Non-O blood group as a risk factor for cerebral vein thrombosis

Abstract

Dear Sirs, Cerebral vein thrombosis (CVT) is a rare cause of acute stroke and an unusual site of venous thromboembolism (VTE) (1). The pathogenic role of risk factors in such venous thromboses may be different compared with deep-vein thrombosis (DVT) of the lower limbs or pulmonary embolism, the most common manifestations of VTE in clinical practice. Both transient or acquired risk factors (pregnancy/puerperium, oral contraceptives, infection, haematological and autoimmune diseases) and inherited thrombophilia (mainly the prothrombin G20210A polymorphism) are identified as predisposing conditions in patients with CVT (2-5). Increasing data recognise the ABO as a susceptibility locus for VTE, non-O blood group carriers sharing a higher risk of VTE than O blood group carriers (6-13). This association, first described in 1969 in women developing VTE on oral contraceptives (6), was confirmed by subsequent studies, even evaluating ABO genotypes (7-10). Two different systematic reviews of literature and metanalyses, including 21 (11) and 38 studies (12), respectively, consistently reported an approximately twofold increase of risk in non-O blood group carriers compared with O-group subjects. These results were

Recurrent venous thromboembolism: a role for ABO blood group?

“…Overall, the great majority of clinical studies agree to consider non-O blood group as one of the most important determinant of unprovoked VTE, being responsible for a moderate (about two-fold) increased risk (14)(15)(16)(17). On the other hand, no study has analysed so far the association between ABO blood type and the risk of recurrent VTE following anticoagulant treatment, which represents on the most challenging issues in the management of these patients (18,19).…”

COVID-19 Infection among Patients Presenting to a Tertiary Care Centre: A Descriptive Cross-sectional Study

“… 10 Non-A group is also associated with a high risk of Cerebrovascular accidents. 11 Blood group AB has been found to have a significant association with preeclampsia with an increased risk of 2.1 folds. 12 Protection against falciparum malaria by reduction of rosette formation is seen in blood group O.…”

Evolutionary aspects of ABO blood group in humans

“…Following these three meta-analyses, results were validated in our clinical experience. In a case-control study comparing the ABO blood group distribution in 77 consecutive patients with cerebral vein thrombosis (CVT) and 4272 blood donors, we observed a higher prevalence of the non-O blood type in CVT patients (75% versus 55%) [50]. Therefore, carriers of the non-O blood group were found to have a 2.4-fold increase of risk of CVT (OR 2.44; 95% CI: 1.42-4.26; P = 0.0008).…”