The limited value of methylmalonic acid, homocysteine and holotranscobalamin in the diagnosis of early B12 deficiency.
Treatment of B12 deficiency is important to prevent progressive neurological and/or hematologic disease but requires a secure diagnosis. The aim of this study was to evaluate second line tests of B12 status as prognostic indicators of a hematologic response to vitamin B12 therapy. Forty-nine patients referred with low, serum vitamin B12 concentrations were treated with intramuscular B12 and re-assessed after 3 months. Methylmalonic acid, homocysteine, holotranscobalamin and neutrophil hypersegmentation index were measured before and after treatment. Before treatment 27/49 patients were anemic or macrocytic of whom 15 had a clear hematologic response. All the tests had a similar prognostic accuracy. Symptomatic improvement did not correlate with hematologic response. Supplementary tests of vitamin B12 status were not significantly better than total serum B12 concentration as predictors of a hematologic response to vitamin B12 therapy.
Goringe
Andrew
A
Department of Haematology, University Hospital of Wales, Cardiff CF14 4XN, UK.
Ellis
Richard
R
McDowell
Ian
I
Vidal-Alaball
Josep
J
Jenkins
Christopher
C
Butler
Christopher
C
Worwood
Mark
M
D003933:Diagnosis; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008764:Methylmalonic Acid / Q000097:blood*; D012680:Sensitivity and Specificity; D014155:Transcobalamins / Q000008:administration & dosage* / Q000032:analysis*; D014806:Vitamin B 12 Deficiency / Q000175:diagnosis*
D014155:Transcobalamins; D006710:Homocysteine; D008764:Methylmalonic Acid