Relationship between homocysteine and neopterin concentrations in patients with gynecological cancer

Elevated concentrations of vascular risk factor homocysteine have been described in patients with malignant diseases, and homocysteine was supposed to be useful as tumor marker. Likewise, elevated concentrations of Th1-type immune activation marker neopterin are frequently observed in patients suffering from cancer and serve as prognostic marker for the survival of patients. In this study, the relationship between homocysteine and neopterin concentrations was examined in 18 patients with gynecological cancer. Concentrations of homocysteine and cysteine were measured by HPLC in sera of patients, folic acid and vitamin B12 levels were determined by radioimmunoassay, and neopterin concentrations were measured by ELISA. Median homocysteine concentration was 11.2 μM (interquartile range: 9.9–13.2 μM), 3 patients had levels higher than 15 μM, the upper limit of the normal range. Neopterin concentrations were increased in 13 patients (median: 11.6; 7.7–24.9 nM), cysteine (median: 234; 216–255 μM), folate (median: 7.8; 6.2–11.7 ng/ml) and vitamin B12 (median: 352; 258–570 pg/ml) concentrations were all within reference ranges although rather at the lower side. Higher homocysteine concentrations correlated inversely with low folate concentrations (rs=−0.605; P<0.01) and tended to be higher in patients with higher cysteine levels (rs=0.457; P<0.06; Fig. 1). No correlation was found between homocysteine and immune activation marker neopterin, although the three patients with elevated homocysteine concentrations tended to have higher neopterin levels as well (P<0.07). In conclusion, only a few patients with gynecological cancer present with elevated homocysteine concentrations and hyperhomocysteinemia seems only weakly related to immune activation phenomena, tumor cell proliferation probably is more important for the increase of homocysteine.