title: Histopathology of liver biopsies from a thiopurine-naïve inflammatory bowel disease cohort: prevalence of nodular regenerative hyperplasia.
abstract: OBJECTIVE
  Nodular regenerative hyperplasia (NRH) and sinusoidal dilatation have been described in relation to thiopurine use in patients with inflammatory bowel disease (IBD). However, there is a dearth of data on the prevalence of these histological abnormalities in general. The aim of our study was to describe the prevalence of these histological liver changes in a thiopurine-naïve IBD cohort.
  
  
  METHODS
  Liver biopsy specimens were obtained from patients who were treated in a referral center and who underwent gastrointestinal surgery for IBD. Patients were excluded if thiopurines were ever used. The liver specimens were pathohistologically assessed with special attention to NRH.
  
  
  RESULTS
  A total of 83, properly stained, liver specimens (Crohn's disease 61%) were evaluated. NRH was observed in 6% compared to sinusoidal dilatation of varying degree in 34% of specimens. An older age at biopsy was correlated with NRH (p=0.015). Fibrosis and steatosis of varying degrees were detected in 31% and 36% of liver biopsies, respectively. No cases of liver cirrhosis were observed.
  
  
  CONCLUSIONS
  Pathohistological hepatic abnormalities are common in non-thiopurine using IBD patients. The association between thiopurine use, NRH and sinusoidal dilatation may be weaker than as reported in recent literature, as there is relatively high background prevalence in selected series.
authors.affiliation: Department of Gastroenterology and Hepatology, VU University Medical Center, Amsterdam, The Netherlands. KHN.deBoer@vumc.nl
authors.forename: Nanne K H
authors.initials: NK
authors.lastname: De Boer
authors.forename: Henriette
authors.initials: H
authors.lastname: Tuynman
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bloemena
authors.forename: Johan
authors.initials: J
authors.lastname: Westerga
authors.forename: Donald L
authors.initials: DL
authors.lastname: Van Der Peet
authors.forename: Chris J J
authors.initials: CJ
authors.lastname: Mulder
authors.forename: Miquel A
authors.initials: MA
authors.lastname: Cuesta
authors.forename: Stephan G M
authors.initials: SG
authors.lastname: Meuwissen
authors.forename: Carin M
authors.initials: CM
authors.lastname: Van Nieuwkerk
authors.forename: Adriaan A
authors.initials: AA
authors.lastname: Van Bodegraven
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001379:Azathioprine / Q000627:therapeutic use*; D001707:Biopsy, Needle; D005260:Female; D006801:Humans; D006965:Hyperplasia; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy / Q000473:pathology*; D008099:Liver / Q000473:pathology*; D008297:Male; D015122:Mercaptopurine / Q000627:therapeutic use*; D008875:Middle Aged
chemical_list: D007166:Immunosuppressive Agents; D015122:Mercaptopurine; D001379:Azathioprine