DIAGNOSTIC PERFORMANCE OF METHYLMALONIC ACID TESTING BY LCMS/MS COMPARED TO HOLOTRANSCOBALAMIN BY IMMUNOASSAY FOR VITAMIN B_(12) DEFICIENCY

摘要

Measurement of total-B12 has been suggested to lack sensitivity to detect vitamin B_(12) deficiency. Methylmalonic acid (MMA) and Holotranscobalamin (Holo-TC) are recommended to be more sensitive markers for B_(12) deficiency. Our preliminary aim was to develop an LC-MS/MS method to measure MMA. We attempted to evaluate the diagnostic accuracy of HoloTC for the detection of B_(12) deficiency based on the surrogate reference criterion of a raised MMA (>500nmol/L).