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.

A Case of A1B3 Child from a Group A Mother and a Group B Father: New Group B Allele Arising from 547G>A / 대한수혈학회지

Group B subtype, A1B3, was observed in a 22-year-old blood donors by conventional serologic test. In our family study, his father demonstrated uncomplicated B phenotype and his mother typed as group A. We sequenced exon 6 and 7 of phenotypically A1B3 propositus and his family members by direct sequencing and PCR-based cloning. And we have identified a novel Bvar allele characterized by a 547G>A polymorphism present in propositus and his father. This suggests that the Bvar allele is expressed differently depending on the co-inherited ABO allele.