Association of fibronectin serum levels with loss of hepatitis B surface antigen in patients with chronic hepatitis B during nucleos(t)ide analogue treatment

Background: Fibronectin is an essential part of the extracellular matrix, and its binding to the surface antigen (HBsAg) of the hepatitis B virus (HBV) has been linked to viral propagation. We aimed to correlate fibronectin serum levels with viral biomarkers in patients with chronic hepatitis B (CHB) during nucleos(t)ide analogue (NUC) therapy.

Method: In this study, 54 patients with HBeAg-positive chronic HBV infection were enrolled. The median duration of NUC therapy was 36 months. The cohort included 17 patients with HBsAg loss, 6 patients with HBeAg loss and 31 HBeAg-positive patients without serologic response. Serum levels of fibronectin, HBV DNA, total HBsAg and the three HBsAg components large (L) HBs, middle (M) HBs and small (S) HBs were measured before and during therapy at months 6, 12 and 24.

Results: The median fibronectin level was lower in patients with HBsAg loss compared to patients without seroconversion at baseline (348.4 µg/mL vs. 203.5 µg/mL, p=0.100), at month 6 (318.2 µg/mL vs. 276.7 µg/mL, p=0.001) and at month 24 (413.3 µg/mL vs. 295.5 µl/mL, p=0.003). There was an increase in median fibronectin levels in patients without serologic response from baseline to month 24 (323.8 µg/mL vs. 407.4 µg/mL, p=0.068). Correlations of fibronectin with HBsAg, HBV DNA, LHBs and MHBs were recorded at month 6 and 24.

Conclusion: Fibronectin serum levels are significantly lower in patients with subsequent HBsAg loss undergoing NUC therapy and correlate with the composition of HBsAg. Further studies are needed to clarify the role of fibronectin in functional cure.

Publication History

Article published online:
20 January 2025