title: Anti-p16 autoantibodies may be a useful biomarker for early diagnosis of esophageal cancer.
abstract: OBJECTIVE
  Our recent work suggested that circulating IgG antibodies to a linear peptide derived from p16 protein were significantly increased in patients with lung cancer. The present study was then designed to test whether such autoantibodies were also altered in esophageal cancer.
  
  
  METHODS
  An enzyme-linked immunosorbent assay was developed in-house to determine circulating IgA and IgG antibodies against p16 protein-derived antigens in 97 patients with esophageal squamous cell carcinoma (ESCC) and 226 healthy subjects.
  
  
  RESULTS
  The levels of anti-p16 IgG but not IgA antibodies were significantly higher in the patient group than the control group (t = 2.81, P = 0.0052); circulating anti-p16 IgG levels were inversely correlated with stages of ESCC (r = -0.30, df = 81, P = 0.0058) and patients with stage I of ESCC had the highest IgG level among all four stages (t = 5.25, P ≤ 0.0001, compared with control subjects). There was no correlation between the levels of IgA and IgG either in the patient group (r = -0.05, df = 86, P = 0.627) or in the control group (r = -0.1, df = 205, P = 0.146).
  
  
  CONCLUSIONS
  Circulating IgG autoantibody to p16 protein may be a potential biomarker for early diagnosis of esophageal cancer.
authors.affiliation: Department of Radiotherapy, Second Hospital of Jilin University, Changchun, China.
authors.forename: Yonglong
authors.initials: Y
authors.lastname: Jin
authors.affiliation: School of Life Science, Jilin Agriculture University, Changchun, China.
authors.forename: Songlei
authors.initials: S
authors.lastname: Guan
authors.affiliation: Department of Radiotherapy, Second Hospital of Jilin University, Changchun, China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Liu
authors.affiliation: School of Public Health and MH Radiobiology Research Unit, Jilin University, Changchun, China.
authors.forename: Shilong
authors.initials: S
authors.lastname: Sun
authors.affiliation: Pei-Ling Guan-Si Hospital, Hsin-Fu Kuansi Township, Hsinchu County, Taiwan.
authors.forename: Kuang-Hui
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Division of Health Research, University of the Highlands & Islands, Centre for Health Science, Inverness, UK.
authors.forename: Jun
authors.initials: J
authors.lastname: Wei
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000097:blood*; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology; D014408:Biomarkers, Tumor / Q000097:blood / Q000276:immunology*; D002294:Carcinoma, Squamous Cell / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D016022:Case-Control Studies; D055088:Early Detection of Cancer; D004797:Enzyme-Linked Immunosorbent Assay; D004938:Esophageal Neoplasms / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000888:Antibodies, Anti-Idiotypic; D001323:Autoantibodies; D001324:Autoantigens; D014408:Biomarkers, Tumor; C048844:anti-IgG
keywords: autoantibody; biomarker; esophageal cancer; p16 protein; tumor immunity