Tocilizumab treatment in patients with rheumatoid arthritis is associated with reduced fibrinogen levels and increased blood loss after total knee arthroplasty

Abstract

Objective: Since IL-6 has been associated with activation of the coagulation cascade and upregulation of fibrinogen transcription, we retrospectively tested the hypothesis that patients with rheumatoid arthritis (RA) treated with tocilizumab (TCZ) may lose more blood when undergoing total knee arthroplasty (TKA).

Methods: This study included 115 RA patients who underwent primary TKA and were preoperatively tested for fibrinogen levels. The blood volume of each patient was calculated using the Nadler formula, and estimated blood loss after TKA was calculated as the change between pre-operative and post-operative hematocrits. If salvaged blood was reinfused, the volume was measured and added to the volume of the estimated blood loss.

Results: We observed that patients treated with TCZ had significantly lower pre-operative fibrinogen levels than those not treated with TCZ (190.0 mg/dL versus 347.0 mg/dL, respectively; p = .00018). We also observed a statistically significant increase in mean total volume of estimated blood loss after TKA in RA patients who had been treated with TCZ compared with those not treated with TCZ (797.1 mL versus 511.4 mL, respectively; p = .0039).

Conclusion: TCZ treatment in patients with RA may increase the risk of blood loss after TKA because of decreased fibrinogen levels.

Keywords:

• Blood loss
• fibrinogen levels
• rheumatoid arthritis
• tocilizumab
• total knee arthroplasty

Acknowledgements

We thank all patients for making this study possible.

Conflict of interest

S. M. received honorarium for the lecture and/or unrestricted research grants from AbbVie, Inc., Asahi Kasei Pharma Corp., Bristol-Myers Squibb Co., Chugai Pharmaceutical Co., Daiichi Sankyo Co., Ltd., Eisai Co., Ltd., Mitsubishi Tanabe Pharma Co., Nakashima Medical Co., Ltd., Santen Pharmaceutical Co., Ltd., Taisho Toyama Pharmaceutical Co., Ltd., and Takeda Pharmaceutical Co., Ltd. K. Y. received honorarium for the lecture from AbbVie, Inc., Asahi Kasei Pharma Corp., Chugai Pharmaceutical Co., Eisai Co., Ltd. Janssen Pharmaceutical K.K., Mitsubishi Tanabe Pharma Co., Pfizer Japan Inc. and Takeda Pharmaceutical Co., Ltd. K. I. received honorarium for the lecture and/or unrestricted research grants from AbbVie, Inc., Asahi Kasei Pharma Corp., Astellas Pharma Inc., Bristol-Myers Squibb Co., Chugai Pharmaceutical Co., Eisai Co., Ltd., Hisamitsu Pharmaceutical Co. Inc., Janssen Pharmaceutical K.K., Kaken Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Co., Santen Pharmaceutical Co., Ltd., Taisho Toyama Pharmaceutical Co. Ltd., and Takeda Pharmaceutical Co., Ltd. The sponsors were not involved in the: study design; collection, analysis, and interpretation of data; writing of the paper; and/or decision to submit for publication.