Serum MUC5AC mucin as a potential marker for cholangiocarcinoma.

Aberrant expression of MUC5AC mucin is obvious in cholangiocarcinoma tissues, however, this mucin has never been detected in the serum. Using immunoblotting marked with antibody vs. MUC5AC core protein, we could detect MUC5AC mucin in the serum of 112 from 179 cholangiocarcinoma patients (62.6% sensitivity), two of the 62 with benign hepatobiliary diseases, six of the 60 with hepato-gastrointestinal cancer, and none in either the 60 active opisthorchiasis or 74 healthy persons. Detection of serum mucin in the serum of cholangiocarcinoma patients corresponded well to the MUC5AC expressed in individual tissues. Serum MUC5AC may be used to enhance the diagnostic accuracy of cholangiocarcinoma.