ABSTRACT
PURPOSE: Neopterin is a degradation product derived from guanosin triphosphate (GTP) during biosynthesis of tetrahydrobiopterin. It is produced by human monocytes/macrophages upon stimulation with interferon-gamma from activated T lymphocytes. Therefore, increased neopterin concentration suggests the activation of cell-mediated immune response during viral infections, autoimmune diseases, allograft rejection, immunodeficiencies and certain types of malignancy. In these diseases, increased neopterin concentrations in serum and urine correlate to the stage of disease and predict worse prognosis. It has been proved that in various malignant disorders, higher neopterin concentrations are associated with more rapid disease progression and are a valuable predictor of stage and extension of the tumor. METHODS: Serum neopterin concentrations were measured by ELISA test in 20 patients with acute lymphocytic leukemia (ALL) at diagnosis and at complete remission after induction chemotherapy, and in 20 normal children that served as the control group. RESULTS: Serum neopterin levels were significantly (P=0.021) increased in the ALL group at diagnosis (9.48 nmol/L) compared to the control group (4.49 nmol/L). In the ALL group, serum neopterin levels were significantly (P=0.015) decreased at complete remission state (6.84 nmol/L) compared to the time of diagnosis (11.96 nmol/L). CONCLUSION: Neopterin was shown to be a valuable indicator of disease activity in childhood ALL and will contribute to predicting the treatment response.