OBJECTIVE: We aim to identify risk factors to enable stratification of patients' susceptibility to inflammatory arthritis immune-related adverse events (IA-irAE). This retrospective study mainly examines whether preexisting osteoarthritis (OA) increases the likelihood of de novo IA-irAE. METHODS: The prevalence of OA among immune checkpoint inhibition (ICI)-treated patients who developed IA-irAE, those who developed other types of irAEs but not IA (non-IA irAE), and those who did not develop any irAEs (non-irAE) were compared. Electronic medical records were reviewed to extract demographic, clinical and laboratory data. Group comparisons and logistic regression analyses were performed. RESULTS: 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 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 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) (OR 2.03, 95% 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. CONCLUSIONS: OA was more prevalent among ICI-treated patients developing IA-irAE than those who did 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.
Chen et al. (2026) studied this question.