (95% CI) compared with the general population was 1.32 (1.11-1.53) for all RA patients, 2.09 (1.45-2.73) for RA-ILD patients, and 1.16 (0.95-1.38) for non-ILD RA patients. Lung cancer and respiratory failure were the most common causes of death in RA-ILD patients. The Multivariable Fine-Gray regression analysis revealed that ILD (adjusted hazard ratio [HR] 2.97 [95% CI 1.95-4.53]), advanced age (1.08 per additional year [1.05-1.10]), and low body mass index (3.07 [2.10-4.49]) were strong predictive factors for mortality in RA patients. HRCT patterns did not affect the risk of death in RA-ILD patients. Conclusions: Regardless of HRCT pattern, RA-ILD contributes to the increased mortality risk in patients with RA.

Treatment of rheumatoid arthritis-associated interstitial lung disease: An appraisal of the 2023 ACR/CHEST guideline

Purpose of review

To summarize the current treatment landscape of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) in the context of the recent 2023 American College of Rheumatology/American College of Chest Physicians guideline for ILD treatment in systemic autoimmune rheumatic diseases.

Recent findings

The guideline conditionally recommends mycophenolate, azathioprine, and rituximab for first-line RA-ILD therapy, with cyclophosphamide and short-term glucocorticoids as additional options. For RA-ILD progression after first line, mycophenolate, rituximab, nintedanib, tocilizumab, cyclophosphamide, and pirfenidone are conditionally recommended, while long-term glucocorticoids are conditionally recommended against. Only three randomized controlled trials (RCTs) enrolled patients with RA-ILD (total n=217). All other recommendations for RA-ILD were based on RCTs for other diseases or observational data. Antifibrotics might be particularly effective for patients with RA-ILD and the usual interstitial pneumonia pattern (RA-UIP). There is uncertainty of the utility of azathioprine and glucocorticoids in RA-UIP since these medications had worse outcomes compared to placebo in an RCT of patients with idiopathic pulmonary fibrosis. RA-ILD treatment decisions should consider articular activity, ILD activity, comorbidities, and potential for infection.

Summary

We summarized the current treatment landscape for RA-ILD. Since only three RCTs included patients with RA-ILD, most guideline recommendations were conditional and based on low-quality evidence. This highlights the urgent need for additional high-quality RCT data for efficacy and safety of anti-inflammatory and antifibrotic medications for RA-ILD.

Updates on interstitial lung disease and other selected extra-articular manifestations of rheumatoid arthritis

PURPOSE OF REVIEW

To discuss changes in epidemiology, recent advances in understanding of the pathogenesis and management of selected extraarticular manifestations of rheumatoid arthritis (ExRA).

RECENT FINDINGS

The incidence of ExRA overall and subcutaneous rheumatoid nodules in particular is declining after 2000. These trends reflect improved RA disease activity with early effective immunosuppressive treatments; changing environmental risk factors can be contributing. ExRA continues to carry a two-fold increased mortality risk. RA-associated interstitial lung disease (RA-ILD) is a major contributor to mortality, with no decline in incidence and scant therapeutic options. Individualized risk stratification for RA-ILD based on patient-level risk factors and biomarker profile is evolving with MUC5B as a major genetic risk factor. Clinical trials are underway to evaluate the benefits of novel antifibrotic therapies and targeted therapies for RA-ILD. The risk of cardiovascular disease in RA is generally amendable to treatment with disease-modifying antirheumatic drugs, although cardiovascular risk associated with JAK inhibition is not fully understood.

SUMMARY

Despite reduction in incidence of ExRA overall, the incidence of RA-ILD shows no significant decline and remains a major therapeutic challenge. The use of novel antifibrotics and immunosuppressive drugs shows promise in slowing the progression of RA-ILD.