Experimental animal models for rheumatoid arthritis-associated interstitial lung disease

Abstract Background Rheumatoid arthritis (RA) is a systemic inflammatory disease primarily affecting the joints of the limbs. As the disease progresses, it can involve multiple organ systems. Interstitial lung disease (ILD) is the most common pulmonary manifestation of RA. Reported animal models of RA-ILD include adjuvant-induced arthritis (AA), collagen-induced arthritis (CIA), and transgenic mouse arthritis. However, the establishment criteria and evaluation methods for these models lack uniform standards, and they fail to fully replicate the clinicopathological characteristics of RA-ILD. This limitation significantly hinders research into the pathogenesis and development of therapeutic drugs for RA-ILD. Objective The aim of the study was to review literature in China and abroad on RA-ILD animal models, analyze current research progress, identify existing issues, and propose research recommendations. Methods Literature searches were conducted using the English keywords “rheumatoid arthritis, interstitial lung disease, model” and the Chinese keywords “(rheumatoid arthritis), (interstitial lung disease), (model)” or “(rheumatoid arthritis), (lung interstitial lesions), (model).” The search was performed in PubMed, Web of Science, CNKI, Wanfang Data, and VIP (China Science and Technology Journal Database) for articles published before November 2024. A total of 41 articles were included. Results and Conclusions The CIA model and the CIA model combined with bleomycin are commonly used due to their similarities to the histopathology and disease manifestations of human RA-ILD. Additionally, these models have appropriate cost and modeling duration, along with a high success rate, making them preferable choices. Transgenic animal models exhibit pathological features similar to the nonspecific interstitial pneumonia subtype of human RA-ILD and are useful for studying the genetic effects on RA-ILD. However, they have drawbacks such as high economic costs, long modeling durations, and a low success rate in some cases. The AA model is easy to establish, requires a short modeling period, and has low experimental costs. However, it lacks the chronic pathological development characteristic of human RA and exhibits a degree of self-limitation in lesion progression. Among other models, the comprehensive HLA-DQ8 transgenic mouse model can be used to study the combined effects of genetic and environmental factors on RA-ILD. The collagen autoantibody-induced arthritis model combined with bleomycin has a short modeling period, but it does not align well with the disease course of RA-ILD. These established animal models provide valuable insights into the pathogenesis of RA-ILD, the identification of novel biomarkers, and the development of new therapeutic approaches. Future research should focus on identifying an animal model that better replicates the physiological and pathological changes of clinical RA-ILD while being more convenient, cost-effective, and comprehensive in reflecting disease progression.