Trafficking of CD34+ cells into the peripheral circulation during collection of peripheral blood stem cells by apheresis

Abstract

Summary:The number of CD34 ؉ cells collected during apheresis is related to the volume of blood processed. In largevolume apheresis (LVL) procedure, more cells can be collected than were originally present in the peripheral blood at the start of the collection procedure. We prospectively studied the levels of CD34 ؉ cells in the blood and apheresis product during LVL procedures for 21 patients with acute myelogenous leukemia or multiple myeloma. These patients experienced a slow decline in blood CD34

Large volume leukapheresis: Efficacy and safety of processing patient’s total blood volume six times

“…Buchta et al [49] showed that prophylactic calcium infusion during LVL reduced the incidence of citrate-related symptoms without affecting the technical performance or the number of CD34+ cells collected, as was confirmed by our results. Our study also confirmed marked platelet decrease after processing each TBV with halved platelet count after LVL [3,48]. The additional heparin administration enables the reduction of infused volume of citrate anticoagulant, but might represent an additional risk factor for bleeding complications in thrombocytopenic Bojanic,19 patients with central venous catheters [50].…”

“…The optimal study design would be to compare products collected during the same procedure at different time, which was done in this study, and differences caused by interindividual variability were excluded. Studies of kinetics of PBSC enrichment during LVL showed variable results [3,[8][9][10][19][20][21][22][23][24][25][26][27][28][29][30][31], which could be consequence of difference in volumes of processed blood. Therefore, processed blood volume in our study was standardized and strictly related to the patient's TBV.…”

“…Kinetic study showed that decrease in CD34+ count is related to the number of the TBVs processed. The drop in CD34+ cell count was most evident at the beginning of leukapheresis, as cells were packed into the apheresis device set [3,26]. At the same time, separator draws patient's blood while returns saline which filled set lines, which can cause hemodilution and contribute to CD34+ cell decrease.…”

“…A limiting factor for widespread use of LVL may be patients' tolerance of the procedure [2,3]. Larger volumes of infused anticoagulants causes electrolyte imbalance such as hypocalcemia, metabolic alkalosis, hypokalemia and hypomagnesemia [48].…”

“…An alternative to repeated aphereses could be processing larger volumes of blood during one procedure. Large-volume leukapheresis (LVL) involves processing patient's total blood volume (TBV) at least three times during single procedure, and differs from standard leukapheresis by processing larger blood volume, increasing blood flow rate, use of additional anticoagulant heparin and longer duration of procedure [1][2][3][4][5]. Unfortunately, there is no standardized protocol for LVL and between centers there are differences regarding blood volume processed and duration of…”