caa a22 4500 44580873X CHVBK 20180317145204.0 cr unu---uuuuu 170323e20110301xx s 000 0 eng 10.1007/s00415-010-5764-4 doi (NATIONALLICENCE)springer-10.1007/s00415-010-5764-4 Utility of measuring vitamin B12 and its active fraction, holotranscobalamin, in neurological vitamin B12 deficiency syndromes [Elektronische Daten] [Wiebke Schrempf, Marco Eulitz, Volker Neumeister, Gabriele Siegert, Rainer Koch, Heinz Reichmann, Alexander Storch] Vitamin B12 (VitB12, cobalamin) deficiency has been associated with various neuropsychiatric conditions, such as peripheral neuropathy, subacute combined degeneration, affective disorders, and cognitive impairment. Current assays analyze vitamin B12, of which only a small percentage is metabolically active. Measurement of its active fraction, holotranscobalamin, might be of greater relevance, but data in populations with neuropsychiatric populations are lacking. In this study, in order to validate VitB12 and holotranscobalamin (holoTC) serum levels for the detection of VitB12 deficiency in neuropsychiatric conditions, we compared the validity of VitB12 and holoTC in a patient cohort with neuropsychiatric conditions suspicious for VitB12 deficiency. The cohort included all patients admitted to the Department of Neurology at our university between 2005 and 2009 with at least two parameters of the VitB12 metabolism available (n=1,279). We used elevated methylmalonic acid as the external validation criterion for VitB12 deficiency and restricted our analyses to subjects with normal renal function. Among all normal renal function patients, 13.2% had VitB12 deficiency. In receiver operating characteristic curve (ROC) analysis, correlation of VitB12 and holoTC with vitamin B12 deficiency was generally weak, and the areas under the curve (AUC) were not significantly different for holoTC compared to vitamin B12 in all subjects (AUC: 0.66 [95%CI: 0.51-0.82]; p=0.04 vs. 0.72 [0.65-0.78], p<0.0001) and in subcohorts of patients with classical VitB12 deficiency syndromes. The positive predictive values for holoTC and vitamin B12 were low (14.7 vs. 21.0%) and both were associated with more false-positive than true-positive test results. holoTC does not show superior diagnostic accuracy compared to VitB12 for the detection of VitB12 deficiency in subjects with neuropsychiatric conditions. Neither test can be recommended to diagnose VitB12 deficiency in subjects with neuropsychiatric disorders. Springer-Verlag, 2010 Vitamin B12 deficiency nationallicence Cobalamin nationallicence Holotranscobalamin (holoTC) nationallicence Methylmalonic acid (MMA) nationallicence Neuropathy nationallicence Dementia nationallicence Schrempf Wiebke Department of Neurology, Dresden University of Technology, Fetscherstrasse 74, 01307, Dresden, Germany aut Eulitz Marco Department of Neurology, Dresden University of Technology, Fetscherstrasse 74, 01307, Dresden, Germany aut Neumeister Volker Institute of Clinical Chemistry, Dresden University of Technology, 01307, Dresden, Germany aut Siegert Gabriele Institute of Clinical Chemistry, Dresden University of Technology, 01307, Dresden, Germany aut Koch Rainer Department of Biometrics and Medical Informatics, Dresden University of Technology, 01307, Dresden, Germany aut Reichmann Heinz Department of Neurology, Dresden University of Technology, Fetscherstrasse 74, 01307, Dresden, Germany aut Storch Alexander Department of Neurology, Dresden University of Technology, Fetscherstrasse 74, 01307, Dresden, Germany aut Journal of Neurology Springer-Verlag 258/3(2011-03-01), 393-401 0340-5354 258:3<393 2011 258 415 https://doi.org/10.1007/s00415-010-5764-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00415-010-5764-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Schrempf Wiebke Department of Neurology, Dresden University of Technology, Fetscherstrasse 74, 01307, Dresden, Germany aut NATIONALLICENCE 700 1- Eulitz Marco Department of Neurology, Dresden University of Technology, Fetscherstrasse 74, 01307, Dresden, Germany aut NATIONALLICENCE 700 1- Neumeister Volker Institute of Clinical Chemistry, Dresden University of Technology, 01307, Dresden, Germany aut NATIONALLICENCE 700 1- Siegert Gabriele Institute of Clinical Chemistry, Dresden University of Technology, 01307, Dresden, Germany aut NATIONALLICENCE 700 1- Koch Rainer Department of Biometrics and Medical Informatics, Dresden University of Technology, 01307, Dresden, Germany aut NATIONALLICENCE 700 1- Reichmann Heinz Department of Neurology, Dresden University of Technology, Fetscherstrasse 74, 01307, Dresden, Germany aut NATIONALLICENCE 700 1- Storch Alexander Department of Neurology, Dresden University of Technology, Fetscherstrasse 74, 01307, Dresden, Germany aut NATIONALLICENCE 773 0- Journal of Neurology Springer-Verlag 258/3(2011-03-01), 393-401 0340-5354 258:3<393 2011 258 415 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer