Conclusion: The present study has shown that increased serum levels of cytokeratin 19 fragment reflect increases in the size of the pancreatic carcinomas, although the sensitivity for detecting small pancreatic carcinomas was low.
Background: Cytokeratin is a member of the intermediate family of filaments in epithelial cells. The cytokeratin 19 fragment is an acidic cytokeratin, which is found in various epithelial tissues. Recently, the serum fragment of cytokeratin 19 has been measured and found to be a good marker for squamous cell carcinoma. Cytokeratin 19 is known to be expressed in normal pancreatic tissues and pancreatic carcinomas. However, serum cytokeratin 19 levels in pancreatic diseases have not been precisely detailed.
Methods: In this study, we evaluated serum cytokeratin 19 levels and the immunohistochemical expression of cytokeratin 19 in various pancreatic diseases.
Results: Serum cytokeratin 19 levels were high (> 2 ng/mL) in 51 of 99 (52%) cases of pancreatic duct cell carcinoma, but were low in all 24 cases of chronic pancreatitis and in 7 cases of islet cell tumors. The sensitivity of the cytokeratin 19 assay increased with increased size of the pancreatic carcinomas, but was not influenced by the presence of obstructive jaundice. Immunohistochemical studies using a monoclonal anticytokeratin 19 antibody showed that staining for cytokeratin was positive in all 38 of the pancreatic carcinomas examined and in 2 of 6 islet tumors.