Total plasma homocysteine analysis by HPLC with SBD-F precolumn derivatization

Over the last two decades, various studies have shown that moderate and persistent hyperhomocysteinemia is implicated in the development of atherosclerosis, which is responsible for 50% of all mortality and morbidity in Western countries. Considering that the most traditional risk factors for heart disease and stroke, such as plasma lipids, cigarette smoking, hypertension, obesity, and diabetes, only account for 50% of cardiovascular disease (1,2), one can understand the reason why homocysteine (Hcy) measurement is included in the list of tests for investigating the causes of atherosclerosis and thrombosis. One of the major problems encountered in studies on the potential atherogenic role of Hcy was the development of an accurate and simple assay, capable of screening, in a normal population, subjects having a congenital predisposition to occlusive vascular disease. Several approaches have been described in literature for measuring total plasma homocysteine (tHcy), which is defined as the sum of free and protein-bound homocysteine, homocystine, and homocysteine-cysteine mixed disulfide. These procedures involve, after a reduction step, the use of gas-chromatography-mass spectrometry (GC-MS) (3), radioenzymic assay (4), and high-performance liquid chromatography (HPLC).