Abstract | BACKGROUND: METHODS: Three hundred and sixty blood samples were collected by five Dutch hospitals. Vitamin B(12) and holoTC in serum were measured (AxSYM; Abbott). MMA in serum was measured by tandem mass spectrometry (LC-MS/MS). RESULTS: Receiver operating curve (ROC) analysis demonstrated a greater area under the curve (AUC) for holoTC than for vitamin B(12) in detecting vitamin B(12) deficiency characterized by three predefined cut-off levels of MMA. A cut-off value of 32 pmol/L of holoTC resulted in the highest sensitivity (83%) with acceptable specificity (60%) in detecting MMA concentrations above 0.45 μmol/L. The combination of vitamin B(12) and holoTC did not improve diagnostic accuracy at this cut-off level. CONCLUSIONS: HoloTC has a better diagnostic accuracy than vitamin B(12) and can replace the existing vitamin B(12) assay as a primary screening test in patients suspected of vitamin B(12) deficiency. Critical evaluation of cut-off values of holoTC indicated that a cut-off value of 32 pmol/L can be considered in screening for metabolic vitamin B(12) deficiency (defined by MMA > 0.45μmol/L) in a mixed patient population.
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Authors | Sandra G Heil, Robert de Jonge, Maurits C F J de Rotte, Merel van Wijnen, Rebecca M R Heiner-Fokkema, Anneke C Muller Kobold, J Maurits M Pekelharing, Henk J Adriaansen, Edward Sanders, Paul H Trienekens, Ton Rammeloo, Jan Lindemans |
Journal | Annals of clinical biochemistry
(Ann Clin Biochem)
Vol. 49
Issue Pt 2
Pg. 184-9
(Mar 2012)
ISSN: 1758-1001 [Electronic] England |
PMID | 22302152
(Publication Type: Journal Article, Multicenter Study)
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Chemical References |
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Topics |
- Adult
- Aged
- Aged, 80 and over
- Chromatography, Liquid
- Female
- Humans
- Limit of Detection
- Male
- Middle Aged
- ROC Curve
- Tandem Mass Spectrometry
- Vitamin B 12
(blood)
- Vitamin B 12 Deficiency
(diagnosis)
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