title: Increased sialylation of anti-Thomsen-Friedenreich antigen (CD176) antibodies in patients with gastric cancer: a diagnostic and prognostic potential.
abstract: OBJECTIVE
  To study whether alterations in the sialylation of antibodies (Ab) specific to the Thomsen-Friedenreich (TF) glycotope have a diagnostic and prognostic potential in gastric cancer.
  
  
  METHODS
  Serum samples were taken from patients with gastric carcinoma (n = 142) and controls (n = 61). The level of TF-specific antibodies and their sialylation was detected using ELISA with synthetic TF-polyacrylamide conjugate as antigen and sialic acid-specific Sambucus nigra agglutinin (SNA).
  
  
  RESULTS
  The level of TF-specific IgM was significantly decreased in cancer compared with controls (P ≤ 0.001). Cancer patients showed a higher level of SNA binding to anti-TF IgM and IgA (P ≤ 0.001) irrespective of disease stage, tumor morphology, and gender. Changes in the SNA/Ab index demonstrated moderate sensitivity (66-71%) and specificity (60-73%) for stomach cancer. The best diagnostic accuracy (100%) was achieved in 29% patients with high SNA binding and low anti-TF IgM level. This subset of patients demonstrated the poorest survival.
  
  
  CONCLUSIONS
  Our findings are the first evidence that the increased sialylation of TF-specific Abs combined with a low level of anti-TF IgM is strongly linked to gastric cancer and patients survival, which can be used as a novel biomarker for cancer detection and prognosis.
authors.affiliation: Department of Oncology and Immunology, National Institute for Health Development, Hiiu 42, Tallinn 11619, Estonia.
authors.forename: Oleg
authors.initials: O
authors.lastname: Kurtenkov
authors.affiliation: Department of Oncology and Immunology, National Institute for Health Development, Hiiu 42, Tallinn 11619, Estonia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Izotova
authors.affiliation: Department of Oncology and Immunology, National Institute for Health Development, Hiiu 42, Tallinn 11619, Estonia.
authors.forename: Kersti
authors.identifier: 0000-0002-1129-9031
authors.initials: K
authors.lastname: Klaamas
authors.affiliation: Department of Oncology and Immunology, National Institute for Health Development, Hiiu 42, Tallinn 11619, Estonia.
authors.forename: Boris
authors.initials: B
authors.lastname: Sergeyev
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies / Q000276:immunology*; D000918:Antibody Specificity / Q000276:immunology; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000276:immunology*; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019158:N-Acetylneuraminic Acid / Q000378:metabolism*; D009367:Neoplasm Staging; D037121:Plant Lectins / Q000378:metabolism; D011336:Probability; D011379:Prognosis; D011485:Protein Binding; D012372:ROC Curve; D054788:Ribosome Inactivating Proteins / Q000378:metabolism; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000276:immunology* / Q000473:pathology; D016019:Survival Analysis
chemical_list: D000906:Antibodies; D015295:Antigens, Tumor-Associated, Carbohydrate; D015415:Biomarkers; D037121:Plant Lectins; C050600:Sambucus nigra lectins; C016467:Thomsen-Friedenreich antigen; C025991:Thomsen-Friedenreich antibodies; D054788:Ribosome Inactivating Proteins; D019158:N-Acetylneuraminic Acid