Serum free light chain is associated with histological activity and cirrhosis in patients with chronic hepatitis B.

Background: The antiviral immune response is the main cause of hepatocyte damage and inflammatory necrosis. The serum free light chain, reflecting the immune function of B-cells, is strongly associated with inflammation and disease activity. We aimed to investigate the association of serum free light chain with the progression of chronic hepatitis B.
Methods: A total of 208 eligible chronic hepatitis B patients who had undergone a liver biopsy were studied. Serum free light chains of all patients were measured by turbidimetry using an immunoassay. Liver histology was assessed according to the METAVIR scoring system (which grades the stage of fibrosis on a five-point scale, F0 = no fibrosis to F4 = cirrhosis, and histological activity on a four-point scale, A0 = no activity to A3 = severe activity). The association of serum free light chains with histological activity and fibrosis progression was evaluated.
Results: The concentration of serum free light chains in CHB patients increased gradually with histological activity and fibrosis progression. The intensity of histological activity was significantly correlated with the serum free kappa chain (r = 0.658, P < 0.001) and the serum free lambda chain (0.675, P < 0.001). The stages of fibrosis were correlated with the serum free kappa chain (r = 0.683, P < 0.001) and serum free lambda chain (0.664, P < 0.001). After adjusting for age, sex and other synergic factors, the serum free kappa chain remained a potential risk factor, but the serum free lambda chain was no longer associated with liver cirrhosis. Similar to FIB-4 and RPR, the serum free kappa chain exhibited excellent performance in the prediction of liver cirrhosis. The AUCs of serum free Kappa chain, FIB-4 and RPR were 0.873, 0.880 and 0.895, respectively, which were significantly higher than those of the AAR and APRI (0.718 and 0.746).
Conclusion: Our work revealed that serum free light chains were associated with histological activity and cirrhosis in chronic hepatitis B, which could play a crucial role in the immunopathogenesis of HBV-associated cirrhosis. In addition, free kappa light chain could be a useful predictor of liver cirrhosis.
(Copyright © 2021. Published by Elsevier B.V.)