title: Albuminuria and posttransplant chronic kidney disease stage predict transplant outcomes.
abstract: In 2012, the KDIGO guidelines updated the classification system for chronic kidney disease to include albuminuria. Whether this classification system predicts adverse clinical outcomes among kidney transplant recipients is unclear. To evaluate this, we conducted a retrospective study using linked databases in Alberta, Canada to follow kidney transplant recipients from 2002-2011. We examined the association between an estimated glomerular filtration rate (eGFR of 60 or more, 45-59, 30-44, 15-29 mL/min/1.73 m2) and albuminuria (normal, mild, heavy) at one year post-transplant and subsequent mortality and graft loss. There were 900 recipients with a functioning graft and at least one outpatient serum creatinine and urine protein measurement at one year post-transplant. The median age was 51.2 years, 38.7% were female, and 52% had an eGFR of 60 mL/min/1.73 m2or more. The risk of all-cause mortality and death-censored graft loss was increased in recipients with reduced eGFR or heavier albuminuria. The adjusted incidence rate per 1000 person-years of all-cause mortality for recipients with an eGFR of 15-29 mL/min/1.73 m2and heavy albuminuria vs. an eGFR 60 mL/min/1.73 m2or more and normal protein excretion was 117 (95% confidence interval 38-371) vs. 15 (9-23) (rate ratio 8). Corresponding rates for death-censored graft loss were 273 (88-1203) vs. 6 (3-9) (rate ratio 49). Reduced eGFR and heavier albuminuria in kidney transplant recipients are associated with an increased risk of mortality and graft loss. Thus, eGFR and albuminuria may be used together to identify, evaluate, and manage transplant recipients who are at higher risk of adverse clinical outcomes.
authors.affiliation: Department of Medicine, Division of Nephrology, University of Alberta, Edmonton, Alberta, Canada. Electronic address: nlam@ualberta.ca.
authors.forename: Ngan N
authors.initials: NN
authors.lastname: Lam
authors.affiliation: Department of Medicine, Division of Nephrology, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Marcello
authors.initials: M
authors.lastname: Tonelli
authors.affiliation: Center for Abdominal Transplantation, Saint Louis University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Krista L
authors.initials: KL
authors.lastname: Lentine
authors.affiliation: Department of Medicine, Division of Nephrology, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Brenda
authors.initials: B
authors.lastname: Hemmelgarn
authors.affiliation: Department of Medicine, Division of Nephrology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Feng
authors.initials: F
authors.lastname: Ye
authors.affiliation: Department of Medicine, Division of Nephrology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Kevin
authors.initials: K
authors.lastname: Wen
authors.affiliation: Department of Medicine, Division of Nephrology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Scott
authors.initials: S
authors.lastname: Klarenbach
mesh_terms: D000328:Adult; D000368:Aged; D000416:Alberta / Q000453:epidemiology; D000419:Albuminuria / Q000453:epidemiology; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology; D016030:Kidney Transplantation / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
keywords: albuminuria; estimated glomerular filtration function; graft loss; kidney transplant recipients; mortality; proteinuria