HCV-associated B cell clonalities in the liver do not carry the t(14;18) chromosomal translocation

Area of Science:

• Hepatology
• Oncology
• Immunology

Background:

• Hepatitis C virus (HCV) infection is associated with an increased risk of B-cell non-Hodgkin lymphoma.
• The specific mechanisms linking HCV to lymphomagenesis, particularly within the liver, require further elucidation.

Purpose of the Study:

• To investigate the presence of Bcl-2/IgH rearrangement and B-cell clonotypes in the liver of HCV-infected patients.
• To correlate these findings with the expression of Bcl-2 protein and the presence of extrahepatic B-cell disorders.

Main Methods:

• Nucleic acids were extracted from liver biopsy samples (using laser capture microdissection) and peripheral blood mononuclear cells (PBMCs) of 16 HCV patients.
• Polymerase chain reaction (PCR) was used to detect Bcl-2/IgH and variable diversity joining (VDJ) IgH gene rearrangements.
• Immunohistochemistry was performed to assess Bcl-2 protein expression in liver tissue.

Main Results:

• Specific Bcl-2/IgH amplicons were not detected in liver tissue or PBMCs.
• Monoclonal or oligoclonal B-cell clonotypes (VDJ rearrangements) were found in 80% of patients with B-cell disorders and 25% without.
• Bcl-2 protein overexpression was observed in 12.5% of patients without extrahepatic disorders.

Conclusions:

• The study suggests that IgH gene rearrangements in the liver are not associated with Bcl-2/IgH chromosomal translocation in HCV infection.
• Liver overexpression of Bcl-2 protein may occur in a subset of HCV patients, independent of chromosomal translocation.
• The presence of B-cell clonotypes in the liver indicates local B-cell proliferation in HCV infection.