Zhu, Xingxing

Objective We aim to identify risk factors to enable stratification of patients' susceptibility to inflammatory arthritis immune‐related adverse events (IA‐irAEs). This retrospective study mainly examines whether preexisting osteoarthritis (OA) increases the likelihood of de novo IA‐irAEs. Methods The prevalence of OA among immune checkpoint inhibitor (ICI)–treated patients who developed IA‐irAE, those who developed other types of irAEs but not IA (non‐IA irAEs), and those who did not develop any irAEs (non‐irAEs) were compared. Electronic medical records were reviewed to extract demographic, clinical, and laboratory data. Group comparisons and logistic regression analyses were performed. Results A total of 181 de novo IA‐irAE patients, 140 non‐IA irAE patients, and 170 non‐irAE patients were included. The prevalence of OA was significantly higher in the IA‐irAE group (69%) than in the non‐IA irAE group (48%) and the non‐irAE group (48%) (both P < 0.001). The IA‐irAE group demonstrated a higher frequency of multisite OA, with more predominant hand involvement (62%) than the non‐IA irAE with OA group (13%) and the non‐irAE with OA group (13%) (both P < 0.001). A family history of autoimmune disease (AID) (odds ratio [OR] 2.03, 95% confidence interval [CI] 1.02–4.05), preexisting OA (OR 2.88, 95% CI 1.85–4.52), and melanoma (OR 2.63, 95% CI 1.56–4.47) were identified as risk factors for the development of IA‐irAE. Conclusion OA was more prevalent among ICI‐treated patients developing IA‐irAE than those who were not. Hand OA was the most common OA pattern in IA‐irAE patients. Preexisting OA, melanoma, and a family history of AID were associated with IA‐irAE.