A CASE OF OVERLAP SYNDROME OF PRIMARY BILIARY CIRRHOSIS AND AUTOIMMUNE HEPATITIS WITH MARKED ELEVATION OF IgM

A 60-year-old woman was admitted to our hospital because of anorexia and vomiting. Hematology revealed elevated levels of hepatobiliary enzymes and positive results for antinuclear antibody (ANA) and antimitochondrial (AMA) M2 antibody. Immunoglobulin (Ig) G and IgM levels were extremely elevated, 3,379 mg/dl and 4,250 mg/dl, respectively. A diagnosis of primary biliary cirrhosis and autoimmune hepatitis (PBC-AIH) overlap syndrome was made. However, IgM levels as high as the level of 4,250 mg/dl in this case has not been reported previously. This case may be of value in studying elevated IgM levels with PBC-AIH overlap syndrome and relationships to the mechanism of onset.