How many valid measurements are necessary to assess liver fibrosis using FibroScan® in patients with chronic viral hepatitis? An analysis of subjects with at least 10 valid measurements.
OBJECTIVE
Using FibroScan® to obtain a reliable liver stiffness measurement (LSM) may require more than 10 valid measurements (VMs), according to the manufacturer's recommendations. However, this requirement lacks scientific evidence in support thereof. We investigated the minimal number of VMs required to assess liver fibrosis without significant loss of accuracy in patients with chronic hepatitis B (CHB) and C (CHC) and predictors of discordance between LSM and liver biopsy (LB).


METHODS
Between January 2005 and December 2009, we prospectively enrolled 182 patients with CHB and 68 patients with CHC who were to undergo LB and LSM before starting antiviral treatment. Only LSMs with at least 10 VMs were considered reliable. The Batts and Ludwig scoring system was used for histologic assessment.


RESULTS
The mean age and body mass index were 46.0 years and 23.4 kg/m² in patients with CHB and 49.7 years and 23.1 kg/m² in those with CHC, respectively. The median elasticity scores from the first 3, first 5, and all VMs taken significantly predicted fibrosis stages ≥F2 and F4 (all p<0.05) without significant differences (all p>0.05 by DeLong's method). Alanine aminotransferase (ALT) was the only predictor of discordance in fibrosis stage as estimated by the median elasticity score from the first 3 VMs and by LB in patients with CHB, whereas no significant predictor was identified in those with CHC.


CONCLUSIONS
After comparison of patients who had more than 10 valid measurements for LSM, three VMs may be enough to assess liver fibrosis using LSM without significant loss of accuracy in patients with CHC and patients with CHB. However, ALT should be considered when interpreting LSM for patients with CHB.
Department of Internal Medicine, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea.
Hui Won
HW
Dang
Seung Up
SU
Kim
Jun Yong
JY
Park
Sang Hoon
SH
Ahn
Kwang-Hyub
KH
Han
Chae Yoon
CY
Chon
Young Nyun
YN
Park
Eun Hee
EH
Choi
Do Young
DY
Kim
D000328:Adult; D000410:Alanine Transaminase / Q000378:metabolism; D005260:Female; D019694:Hepatitis B, Chronic / Q000150:complications* / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008103:Liver Cirrhosis / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
D000410:Alanine Transaminase