Haemostatic genetic variants, ABO blood group and bleeding risk during oral anticoagulant treatment after cerebral ischaemia of arterial origin

Hemostasis, cancer, and ABO blood group: the most recent evidence of association

Human ABO blood group antigens are expressed on the surface of red blood cells and a variety of human cells and tissues. However, an increasingly number of studies show that the ABO blood group, in addition to its fundamental role in transfusion medicine and in several other disciplines, has a causal role in predisposing to several human diseases, including hemostasis and neoplastic disorders, which will be the focus of this narrative review.

ABO blood group, hypercoagulability, and cardiovascular and cancer risk

The antigens of the ABO system (A, B, and H determinants, respectively) consist of complex carbohydrate molecules. It has been known for nearly half a century that the ABO blood group exerts a major influence on plasma levels of the von Willebrand factor (VWF)-factor VIII (FVIII) complex and that normal group O individuals have significantly lower levels of VWF and FVIII than do non-O individuals. As a consequence, several investigators have studied the association between ABO blood group and the risk of developing bleeding or thrombotic events. A number of epidemiological studies have also analyzed the biologic relevance of this interaction by assessing whether the ABO blood group could influence human longevity through the regulation of VWF-FVIII plasma levels. In this review, the molecular mechanisms by which the ABO blood group determines plasma VWF and consequently, FVIII levels, the possible clinical implications, and the current knowledge on the association between the ABO blood group and the risk of developing certain cancers will be reviewed.