Immunopathology of Chronic Hepatitis B

Chronic hepatitis B is widespread in sub-Saharan Africa and is a major cause of liver morbidity. Viral persistence depends in part on a state of immune tolerance, which is still poorly characterized in practice. We report the case of a 45-year-old man, a chronic HBsAg carrier, discovered during a blood donation. Clinical examination, liver enzymes, and liver elastometry were normal, with a low viral load (<200 IU/mL). Global lymphocyte immunophenotyping revealed a decrease in NK cells (120 cells/μL), CD4 + T cells (350 cells/μL), and CD8 + cells (180 cells/μL). Cytokine analysis by CBA showed lowered levels of TNF-α (6 pg/μL) and IFN-γ (4 pg/μL) and normal levels of IL-6 (2.5 pg/μL). Although these techniques, which are restricted to specialized research laboratories, do not allow the identification of HBV-specific cells, they suggest a state of immune tolerance characterized by a weakened but nondeleterious antiviral response. A better characterization of such immunological profiles could help improve clinical monitoring and identify relevant targets for future immunotherapeutic approaches, particularly in resource-limited settings.