Core Viewpoint - CAR-T cell therapy, originally developed for cancer treatment, shows promising results in treating autoimmune diseases such as systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and idiopathic inflammatory myopathy (IIM) [1][2] Group 1: Research Findings - A study by Georg Schett's team found that 77% of autoimmune disease patients experienced a specific adverse reaction called Local Immune Effector Cell-Associated Toxicity Syndrome (LICATS) after CD19-targeted CAR-T cell therapy [2][7] - The study included 39 patients treated between March 2021 and October 2024, with a median age of 36 years, and observed 54 adverse reactions classified as LICATS [6][7] - The most affected organs were skin (35%), kidneys (22%), and musculoskeletal system (19%), with most symptoms being mild [7][9] Group 2: Distinction from Disease Relapse - LICATS is distinct from disease relapse, occurring only in previously affected organs and typically resolving without treatment or with minimal corticosteroid use [10][12] - Symptoms of LICATS appear during the active phase of CAR-T cell therapy and do not involve systemic adverse events, differentiating it from cytokine release syndrome (CRS) seen in cancer treatments [10][11] Group 3: Implications for Treatment - The study suggests that LICATS should not be misinterpreted as disease relapse, emphasizing the need for careful monitoring of skin, kidney, and musculoskeletal symptoms in autoimmune patients undergoing CAR-T therapy [12] - The transient local inflammation observed may indicate a potential therapeutic effect rather than a negative outcome, highlighting the importance of understanding these reactions in the context of treatment [12]