Flow Cytometric Method for Counting Residual Leukocytes / 대한수혈학회지

BACKGROUND: Simple manual method using a Nageotte hemocytometer counting residual leukocytes [White blood cells(WBC)] in blood components is subjective, labor-intensive, time consuming and variable within and between laboratories. The aim of this study was to evaluate usefulness for flow cytometric method to determinate very low numbers of leukocytes in leukocyte-free blood components. METHODS: Epics XL-MCL (Beckman Coulter Co.) was used for determination of fluorescence-labelled cells. The DNA in leukocytes was stained using propidium iodide (PI) and leukocytes were automatically analysed by flow cytometer. RESULTS: Linearity determined over a range of 0.5-50 WBC/muL was a value of r=0.994. The detection limit of this method was 4.4 WBC/muL and accuracy was 86.6% with linearity of r=0.991 over the 5-50 WBC/muL. Reproducibility was CV of 9.1% for 25.8 WBC/muL and 14.7% for 7.1 WBC/muL, respectively. CONCLUSION: Flow cytometric techniques provide a reproducible and objective tool for counting residual WBC in leukocyte free blood components compared with the Nageotte hemocytometer.

The Characteristics of Residual Leukocyte in Sepacell PLS-5A Filtered Platelet Concentrates / 대한혈액학회지

BACKGROUND: We evaluated residual leukocytes characteristics of white cell(WBC) reduction filter in platelet concentrates. Differential count and lymphocyte subset changes were measured before and after leukocyte filtration in platelet concentrates. MATERIAL AND METHODS: Ten units of platelet concentrates were prepared and were filtered with WBC-reduction filter(Sepacell PLS 5A, Japan). After filtration of blood products, WBC and differential leukocyte count and lymphocyte subsets were counted by microscopic examination of Wright-Giemsa stained smear and Facscan(Becton-Dickinson, USA). Monoclonal antibodies used for lymphocyte subset test were CD3(FITC), CD4(FITC), CD8(PE), CDl4(PE), CDl6(PE), CDl9(PE), CD33(PE), CD56(PE), IgGl(FITC), IgG2(PE). RESULTS: The main population of residual leukocytes after filtration was mainly lymphocytes(96.7%), and CD3 positive T lymphocytes showed 23.8% positivity of residual leukocyctes and the next were NK cell(8.7%). B lymphocytes were rarely found(<0.01%) and CD4/ CD8 ratio was within normal limits. CONCLUSION: The leukocyte reduction filters(Sepacell PLS-5A) would be effective for prevention of platelet alloimmunization but not sure about the effect for prevention of TA GVHD.