These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Holotranscobalamin as a predictor of vitamin B12 status.
    Author: Hvas AM, Nexo E.
    Journal: Clin Chem Lab Med; 2003 Nov; 41(11):1489-92. PubMed ID: 14656030.
    Abstract:
    We report on the performance of a new test, holotranscobalamin, as compared to well established markers of vitamin B12 deficiency (plasma cobalamins, methylmalonic acid, and homocysteine). Holotranscobalamin was analyzed in 143 samples by a competitive radiobinding assay (Axis-Shield). Employing a cut-off value of 50 pmol/l, holotranscobalamin showed a sensitivity of 1.00 and a specificity of 0.89 as regards discriminating between individuals with test results indicating vitamin B12 deficiency (methylmalonic acid > 0.70 micromol/l and plasma cobalamins < 200 pmol/l, n = 35) and individuals with test results inside the reference intervals (methylmalonic acid < 0.29 micromol/l and plasma cobalamins > or = 200 pmol/l, n = 35). In a group (n = 37) with low plasma cobalamins (< 200 pmol/l) and normal methylmalonic acid (< 0.29 micromol/l), 27 individuals had low holotranscobalamin, and in nine of these individuals plasma homocysteine supported the deficiency state (homocysteine > 15 micromol/l). Holotranscobalamin was low in 12 individuals with increased methylmalonic acid (> 0.40 micromol/l) and normal plasma cobalamins (> or = 200 pmol/l) (n = 36), and plasma homocysteine supported the deficiency state in four of these individuals. We conclude that holotranscobalamin is likely to be a sensitive marker of vitamin B12 deficiency that also has a reasonable specificity. Large-scale clinical studies are warranted in order to clarify the usefulness of holotranscobalamin in the clinical setting.
    [Abstract] [Full Text] [Related] [New Search]