title: Specificity of squamous cell carcinoma antigen (SCCA)-IgM detection in patients with HCV infection and rheumatoid factor seropositivity.
abstract: IgM antibodies bound to different cancer antigens have shown recently a higher diagnostic value, compared with the corresponding free molecule, giving rise to a new family of biomarkers. High or increasing levels of Squamous Cell Carcinoma Antigen (SCCA)-IgM immune complexes were associated with more advanced liver disease and increased risk of development of HCC. Rheumatoid factor (RF) represents a long-standing problem of interference for immunometric assays. The aim of the present study was to examine the specificity of SCCA-IgM in relation to the presence of RF reactivity in patients infected with hepatitis C virus (HCV). Sera of 73 patients with cirrhosis, infected with HCV, (mean age ± SD: 66 ± 13 years; M/F: 45/28), including 21 patients with HCC, were studied. SCCA-IgM immune complexes levels were measured by a commercial ELISA. To evaluate the possible interfering effect of RF, the standard calibrator, positive for SCCA-IgM, was spiked with serial dilutions of a RF positive or negative serum. SCCA-IgM immune complexes were positive in 35 out of 73 (48%) patients, while RF activity was found in 10 out of 73 (14%) patients. Patients with cirrhosis with RF activity had significantly higher levels of SCCA-IgM, compared to RF negative cases; however, no significant correlation between SCCA-IgM and RF values was observed. In samples created artificially the same results in terms of reactivity for SCCA-IgM were obtained, regardless of the presence of RF activity. These findings support the lack of correlation between the two parameters found in sera of patients infected with HCV.
authors.affiliation: Department of Medicine-DIMED, University of Padua, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Biasiolo
authors.forename: Natascia
authors.initials: N
authors.lastname: Tono
authors.forename: Martina
authors.initials: M
authors.lastname: Zaninotto
authors.forename: Carlo
authors.initials: C
authors.lastname: Merkel
authors.forename: Giorgio
authors.initials: G
authors.lastname: Fassina
authors.forename: Mario
authors.initials: M
authors.lastname: Plebani
authors.forename: Angelo
authors.initials: A
authors.lastname: Gatta
authors.forename: Patrizia
authors.initials: P
authors.lastname: Pontisso
mesh_terms: D000368:Aged; D000936:Antigen-Antibody Complex / Q000097:blood*; D000951:Antigens, Neoplasm / Q000097:blood* / Q000276:immunology; D002138:Calibration; D006528:Carcinoma, Hepatocellular / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D016174:Hepacivirus / Q000276:immunology; D006526:Hepatitis C / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D008103:Liver Cirrhosis / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D008113:Liver Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D008297:Male; D008875:Middle Aged; D012217:Rheumatoid Factor / Q000097:blood* / Q000276:immunology; D012680:Sensitivity and Specificity; D015843:Serpins / Q000097:blood* / Q000276:immunology
chemical_list: D000936:Antigen-Antibody Complex; D000951:Antigens, Neoplasm; D007075:Immunoglobulin M; D015843:Serpins; C051072:squamous cell carcinoma-related antigen; D012217:Rheumatoid Factor