Stabilization of Blood Homocysteine by 3-Deazaadenosine

Abstract

The link between homocysteine and the vascular pathology of arteriosclerosis was first described almost 30 years ago.' However, it is only recently that hyperhomocysteinaemia has achieved widespread recognition as an indepen­ dent risk factor for vascular disease, including coronary heart disease, stroke and peripheral vascular disease.' This renewed interest has stimulated laboratories to re-examine meth­ ods for the estimation of homocysteine in plasma. The major problem that bedevils epidemiolo­ gical and clinical studies of homocysteine is the increase in plasma homocysteine concentration that occurs if blood is not centrifuged immedi­ ately after collection. Plasma total homocysteine concentration rises by up to 10% per hour in blood kept at room temperature, largely as a result of the conversion of S-adenosylmethionine and S-adenosylhomocysteine to homocysteine within erythrocytes.' Since this laboratory receives blood samples for epidemiological studies by post, our aim was to identify an additive to blood which would stabilize homo­ cysteine levels for up to 72 h, thereby avoiding the need to centrifuge samples immediately after collection.