In:
Journal of Investigative Medicine, SAGE Publications, Vol. 63, No. 4 ( 2015-04), p. 636-640
Abstract:
Myeloproliferative disorders are characterized by proliferation of 1 or more lineage of hematologic cells. Rapid proliferation of cells may lead to depletion of vitamin B 12 , which may be falsely elevated by conventional assays in these disorders. We evaluated vitamin B 12 status with conventional vitamin B 12 assay and levels of serum methylmalonic acid (MMA), serum holotranscobalamin (holoTC), and plasma homocysteine in myeloproliferative disorders. Methods In 58 patients who had myeloproliferative disorders and normal serum creatinine levels, we measured levels of vitamin B 12 , MMA, holoTC, and homocysteine. Correlations were evaluated between these tests, with MMA as the reference standard for vitamin B 12 deficiency. Results Prevalence of vitamin B 12 deficiency was 69%, despite high serum vitamin B 12 levels. Levels of holoTC of 40.6 pmol/L or less and homocysteine of greater than 14 mol/L were the best cutoff levels with sensitivity values of 75% and 70%, specificity values of 80% and 68%, and positive predictive values of 88% and 80%. Logistic regression showed that cutoff values of holoTC of 40.6 pmol/L or less and homocysteine of greater than 14 mol/L resulted in odds ratio 15.5 for low versus high holoTC, and odds ratio 5.4 for high versus low homocysteine, to confirm vitamin B 12 deficiency. Conclusions Patients who had myeloproliferative disorders had a high prevalence of vitamin B 12 deficiency, despite high serum vitamin B 12 levels. Therefore, vitamin B 12 status should be evaluated in patients with myeloproliferative disorders. Holotranscobalamin level may be the best initial test and may replace vitamin B 12 assay to accompany MMA and homocysteine levels.
Type of Medium:
Online Resource
ISSN:
1081-5589
,
1708-8267
DOI:
10.1097/JIM.0000000000000187
Language:
English
Publisher:
SAGE Publications
Publication Date:
2015
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