SNFGE SNFGE
 
Thématique :
- Foie
Originalité :
Intermédiaire
Solidité :
Intermédiaire
Doit faire évoluer notre pratique :
Dans certains cas
 
 
Nom du veilleur :
Professeur Jean-Marie PERON
Coup de coeur :
 
 
Gastroenterology
  2017/09  
 
  2017 Sep;153(3):753-761  
  doi: 10.1053/j.gastro.2017.06.005.  
 
  Agreement Between Magnetic Resonance Imaging Proton Density Fat Fraction Measurements and Pathologist-Assigned Steatosis Grades of Liver Biopsies From Adults With Nonalcoholic Steatohepatitis.  
 
  Middleton MS, Heba ER, Hooker CA, Bashir MR, Fowler KJ, Sandrasegaran K, Brunt EM, Kleiner DE, Doo E, Van Natta ML, Lavine JE, Neuschwander-Tetri BA, Sanyal A, Loomba R, Sirlin CB; NASH Clinical Research Network.  
  https://www.ncbi.nlm.nih.gov/pubmed/28624576  
 
 

Abstract

BACKGROUND & AIMS:

We assessed the diagnostic performance of magnetic resonance imaging (MRI) proton density fat fraction (PDFF) in grading hepatic steatosis and change in hepatic steatosis in adults with nonalcoholic steatohepatitis (NASH) in a multi-center study, using central histology as reference.

METHODS:

We collected data from 113 adults with NASH participating in a multi-center, randomized, double-masked, placebo-controlled, phase 2b trial to compare the efficacy cross-sectionally and longitudinally of obeticholic acid vs placebo. Hepatic steatosis was assessed at baseline and after 72 weeks of obeticholic acid or placebo by liver biopsy and MRI (scanners from different manufacturers, at 1.5T or 3T). We compared steatosis estimates by PDFF vs histology. Histologic steatosis grade was scored in consensus by a pathology committee. Cross-validated receiver operating characteristic (ROC) analyses were performed.

RESULTS:

At baseline, 34% of subjects had steatosis grade 0 or 1, 39% had steatosis grade 2, and 27% had steatosis grade 3; corresponding mean PDFF values were 9.8%±3.7%, 18.1%±4.3%, and 30.1%±8.1%. PDFF classified steatosis grade 0-1 vs 2-3 with an area under the ROC curve (AUROC) of 0.95 (95% CI, 0.91-0.98), and grade 0-2 vs grade 3 steatosis with an AUROC of 0.96 (95% CI, 0.93-0.99). PDFF cut-off values at 90% specificity were 16.3% for grades 2-3 and 21.7% for grade 3, with corresponding sensitivities of 83% and 84%. After 72 weeks' of obeticholic vs placebo, 42% of subjects had a reduced steatosis grade (mean reduction in PDFF from baseline of 7.4%±8.7%), 49% had no change in steatosis grade (mean increase in PDFF from baseline of 0.3%±6.3%), and 9% had an increased steatosis grade (mean increase in PDFF from baseline of 7.7%±6.0%). PDFF change identified subjects with reduced steatosis grade with an AUROC of 0.81 (95% CI, 0.71-0.91) and increased steatosis grade with an AUROC of 0.81 (95% CI, 0.63-0.99). A PDFF reduction of 5.15% identified subjects with reduced steatosis grade with 90% specificity and 58% sensitivity, whereas a PDFF increase of 5.6% identified those with increased steatosis grade with 90% specificity and 57% sensitivity.

CONCLUSIONS:

Based on data from a phase 2 randomized controlled trial of adults with NASH, PDFF estimated by MRI scanners of different field strength and at different sites, accurately classifies grades and changes in hepatic steatosis when histologic analysis of biopsies is used as a reference.

 
Question posée
 
L’IRM peut-elle remplacer la biopsie pour l’évaluation de la stéatose?
 
Question posée
 
L’IRM permet une bonne évaluation de la stéatose et également de l’évolution de la stéatose sous traitement.
 
Commentaires

Pas de comparaison avec le CAP (élastométrie) dans cette étude, pas de données sur l’inflammation intrahépatique non plus.

 
www.snfge.org