title: The effect of hemodialysis on liver stiffness measurement:  a single-center series.
abstract: OBJECTIVE
  The noninvasive measurement of liver stiffness using transient elastography (TE) is increasingly being used alongside liver biopsy. However, several conditions may lead to higher liver stiffness values without reflecting more fibrosis. Such conditions (e.g. hepatitis, cholestasis, heart failure, mechanical ventilation) limit the interpretation of liver stiffness measurements. The influence of hemodialysis on the measurement of liver stiffness has not been investigated to date. Here, we analyzed liver stiffness assessed by fibroscan in 17 patients directly before and after a hemodialysis session.
  
  
  METHODS
  Measurement of hepatic stiffness by TE was carried out using the Fibroscan device with the 'M probe' directly before and directly after one session of hemodialysis. Each measurement consisted of at least 10 individual and valid measurements, with a success rate of at least 60%, and an interquartile range of less than 25%. All measurements were carried out by one investigator not involved in patient management.
  
  
  RESULTS
  Before dialysis, the median TE was 5.1 kPa (2.8-17 kPa). Ten patients had values below the threshold of 7.1 kPa and seven patients had TE>7.1 kPa. The median net fluid withdrawal by hemodialysis was 2.5 l (0.4-3.1 l) and did not differ between patients. After dialysis, the TE median was 7.4 kPa (3.5-12.5 kPa) and had changed in all patients except one. Liver stiffness increased significantly when the initial TE was lower than 7.1 kPa (P=0.05), but not when the initial TE was higher than 7.1 kPa. Furthermore, the magnitude of the change in TE after hemodialysis correlated inversely with the liver stiffness before hemodialysis (P=0.03) and with spleen length measured by ultrasound (P=0.03).
  
  
  CONCLUSIONS
  This study is the first to report on the influence of hemodialysis on liver stiffness measurement. In contrast to previous reports, liver stiffness might increase after fluid withdrawal if patients do not show significant fibrosis. We conclude that before dialysis, TE possibly better differentiates between patients with or without significant fibrosis.
authors.affiliation: Department of Internal Medicine I, University of Bonn, Bonn, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Kellner
authors.forename: Evrim
authors.initials: E
authors.lastname: Anadol
authors.forename: Robert
authors.initials: R
authors.lastname: Hüneburg
authors.forename: Felix
authors.initials: F
authors.lastname: Hundt
authors.forename: Dominik
authors.initials: D
authors.lastname: Bös
authors.forename: Burkhard
authors.initials: B
authors.lastname: Klein
authors.forename: Rainer P
authors.initials: RP
authors.lastname: Woitas
authors.forename: Ulrich
authors.initials: U
authors.lastname: Spengler
authors.forename: Tilman
authors.initials: T
authors.lastname: Sauerbruch
authors.forename: Jonel
authors.initials: J
authors.lastname: Trebicka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D004548:Elasticity; D054459:Elasticity Imaging Techniques; D005260:Female; D005858:Germany; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging*; D008103:Liver Cirrhosis / Q000097:blood / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D006435:Renal Dialysis / Q000009:adverse effects; D013154:Spleen / Q000000981:diagnostic imaging; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers