IGA DIRECTED AGAINST EARLY ANTIGEN OF EPSTEIN-BARR-VIRUS IS NO SPECIFIC MARKER FOR THE DIAGNOSIS OF NASOPHARYNGEAL CARCINOMA

The aim of this study was to evaluate the significance and specificity of IgA directed against Epstein-Barr virus (EBV)-specific early antig ens (EA) for the unequivocal diagnosis of nasopharyngeal carcinoma (NP C). Therefore, sera from patients with diseases other than NPC, select ed on the basis of elevated antibody titres against EBV antigens, were compared to sera from NPC patients with regard to the presence of IgA directed against EBV viral capsid antigen (VCA-IgA) and IgA directed against EA (EA-IgA). Four hundred forty-seven out of 7,508 non-NPC ser a tested showed high titres (>512) of IgG directed against Epstein Bar r viral capsid antigen (VCA-IgG) and positive VCA-IgA (greater than or equal to 32). Two hundred twenty-seven of these sera were compared to 51 VCA-IgA-positive sera from NPC patients regarding the titre of EA- IgA. 60.7% of VCA-IgA-positive NPC sera showed positive EA-IgA, howeve r 33% of VCA-IgA-positive non-NPC patients also exhibited EA-IgA. This result demonstrates that EA-IgA is not specific for NPC and does not allow an unequivocal serological diagnosis of NPC in individual cases. It seems therefore to be of questionable use for screening programs i n NPC low-risk areas. The data do not contradict the usefulness of thi s marker for monitoring of patients treated for NPC and for screening programmes in high-risk areas. C) 1994 Wiley-Liss, Inc.