title: Interstitial fibrosis is the critical determinant of impaired renal function in transplant glomerulopathy.
abstract: OBJECTIVE
  Transplant glomerulopathy (TG) is a feature of chronic antibody-mediated injury in the glomerular capillaries in renal transplant recipients. TG is generally associated with proteinuria; however, renal function at the diagnosis of TG varies. This study aimed to determine which morphological abnormalities are associated with renal function and proteinuria at the diagnosis of TG.
  
  
  METHODS
  A total of 871 renal transplantations were performed at Tokyo Women's Medical University between 2005 and 2013. TG was diagnosed in 127 biopsies from 58 (6.7%) recipients. Renal function was evaluated by the estimated glomerular filtration rate (eGFR). Proteinuria was assessed by a dipstick test: positive for +1 and over.
  
  
  RESULTS
  At diagnosis, of 127 biopsies, 72, 37, and 18 had mild, moderate, and severe TG (Banff cg). The severity of TG was not associated with decreased eGFR at the time of biopsy (cg1: 36.1 ± 14.8, cg2-3: 38.8 ± 14.5 mL/min per 1.73 m(2) , P = 0.25), whereas the severity of interstitial fibrosis (IF) (Banff ci) was significantly associated with decreased eGFR (ci0-1: 42.75 ± 13.32, ci2-3: 27.69 ± 11.94 mL/min per 1.73 m(2) , P < 0.0001). The multivariate analysis revealed that IF was the only independent risk factors for decreased eGFR (OR = 4.38, P = 0.0006). Meanwhile, TG was identified as the only independent risk factor for the incidence of proteinuria (OR = 2.67, P = 0.014).
  
  
  CONCLUSIONS
  Interstitial fibrosis was a critical determinant of impaired renal function at the diagnosis of TG. The severity of TG was significantly associated with proteinuria, but did not contribute to renal dysfunction.
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Yachiyo Medical Center, Chiba, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Toki
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Yachiyo Medical Center, Chiba, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Inui
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ishida
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Okumi
authors.affiliation: Department of Urology, Toda General Hospital, Saitama, Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Department of Urology, Okubo Hospital, Tokyo, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shirakawa
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Omoto
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Unagami
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Yachiyo Medical Center, Chiba, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Setoguchi
authors.affiliation: Department of Pathology, Kawasaki City Tama-Hospital, Kanagawa, Japan.
authors.forename: Junki
authors.initials: J
authors.lastname: Koike
authors.affiliation: Department of Pathology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Kazuho
authors.initials: K
authors.lastname: Honda
authors.affiliation: Yamaguchi's Pathological Laboratory, Chiba, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Tanabe
mesh_terms: D000328:Adult; D064591:Allografts; D001706:Biopsy; D016009:Chi-Square Distribution; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D005355:Fibrosis; D005919:Glomerular Filtration Rate; D005921:Glomerulonephritis / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D006084:Graft Rejection / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D006785:Hospitals, University; D006801:Humans; D007678:Kidney Glomerulus / Q000473:pathology / Q000503:physiopathology*; D016030:Kidney Transplantation / Q000009:adverse effects*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011379:Prognosis; D011507:Proteinuria / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D012307:Risk Factors; D012720:Severity of Illness Index; D014041:Tokyo; D016896:Treatment Outcome; D016482:Urinalysis
keywords: chronic rejection; interstitial fibrosis; kidney transplantation; proteinuria transplant glomerulopathy