title: Cystatin C estimated glomerular filtration rate to assess renal function in early stages of autosomal dominant polycystic kidney disease.
abstract: OBJECTIVE
  Height-adjusted total kidney volume (htTKV) is the best marker of disease progression in early autosomal dominant polycystic kidney disease (ADPKD) when renal function still remains normal. The usefulness of cystatin-C as a biomarker to assess renal function according to renal volume has not been studied in ADPKD patients.
  
  
  METHODS
  Observational and cross-sectional study of 62 ADPKD patients. htTKV, creatinine and cystatin-C estimated glomerular filtration rate (eGFR) were determined. Correlations between htTKV and eGFR were studied. A control group was used to determine the association between renal function differences and htTKV.
  
  
  RESULTS
  htTKV significantly correlated with cystatin-C-eGFR (r = -0.384, p = 0.002) but not with creatinine-eGFR (r = -0.225, p = 0.078). With htTKV stratified into tertiles, a significant difference of cystatin-C-eGFR but not in creatinine-eGFR was detected in the third tertile when compared with the first tertile group (110.0±22.2 vs 121.3±7.2; p = 0.023 and 101.8±17.2 vs 106.9±15.1; p = 0.327 respectively). When cystatin-C-eGFR of the controls was used as the reference, htTKV above 605 ml/m identified with a 75% sensitivity and 84.9% specificity those patients with a significant worse kidney function. However, this cut-off value could not be identified using creatinine-eGFR.
  
  
  CONCLUSIONS
  Cystatin-C-eGFR but not creatinine-eGFR correlated with htTKV in ADPKD patients in early stages of the disease. Differences in cystatin-C-eGFR but not in creatinine-eGFR have been identified through htTKV tertiles. A htTKV above 605 ml/m is associated with a worse renal function only if cystatin-C-eGFR is used. Cystatin-C-eGFR should be studied in prospective studies of early stages of ADPKD to determine its usefulness as an early marker of disease progression.
authors.affiliation: Department of Nephrology, Hospital del Mar, Barcelona, Spain.|Institut Mar for Medical Research, Barcelona, Spain.|Red Temática de Investigación Cooperativa (RedinRen), Instituto Carlos III, Madrid, Spain.
authors.forename: Laia
authors.initials: L
authors.lastname: Sans
authors.affiliation: Department of Radiology, Hospital del Mar, Barcelona, Spain.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Radosevic
authors.affiliation: Department of Radiology, Fundació Puigvert, Barcelona, Spain.
authors.forename: Claudia
authors.initials: C
authors.lastname: Quintian
authors.affiliation: Laboratory Department, Fundació Puigvert, Barcelona, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Montañés
authors.affiliation: Laboratory Department, Fundació Puigvert, Barcelona, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Gràcia
authors.affiliation: Laboratory Department, Laboratori de Referència de Catalunya, Barcelona, Spain.
authors.forename: Carles
authors.initials: C
authors.lastname: Vilaplana
authors.affiliation: Institut Mar for Medical Research, Barcelona, Spain.
authors.forename: Sergi
authors.initials: S
authors.lastname: Mojal
authors.affiliation: Red Temática de Investigación Cooperativa (RedinRen), Instituto Carlos III, Madrid, Spain.|Department of Nephrology, Fundació Puigvert, Barcelona, Spain.|Universitat Autònoma de Barcelona. Instituto de Investigación Biomédica Sant Pau (IIB Sant Pau), Barcelona, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Ballarin
authors.affiliation: Department of Nephrology, Fundació Puigvert, Barcelona, Spain.|Universitat Autònoma de Barcelona. Instituto de Investigación Biomédica Sant Pau (IIB Sant Pau), Barcelona, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Fernández-Llama
authors.affiliation: Red Temática de Investigación Cooperativa (RedinRen), Instituto Carlos III, Madrid, Spain.|Department of Nephrology, Fundació Puigvert, Barcelona, Spain.|Universitat Autònoma de Barcelona. Instituto de Investigación Biomédica Sant Pau (IIB Sant Pau), Barcelona, Spain.
authors.forename: Roser
authors.initials: R
authors.lastname: Torra
authors.affiliation: Department of Nephrology, Hospital del Mar, Barcelona, Spain.|Institut Mar for Medical Research, Barcelona, Spain.|Red Temática de Investigación Cooperativa (RedinRen), Instituto Carlos III, Madrid, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Pascual
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood*; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D009929:Organ Size / Q000502:physiology; D016891:Polycystic Kidney, Autosomal Dominant / Q000097:blood* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011446:Prospective Studies; D014463:Ultrasonography
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine