目的 探讨托珠单抗（TCZ）导致风湿免疫性疾病患者低纤维蛋白原血症的风险及安全性。方法 回顾分析 1例以TCZ治疗血管炎致低纤维蛋白原血症患儿的临床资料，并复习相关文献。结果 患儿，男，12岁。表现为四肢痛性 红斑样皮疹，伴下肢肿痛及活动受限，皮肤病理示血管炎样改变。患儿应用泼尼松及环磷酰胺治疗效果欠佳，加用TCZ治 疗2周后即出现低纤维蛋白原血症，停用TCZ 6周后纤维蛋白原上升，期间出现2次极少量咯血。国外文献报道，TCZ治疗 者的手术出血风险更高。TCZ导致低纤维蛋白原血症可能与药物引起细胞因子不平衡以及继发凝血因子ⅩⅢ缺乏有关。 结论 TCZ治疗可引起低纤维蛋白原血症，甚至继发严重出血；治疗过程应监测凝血功能，尤其纤维蛋白原水平和凝血因 子ⅩⅢ活性。

Objective To explore the risk and safety of tocilizumab (TCZ) induced hypofibrinogenemia in patients with rheumatic immune diseases. Methods The clinical data of hypofibrinogenemia caused by TCZ in the treatment of vasculitis in a child were retrospectively analyzed, and the relevant literature was reviewed. Results A 12 -year-old boy presented with a painful erythema-like rash on the limbs, accompanied by swelling and pain in the lower limbs and restricted mobility. The skin pathology showed vasculitis-like changes. The treatment effect of prednisone and cyclophosphamide in the child was not satisfactory. Hypofibrinogenemia occurred 2 weeks after the treatment with TCZ, and the level of fibrinogen increased 6 weeks after discontinuation of TCZ. There were minimal hemoptysis twice during the period. Foreign literature has reported that patients treated with TCZ have a higher risk of surgical bleeding. TCZ induced hypofibrinogenemia may be related to drug-induced cytokine imbalance and secondary coagulation factor ⅩⅢ deficiency. Conclusion TCZ treatment can cause hypofibrinogenemia and even secondary severe bleeding. The coagulation function should be monitored during the treatment process, especially the level of fibrinogen and the activity of coagulation factor ⅩⅢ.