title: The severity of steatosis influences liver stiffness measurement in patients with nonalcoholic fatty liver disease.
abstract: In nonalcoholic fatty liver disease, the influence of severity of steatosis on liver stiffness measurement (LSM) is poorly studied and still debated. We assessed the impact of steatosis severity and its ultrasonographic (US) sign, severe bright liver echo pattern, on LSM values and on transient elastography accuracy for the diagnosis of liver fibrosis in a cohort of consecutive patients with nonalcoholic fatty liver disease. Patients (n = 253) were assessed by clinical, US, and histological (Kleiner score) features. Transient elastography was performed using the M probe. Among patients with low amounts of fibrosis (F0-F1 and F0-F2), median LSM values, expressed in kilopascals, were significantly higher in subjects with severe steatosis (≥66% at liver biopsy) compared to those without (F0-F1 6.9 versus 5.8, P = 0.04; F0-F2 7.4 versus 6.0, P = 0.001) as well as in patients with severe bright liver echo pattern on US compared to their counterparts (F0-F1 7.3 versus 5.6, P = 0.001; F0-F2 7.6 versus 6.0, P < 0.001). In subjects without significant fibrosis (F0-F1) and without severe fibrosis (F0-F2), a higher rate of false-positive LSM results was observed in patients with steatosis ≥66% compared to those without (F0-F1 23.6% versus 14.9%, F0-F2 33.3% versus 13.2%) and in patients with severe bright liver echo pattern on US (F0-F1 22.2% versus 15.4%, F0-F2 28.8% versus 15.6%) compared to their counterparts.
  
  
  CONCLUSIONS
  In patients with nonalcoholic fatty liver disease, the presence of severe steatosis, detected by histology or by US, should always be taken into account in order to avoid overestimations of liver fibrosis assessed by transient elastography.
authors.affiliation: Sezione di Gastroenterologia, Di.Bi.M.I.S., University of Palermo, Palermo, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Petta
authors.affiliation: Sezione di Gastroenterologia, Di.Bi.M.I.S., University of Palermo, Palermo, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Maida
authors.affiliation: Sezione di Gastroenterologia, Di.Bi.M.I.S., University of Palermo, Palermo, Italy.
authors.forename: Fabio Salvatore
authors.initials: FS
authors.lastname: Macaluso
authors.affiliation: Sezione di Gastroenterologia, Di.Bi.M.I.S., University of Palermo, Palermo, Italy.
authors.forename: Vito
authors.initials: V
authors.lastname: Di Marco
authors.affiliation: Sezione di Gastroenterologia, Di.Bi.M.I.S., University of Palermo, Palermo, Italy.
authors.forename: Calogero
authors.initials: C
authors.lastname: Cammà
authors.affiliation: Cattedra di Anatomia Patologica, University of Palermo, Palermo, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Cabibi
authors.affiliation: Sezione di Gastroenterologia, Di.Bi.M.I.S., University of Palermo, Palermo, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Craxì
mesh_terms: D005234:Fatty Liver / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000000981:diagnostic imaging; D012720:Severity of Illness Index; D014463:Ultrasonography