To study association of holotranscobalamin as a risk factor and its performance as a marker in acute stroke when compared to cobalamin and homocysteine.

Hyperhomocysteinemia is associated with increased risk of cardiovascular and cerebrovascular disease. Vitamin B12 deficiency is prevalent in most developing countries, including India and may account for hyperhomocysteinemia and increased risk of stroke. Holotranscobalamin is the only available active fraction of circulating cobalamin for tissue utilization. Low holotranscobalamin concentration is the earliest marker of vitamin B12 deficiency/insufficiency.

Serum samples of  holotranscobalamin, homocysteine andcobalamin of 100 successive patients of acute stroke were taken within 24 hours of stroke onset. 100 age and gender matched controls were enrolled.

35 % of cases and only 9 % of controls were found to have low holotranscobalamin levels. 44 % of cases and 18 % of controls had hyperhomocysteinemia. 20 % of cases and 12 % of controls had cobalamin deficiency. The performance of holotranscobalamin was enhanced by selecting best trade-off between sensitivity and specificity on ROC curve with a cut-off value of <52.3 pmol/L, and we achieved a fair sensitivity (56 %) and still an impressive specificity (83 %).

Low holotranscobalamin is an established risk factor for CAD, with this study we conclude that it is also a risk factor for acute stroke. The performance of holotranscobalamin in cases and controls as a marker in acute stroke, based on sensitivity and specificity, was better than cobalamin and homocysteine. To the best of our knowledge, this is the first Indian study to assess holotranscobalamin in first ever acute stroke. Holotranscobalamin can be used as a reliable, promising, non-invasive and a rapid diagnostic test for vitamin B12 insufficiency/deficiency state before symptoms emerge, and by mere vitamin B12 supplementation an attempt can be made to reduce risk for occurrence of stroke, effectively.