The Role of ABO Blood Type in Thrombosis Scoring Systems.

In addition to their major role in transfusion medicine, there is increasing evidence that ABO blood group antigens (complex carbohydrate molecules widely expressed on the surface of red blood cells and several other cell types) are implicated in the development of a wide array of pathologic conditions. In particular, intense research has been dedicated over the last 50 years to the study of the association between non-O blood type and the risk of developing cardiovascular disorders. Several pathways have been hypothesized to explain this relationship, the most reasonable implying the influence of the ABO blood group on circulating plasma levels of von Willebrand factor, factor VIII, and several inflammatory cytokines. This narrative review summarizes the current knowledge on the role of ABO antigens in both venous and arterial thromboses, focusing on their association with clinical scoring systems evaluating thrombotic risk.