title: [A dynamic study on titer of EB virus VCA/IgA and EA/IgA in nasopharygeal carcinoma patients].
abstract: OBJECTIVE
  To analyze the change of EB virus VCA/IgA and EA/IgA titer during the development of nasopharyngeal carcinoma (NPC), and the role in screening for NPC.
  
  
  METHODS
  VCA/IgA and EA/IgA were monitored in a period of 12 years by immunoenzymatic titration from the sera of 54 NPC patients after primary serological screening.
  
  
  RESULTS
  VCA/IgA and EA/IgA titer had shown gradual increment 1 - 7 years before NPC was pathologically diagnosed. The mean titer of VCA/IgA was 1:21.04, 7 - 4 years before diagnosis. VCA/IgA titer ascended quickly within 3 years before diagnosis. The geometric mean titer (GMT) of VCA/IgA and EA/IgA were 1:76.86 and 1:6.49 when NPC was diagnosed, which descended quickly after radiotherapy and, in 4 years, approached the average titer of VCA/IgA positive population.
  
  
  CONCLUSIONS
  VCA/IgA titer rises uninterruptedly 3 years before NPC is diagnosed pathologically in most patients but their EA/IgA titer rises slowly. The detection of VCA/IgA titer can be used to find early NPC, whereas EA/IgA can not. The pre-clinical phase of NPC is 3 years according to this dynamic study.
authors.affiliation: Cancer Institute, Zhongshan City 528403, China.
authors.forename: Ming-fang
authors.initials: MF
authors.lastname: Ji
authors.forename: Yuan-qing
authors.initials: YQ
authors.lastname: Guo
authors.forename: Jin-sheng
authors.initials: JS
authors.lastname: Liang
authors.forename: Shou-ang
authors.initials: SA
authors.lastname: Zheng
authors.forename: Wei-min
authors.initials: WM
authors.lastname: Cheng
authors.forename: Bing-hui
authors.initials: BH
authors.lastname: Yu
authors.forename: Xing-tai
authors.initials: XT
authors.lastname: Ou
authors.forename: De-kun
authors.initials: DK
authors.lastname: Wang
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000276:immunology*; D036022:Capsid Proteins / Q000276:immunology*; D055088:Early Detection of Cancer; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis / Q000821:virology*
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D036022:Capsid Proteins; C041788:Epstein-Barr viral capsid antigen; C033305:Epstein-Barr virus early antigen; D007070:Immunoglobulin A