Reference standard of serum neopterin concentration in healthy children

Introduction: Increased neopterin concentrations are observed in many diseases in which cell immunity is stimulated. A quick and sensitive method for monitoring the changes in immune system can be useful for understanding etiopathogenesis of the disease and choosing the appropriate treatment. There are only few known data concerning normal serum neopterin value in children, therefore the wide clinical use of this parameter is limited. Aim: to evaluate the referential neopterin concentration in serum in healthy children according to age and gender. Patients and methods: 105 healthy children, 47 girls and 58 boys, aged 1 month - 17.9 years were examined. Clinical examinations and laboratory test including whole blood count, serum C-reactive protein, urea, and creatinine level, were conducted. The serum neopterin level was analyzed by ELISA (BRAHMS, Hennigsdorf/Berlin, Germany). The results were used for reference standard evaluation of serum neopterin level in healthy children. Results: The serum neopterin concentrations in children were 2.87 - 14.78, mean 5.47 +/- 2.58 nmol/L. No significant correlation was found between children's age and serum neopterin level. There were also no differences among serum neopterin level in different age groups: under 5, 5 to 10, and over 10 years, and between girls and boys. The estimated cut-off value 11 nmol/L of serum neopterin level for whole group of children made the 94.3% test sensitivity. Conclusion: Serum neopterin concentration is lower than 11 nmol/L in healthy children after neonatal period, and is independent of childrens' age or gender.