title: Nodular regenerative hyperplasia and severe portal hypertension in cystinosis.
abstract: OBJECTIVE
  Cystinosis is a rare autosomal-recessive disorder characterized by the intralysosomal accumulation of cystine, which is responsible for widespread tissue destruction. Liver biopsy specimens of patients with cystinosis show cystine crystal formation in Kupffer cells. However, significant liver disease and portal hypertension is not a common complication of cystinosis. We report the case histories of 2 young men with poorly treated nephropathic cystinosis who developed noncirrhotic portal hypertension with evidence of nodular regenerative hyperplasia (NRH).
  
  
  METHODS
  Liver biopsy examinations, upper and lower endoscopy with biopsy examination, imaging studies, venous pressure measurements, and laboratory investigations were used to evaluate the causes of the liver disease and portal hypertension.
  
  
  RESULTS
  Histologic examination of liver biopsy specimens from both patients showed changes characteristic of NRH with portal hypertension documented by measurement of pressure gradients. In addition, endoscopy in the first patient showed varices and portal hypertensive gastropathy.
  
  
  CONCLUSIONS
  NRH was confirmed by histologic examination of the liver in both patients and is the likely cause of their portal hypertension. NRH may represent a rare, late complication of cystinosis, although the mechanism remains undefined.
authors.affiliation: Section on Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892-1851, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: O'Brien
authors.forename: Nadeem
authors.initials: N
authors.lastname: Hussain
authors.forename: Bradley A
authors.initials: BA
authors.lastname: Warady
authors.forename: David E
authors.initials: DE
authors.lastname: Kleiner
authors.forename: Robert
authors.initials: R
authors.lastname: Kleta
authors.forename: Isa
authors.initials: I
authors.lastname: Bernardini
authors.forename: Theo
authors.initials: T
authors.lastname: Heller
authors.forename: William A
authors.initials: WA
authors.lastname: Gahl
mesh_terms: D000328:Adult; D003554:Cystinosis / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D006965:Hyperplasia / Q000209:etiology; D006975:Hypertension, Portal / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D008099:Liver / Q000473:pathology*; D008297:Male