Holotranscobalamin in laboratory diagnosis of cobalamin deficiency compared to total cobalamin and methylmalonic acid
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Rima Obeid
Abstract
Background: Cobalamin-saturated transcobalamin, also called holotranscobalamin (holoTC), constitutes only between 6% and 20% of total plasma B12. Serum concentration of holoTC is a new marker in laboratory diagnosis of cobalamin deficiency. We tested the utility of holoTC in assessing vitamin B12 status.
Methods: We measured concentrations of holoTC and methylmalonic acid (MMA) in 1018 serum samples that were referred to our laboratory for total cobalamin testing.
Results: Concentrations of MMA were lower in females compared to males and this difference was no more significant after adjusting for serum creatinine. Moreover, age was associated with higher concentrations of serum MMA, higher holoTC and slightly higher concentrations of total cobalamin. Higher concentrations of serum creatinine were associated with higher concentrations of MMA and holoTC. However, no association between serum creatinine and total cobalamin was observed. Only subjects with normal serum creatinine showed a negative correlation between serum holoTC and MMA (r= –0.36, p<0.001). In subjects with MMA ≥300 nmol/L and holoTC ≤35 pmol/L, concentrations of total cobalamin were well within the normal range (median; 25th/75th percentiles=212; 171/272 pmol/L). Receiver operating characteristic (ROC) curve analysis displayed a higher sensitivity and specificity for holoTC compared with vitamin B12 for detecting concentrations of MMA ≥300 nmol/L in individuals with normal renal function.
Conclusions: Compared to total cobalamin, we observed a better performance of holoTC assay in detecting elevated concentrations of MMA in subjects with normal renal function. The majority of subjects with combined low holoTC and elevated MMA had normal concentrations of total cobalamin. HoloTC can be used as a first line parameter in detecting cobalamin deficiency.
Clin Chem Lab Med 2007;45:1746–50.
©2007 by Walter de Gruyter Berlin New York
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- The role of hyperhomocysteinemia and B-vitamin deficiency in neurological and psychiatric diseases
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- Biomarkers of folate and vitamin B12 status in cerebrospinal fluid
- The role of hyperhomocysteinemia as well as folate, vitamin B6 and B12 deficiencies in osteoporosis – a systematic review
- Homocysteine, brain natriuretic peptide and chronic heart failure: a critical review
- Homocysteine, left ventricular dysfunction and coronary artery disease: is there a link?
- Hyperhomocysteinemia and high-density lipoprotein metabolism in cardiovascular disease
- Hyperhomocysteinemia, DNA methylation and vascular disease
- Measuring subclinical atherosclerosis: is homocysteine relevant?
- Plasma protein homocysteinylation in uremia
- Homocysteine and asymmetric dimethylarginine (ADMA): biochemically linked but differently related to vascular disease in chronic kidney disease
- Hyperhomocysteinemia – association with renal transsulfuration and redox signaling in rats
- Metabolic regulatory properties of S-adenosylmethionine and S-adenosylhomocysteine
- Defects in homocysteine metabolism: diversity among hyperhomocyst(e)inemias
- The molecular basis of homocysteine thiolactone-mediated vascular disease
- Importance of folate-homocysteine homeostasis during early embryonic development
- Association between homocysteine, vitamin B6 concentrations and inflammation
- Quantitative profiling of folate and one-carbon metabolism in large-scale epidemiological studies by mass spectrometry
- Holotranscobalamin in laboratory diagnosis of cobalamin deficiency compared to total cobalamin and methylmalonic acid
- Haptocorrin in humans
- Small ubiquitin-like modifier-1 (SUMO-1) modification of thymidylate synthase and dihydrofolate reductase
- Decreased p66Shc promoter methylation in patients with end-stage renal disease
- Synergism between AT1 receptor and hyperhomocysteinemia during vascular remodeling
- Differential expression of γ-aminobutyric acid receptor A (GABAA) and effects of homocysteine
- The effect of B-vitamins on biochemical bone turnover markers and bone mineral density in osteoporotic patients: a 1-year double blind placebo controlled trial
- Acknowledgement
- Contents, Volume 45, 2007
- Author Index
- Subject Index
Articles in the same Issue
- Homocysteine research: alive and kicking!
- Homocysteine-lowering trials for prevention of vascular disease: protocol for a collaborative meta-analysis
- Perspective on the efficacy analysis of the Vitamin Intervention for Stroke Prevention trial
- Homocysteine-lowering vitamin B treatment decreases cardiovascular events in hemodialysis patients
- The role of hyperhomocysteinemia and B-vitamin deficiency in neurological and psychiatric diseases
- Management of L-Dopa related hyperhomocysteinemia: catechol-O-methyltransferase (COMT) inhibitors or B vitamins? Results from a review
- Biomarkers of folate and vitamin B12 status in cerebrospinal fluid
- The role of hyperhomocysteinemia as well as folate, vitamin B6 and B12 deficiencies in osteoporosis – a systematic review
- Homocysteine, brain natriuretic peptide and chronic heart failure: a critical review
- Homocysteine, left ventricular dysfunction and coronary artery disease: is there a link?
- Hyperhomocysteinemia and high-density lipoprotein metabolism in cardiovascular disease
- Hyperhomocysteinemia, DNA methylation and vascular disease
- Measuring subclinical atherosclerosis: is homocysteine relevant?
- Plasma protein homocysteinylation in uremia
- Homocysteine and asymmetric dimethylarginine (ADMA): biochemically linked but differently related to vascular disease in chronic kidney disease
- Hyperhomocysteinemia – association with renal transsulfuration and redox signaling in rats
- Metabolic regulatory properties of S-adenosylmethionine and S-adenosylhomocysteine
- Defects in homocysteine metabolism: diversity among hyperhomocyst(e)inemias
- The molecular basis of homocysteine thiolactone-mediated vascular disease
- Importance of folate-homocysteine homeostasis during early embryonic development
- Association between homocysteine, vitamin B6 concentrations and inflammation
- Quantitative profiling of folate and one-carbon metabolism in large-scale epidemiological studies by mass spectrometry
- Holotranscobalamin in laboratory diagnosis of cobalamin deficiency compared to total cobalamin and methylmalonic acid
- Haptocorrin in humans
- Small ubiquitin-like modifier-1 (SUMO-1) modification of thymidylate synthase and dihydrofolate reductase
- Decreased p66Shc promoter methylation in patients with end-stage renal disease
- Synergism between AT1 receptor and hyperhomocysteinemia during vascular remodeling
- Differential expression of γ-aminobutyric acid receptor A (GABAA) and effects of homocysteine
- The effect of B-vitamins on biochemical bone turnover markers and bone mineral density in osteoporotic patients: a 1-year double blind placebo controlled trial
- Acknowledgement
- Contents, Volume 45, 2007
- Author Index
- Subject Index
