title: Increased risk of venous thrombosis by AB alleles of the ABO blood group and Factor V Leiden in a Brazilian population.
abstract: Most cases of a predisposition to venous thrombosis are caused by resistance to activated protein C, associated in 95% of cases with the Factor V Leiden allele (FVL or R506Q). Several recent studies report a further increased risk of thrombosis by an association between the AB alleles of the ABO blood group and Factor V Leiden. The present study investigated this association with deep vein thrombosis (DVT) in individuals treated at the Hemocentro de Pernambuco in northeastern Brazil. A case-control comparison showed a significant risk of thrombosis in the presence of Factor V Leiden (OR = 10.1), which was approximately doubled when the AB alleles of the ABO blood group were present as well (OR = 22.3). These results confirm that the increased risk of deep vein thrombosis in the combined presence of AB alleles and Factor V Leiden is also applicable to the Brazilian population suggesting that ABO blood group typing should be routinely added to FVL in studies involving thrombosis.
authors.affiliation: Laboratório de Biologia Celular e Molecular, Fundação Centro de Hemoterapia e Hematologia do Pará, Belém, PA Brazil.
authors.forename: Magaly B P L V
authors.initials: MB
authors.lastname: Lima
authors.forename: Aldemir Branco
authors.initials: AB
authors.lastname: de Oliveira-Filho
authors.forename: Júlia F
authors.initials: JF
authors.lastname: Campos
authors.forename: Fárida C B C
authors.initials: FC
authors.lastname: Melo
authors.forename: Washington Batista das
authors.initials: WB
authors.lastname: Neves
authors.forename: Raul Antônio Morais
authors.initials: RA
authors.lastname: Melo
authors.forename: José Alexandre Rodrigues
authors.initials: JA
authors.lastname: Lemos