Diffuse large B-cell lymphoma (DLBCL) is currently the most common non-Hodgkin lymphoma worldwide. Chimeric antigen receptor T-cell immunotherapy (CAR-T) involves the genetic modification and massive expansion of T cells, which are then re-infused into the patient. This therapy can be likened to the "fire pathogen" in Traditional Chinese Medicine (TCM), caused by external influences such as the six evils. Thrombocytopenia is one of the most common hematologic adverse reactions associated with this therapy. According to Tang Zonghai, "blood and fire are one family" and "treating fire is treating blood" . In Jingyue Quanshu (The Complete Works of [Zhang] Jing-yue), the pathogenesis of bleeding is summarized as "excessive fire" and "qi injury" , where "blood movement is caused by fire and qi" . Externally, excessive fire agitates the blood, and internally, dysfunction in the five organs—especially the spleen—leads to stagnation of blood circulation. Therefore, in treating thrombocytopenia related to CAR-T therapy, the initial focus should be on clearing fire from the heart and liver; in the intermediate stage, tonifying the spleen and blood, and nourishing spleen yin; and in the later stage, balancing metal and water while also addressing the lung and kidney. This article discusses the treatment of thrombocytopenia after CAR-T therapy for DLBCL based on the "fire and blood as one disease" concept and presents clinical case studies.

CAR-T;fire and blood as one disease;DLBCL;thrombocytopenia