Homocysteine is a risk factor for venous thrombosis. Elevated concentrations can be treated with folic acid, vitamin B6 and vitamin B12. The main study (chapter 9) in this thesis is a randomized... Show moreHomocysteine is a risk factor for venous thrombosis. Elevated concentrations can be treated with folic acid, vitamin B6 and vitamin B12. The main study (chapter 9) in this thesis is a randomized placebo-controlled trial in which patients with a first event of deep-vein thrombosis or pulmonary embolism are treated with above mentioned vitamins or a placebo. There was no effect of vitamin treatment on recurrent thrombosis. A case-control study is described whichs shows that elevated homocysteine concentrations are a risk factor for venous thrombosis and pulmonary embolism in elderly patients (chapter 7). Two studies deal with acidic citrate as an anticoagulant in blood collection tubes. We show that acidic citrate stabilizes homocysteine concentrations at room temperature (chapter 3) and that the homocysteine concentrations measured in blood collection tubes with acidic citrate as anticoagulant correlate well with the concentrations measured in blood tubes with EDTA as anticoagulant (chapter 4). One study compared patients on and off anticoagulant therapy. There was no influence of coumarin derivatives on plasma homocysteine concentrations (chapter 5). The endogeous thrombin potential is not different in patients with high homocysteine concentrations in comparison to patients with low homocysteine concentrations (chapter 6). Show less
