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Disease Markers
Volume 2015 (2015), Article ID 761908, 8 pages
Research Article

Increased Avidity of the Sambucus nigra Lectin-Reactive Antibodies to the Thomsen-Friedenreich Antigen as a Potential Biomarker for Gastric Cancer

Department of Oncology and Immunology, National Institute for Health Development, Hiiu 42, 11619 Tallinn, Estonia

Received 23 July 2015; Accepted 2 November 2015

Academic Editor: Hamid Raziee

Copyright © 2015 Oleg Kurtenkov and Kersti Klaamas. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Aim. To determine whether the naturally occurring Thomsen-Friedenreich (TF) antigen-specific antibodies differ in avidity between cancer patients and controls to find a novel biomarker for stomach cancer. Methods. Serum samples were taken from patients with cancer and controls. The level of TF-specific antibodies and their sialylation were determined using ELISA with synthetic TF-polyacrylamide conjugate as antigen and sialic acid-specific Sambucus nigra agglutinin (SNA). The avidity was determined using ammonium thiocyanate as a chaotrope. Results. A significantly higher SNA lectin binding to anti-TF antibodies was found in cancer patients irrespective of disease stage. The avidity of only IgM TF-specific antibodies was significantly higher in cancer patients compared to controls. The SNA-positive anti-TF antibodies of cancer patients showed a significantly higher avidity, . The sensitivity and specificity of this increase for gastric cancer were 73.53% and 73.08%, respectively, with a 73.2% diagnostic accuracy. The higher avidity of SNA-reactive anti-TF antibodies was associated with a benefit in survival of stage 3 cancer patients. Conclusion. The SNA-reactive TF-specific antibodies display a significantly higher avidity in gastric cancer patients compared to controls, which can be used as a potential serologic biomarker for gastric cancer. It appears that IgM is the main target responsible for the above changes.