Abstract: Objective Therapeutic plasma exchange (TPE) is an effective and specific blood purification. However, studies about the single plasma exchange on hematocytes and electrolytes are limited. Methods Forty TPE sessions from 21 patients were enrolled in this prospective study. Hematocytes and electrolytes
including albumin, calcium and potassium were measured before and after the TPE sessions. Results No difference in white blood cell count was found after TPE sessions, but lymphocyte counts decreased by 24.41% (0.70±0.52×109/L vs. 0.42±0.33×109/L, t=3.645, P=0.001). Plasma volume for exchange (β=-0.329, P=0.013) and total exchange volume (β=0.576, P=0.001) were the two independent factors for the change of lymphocyte count. Hemoglobin and platelet count decreased by 6.92% (87.21±10.72 g/L vs. 80.92±10.61 g/L, t= 5.222, P<0.001) and 12.83% (167.63±76.69×109/L vs. 149.13±72.47×109/L, t=5.346, P＜0.001), respectively. The reduction of hemoglobin was negatively correlated with the dosage of low molecular weight heparin (r= -0.330, P=0.043). The reduction of platelet count was positively correlated with the coagulation in blood circuit (r=0.388, P=0.016), and was negatively correlated with the dosage of low molecular weight heparin (r=- 0.425, P=0.008). Multivariate regression demonstrated that coagulation in blood circuit was the independent factor for reduction of platelet count (β =-14.562, P=0.008). Serum calcium decreased by 2.84% (2.16±0.14 mmol/L vs. 2.09±0.18 mmol/L, t=2.289, P=0.029), and was negatively correlated with the albumin volume used (r=-0.672, P＜0.001). Multivariate regression revealed that albumin volume used was the independent factor for reduction of calcium (β =-0.003, P＜0.001). Conclusions TPE via membrane filtration is a safe approach for blood purification. Mild reduction in hemoglobin, platelet and calcium were found after the sessions. Sufficient anticoagulation and supplement of calcium are necessary.

Key words: Plasma exchange, Membrane filtration, Adverse reaction