title: Temporal serum creatinine increase and exacerbation of tubulointerstitial inflammation during the first two months in resolving polyomavirus BK nephropathy.
abstract: OBJECTIVE
  Polyomavirus BK nephropathy (BKVN) is an important complication in kidney transplantation. After immunosuppressive agents are reduced, some patients experience a temporal increase in serum creatinine (sCr) before viral clearance. The histological characteristics of re-biopsies were therefore investigated to evaluate the time course of remission.
  
  
  METHODS
  sCr was measured and urinary cytology evaluated periodically in 14 patients with biopsy-proven BKVN. Remission of BKVN was defined as re-biopsies negative for SV40 large T antigen (SV40-TAg) or for decoy cells on at least three consecutive cytology tests. Early changes in sCr were correlated with re-biopsy findings.
  
  
  RESULTS
  Mean sCr was 1.6 ± 0.6 mg/dL at diagnosis, increasing during the first 2 months to 2.6 ± 2.0 mg/dL, and decreasing thereafter, to 2.3 ± 1.2 mg/dL at 3-4 months. Two patients who experienced further increases in sCr at 3 months showed early graft loss, while the others showed clinical or histological remission. Nineteen re-biopsies were obtained from eight patients over 4 months. Banff i-scores were higher in re-biopsies obtained during the first 2 months than the index biopsies and re-biopsies at 2-4 months (P = 0.02). SV40-TAg positivity was common in re-biopsies during the first 2 months (10/11 biopsies), but rarer at 2-4 months (2/8 biopsies, P = 0.001).
  
  
  CONCLUSIONS
  Temporal graft dysfunction and increased inflammation, called immune reconstitution, were observed at 2 months. Later sCr reversal is associated with remission.
authors.affiliation: Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Masutani
authors.affiliation: Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tsuchimoto
authors.affiliation: Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Matsukuma
authors.affiliation: Department of Surgery and Oncology, Kyushu University, Fukuoka, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Kurihara
authors.affiliation: Department of Surgery and Oncology, Kyushu University, Fukuoka, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Nishiki
authors.affiliation: Department of Surgery and Oncology, Kyushu University, Fukuoka, Japan.
authors.forename: Hidehisa
authors.initials: H
authors.lastname: Kitada
authors.affiliation: Department of Surgery and Oncology, Kyushu University, Fukuoka, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan.
authors.forename: Takanari
authors.initials: T
authors.lastname: Kitazono
authors.affiliation: Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan.|Integrated Therapy for Chronic Kidney Disease, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Tsuruya
mesh_terms: D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001739:BK Virus / Q000187:drug effects* / Q000276:immunology / Q000472:pathogenicity; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D003404:Creatinine / Q000097:blood*; D057915:Drug Substitution; D004359:Drug Therapy, Combination; D005260:Female; D006085:Graft Survival; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage* / Q000009:adverse effects; D007668:Kidney / Q000187:drug effects* / Q000276:immunology / Q000473:pathology / Q000821:virology; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009395:Nephritis, Interstitial / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D009894:Opportunistic Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D027601:Polyomavirus Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D011237:Predictive Value of Tests; D012074:Remission Induction; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014412:Tumor Virus Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology / Q000821:virology
chemical_list: D000998:Antiviral Agents; D015415:Biomarkers; D007166:Immunosuppressive Agents; D003404:Creatinine
keywords: SV40 large T antigen; immune reconstitution syndrome; immunosuppression; re-biopsy; tubulitis