vitamin-k-semiquinone-radical and Retinal-Vein-Occlusion

Venous thrombosis typically involves the lower extremities. Rarely, it can occur in cerebral, splanchnic, or renal veins, with a frightening clinical impact. Other rare manifestations are upper-extremity deep vein thrombosis, that can complicate with pulmonary embolism and post-thrombotic syndrome, and retinal vein occlusion, significantly affecting the quality of life. This review is focused on venous thromboses at unusual extra-abdominal sites. Local infections or cancer are frequent in cerebral sinus-venous thrombosis. Upper-extremity deep vein thrombosis is mostly due to catheters or effort-related factors. Common risk factors are inherited thrombophilia and oral contraceptive use. Acute treatment is based on heparin; in cerebral sinus-venous thrombosis, local or systemic fibrinolysis should be considered in case of clinical deterioration. Vitamin-K antagonists are recommended for 3-6 months; indefinite anticoagulation is suggested for recurrent thrombosis or unprovoked thrombosis and permanent risk factors. However, such recommendations mainly derive from observational studies; there are no data about long-term treatment of retinal vein occlusion.

Topics: Anticoagulants; Catheters; Contraceptives, Oral; Heparin; Humans; Postthrombotic Syndrome; Pulmonary Embolism; Retinal Vein Occlusion; Risk Factors; Thrombophilia; Upper Extremity Deep Vein Thrombosis; Vitamin K; Warfarin

Retinal vein occlusion (RVO) is a major vision-threatening disease. Vitamin K epoxide reductase recycles reduced vitamin K, which is essential for the gamma carboxylation of clotting factors II, VII, IX, X and proteins C and S. Recently, the vitamin K epoxide reductase complex subunit 1 (VKORC1) -1639G>A (rs9923231) polymorphism has been reported as a novel risk factor for RVO in a Turkish population. The present study was set to confirm or to refute this association in a larger cohort of patients with RVO.. The present case-control study comprised 285 patients with central RVO, 401 patients with branch RVO and 333 control subjects. Genotypes of the VKORC1 -1639G>A polymorphism were determined by 5' exonuclease assay (TaqMan).. No significant differences in either genotype distributions or allele frequencies of the vitamin K epoxide reductase complex subunit 1 -1639G>A polymorphism were found between patients and control subjects (p > 0.05). In a logistic regression analysis neither branch nor central RVO was predicted by the vitamin K epoxide reductase complex subunit 1 -1639G>A genotypes, but by arterial hypertension, ever-smoking status and in case of central RVO additionally by diabetes mellitus.. Our data suggest that the vitamin K epoxide reductase complex subunit 1 -1639G>A gene polymorphism is unlikely a major risk factor for patients with either central or branch RVO.

Topics: Aged; Aged, 80 and over; Case-Control Studies; Female; Genetic Predisposition to Disease; Genotype; Humans; Logistic Models; Male; Middle Aged; Polymorphism, Single Nucleotide; Retinal Vein Occlusion; Risk Factors; Vitamin K; Vitamin K Epoxide Reductases