Thrombocytopenia Experienced by Healthy Peripheral Blood Stem Cell Donors at a Tertiary Hospital in Korea / 대한수혈학회지

In healthy peripheral blood stem cell (PBSC) donors, rare cases of transient thrombocytopenia have been reported due to the administration of granulocyte colony-stimulating factor (G-CSF) or the apheresis itself. Meanwhile, differentiating pseudothrombocytopenia induced by anticoagulants is crucial, as it can result in false low platelet counts. This study aimed to investigate the causes of thrombocytopenia in healthy PBSC donors. We investigated PBSC donors who experienced thrombocytopenia during transplantation at St. Mary’s Hospital, Seoul. Three donors were identified and donor workup studies were within the normal limits. After G-CSF administration prior to transplantation, the donors experienced a significant reduction in platelet counts. Apheresis resulted in lower levels, yet platelet counts returned to normal levels approximately two weeks later. In donor 3, thrombocytopenia was seen during the donor workup and ethylenediaminetetraacetic acid (EDTA)-induced pseudothrombocytopenia was identified after the supplementation of amikacin. For donor 3, we investigated whether his recipient’s sample showed EDTA-induced pseudothrombocytopenia through a review of any platelet clumping in the apheresis product and the presence of immunoglobulin M (IgM) or IgG antiplatelet antibodies in the recipient’s peripheral blood. In conclusion, the risk of severe thrombocytopenia with G-CSF administration in PBSC donors should be considered and accurate differentiation of pseudothrombocytopenia is imperative.

Enumeration of CD34-positive Stem Cells Using the ADAMII Image-based Fluorescence Cell Counter

BACKGROUND: It is very important to accurately enumerate CD34-positive (CD34+) cells for successful hematopoietic stem cell transplantation (HSCT). We evaluated the ability of the newly developed image based-immunofluorescence cell counter ADAMII (NanoEntek, Seoul, Korea) to enumerate CD34+ cells, which was improved through simultaneous CD45 analysis. METHODS: We enumerated CD34+ cells with ADAMII using 19 peripheral blood (PB) and 91 leukapheresis samples from HSCT donors. Analytical performance, including precision and linearity, was analyzed, and sample stability during storage was evaluated. Viable CD34+ cell count (vCD34) and viable CD45+ cell count (vCD45) and the percentage of viable CD34+ cells among viable CD45+ cells (CD34/CD45) as measured by ADAMII were compared with the corresponding values from two flow cytometry assays, using regression analysis. RESULTS: ADAMII demonstrated acceptable precision, as CV values of vCD34 from six samples with different counts were all < 10% (range: 3.49–9.51%). CV values of the vCD45 and CD34/45 ranged from 4.03% to 9.67% and from 2.48% to 10.07%, respectively. The linearity of vCD34 showed an excellent R 2 value (0.99) when analyzed using the intended count and flow cytometry data. The ADAMII and two flow cytometry-based assays generated very similar data for the PB and leukapheresis samples. CONCLUSIONS: ADAMII demonstrated excellent performance for use as a routine clinical assay in terms of CD34+ cell enumeration from PB and leukapheresis samples. Moreover, it could be used as a point-of-care-test for determining mobilization time and predicting an adequate apheresis stem cell product.