Improved sensitivity of detection by avidin-biotin complex (ABC) immunocytochemistry in Epstein-Barr virus serology.
Serum antibodies against Epstein-Barr virus (EBV)-determined antigens have traditionally been titrated by the indirect immunofluorescence (IIF) technique. The avidin-biotin complex (ABC) immunocytochemical technique was used to determine the serum levels of IgA against EBV viral capsid antigen (IgA/VCA) and IgA against EBV early antigen (IgA/EA) in sera of 106 nasopharyngeal carcinoma (NPC) patients prior to treatment and 100 normal individuals. The sensitivity of the ABC technique is enhanced by an amplification of the antigen-antibody reaction, which involves the binding of the enzyme-linked ABC to the second biotinylated antibody. There was a good correlation (r = 0.9988) between ABC and IIF-determined IgA/VCA-positive titres, with the ABC technique being more sensitive than IIF in the detection of IgA/VCA in NPC sera: 94% (99/106) and 76% (80/106), respectively. The frequency of IgA/EA reactivity in NPC sera was also markedly increased by immunodetection with the ABC technique as compared with IIF technique: 63% (69/106) and 28% (30/106) respectively. Both the immunocytochemical techniques were equally specific in discriminating between elevated serum titres of IgA/VCA and IgA/EA in NPC sera from normal human sera.
Thoe
S Y
SY
Institute of Advanced Studies, University of Malaya, Kuala Lumpur, Malaysia.
Sam
C K
CK
Cheng
H M
HM
Prasad
U
U
D000914:Antibodies, Viral / Q000276:immunology; D000956:Antigens, Viral / Q000032:analysis*; D001360:Avidin; D001710:Biotin; D036022:Capsid Proteins; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D007150:Immunohistochemistry; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D014407:Tumor Cells, Cultured
D000914:Antibodies, Viral; D000956:Antigens, Viral; D036022:Capsid Proteins; C041788:Epstein-Barr viral capsid antigen; D007070:Immunoglobulin A; D001360:Avidin; D001710:Biotin