Diagnostic value of neopterin during neutropenic fever and determination of disease burden in childhood leukemias

Neopterin is secreted from macrophages on stimulation by IFN-?. We investigated levels of neopterin at the time of diagnosis of childhood leukemia, throughout induction therapy and in neutropenic fever.18 ALL/5AML (0-18 ages) were determined as `Newly diagnosed leukemia group?. Samples for neopterin levels were taken at 0, 15th , 33rd day of induction therapy in ALL and 0, 15th in AML and tested with ELISA. Neutrophil count (WBC), absolute neutrophil count (ANC), absolute phagocyte count (APC), c-reactive protein (CRP), bone marrow blast percentages were determined. All these parameters and neopterin levels decreased towards 33rd day. As a second group named `neutropenic fever group?; 30 neutropenic fever episodes, in 19 childhood leukemia patients (15 ALL, 4 AML, aged 1-18 years) were studied. WBC, ANC, APC, CRP, neopterin levels were determined at 0, 3, 5th day of the fever. Increase in ANC, APC were seen between 3-5th days (p<0,05); however CRP, neopterin levels didn?t change (p>0,05). Episodes were classed as; clinically documented (n:15); microbiologically documented infection (n:7) and fever of unknown origin (n:8). Neopterin levels were not different among these groupsNewly diagnosed and neutropenic fever groups were compared with infection control (n:19) (1-18 ages) and healthy control groups (n:21) (6-18 ages). Median neopterin level was: 7,03 ng/ml (0,1-17,04) in newly diagnosed; 0,56 ng/ml (0,1-21,85) in neutropenic fever; 7,02 ng/ml (0,1-27,22) in infection control and 0,1 ng/ml (0,1-4,29) in healthy control groups. Levels in infection control and newly diagnosed groups were the highest within all groups. We showed that neopterin levels are high at the time of diagnosis, decrease to normal levels during induction therapy, so can be used in determination of activity of childhood leukemia.