Neopterin, tryptophan and kynurenine as biomarkers in glioblastoma

Glioblastoma (GBM) is a highly aggressive brain tumor with limited prognostic markers to predict patient outcomes reliably. This study investigates the perioperative levels of tryptophan, kynurenine, and neopterin in patients with GBM to assess their potential as biomarkers for prognosis. Twenty-four patients with supratentorial GBM and 24 age- and gender-matched healthy controls were included. Blood and urine samples were collected at four time points: preoperatively, three days postoperatively, prior to adjuvant therapy, and post-adjuvant therapy. Analytical measurements of tryptophan, kynurenine, and neopterin levels were conducted using liquid chromatography-tandem mass spectrometry, and statistical analyses were performed to determine their correlation with survival outcomes. The analysis revealed significant perioperative fluctuations in neopterin, kynurenine and tryptophan levels in GBM patients. Moreover, a trend (p = 0.08) of an association between preoperatively obtained blood level of kynurenine and survival probability was observed supporting further validation of kynurenine-pathway biomarkers in larger, molecularly annotated cohorts.