Serum immunoglobulin levels in hepatitis non-A, non-B: a comparison with hepatitis A and B.

The serum levels of IgA, IgG and IgM were determined by the single radial immunodiffusion method in 86 patients with acute viral hepatitis serologically differentiated by radioimmunoassays. The levels of IgA and IgG were similar in patients with hepatitis A, B and non-A, non-B, while differences in IgM levels were observed between the three groups. The hepatitis non-A, non-B group had significantly lower levels of IgM than both the hepatitis A and hepatitis B group, a finding which may be diagnostically useful if hepatitis A serology fails.