Cell-mediated immunity in acute and chronic hepatitis

Area of Science:

• Immunology
• Hepatology
• Cell Biology

Background:

• Hepatitis B virus (HBV) infection can lead to acute (AH) and chronic (CAH, CPH) liver disease.
• The role of peripheral T-lymphocyte function in hepatitis pathogenesis is not fully understood.
• Investigating lymphocyte cytotoxicity and blast transformation is crucial for understanding immune responses in viral hepatitis.

Purpose of the Study:

• To evaluate the in vitro cytotoxicity and blast transformation of peripheral lymphocytes in patients with various forms of hepatitis B.
• To determine the influence of hepatitis B surface antigen (HBsAg) status on lymphocyte function.
• To assess the impact of serum factors and prednisone therapy on lymphocyte-mediated immune responses.

Main Methods:

• Peripheral lymphocytes from hepatitis patients and controls were incubated with 51Cr-labeled Chang liver cells to measure cytotoxicity.
• Thymus cell-dependent (T) lymphocyte function was assessed via concanavalin A (Con A)-stimulated blast transformation and cytotoxicity.
• Lymphocyte function was evaluated in the presence of autologous/homologous serum and after prednisone therapy.

Main Results:

• Lymphocytes from patients with acute hepatitis (AH) demonstrated significant cytotoxicity against Chang liver cells.
• Serum from patients with acute and chronic hepatitis inhibited both spontaneous and Con A-induced lymphocyte cytotoxicity and blast transformation.
• Prednisone therapy in chronic active hepatitis (CAH) patients markedly reduced lymphocyte cytotoxicity, even when stimulated by Con A.

Conclusions:

• Patients with AH possess circulating T lymphocytes capable of inducing liver cell destruction.
• No intrinsic defect in T-cell function was observed in hepatitis patients when stimulated by Con A.
• Serum factors in hepatitis patients and prednisone treatment impair lymphocyte-mediated cytotoxicity and blast transformation.