Abnormal Coagulation Function in Chimeric Antigen Receptor T Cell Treatment of Hematologic Malignancies

Chimeric Antigen Receptor T cell( CAR-T) is an effective treatment for refractory recurrent hematologic malignancies nowdays. However, CAR T cells can potentially damage normal tissues by specifically targeting a tumor-associated antigen that is also expressed on those tissues. Cytokine release syndrome (CRS), a systemic inflammatory response caused by cytokines, is the most common type of toxicity, including fever, hyoxemia, pain and so on. In our study, we found 6 cases abnormal coagulation function which was not very common complication after CAR-T infusion. 4 cases relapsed/refractory acute B lymphoblastic leukemia(B-ALL), including 2 female 53 and 45 years old, 2 male 20 and 6 years old. 1 case multiple myeloma(MM), female 65 years old and 1 case relapsed/refractory diffuse large B-cell lymphoma (DLBCL), male 17 years old. After conditioning chemotherapy with fludarabine and cyclophosphamide, CAR-T cells were infused into patients. In these cases, female 65 years old B-ALL patient had the most severe cytokine release reactions, multiple organ function damage, and abnormal coagulation function that prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged and reached a peak (Too long to detect) on the 14th day after CAR-T infusion, while fibrinogen (FIB) was reduce d (peak on the 14 day, 0.328g/L) and D-Dimer, fibrinogen degradation products (FDP) significantly increased (peak on the 12th day, 28.7ug/mL and more than 10mg/L respectively). After positive hemostasis and other treatments with amperenic acid, vitamin K1 and so on, the level of PT, APTT, FIB, etc were returned to normal on the 19thday. The other 5 patients went through the same process, only slightly. Patients with severe abnormal coagulation function were prone to bleed and even life-threatening, and giving active treatment, finally they all recovered. For the first time, we reported the abnormal coagulation function after CAR-T infusion in hematologic malignancies.