The Clinical Significance of Serum Cystatin C in Critically Ill Newborns With Normal Serum Creatinine

Background The aim of this study is to evaluate the clinical significance of cystatin C ( C ys C ) in the newborns who show normal serum creatinine ( C r) and who are in an intensive care unit. Methods From July 2009 to May 2010, a total of 106 patients (53 male and 53 female newborns) in a neonatal intensive care unit at Kyung Hee Medical Center were enrolled in this study. When clinicians ordered C ys C , it was tested using HiSens Cystatin‐ C LTIA (HBi, An‐yang, Korea) on a Toshiba chemical analyzer (Toshiba, Nasushiobara, Japan). Results The range of serum C r and C ys C was from 0.1 to 0.8 mg/dL and from 1.0 to 2.3 mg/L, respectively. C ys C presented the wider amplitude of the changes in acute renal failure. Conclusion In this study, C ys C without an increased C r showed only a mild increase. However, C ys C reflected more delicate changes in newborns than the serum C r. This characteristic of C ys C could make it very appropriate for a pediatric population, especially for critically ill newborns. J. Clin. Lab. Anal. 26:267‐271, 2012. © 2012 Wiley Periodicals, Inc.