Plasma Exchange to Treat Cytokine Release Syndrome and Immune Effector Cell-Associated Neurotoxicity Syndrome after Anti-CD19 Chimeric Antigen Receptor-T Cell Infusion: A Case Report

Adoptive cell immunotherapy with chimeric antigen receptor-T (CAR-T) cells has shown remarkable clinical out-comes. However, cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are the two most significant toxicities during this therapy and can be life-threatening. We described a 12-year-old juvenile who had been diagnosed with relapsed and refractory B-cell acute lymphocytic leukemia (r/r B-ALL). The patient was recruited into our phase I clinical trial concerning ssCAR-T-19 (anti-CD19 CAR-T cells with shRNA targeting IL-6), and 5*10⁶/kg of engineered ssCAR-T-19 cells were administered. After infusion, the patient underwent a typical CRS reaction, with fever and increased cy-tokine levels. He was treated with antipyretic drugs, methylprednisolone, and tocilizumab, but the effect was limited. He devel-oped coagulation abnormalities, multiple organ dysfunction, lung infection and ICANS. Apart from the necessary supportive and symptomatic treatment, plasma exchange was performed three times in four days while methylprednisolone pulse was performed for two consecutive days. After that, the body temperature, heart rate, and especially the cytokine levels declined. But digestive tract hemorrhage occurred to him and he was transferred to intensive care unit. To make things worse, he developed acute re-spiratory failure and received intubation and mechanical ventilation. In addition, symptomatic treatment such as suppression of stomach acid and anti-infection was given. The bleeding was controlled, and his respiratory function improved, and the CRS and ICANS-related symptoms were relieved. He received extubation and was transferred back to the general ward. Additionally, a bone marrow smear showed no lymphoblast cells, and minimal residual disease in bone marrow was negative on day +22 and day +30. The patient was eventually discharged in a normal condition. In conclusion, CRS and ICANS as two most common toxici-ties after CAR-T therapy, which often cause patient death. Several methods such as anti-IL-6 therapy and/or corticosteroids have been adopted in the management guidelines of CRS and ICANS except plasma exchange. This case shows the validity of plasma exchange in a patient with severe CRS and ICANS after receiving ssCAR-T.