Effect of vitamin B12 treatment on haptocorrin.

Autor:	Mørkbak AL; Department of Clinical Biochemistry, Aarhus Sygehus, Denmark. almor@as.aaa.dk, Hvas AM, Lloyd-Wright Z, Sanders TA, Bleie O, Refsum H, Nygaard OK, Nexø E
Jazyk:	angličtina
Zdroj:	Clinical chemistry [Clin Chem] 2006 Jun; Vol. 52 (6), pp. 1104-11. Date of Electronic Publication: 2006 Apr 13.
DOI:	10.1373/clinchem.2005.061549
Abstrakt:	Background: Haptocorrin (HC) carries the major part of circulating cobalamin, but whether HC is altered on treatment with vitamin B12 remains unknown. Methods: Our study included 3 populations: a population of vegan men (n = 174; vegan population), of whom 63 were treated daily with 5 mg of oral vitamin B12 for 3 months; a group of patients with a previous methylmalonic acid (MMA) concentration >0.4 micromol/L (n = 140; population with suspected deficiency), of which 69 were treated with weekly vitamin B12 injections (1 mg) for 4 weeks; and a subgroup of participants in a vitamin B intervention study (n = 88; nondeficient population), of whom 45 were treated daily with 0.4 mg of oral vitamin B12 for 3 months. Total HC and holoHC were measured by ELISA. Cobalamin was measured by an intrinsic factor (IF)-based assay. Samples were collected at baseline and 3 months after start of treatment. Results: Compared with baseline results for the 3 study populations, total HC and holoHC increased 30 pmol/L for every 100 pmol/L increase in cobalamin. After treatment with vitamin B12, holoHC (P <0.0001) and total HC (P <0.0001) increased significantly in the vegan population. Only holoHC increased in the population with suspected deficiency (P <0.0001), whereas no alteration was observed in the nondeficient population. Conclusions: The HC concentration is decreased in severely cobalamin-deficient individuals and increases on treatment. The concentration of cobalamin also relates significantly to the HC concentration in nondeficient individuals.
Databáze:	MEDLINE
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