Cystatin C and renal function in pediatric kidney transplant recipients

Author(s)

M.C.P. Franco ^[1] ; S.S. Nagasako ^[2] ; P.G. Machado ^[3] ; P.C.K. Nogueira ^[4] ; J.O.M. Pestana ^[5] ; R. Sesso ^[6]

Affiliation

^[1] Universidade Federal de São Paulo. Departamento de Medicina. Disciplina de Nefrologia

^[2] Universidade Federal de São Paulo. Departamento de Pediatria - Brasil

^[3] Universidade Federal de São Paulo. Departamento de Medicina. Disciplina de Nefrologia

^[4] Universidade Federal de São Paulo. Departamento de Pediatria - Brasil

^[5] Universidade Federal de São Paulo. Departamento de Medicina. Disciplina de Nefrologia

^[6] Universidade Federal de São Paulo. Departamento de Medicina. Disciplina de Nefrologia

• Document type: Journal article
• Source: Brazilian Journal of Medical and Biological Research; v. 42, n. 12, p. 1225-1229, 2009-12-00.

Abstract

In clinical practice, the glomerular filtration rate (GFR) is often determined with serum creatinine. However, studies have shown cystatin C to be a better parameter for the diagnosis of impaired renal function. We compared GFR estimated by plasma cystatin C with GFR estimated by serum creatinine in a sample of 50 pediatric renal transplant recipients and 24 healthy children. The correlation between GFR estimated by serum creatinine and by cystatin C was significant (r = 0.75; P < 0.001, Person’s correlation); however, in pediatric kidney transplant recipients, the GFR was 6.7 mL/min lower when determined using cystatin C rather than serum creatinine. Moreover, using GFR estimated by cystatin C we found that 42% of the pediatric kidney transplant recipients had an estimated GFR <60 mL·min-1·1.73 (m²)-1, whereas when GFR was estimated by the serum creatinine formula only 16% of the children had values below this cutoff point indicative of chronic kidney disease (P < 0.001). We conclude that, in pediatric kidney transplant recipients, estimation of GFR yields lower values when cystatin C is used rather than serum creatinine. (AU)