DETERMINATION OF PLASMA HOMOCYSTEINE BY HPLC WITH FLUORESCENCE DETECTION - A SURVEY OF CURRENT METHODS

Homocysteine is a sulfur-containing amino acid whose utility as a marker in the clinical setting is being extensively explored. Persons with extremely high blood levels of homocysteine, resulting from an enzyme deficiency in the homocysteine trans-sulfuration pathway (homocystinurics) exhibit high mortality rates at an early age due to venous thromboembolism. Moreover, recent research indicates that even moderately elevated plasma homocysteine concentrations may be an independent risk factor for premature vascular disease. In addition to vascular disease risk assessment, the monitoring of plasma homocysteine levels has application in the evaluation of folate and vitamin B-12 status, determination of drug efficacy, along with the estimation of renal status and relative tumor burden. The current method of choice for homocysteine analysis is high performance liquid chromatography (HPLC) using pre-column derivatization prior to reverse phase separation and fluorescence detection. This article discusses a set of current papers that use this particular method for homocysteine analysis in plasma or serum. The difficulties encountered in homocysteine analysis by this technique are discussed, with particular attention paid to sample collection and preparation aspects representing sources of variation within and between methods. The views expressed in this material are those of the author, and do not reflect the official policy or position of the U.S. Government, the Department of Defense, or the Department of the Air Force.