Increased tumor necrosis factor-alpha receptor number in chronic hepatitis B virus infection

Production of the antiviral cytokine, tumor necrosis factor-alpha is increased in chronic hepatitis B virus infection, and clinical studies of tumor necrosis factor-alpha have indicated a proviral effect at higher doses. To determine whether this might be related to abnormal cell surface tumor necrosis factor-alpha receptor expression, binding characteristics of cell surface tumor necrosis factor-alpha receptor on peripheral blood mononuclear cells in chronic hepatitis B virus carriers were studied using radioiodinated recombinant tumor necrosis factor-alpha. The specific binding curves generated were analyzed according to the method of Scatchard to determine cell surface receptor numbers and dissociation constants. A single class of cell surface tumor necrosis factor-alpha receptor was demonstrated on peripheral blood mononuclear cells and mononuclear subsets. The median number (range) of cell surface tumor necrosis factor-alpha receptors on peripheral blood mononuclear cells from controls (n = 11), chronic hepatitis B virus patients seropositive for hepatitis B virus DNA (n = 8) and seronegative for hepatitis B virus DNA (n = 8) were 2,329 (range = 1,538 to 3,133), 3,375 (range = 2,300 to 6,718) (p less than 0.01) and 3,113 (range = 2,229 to 5,246) (p less than 0.05) sites/cell, respectively. They all had similar dissociation constants of 8.4 x 10(-10) mol/L (range = 4.1 to 16.9), respectively. Further dissection of the peripheral blood mononuclear cells showed that this increase in cell surface receptor number was confined to the monocyte fraction (p less than 0.01). Plasma tumor necrosis factor-alpha levels in five patients with increased monocyte cell surface tumor necrosis factor-alpha receptor numbers were also elevated.(ABSTRACT TRUNCATED AT 250 WORDS)