Adult cystatin C reference intervals determined by nephelometric immunoassay

Objective: The aim of this study was to determine the adult reference values for cystatin C (CysC) and to evaluate their consistence with those reported in the literature. Design and methods: CysC was analyzed in a consecutive series of subjects (100 males and 100 females) by a nephelometric immunoassay. Medline was searched for CysC reference values. Results: CysC reference intervals showed 4–11% of variation at the upper limit. The mean upper limit was ≤ 1.0 mg/L of CysC. Conclusion: Nephelometric CysC reference intervals are consistent among different populations.