Affiliations: [a] Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand | [b] Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand | [c] Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand | [d] Department of Surgery, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand | [e] Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand | [f] Department of Veterinary Technology, Faculty of Veterinary Technology, Kasetsart University, Bangkok, Thailand | [g] Department of Clinical Pathology, Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Bangkok 10300, Thailand
Correspondence:
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Corresponding author: Somchai Pinlaor, Department of Parasitology, Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. Tel.: +66 43 348387; Fax: +66 43 202475; E-mail:psomec@kku.ac.th
Abstract: BACKGROUND: Cholangiocarcinoma (CCA), a malignant tumor of the
biliary epithelium, is a tumor with an ineffective diagnosis and poor
prognosis. We have previously identified an overexpression of orosomucoid 2
(ORM2) along with CCA development in hamsters using a proteomics technique. OBJECTIVE: To evaluate plasma ORM2 as a candidate risk biomarker
for CCA in humans. METHODS: Overexpression of ORM2 in CCA patients was assessed by
western blotting and immunohistochemistry. The diagnostic efficacy of ORM2
was investigated in the plasma of patients with hepatobiliary diseases -
including 46 cholangitis patients and 70 CCA patients - compared with 20
healthy individuals, using enzyme-linked immunosorbent assay (ELISA). RESULTS: Overexpression of ORM2 was observed in the cytoplasm of
bile duct tumor cells and in the adjacent normal hepatocytes at a much
higher intensity than in normal bile duct cells. Western blot analysis
revealed that its expression was significantly higher in the plasma of CCA
patients compared with that of healthy individuals (P < 0.01). ELISA showed
that plasma ORM2 levels were significantly elevated in CCA and cholangitis
groups compared with healthy individuals (P < 0.0001). The sensitivity and
specificity of ORM2 in distinguishing CCA patients from healthy patients
were 92.86% and 73.68%, respectively. CONCLUSIONS: Plasma ORM2 could serve as a new risk marker for CCA.
