Clinical observation of hypofibrinogenemia induced by the treatment of tocilizumab in rheumatic diseases and exploration of risk factor for hypofibrinogenemia.

Although bleeding symptoms were not observed in this study, the incidence of hypofibrinogenemia remained high after TCZ treatment, usually occurring within 3 months of treatment. Therefore, it is necessary to monitor FIB levels during TCZ treatment. In addition, clinicians can use the nomogram model developed from this study to predict the incidence of hypofibrinogenemia after TCZ treatment in RA patients. Key Points • Hypofibrinogenemia often occurs during TCZ treatment for rheumatic diseases. • PDW, PTH, BMD, tender joint count, and swollen joint count are risk factors for the occurrence of hypofibrinogenemia. • It is necessary to monitor FIB levels during TCZ treatment to avoid bleeding tendency.