Clinically relevant hypokalaemia, hypocalcaemia, and loss of hemoglobin and platelets during stem cell apheresis

Since the introduction of hematopoietic growth factors, the collection of m obilized stem cells via leukapheresis has widely replaced the han est of bo ne marrow in both autologous and allogeneic transplantation settings. We in vestigated the frequency and the extent of anticoagulant-induced electrolyt e changes and the cell-separation-related loss of hemoglobin and platelets. In our study a total of 200 leukaphereses were performed on 60 patients wi th hematological malignancies. The electrolytes (calcium and potassium) wer e determined photometrically pre- and post-apheresis. Blood counts were ana lyzed to calculate the relative decline in hemoglobin and platelet counts. Stem cells were collected by processing a mean total blood volume of 11.6 /- 3.9 L with a citrate consumption of 1,345 +/- 126 mL. More than 50% of a ll patients needed replacement therapy of either potassium or calcium. In n on-substituted patients the initial serum potassium concentration dropped b y 11.3 +/- 7.0% to 3.25 +/- 0.33 mmol/L post apheresis. In 21% of non-subst ituted patients, clinical relevant hypokalaemia was observed with levels < 3 mmol/L. The mean citrate-induced reduction of the total calcium was 5.5 /- 6.0%. In addition the relative loss of hemoglobin and platelet counts am ounted to 10.7 +/- 5.2% and 23.2 +/- 12.5%, respectively. Tn addition to th e well-documented citrate-induced hypocalcaemia, we observed a considerable reduction in serum potassium during stem cell apheresis. This can result i n a clinically relevant, substitution requiring hypokalaemia. The modest de cline in hemoglobin and platelet counts suggested that levels of >9g/dl (Hb ) and platelets >30 x 10(9)/L are sufficient for a safe standard leukaphere sis. J. Clin. Apheresis 15:230-235, 2000. (C) 2000 Wiley-Liss. Inc.