Biological variation of holotranscobalamin and cobalamin in healthy individuals

• Published in: Scandinavian journal of clinical and laboratory investigation Vol. 77; no. 6; pp. 433 - 436
• Main Authors: Brokner, Mette, Hager, Helle Borgstrøm, Lindberg, Morten
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 18.08.2017
• Subjects: Adult; Aged; biological variation; cobalamin; Female; Health; healthy volunteers; holotranscobalamin; Humans; index of individuality; Male; Middle Aged; reference change value; Reference Values; Transcobalamins - analysis; Vitamin B 12 - blood; Vitamin B12; Young Adult; holotranscobalamin; cobalamin; biological variation; healthy volunteers; Vitamin B12; humans; reference change value; index of individuality
• ISSN: 0036-5513; 1502-7686
• DOI: 10.1080/00365513.2017.1335881

Data on biological variation for cobalamin and holotranscobalamin (holoTC) are limited. The aim of this study was to determine within-subject (CV I ) and between-subject (CV G ) biological variations for these analytes in a healthy population. We collected blood samples from 15 healthy volunteers (12 women and three men, 22-66 years) on the same weekday for 10 consecutive weeks. Serum samples were stored at -80 °C until analysis in duplicate in a single analytical run. The CV I and CV G were estimated by nested ANOVA. The CV I (95% CI) for cobalamin and holoTC was 6.7% (5.7-7.7) and 13.0% (11.5-15.0), respectively. The corresponding CV G was 24.1% (16.4-36.0) and 24.6% (16.3-37.7). The analytical variation (CV A ) (95% CI) was 3.5% (3.2-4.0) for cobalamin and 2.4% (2.1-2.6) for holoTC. The index of individuality (II) was low (<0.6) for both cobalamin and holoTC and the reference change value (RCV) was 20.1% for cobalamin and 36.6% for holoTC. Our study describes the components of biological variation of cobalamin and holoTC in a healthy population, contributing to a better clinical interpretation of these biomarkers.