Detection of Epstein-Barr virus antigens with enzyme-conjugated antibody.

Monospecific conjugated (fluorescein isothiocynate and horseradish peroxidase) goat antisera, prepared against three human immunoglobulin classes, IM (mu), IgG (gamma) and IgA (alpha), were compared for their ability to detect human Ig classes possessing specificity for Epstein-Barr virus (EBV) viral capsid antigens (VCA) in a chronically infected human lymphoid cell line, P3J-HRIK. It was determined that the enzyme system was significantly more sensitive than immunofluorescence in detecting most of the immunoglobulins in sera from cancer patients. Some patients with nasopharyngeal carcinomas (NPC) had extremely high levels of EBV-specific IgA, whereas cancers other than NPC may have lower EBV-specific IgA titers.