title: Detection of annexin A autoantibodies in sera from colorectal cancer patients.
abstract: BACKGROUND
  Annexins (ANXAs) belong to a superfamily of closely related calcium and membrane-binding proteins and are overexpressed in some carcinomas. The overexpression of ANXAs presumably induces an autoantibody response, but this has not been demonstrated for sera from colorectal cancer (CRC) patients.
  
  
  METHODS
  We examined serum samples from 220 CRC patients and 216 healthy volunteers to evaluate the ANXA autoantibody response in patients by using an enzyme-linked immunosorbent assay with recombinant ANXA A4 as the antigen.
  
  
  RESULTS
  The sensitivity of the anti-ANXA response from CRC patient sera was about 85% and the specificity was about 61.6%. When a cut-off value of 5.0 ng/mL was chosen for carcinoembryonic antigen (CEA) in the same sera samples, the sensitivity and specificity values were 43.2% and 85.2%, respectively. Combined detection using ANXA autoantibodies and CEA produced better sensitivity (71.8%) and specificity (79.2%) compared with CEA sensitivity (43.2%) and anti-ANXA specificity (61.6%). The area under a receiver operating characteristic curve was 0.794 for ANXA autoantibodies, 0.666 for CEA, and 0.84 for both markers together. Importantly, in comparison to CEA (27.5% seropositivity), ANXA autoantibody showed a remarkable change (81.3% seropositivity) at the early stage of CRC.
  
  
  CONCLUSIONS
  Measurement of ANXA autoantibody levels may provide an alternative detection indicator for CRC, particularly among early-stage patients.
authors.affiliation: Colorectal Section, Department of Surgery, Chang Gung Memorial Hospital, Tao Yuan, Taiwan.
authors.forename: Jinn-Shiun
authors.initials: JS
authors.lastname: Chen
authors.forename: Yeh-Pin
authors.initials: YP
authors.lastname: Chou
authors.forename: Kuei-Tien
authors.initials: KT
authors.lastname: Chen
authors.forename: Ray-Ping
authors.initials: RP
authors.lastname: Hung
authors.forename: Jau-Song
authors.initials: JS
authors.lastname: Yu
authors.forename: Yu-Sun
authors.initials: YS
authors.lastname: Chang
authors.forename: Err-Cheng
authors.initials: EC
authors.lastname: Chan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017314:Annexin A4 / Q000235:genetics / Q000276:immunology; D017302:Annexins / Q000235:genetics / Q000276:immunology*; D000918:Antibody Specificity; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D015179:Colorectal Neoplasms / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D017314:Annexin A4; D017302:Annexins; D001323:Autoantibodies; D011994:Recombinant Proteins