Interferon-γ receptor expression in chronic hepatitis B virus infection

Abstract

It is known that interferon-γ (IFNγ) is not effective in inducing a sustained inhibition of HBV replication in patients with chronic HBV infection in contrast to interferon-α (IFNα). To determine whether this was related to IFNγ receptor (IFNγ-R) underexpression, binding characteristics of IFNγ to peripheral blood lymphocytes were studied in chronic HBV infection using radioiodinated recombinant IFNγ. Peripheral blood lymphocytes from patients with chronic HBV infection ( n = 20), normal healthy controls ( n = 12) and patients with non-viral related chronic liver disease expressed a similar number of IFNγ-R (medians (ranges): 1891 (1581–2515); 1916 (1589–2441); 1893 (1692–2104) sites/cell, respectively, p = N.S.) with a similar dissociation constant ( K d ≈ 0.7–2.7 nM). There was no correlation between IFNγ-R expression and serum transaminase, serum HBsAg and HBV-DNA titres and liver histology. IFNa therapy in vivo also did not enhance IFNγ-R expression ( n = 3). There is therefore, no evidence from this data that IFNγ-R is underexpressed in patients with chronic HBV infection to account for the difference in clinical response to these two forms of therapy.