Discordance in fibrosis staging between liver biopsy and transient elastography using the FibroScan XL probe.
OBJECTIVE
The FibroScan XL probe facilitates liver stiffness measurement (LSM) by transient elastography (TE) in obese patients, yet factors affecting its accuracy have not been described. Our objectives were to examine the prevalence, risk factors, and causes of discordance between fibrosis estimated by the FibroScan XL probe and biopsy.


METHODS
Two hundred and ten patients with chronic liver disease (45% viral hepatitis, 55% nonalcoholic fatty liver disease (NAFLD) and a body mass index (BMI) ≥ 28 kg/m(2)) underwent liver biopsy and TE with the FibroScan XL probe. Predictors of discordance ≥ 2 fibrosis stages between measures, which occurred in 11% of patients (n=24), were identified by comparing patient, TE, and biopsy characteristics of discordant and non-discordant cases.


RESULTS
Fibrosis estimated by the FibroScan XL probe was greater than biopsy in 75% (18/24) of discordant cases. Although biopsy quality was not associated with discordance, discordant cases were less likely to have ≥ 10 valid shots (75% vs. 97%; p=0.001), a success rate ≥ 60% (67% vs. 95%; p <0.0005), and an interquartile range over median liver stiffness (IQR/M) <21% (37% vs. 57%; p=0.07) than non-discordant cases. However, only increased BMI (odds ratio [OR] 1.09 per kg/m(2); 95% confidence interval [CI] 1.01-1.18; p=0.04) was independently associated with discordance; liver stiffness was of borderline significance (OR 1.73 per log(10)-transformed value; 95% CI 0.95-3.18; p=0.08). Discordance was 4- to 5-fold more frequent among patients with severe obesity (BMI ≥ 40 kg/m(2): 32% vs. 8%) and liver stiffness above the median of 7.0 kPa (20% vs. 4%; both p <0.0005).


CONCLUSIONS
Discordance between liver fibrosis estimated by biopsy and TE using the FibroScan XL probe was infrequent in this obese population. Patients with severe obesity and elevated liver stiffness have the greatest risk of discordance.
Liver Unit, Division of Gastroenterology and Hepatology, Department of Medicine, University of Calgary, Calgary, Alberta, Canada. rpmyers@ucalgary.ca
Robert P
RP
Myers
Gilles
G
Pomier-Layrargues
Richard
R
Kirsch
Aaron
A
Pollett
Melanie
M
Beaton
Mark
M
Levstik
Andres
A
Duarte-Rojo
David
D
Wong
Pam
P
Crotty
Magdy
M
Elkashab
D000328:Adult; D001706:Biopsy / Q000379:methods*; D002908:Chronic Disease; D054459:Elasticity Imaging Techniques / Q000295:instrumentation* / Q000379:methods*; D005234:Fatty Liver / Q000453:epidemiology / Q000473:pathology*; D005260:Female; D006801:Humans; D008099:Liver / Q000473:pathology*; D008103:Liver Cirrhosis / Q000453:epidemiology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease; D009765:Obesity / Q000453:epidemiology / Q000473:pathology; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index