title: A comparison of cystatin C concentrations between patients with chronic interstitial nephritis and glomerular diseases.
abstract: OBJECTIVE
  Cystatin C have shown to be a renal function parameter with higher sensitivity and specificity than serum creatinine. In tubular diseases, cystatin C degradation and an increase in its urinary elimination would be observed. We have tried to define if different kinds of kidney diseases may significantly affect the serum levels of cystatin C.
  
  
  METHODS
  Four hundred and four patients were studied: 249 men and 155 women, mean age was 64.3±10.1 years. Patients were classified into three groups: (1) Chronic interstitial nephropathy (CIN), (2) Glomerular nephropathy (GN), and (3) Non- CKD patients (control). GFR was estimated though the CKD-EPI equation and the Hoek formula.
  
  
  RESULTS
  Median of serum creatinine levels was higher in CIN group than in GN and control groups. Median cystatin C levels were lower in control group compared with CIN and GN groups. No significant differences were found between CIN group and GN group. Nevertheless, the cystatin/creatinine rate was lower in the CIN group patients (0.94, 0.81-1.11) than in the GN group (1.02,I 0.85-1.25) as well as the control group (1.02, I 0.88-1.20). The cystatin C-estimated GFR/creatinine-estimated GFR rate was higher in the CIN group (1.18, 1.03-1.36) than in the GN patients (1.03, 0.88-1.21) and control ones (1.07, 0.88-1.20).
  
  
  CONCLUSIONS
  Patients with CIN had lower serum levels of cystatin C defined as cystatin C/creatinine rate when they were compared with GN subject and control ones. In the same way, the index between cystatin C-estimated GFR and creatinine-estimated GFR was higher in CIN patients.
authors.affiliation: Servicio de Nefrologia. Hospital Infanta Cristina, Badajoz, Spain.
authors.forename: Nicolas Roberto
authors.identifier: http://orcid.org/0000-0003-4984-6691
authors.initials: NR
authors.lastname: Robles
authors.affiliation: Centro de Salud "Jose María Alvarez", Don Benito, Spain.
authors.forename: Candido
authors.initials: C
authors.lastname: Mena
authors.affiliation: Servicio de Nefrologia. Hospital Infanta Cristina, Badajoz, Spain.
authors.forename: Edgar
authors.initials: E
authors.lastname: Chavez
authors.affiliation: Servicio de Nefrologia. Hospital Infanta Cristina, Badajoz, Spain.
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Bayo
authors.affiliation: Servicio de Nefrologia. Hospital Infanta Cristina, Badajoz, Spain.
authors.forename: Boris
authors.initials: B
authors.lastname: Gonzalez Candia
authors.affiliation: Servicio de Analisis Clínicos, Hospital de Don Benito-Villanueva de la Serena, Don Benito, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Cidoncha
authors.affiliation: Servicio de Analisis Clínicos, Hospital Infanta Cristina, Badajoz, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Lopez Gomez
authors.affiliation: Servicio de Nefrologia. Hospital Infanta Cristina, Badajoz, Spain.
authors.forename: Juan Jose
authors.initials: JJ
authors.lastname: Cubero
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009395:Nephritis, Interstitial / Q000097:blood* / Q000453:epidemiology; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000453:epidemiology
chemical_list: D055316:Cystatin C; D003404:Creatinine
keywords: chronic interstitial nephropathy; chronic kidney disease; cystatin C