title: Creatinine reduction ratio: a useful marker to identify medium and high-risk renal transplants.
abstract: BACKGROUND
  Delayed graft function (DGF) has a major impact on long-term renal transplant survival. However, it is a diagnosis made retrospectively with little opportunity to modify treatment protocols. A classification based on creatinine reduction ratio between days 1 and 2 (CRR2) suggests that patients with CRR2 less than or equal to 30% (nondialysis requiring DGF [ND-DGF]) have similar outcomes to those with dialysis-requiring delayed graft function (D-DGF). We retrospectively applied this definition in our cohort of patients to examine outcomes.
  
  
  METHODS
  We studied the association between CRR2 and graft outcomes in all 367 patients transplanted between 1996 and 2004 at our center. Patients were divided into the following three groups: IGF (immediate graft function; CRR2 >30%), D-DGF, and ND-DGF. Mean follow-up was 4.2 years.
  
  
  RESULTS
  IGF accounted for 36% of patients, D-DGF for 22%, and ND-DGF for 42%. CRR2 was inversely correlated with serum creatinine on days 7, 30, 90, and 365 (r ranging from -0.65 to -0.22, P<0.001). Graft survival at 5 years was 98% (IGF), 74% (D-DGF), and 89% (ND-DGF). There was a significant difference in graft survival between IGF and D-DGF (P<0.001) and IGF and ND-DGF (P=0.005). In a multivariate analysis adjusting for recipient age and sex, donor age and sex, and human leukocyte antigen mismatch, graft failure was 2.4 times more likely to occur in patients with D-DGF than those with ND-DGF(P=0.02).
  
  
  CONCLUSIONS
  Our study shows CRR2 influences long-term graft outcomes. Unlike the original description, patients with ND-DGF carry an intermediate risk and perhaps should be considered on day 2 for alternative treatment protocols.
authors.affiliation: Department of Nephrology, Royal London Hospital, London, United Kingdom.
authors.forename: Enric
authors.initials: E
authors.lastname: Vilar
authors.forename: Mira
authors.initials: M
authors.lastname: Varagunam
authors.forename: Muhammad M
authors.initials: MM
authors.lastname: Yaqoob
authors.forename: Martin
authors.initials: M
authors.lastname: Raftery
authors.forename: Raj
authors.initials: R
authors.lastname: Thuraisingham
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood*; D051799:Delayed Graft Function / Q000453:epidemiology / Q000503:physiopathology; D004359:Drug Therapy, Combination; D005260:Female; D006084:Graft Rejection / Q000453:epidemiology / Q000503:physiopathology*; D006085:Graft Survival / Q000276:immunology / Q000502:physiology; D006650:Histocompatibility Testing; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016030:Kidney Transplantation / Q000276:immunology / Q000401:mortality / Q000502:physiology* / Q000706:statistics & numerical data; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D040242:Risk Reduction Behavior; D015996:Survival Rate; D017741:Survivors; D014019:Tissue Donors / Q000706:statistics & numerical data; D017211:Treatment Failure
chemical_list: D015415:Biomarkers; D007166:Immunosuppressive Agents; D003404:Creatinine