EBV specific antibody-based and DNA-based assays in serologic diagnosis of nasopharyngeal carcinoma.
We assessed 5 EBV specific assays for their capacity to effect serologic diagnosis of suspected NPC. The assays were the immunofluorescent assays, VCA IgA and EA IgA, the enzyme-linked immunosorbent assays specific for EBNA 1 IgA or zta IgG and an EBV DNA assay. Serum samples were taken from 218 symptomatic NPC patients presenting consecutively at a public hospital in Hong Kong, 51 of whom were subsequently diagnosed as having NPC; 4 had EBV-associated lung cancer with similar serology as NPC. The remaining patients included 23 who had other cancers and 140 who had other diseases. Objectives of serodiagnosis under such clinical settings, therefore, are to both exclude and predict a diagnosis of NPC. None of the assays individually can meet both requirements adequately, however. The difficulty was best overcome by combining EBNA 1 IgA and zta IgG. It was shown that 68.3% of the patients gave a confirmed test results, negative or positive, by both tests. A confirmed negative result was associated with a negative predictive value of 99.1%, providing a clear indication to exclude a diagnosis of NPC; a confirmed positive result was associated with a positive predictive value of 86.8%, providing a clear indication to proceed with diagnostic work-up of NPC. The remaining patients gave equivocal test results, being positive for one or the other test, which were associated with a positive predictive value of 43.3% and 24.2%, respectively.
Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China.
Kwok H
KH
Chan
Yao L
YL
Gu
Fai
F
Ng
Park S P
PS
Ng
Wing H
WH
Seto
Jonathan S T
JS
Sham
Daniel
D
Chua
William
W
Wei
Yue L
YL
Chen
Winsie
W
Luk
Yong S
YS
Zong
Mun H
MH
Ng
D000914:Antibodies, Viral / Q000097:blood*; D000918:Antibody Specificity; D000956:Antigens, Viral / Q000276:immunology; D036022:Capsid Proteins / Q000276:immunology; D002277:Carcinoma / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D002294:Carcinoma, Squamous Cell / Q000097:blood / Q000175:diagnosis / Q000276:immunology / Q000821:virology; D004279:DNA, Viral / Q000097:blood*; D004268:DNA-Binding Proteins / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D020031:Epstein-Barr Virus Infections / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D019309:Epstein-Barr Virus Nuclear Antigens / Q000276:immunology; D019084:Fluorescent Antibody Technique, Indirect; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D006723:Hong Kong; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008175:Lung Neoplasms / Q000097:blood / Q000175:diagnosis / Q000276:immunology / Q000821:virology; D009303:Nasopharyngeal Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D009369:Neoplasms / Q000097:blood / Q000175:diagnosis / Q000276:immunology / Q000821:virology; D011237:Predictive Value of Tests; D015534:Trans-Activators / Q000276:immunology; D014412:Tumor Virus Infections / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D014764:Viral Proteins / Q000276:immunology
D000914:Antibodies, Viral; D000956:Antigens, Viral; C063676:BZLF1 protein, Herpesvirus 4, Human; D036022:Capsid Proteins; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D019309:Epstein-Barr Virus Nuclear Antigens; C041788:Epstein-Barr viral capsid antigen; C033305:Epstein-Barr virus early antigen; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D015534:Trans-Activators; D014764:Viral Proteins; C417029:EBV-encoded nuclear antigen 1