| Autor: |
Bamonti, Fabrizia, Moscato, Giovanna Antonella, Novembrino, Cristina, Gregori, Dario, Novi, Claudia, De Giuseppe, Rachele, Galli, Claudio, Uva, Valentina, Lonati, Silvia, Maiavacca, Rita |
| Předmět: |
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| Zdroj: |
Clinical Chemistry & Laboratory Medicine; Feb2010, Vol. 48 Issue 2, p249-253, 5p, 2 Charts |
| Abstrakt: |
Background: A reliable early marker is required for diagnosis of cobalamin deficiency. We calculated an appropriate holotranscobalamin (HoloTC) cut-off point for identifying cobalamin deficiency using an immunoenzymatic assay. Methods: Determination of the cut-off threshold and correlation between HoloTC and the other diagnostic parameters routinely used for vitamin B12 deficiency [total vitamin B12 (tB12), folate, homocysteine] were measured in 250 routine blood specimens from 107 men (mean age 59.0±18.8 years) and 143 women (mean age 54.2±23.1 years). The inclusion criterion was serum tB12 concentration ≤221 pmol/L. Results: Analytical performance results agreed with those reported by others. A weak correlation (R=0.42) was found between HoloTC and tB12. A 40 pmol/L cut-off threshold was chosen for HoloTC and the associated sensitivity and specificity was 0.86 and 0.66, respectively. Out of 250 tested samples, 126 showed tB12 concentrations 139–221 pmol/L (gray zone, GZ) and 124 had tB12 concentrations <139 pmol/L (low, L). Values less than the cut-off for HoloTC were present in 68.2% and 37.9% of cases in the GZ and L group, respectively (p<0.01), and in 53.2% of subjects. Conclusions: Our results confirmed the analytical reliability of the AxSYM HoloTC assay. The method is adequate for routine use and a cut-off threshold of 40 pmol/L is appropriate for assessing cobalamin deficiency in populations with reduced tB12 values. Clin Chem Lab Med 2010;48:249–53. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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