Liver fibrosis steadily increases in untreated HBV with stable viral load
medwireNews: Liver fibrosis, estimated using the Fibrosis-4 index (FIB4), increases significantly over time in untreated patients with hepatitis B (HBV) infection, despite viral loads remaining largely stable, US researchers report.
This finding highlights “the importance of monitoring untreated patients for progression of liver fibrosis,” particularly as previous studies have shown that “increasing FIB4 is associated with greater risk of [hepatocellular carcinoma],” Mei Lu (Henry Ford Health System, Detroit, Michigan) and colleagues remark.
Analysis of data for 342 untreated participants in the Chronic Hepatitis Cohort Study showed that viral load did not change significantly (p=0.762) in the 5 months following the first measurement after HBV diagnosis. It then decreased by 3.1% per month (p<0.001) until month 28, when the level remained stable until year 5.
By contrast, FIB4 remained stable in untreated patients during the first 28 months post-index date, but then began to increase by a significant 0.9% per month (11% per year, p<0.001) until the end of the 5-year follow-up period. And the researchers estimated that FIB4 would double within 6.5 years in untreated patients, regardless of their initial FIB4 level.
A subgroup analysis of 100 “immune inactive” untreated patients also showed significant FIB4 progression with an average annual increase of 4.7% (p=0.002) throughout the study, suggesting that “fibrosis steadily increases in such untreated patients even in the absence of immunological activity,” Lu et al write.
Among the 424 treated patients also studied, viral load decreased by 31.8% per month (p<0.001) in the first 5 months after treatment initiation. The decline then slowed to 1.7% per month between 5 and 28 months (p=0.004) and to 1.4% per month from 28 months onward (p=0.019).
FIB4 also demonstrated a biphasic decay pattern in the treated patients, with no significant change in the first 5 months (p=0.784), followed by a significant decline of 0.5% per month (p<0.001) between months 5 and 28, which stabilized at 28 months.
This indicates that there is a “delayed but significant regression of liver fibrosis” in the patients undergoing treatment, the researchers remark. They also point out that FIB4 levels in untreated patients became significantly different from those of treated patients at around 33 months after the initial measurement.
Writing in the Journal of Gastroenterology and Hepatology, Lu and co-authors note that a recent study found surveillance of chronic HBV infection in untreated patients is often inadequate.
“This may be cause for concern, as we observe that FIB4 increases in our untreated patient sample, suggesting fibrosis progression—even among the subset of patients who were not candidates for therapy based on current guidelines,” they conclude.
By Laura Cowen
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