title: High prevalence of renal dysfunction in children after liver transplantation: non-invasive diagnosis using a cystatin C-based equation.
abstract: BACKGROUND
  Chronic kidney disease (CKD) has been increasingly shown to be a negative prognostic factor after liver transplantation (Ltx). Creatinine-based glomerular filtration rate (GFR) formulas are notoriously insensitive. In children, non-invasive determination of GFR by measurement of serum cystatin C is feasible and repeatedly correlated to the gold standards of GFR measurements. The aim of our study was to determine GFR using cystatin C (GFR(cys)) in comparison with conventional calculated creatinine clearance (GFR(crea)) in the long-term follow-up after paediatric liver transplantation (pLtx) in a large number of patients.
  
  
  METHODS
  GFR of 168 children following liver transplantation was determined using cystatin C (GFR(cys)) and the Schwartz formula (GFR(crea)). In order to evaluate risk factors for CKD, a logistic regression analysis was performed. A multivariate model was applied to assess the impact of immunosuppressive treatment.
  
  
  RESULTS
  The mean follow-up after transplantation was 7.8 (0.44-15.72) years. Due to a high overestimation of GFR as demonstrated in a Bland-Altman plot, only three patients with CKD stages 2-3 were detected with GFR(crea) compared with 34 with GFR(cys) (P < 0.001). Thus, prevalence of CKD with GFR((cys)) < 90 mL/min/1.73 m2; was 30.4%, 7.6% and 27% in patients with 5, 10 and > 10 years of follow-up, respectively. Patients on cyclosporine had a significantly lower GFR than patients on tacrolimus. Logistic regression analysis did not show any significant risk factor for the development of CKD.
  
  
  CONCLUSIONS
  The cystatin C equation is a non-invasive and sensitive diagnostic tool to detect renal dysfunction in children after Ltx at an early stage. The choice of first-line calcineurin inhibitor has an important impact on the development of CKD.
authors.affiliation: Department of Pediatrics, Pediatric Gastroenterology and Hepatology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. f.brinkert@uke.de
authors.forename: Florian
authors.initials: F
authors.lastname: Brinkert
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Kemper
authors.forename: Andrea
authors.initials: A
authors.lastname: Briem-Richter
authors.forename: Michael
authors.initials: M
authors.lastname: van Husen
authors.forename: Andras
authors.initials: A
authors.lastname: Treszl
authors.forename: Rainer
authors.initials: R
authors.lastname: Ganschow
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007223:Infant; D007677:Kidney Function Tests; D016031:Liver Transplantation / Q000009:adverse effects*; D008297:Male; D011379:Prognosis; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000175:diagnosis* / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate
chemical_list: D055316:Cystatin C