Clinical Utility of Serum Holotranscobalamin Measurements in Patients with First-Ever Ischemic Stroke

BACKGROUND: Whether holotranscobalamin (holoTC) indicates B12 deficiency more sensitively than total vitamin B12 (B12) is unclear. This study is aimed at determining the impact of serum holoTC level as a risk factor for ischemic stroke and investigating its association with disease severity and short-term outcomes. METHODS: Serum holoTC, total B12, and homocysteine levels were compared between 130 stroke patients and 138 healthy controls. Biomarker level correlations with disease severity and stroke functional outcomes were investigated. RESULTS: holoTC levels were lower and homocysteine levels were higher in stroke patients than in healthy controls (P < 0.05). The holoTC/total B12 ratio and homocysteine level significantly predicted ischemic stroke in the multivariable regression analysis (P < 0.05). Along with hyperhomocysteinemia, patients more often had holoTC than total B12 deficiency (6.2% vs. 3.1%). holoTC levels negatively correlated with homocysteine levels (partial R -0.165, P < 0.05) in stroke patients in multiple linear regression analyses, but not total B12 levels. The holoTC level and holoTC/total B12 ratio, but not homocysteine and total B12 levels, negatively correlated with the National Institute of Health Stroke Scale (partial R, -0.405 and -0.207, respectively, P < 0.01). CONCLUSIONS: Measurements of serum holoTC levels combined with total B12 and homocysteine levels may provide valuable information for predicting ischemic stroke and its severity and short-term outcomes of ischemic stroke patients.