Effect of White Blood Cell Removal on Glucose-6-Phosphate Dehydrogenase Activity Analysis

Abstract

Objective To standardize the pre-analytical procedure of RBC glucose-6-phosphate dehydrogenase (G6PD) activity analysis by judging whether WBC could be an interference factor.Methods From 9 September to 27 October 2010,a total of 49 newborns with hyperbilirubinemia who were treated in West China Second University Hospital,Sichuan University,were included in this study.4 mL whole blood samples were collected from each case.Then according to whether washing the WBC,these samples were divided into two equal parts,as washed group (n=49) and unwashed group (n=49).7600-010 automatic biochemical analyzer was used to measure RBC G6PD activity and WBC G6PD of blood samples in each group and WBC content in RBC dissolve blood.The relationship between G6PD activity testing in whole blood and WBC G6PD activity was evaluated based on above results (The study protocol was approved by the Ethical Review Board of Investigation in Human Being of West China Second University Hospital,Sichuan University).Results Median RBC G6PD activity in unwashed group was 1096 U/L [(137-2512)U/L] which was significant higher than in washed group [861 U/L (94-2357) U/L].There was a positive correlation between RBC G6PD activities in two groups (r=0.963,P＜0.01).Regression equation was y=0.895x-83.365 (y stands for the RBC G6PD activity with WBC washing out,whlie x stands for the RBC G6PD activity without WBC washing out).Linear regression showed that there was close correlation between RBC G6PD activities in groups (r2 =0.927,df=47,F=592.797;P＜0.01).Conclusions WBC in whole blood samples would be a interference factor which made a higher RBC G6PD activity results and G6PD deficiency undetected.It is very important to wash out all the WBC in the pre-analytical procedure in RBC activity detection to provide reliable data for clinical diagnosis. Key words: glucose-6-phosphate dehydrogenase activity; white blood cell