title: Assessment of Kidney Graft Function Evolution Measured by Creatinine and Cystatin C.
abstract: BACKGROUND
  The 2013 Kidney Disease Outcomes Quality Initiative Clinical Practice Guideline suggests measuring cystatin C (sCys) in adults with glomerular filtration rate (GFR) based on creatinine (sCr) between 45 and 59 mL/min/1.73 m2if confirmation of chronic kidney disease (CKD) is required. There is not enough evidence to recommend the use of sCys or sCr to estimate GFR in kidney transplant recipients.
  
  
  OBJECTIVE
  Our aims were to describe the evolution of sCr, sCys, and GFR in a group of kidney transplant patients and to determine their association with some markers of morbidity at 1 year.
  
  
  METHODS
  A total of 54 patients were included. Analytical and clinical data were recorded. Renal function was analyzed using the CKD Epidemiology Collaboration (EPI) sCr equation and CKD-EPI sCys equation.
  
  
  RESULTS
  sCys-estimated GFR was higher than estimated from sCr by CKD-EPI. The values of sCys have more variability than those of sCr. The agreement between the stages of CKD by sCr or sCys-estimated GFR measured by Cohen's kappa coefficient was only fair. One-year CKD-associated variables correlated differently with sCr and sCys-estimated GFR. Hemoglobin, uric acid, calcium, and phosphorus related to sCr-estimated GFR, whereas serum albumin was associated with sCys-estimated GFR.
  
  
  CONCLUSIONS
  sCys values have a higher variability than sCr in kidney transplant recipients. sCys- or sCr-based GFRs have a nonsimilar behavior in these patients with weak agreement to stratify CKD stages and a different relationship to CKD-related comorbid conditions.
authors.affiliation: Nephrology Investigation Unit, University Hospital Marques de Valdecilla, IDIVAL (Instituto de Investigacion Valdecilla), Santander, Spain. Electronic address: ramosbarron@gmail.com.
authors.forename: M A
authors.initials: MA
authors.lastname: Ramos-Barron
authors.affiliation: Nephrology Investigation Unit, University Hospital Marques de Valdecilla, IDIVAL (Instituto de Investigacion Valdecilla), Santander, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Hernandez Bejarano
authors.affiliation: Nephrology Investigation Unit, University Hospital Marques de Valdecilla, IDIVAL (Instituto de Investigacion Valdecilla), Santander, Spain; Nephrology Department, University Hospital Marqués de Valdecilla, Santander, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Rodrigo
authors.affiliation: Clinical Analysis Laboratory, University Hospital Marqués de Valdecilla, Santander, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Cruz Iglesias
authors.affiliation: Nephrology Investigation Unit, University Hospital Marques de Valdecilla, IDIVAL (Instituto de Investigacion Valdecilla), Santander, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Benito Hernandez
authors.affiliation: Nephrology Investigation Unit, University Hospital Marques de Valdecilla, IDIVAL (Instituto de Investigacion Valdecilla), Santander, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Agueros Blanco
authors.affiliation: Toxicology Unit, University Hospital Salamanca, Salamanca, Spain.
authors.forename: A I
authors.initials: AI
authors.lastname: Morales Martin
authors.affiliation: Toxicology Unit, University Hospital Salamanca, Salamanca, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Prieto Vicente
authors.affiliation: Investigation Unit, University Hospital Salamanca, Salamanca, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Lopez Hernandez
authors.affiliation: Nephrology Investigation Unit, University Hospital Marques de Valdecilla, IDIVAL (Instituto de Investigacion Valdecilla), Santander, Spain; Nephrology Department, University Hospital Marqués de Valdecilla, Santander, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Arias
authors.affiliation: Nephrology Investigation Unit, University Hospital Marques de Valdecilla, IDIVAL (Instituto de Investigacion Valdecilla), Santander, Spain; Nephrology Department, University Hospital Marqués de Valdecilla, Santander, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Gomez-Alamillo
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D003404:Creatinine / Q000378:metabolism*; D055316:Cystatin C / Q000378:metabolism*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000502:physiology; D007677:Kidney Function Tests; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000503:physiopathology / Q000601:surgery; D019737:Transplants / Q000502:physiology*
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine