Serum levels of soluble CD4 and CD8 in patients with chronic viral hepatitis

The blood levels of soluble CD8 (sCD8) and soluble CD4 (sCD4) were measured in patients with various liver diseases, and their significance was studied. The levels of sCD8 were significantly higher in patients with chronic active hepatitis (CAH), autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), acute hepatitis (AH), fulminant hepatitis (FH) and liver cirrhosis (LC) as compared with the normal controls (NC), and correlated positively with those of GPT (r = 0.67, p < 0.001). In addition, a comparison of the exacerbation of CAH with remission showed that the sCD8 levels were significantly higher in the former. On the other hand, there was no significant rise in the level of sCD4 in patients with any liver disease, except FH, no definite relationship between sCD4 and sGPT, and no consistant tendency in sCD4 levels between exacerbation and remission. The reason for an insignificant elevation of the sCD4 level is the fact that in hepatitis the CD8-positive cells, which are cytotoxic T cells, are directly involved in hepatocyte damage; therefore the CD8-positive cells are predominantly activated, while the activity of the CD4-positive cells is considered to be lower. Instead of determining the number of CD4-positive cells and CD8-positive cells in the mononuclear cells of peripheral blood, serum sCD4 and sCD8 levels can be measured simply and inexpensively. Thus, these levels may be useful immune markers.