Utility of measuring vitamin B12 and its active fraction, holotranscobalamin, in neurological vitamin B12 deficiency syndromes

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Wiebke Schrempf - , Technische Universität Dresden (Autor:in)
  • Marco Eulitz - , Technische Universität Dresden (Autor:in)
  • Volker Neumeister - , Institut für Klinische Chemie und Laboratoriumsmedizin (Autor:in)
  • Gabriele Siegert - , Technische Universität Dresden (Autor:in)
  • Rainer Koch - , Technische Universität Dresden (Autor:in)
  • Heinz Reichmann - , Klinik und Poliklinik für Neurologie (Autor:in)
  • Alexander Storch - , Technische Universität Dresden (Autor:in)

Abstract

Vitamin B 12 (VitB 12, 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 B 12, 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 VitB 12 and holotranscobalamin (holoTC) serum levels for the detection of VitB 12 deficiency in neuropsychiatric conditions, we compared the validity of VitB 12 and holoTC in a patient cohort with neuropsychiatric conditions suspicious for VitB 12 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 VitB 12 metabolism available (n = 1,279). We used elevated methylmalonic acid as the external validation criterion for VitB 12 deficiency and restricted our analyses to subjects with normal renal function. Among all normal renal function patients, 13.2% had VitB 12 deficiency. In receiver operating characteristic curve (ROC) analysis, correlation of VitB 12 and holoTC with vitamin B 12 deficiency was generally weak, and the areas under the curve (AUC) were not significantly different for holoTC compared to vitamin B 12 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 VitB 12 deficiency syndromes. The positive predictive values for holoTC and vitamin B 12 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 VitB 12 for the detection of VitB 12 deficiency in subjects with neuropsychiatric conditions. Neither test can be recommended to diagnose VitB 12 deficiency in subjects with neuropsychiatric disorders.

Details

OriginalspracheEnglisch
Seiten (von - bis)393-401
Seitenumfang9
FachzeitschriftJournal of neurology
Jahrgang258
Ausgabenummer3
PublikationsstatusVeröffentlicht - März 2011
Peer-Review-StatusJa

Externe IDs

PubMed 20890610

Schlagworte

ASJC Scopus Sachgebiete

Schlagwörter

  • Cobalamin, Dementia, Holotranscobalamin (holoTC), Methylmalonic acid (MMA), Neuropathy, Vitamin B deficiency