IgA antibodies to Epstein-Barr viral capsid antigens in saliva of nasopharyngeal carcinoma patients.

THE majority of sera from naso-pharyngeal carcinoma (NPC) patients studied to date was shown to have a titre of IgA antibodies to the Epstein-Barr viral capsid antigen (VCA) of 1/10, while the same reactivity was seldom detectable in the sera of controls consisting of patients with other cancers and healthy subjects (Henle and Henle, 1976; Ho et al., 1976 and in preparation). In all these sera, the detection of IgA reactivity to VCA was concomitant with high titres of IgG anti-bodies to VCA. This led to the conclusion that both serum reactivities might reflect the intensity of systemic stimulation by EBV-specific antigens (Ho et al., 1976). However, these findings did not exclude a concurrent production of local antibodies. Indeed, in view of the fact that discharge from NPC readily finds its way to the oral cavity and the saliva, and the close association known to exist between the neoplastic disease and EBV (Klein, 1973; Ho, 1975; de-The, et al., 1975), production of local antibodies to VCA may well be anticipated. We therefore tested the saliva obtained from NPC patients and controls for the presence of IgA antibodies to EBV VCA. Parallel specimens of saliva and sera were obtained from 30 histologically confirmed NPC patients before treatmen