Safety profiles of CAR-T cell therapy in systematic autoimmune diseases: a systematic review and analysis.

Chimeric antigen receptors (CARs)-T cell therapy is emerging as a potent approach for autoimmune diseases. However, its application in autoimmune conditions remains limited, and safety outcomes observed in malignancies can't reliably serve as a reference. Therefore, it's necessary to summarize the safety profiles in autoimmune diseases to provide evidence for future expanding trials. A systematic review was conducted to analyze the CAR-T therapy safety in rheumatic diseases via database searches up to December 2025. Studies reporting safety data were included, while abstracts, reviews, and cases with malignancies were excluded. Factors associated with cytokine release syndrome (CRS) were analyzed using Firth's penalized logistic regression. This study included 38 studies, involving a total of 115 patients with autoimmune disease. Severe adverse events were rare. CRS and immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 70.4% and 4.3% of patients, respectively. Most CRS were low-grade. Multivariate analysis identified BCMA-targeted therapy and allogeneic CAR-T products may as independent factors associated with a reduced risk of CRS. Transient hematologic toxicity and hypogammaglobulinemia were frequently reported, with infections occurring in nearly half of the patients. However, prolonged cytopenia and severe infection were infrequent. Based on the current available evidence, CAR-T therapy appears to have a generally manageable safety profile in autoimmune diseases, supporting its potential as a promising treatment option for patients with relapsed or refractory autoimmune diseases. However, these findings remain preliminary, and further expanded studies are warranted in the future to provide higher-level evidence.