TY - JOUR
T1 - Determination of serum holotranscobalamin concentrations with the AxSYM active B12 assay
T2 - Cut-off point evaluation in the clinical laboratory
AU - Bamonti, Fabrizia
AU - Moscato, Giovanna Antonella
AU - Novembrino, Cristina
AU - Gregori, Dario
AU - Novi, Claudia
AU - De Giuseppe, Rachele
AU - Galli, Claudio
AU - Uva, Valentina
AU - Lonati, Silvia
AU - Maiavacca, Rita
PY - 2010/2/1
Y1 - 2010/2/1
N2 - 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 12 values.
AB - 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 12 values.
KW - Analytical performance
KW - Holotranscobalamin
KW - Immunoenzymatic assay
KW - Vitamin B
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U2 - 10.1515/CCLM.2010.032
DO - 10.1515/CCLM.2010.032
M3 - Article
C2 - 19961395
AN - SCOPUS:76649114666
VL - 48
SP - 249
EP - 253
JO - Clinical Chemistry and Laboratory Medicine
JF - Clinical Chemistry and Laboratory Medicine
SN - 1434-6621
IS - 2
ER -