Fas/FasL and Complement Activation are Associated with Chronic Active Epstein-Barr Virus Hepatitis

Area of Science:

• Hepatology
• Virology
• Immunology

Background:

• Chronic active Epstein-Barr virus hepatitis (CAEBVH) is a rare, lethal condition causing liver inflammation and enlargement.
• Understanding its clinicopathological features and disease mechanisms is crucial for patient outcomes.

Purpose of the Study:

• To investigate the clinicopathological characteristics of CAEBVH.
• To elucidate the pathogenic mechanisms underlying CAEBVH.

Main Methods:

• Analysis of clinicopathological data from ten CAEBVH patients.
• Flow cytometry for immune cell phenotyping.
• Whole exome sequencing and immunohistochemistry for genetic and molecular mechanisms.

Main Results:

• Patients presented with fever, hepatosplenomegaly, abnormal liver function, and CD8+ T cell lymphopenia.
• Liver biopsies showed lymphocytic infiltration and Epstein-Barr virus-encoded small RNA (EBER) positivity.
• Enhanced expression of cytotoxic T lymphocyte markers, apoptosis-related proteins (Fas/FasL, Caspase-8), and complement components (C1q, C3d) was observed.

Conclusions:

• CAEBVH is characterized by fever, hepatosplenomegaly, and lymphadenopathy.
• Histopathology reveals lymphocytic infiltration and EBER positivity.
• Fas/FasL pathway and complement activation are implicated in CAEBVH pathogenesis.