Preexisting autoimmune disease is a risk factor for immune-related adverse events: a meta-analysis

Purpose Patients with preexisting autoimmune disease (PAD) are often excluded from clinical trials assessing immune checkpoint inhibitors (ICIs). Therefore, the safety of ICI therapy in patients with PAD remains unclear. Herein, we evaluated the incidence of immune-related adverse events (irAEs) in patients with PAD when compared with non-PAD patients. Methods We searched MEDLINE/PubMed, Web of Science, and Google Scholar for eligible studies from inception to January 2021. Observational studies reporting the incidence of irAEs in patients with and without PAD were included. We then performed a meta-analysis of eligible studies using forest plots. The primary endpoint of this study was the incidence rate of irAEs between patients with and without PAD. Results We identified three prospective and three retrospective studies involving 206 patients with PAD and 3078 patients without PAD. In the meta-analysis, 128 patients with PAD (62.1%) experienced irAEs, which occurred in 51.9% of non-PAD patients, resulting in an odds ratio (OR) of 2.14 (95% confidence interval [CI] 1.58-2.89). In the subgroup analysis, the incidence of irAEs was significantly higher in patients with PAD (OR = 2.19, 95% CI [1.55-3.08]). Furthermore, no significant heterogeneity or publication bias was detected, indicating that our meta-analysis could be generalized to clinical settings. Conclusion This meta-analysis demonstrated that PAD was a risk factor for irAE incidence. These results suggest that monitoring the occurrence of irAEs in patients with PAD is required to manage irAEs appropriately.