Association between homocysteine and neopterin in healthy subjects measured by a simple HPLC-fluorometric method

Objectives: Neopterin and homocysteine promote vascular smooth muscle cell proliferation through the activation of nuclear factor, B. The aim of this study was to investigate the relation between these two compounds in health y subjects by a rapid HPLC-fluorometric method which simplifies sample pret reatment for the measurement of neopterin in serum. Design and methods: In 40 healthy subjects (45.9 +/- 2.1 yr, mean +/- SEM, 10 males, 30 females) serum neopterin concentrations were measured by HPLC- fluorometry and enzyme-linked immunusorbant assay-ELISA and the results we re compared. Urinary neopterin and plasma total homocysteine concentrations were assayed by HPLC-fluorometry. Results: Serum neopterin concentrations measured by HPLC and ELISA were 7.5 +/- 0.4 and 7.4 +/- 0.3 nmol/L, respectively, r = 0.92, p < 0.01. Urinary neopterin level was 163.9 +/- 11.0 nmol/mmol creatinine and plasma total ho mocysteine 7.6 +/- 0.4 mu mol/L. A significant positive correlation was obs erved between serum neopterin and plasma total homocysteine (r = 0.59, p < 0.01). Conclusions: A simple and rapid sample pretreatment for the measurement of neopterin in serum has been introduced. The significant positive correlatio n between neopterin and homocysteine implies that, interference with leukoc yte function might be a new possible mechanism for the deleterious effects of homocysteine on vascular function. <(c)> 2001 The Canadian Society of Cl inical Chemists. All rights reserved.