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.