Proper use of serum antibody titres against Epstein-Barr virus in nasopharyngeal carcinoma: IgA/virus capsid antigen for diagnosis and EBV-related nuclear antigen-2 for follow-up

Sera from patients with nasopharyngeal carcinoma (NPC) show high titres of IgA antibodies to Epstein-Barr viral capsid antigen (IgA/VCA). We reported previously that the serum titres for Epstein-Barr virus-related nuclear ant igen-2 (EBNA2) correlated with NPC patients' prognosis. To investigate whic h is better for diagnosing NPC and predicting patient prognosis, the titrat ion of serum IgA/VCA or EBNA2, we examined the same serum titres. Sixteen c ases of NPC in which serum EBNA2 antibody titres had been tested, were inve stigated for the serum IgA/VCA antibody titres before and after radiation t reatment. All NPC cases showed positive reactions with indirect immunofluor escence staining, and the median titre was 252. Twelve normal controls, 5 m esopharyngeal carcinoma patients, 4 hypopharyngenl carcinoma patients. 4 la ryngeal carcinoma patients and 6 malignant lymphoma were also examined, but they showed negative or relatively low titres. A follow-up study revealed that IgA/VCA titres remained mostly stable. These results indicate a close relationship between IgA/VCA and NPC, however, prognosis correlated better with EBNA2 titres than with IgA/VCA titres.