title: Clinical and pathological analyses of interstitial fibrosis and tubular atrophy cases after kidney transplantation.
abstract: OBJECTIVE
  We carried out a clinicopathological analysis of cases presenting with interstitial fibrosis and tubular atrophy (IF/TA) after renal transplantation in an attempt to clarify the mechanisms underlying the development and prognostic significance of IF/TA.
  
  
  METHODS
  IF/TA was diagnosed in 35 renal allograft biopsy specimens (BS) obtained from 35 renal transplant recipients under follow up at the Department of Transplant Surgery, Kidney Center, Toda Chuo General Hospital, between January 2014 and March 2015.
  
  
  RESULTS
  IF/TA was diagnosed at a median of 39.9 months after the transplantation. Among the 35 patients with IF/TA, 19 (54%) had a history of acute rejection. Among the 35 BS showing evidence of IF/TA, the IF/TA was grade I in 25, grade II in 9, and grade III in 1. Arteriosclerosis of the middle-sized arteries was observed in 30 BS (86%). We then classified the 35 BS showing evidence of IF/TA according to their overall histopathological features, as follows; IF/TA alone (6 BS; 17%), IF/TA + medullary ray injury (12 BS; 34%), and IF/TA + rejection (12 BS; 34%). Loss of the renal allograft occurred during the observation period in one of the patients (3%). Of the remaining patients with functioning grafts, deterioration of the renal allograft function after the biopsies occurred in 15 patients (43%).
  
  
  CONCLUSIONS
  The results of our study suggests that rejection contributes to IF/TA in 30-40% of cases, medullary ray injury in 30-40% of cases, and nonspecific injury in 20% of cases. IF/TA contributes significantly to deterioration of renal allograft function.
authors.affiliation: Department of Transplant Surgery, Kidney Center, Toda Chuo General Hospital, Saitama, Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Department of Transplant Surgery, Kidney Center, Toda Chuo General Hospital, Saitama, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Toma
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Hayakawa
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Rumi
authors.initials: R
authors.lastname: Shibahara
authors.affiliation: Department of Transplant Surgery, Kidney Center, Toda Chuo General Hospital, Saitama, Japan.
authors.forename: Ryou
authors.initials: R
authors.lastname: Ishiyama
authors.affiliation: Department of Transplant Surgery, Kidney Center, Toda Chuo General Hospital, Saitama, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hayashida
authors.affiliation: Department of Transplant Surgery, Kidney Center, Toda Chuo General Hospital, Saitama, Japan.
authors.forename: Daiji
authors.initials: D
authors.lastname: Fujimori
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Kuniko
authors.initials: K
authors.lastname: Tsunoyama
authors.affiliation: Department of Transplant Surgery, Kidney Center, Toda Chuo General Hospital, Saitama, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Ikezawa
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Kitajima
authors.affiliation: Department of Transplant Surgery, Kidney Center, Toda Chuo General Hospital, Saitama, Japan.
authors.forename: Shoichi
authors.initials: S
authors.lastname: Iida
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: Kazunari
authors.initials: K
authors.lastname: Tanabe
authors.affiliation: Department of Anatomy, Showa University, Tokyo, Japan.
authors.forename: Kazuho
authors.initials: K
authors.lastname: Honda
authors.affiliation: Department of Pathology, Kawasaki Municipal Tama Hospital, Kanagawa, Japan.
authors.forename: Junki
authors.initials: J
authors.lastname: Koike
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D064591:Allografts; D001284:Atrophy; D001706:Biopsy; D018450:Disease Progression; D005260:Female; D005355:Fibrosis; D006084:Graft Rejection / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D006085:Graft Survival; D006769:Hospitals, General; D006801:Humans; D007564:Japan; D007674:Kidney Diseases / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D007677:Kidney Function Tests; D016030:Kidney Transplantation / Q000009:adverse effects*; D007684:Kidney Tubules / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: calcineurin inhibitor arteriolopathy; interstitial fibrosis and tubular atrophy; kidney transplantation; medullary ray injury; rejection