Incidence, risk factors, and prognosis of acute exacerbation of rheumatoid arthritis-associated interstitial lung disease: a systematic review and meta-analysis.

INTRODUCTION: Acute exacerbation (AE) is a devastating complication of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) and leads to high mortality. This study aimed to investigate the incidence, risk factors, and prognosis of acute exacerbation of rheumatoid arthritis-associated interstitial lung disease (AE-RA-ILD). METHODS: PubMed, EMBASE, Web of Science, and Medline were searched through 8 February 2023. Two independent researchers selected eligible articles and extracted available data. The Newcastle Ottawa Scale was used to assess the methodological quality of studies used for meta-analysis. The incidence and prognosis of AE-RA-ILD were investigated. Weighted mean differences (WMDs) with corresponding 95% confidence intervals (CIs) and pooled odds ratios (ORs) with 95% CIs were calculated to explore the risk factors of AE in RA-ILD. RESULTS: Twenty-one of 1,589 articles were eligible. A total of 385 patients with AE-RA-ILD, of whom 53.5% were male, were included. The frequency of AE in patients with RA-ILD ranged from 6.3 to 55.6%. The 1-year and 5-year AE incidences were 2.6-11.1% and 11-29.4%, respectively. The all-cause mortality rate of AE-RA-ILD was 12.6-27.9% at 30 days and 16.7-48.3% at 90 days. Age at RA diagnosis (WMD: 3.61, 95% CI: 0.22-7.01), male sex (OR: 1.60, 95% CI:1.16-2.21), smoking (OR: 1.50, 95% CI: 1.08-2.08), lower forced vital capacity predicted (FVC%; WMD: -8.63, 95% CI: -14.68 to - 2.58), and definite usual interstitial pneumonia (UIP) pattern (OR: 1.92, 95% CI: 1.15-3.22) were the risk factors of AE-RA-ILD. Moreover, the use of corticosteroids, methotrexate, and biological disease-modifying anti-rheumatic drugs, was not associated with AE-RA-ILD. CONCLUSION: AE-RA-ILD was not rare and had a poor prognosis. Age at RA diagnosis, male sex, smoking, lower FVC%, and definite UIP pattern increased the risk of AE-RA-ILD. The use of medications, especially methotrexate and biological disease-modifying anti-rheumatic drugs, may not be related to AE-RA-ILD. REGISTRATION: CRD42023396772.