[Biological variation and analytical performance specification study of erythrocyte and related parameters]

Objective: To study biological variation (BV) and analytical performance specifications (APS) of 15 erythrocyte and related parameters. Methods: Sixty healthy participants from Beijing Hospital were prospectively recruited for the study, from July to December, 2023, including 30 males [aged (41.3±11.9) years] and 30 females [aged (40.3±12.4) years]. The study was designed based on the Biological Variation Data Critical Appraisal Checklist and the characteristics of erythrocyte detection. Whole blood samples were collected 10 times at 2-week intervals during 20 weeks. All samples were tested in duplicate using Mindray BC-7500 hematology analyzer and its accompanying reagents. Within-subject biological variation (CV_I) and between-subject biological variation (CV_G) were estimated by the nested ANOVA method. The BV data in this study were compared with the BV data of the European Database of Biological Variation. APS, reference change value (RCV) and index of individuality (II) were calculated. Results: The CV_I for 15 parameters ranged from 0.49% to 86.46%, and the CV_I data for red cell distribution width (RDW)-CV, RDW-SD, reticulocyte (RET) percentage, RET count, reticulocyte hemoglobin content (RHE), medium fluorescence reticulocyte (MFR) and high fluorescence reticulocyte (HFR) were significantly higher in females than in males (all P<0.05). The CV_G ranged from 1.27% to 100.79%, and the CV_G data for HFR were significantly different between genders (P<0.05). The CV_I data for red blood cell (RBC), hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC) and RHE in this study were lower than those recommended by the European database. The derived indicators of most parameters were influenced by gender. The II values for all parameters were<1.4, where the II values of MCHC and HFR were between 0.6 and 1.4; the II values for the remaining 13 parameters were<0.6. Conclusions: A BV study protocol for erythrocyte parameters is designed. When the reference intervals differ between genders, BV data should be calculated separately and the lower BV data are recommended for calculating APS; the RCV should be set separately for each gender.