Abstract:

Objective To analyze the clinical role of plasma antithrombin（AT） activities in patients with multiple myeloma（MM） with renal injury. Methods The data of 60 newly diagnosed MM patients（MM group） and 60 newly diagnosed patients with kidney disease（control group） from the Affiliated Hospital of Chengde Medical College from January 2018 to October 2020 were collected. The differences in AT activity among different immunological types of MM patients were compared. According to serum creatinine（SCr） level，the MM group and the control group were further classified into normal renal function，impaired renal function，normal renal function control group and impaired renal function control group. Pearson correlation analysis was used to evaluate the correlation between AT activity and cystatin C（Cys C） in MM patients. Receiver operating characteristic（ROC） curve was used to evaluate the efficacy of AT and Cys C in diagnosing renal injury in MM patients. Follow-up was conducted for MM patients，and the differences in survival time after chemotherapy among patients with different AT activities and Cys C levels were compared. Results There was statistical significance in AT activity among patients with different immune types of MM（F=13.144，P<0.05）. The AT activity increased in the order of light chain type，IgG type，IgA type and non-secretory type MM patients. The plasma AT activity of MM patients with normal renal function was better than that of MM patients with impaired renal function（P<0.05），and the plasma AT activity of impaired renal function control group was lower than that of normal renal function control group（P<0.05）. The plasma AT activity in impaired renal function group was higher than that in impaired renal function control group（P<0.05）. The AT activity and Cys C of MM patients with renal injury were negatively correlated（r=-0.554，P=0.004）. The areas under curves（AUC） of AT activity and Cys C for diagnosing renal injury in MM patients were 0.887 and 0.625，respectively. The survival time after treatment was longer in MM patients with normal AT activity and normal Cys C than in MM patients with reduced AT activity and increased Cys C，and also longer than in MM patients with normal AT activity and increased Cys C（P<0.05）. Conclusions The plasma AT activity in MM patients is related to the immunological type of the patients. The AT activity can be used to assess renal injury in MM patients.

Key words: Antithrombin, Multiple myeloma, Renal injury, Creatinine, Cystatin C