RESUMEN
OBJECTIVE: Cystatin C (Cys-C) concentration has not been examined sufficiently among healthy newborn population, particularly in terms of reference values. This study aimed to establish gender-, postnatal age- and birth weight-specific Cys-C concentration for healthy term newborns. Its objective was also to examine if there were any differences between our measured concentration and the reference interval established by the CALIPER study. METHODS: Serum samples from a total of 90 healthy term newborns were used to determine Cys-C concentration. Cys-C was measured within first three days of birth using particle-enhanced turbidimetric immunoassay (PETIA) on the Architect plus ci8200 analyzer. RESULTS: Median concentration of the Cys-C was 2.05 mg/L. There were no statistically significant differences in Cys-C concentration regarding gender (p=0.779), birth weight (p=0.505), postnatal age (p=0.512) or Apgar score (p=0.799). The value of the 2.5th and 97.5th percentile for Cys-C concentrations for girls was 0.93-3.15 mg/L and for boys it was 1.5-3.36 mg/L. CONCLUSION: Cys-C concentration in healthy term newborns does not depend on gender, birth weight, postnatal age, or Apgar score. Our measured concentration range of CyS-C in healthy newborns turned out to be slightly wider than the interval determined in the CALIPER study.