THE EPSTEIN-BARR-VIRUS (EBV) MAJOR ENVELOPE GLYCOPROTEIN GP350 220-SPECIFIC ANTIBODY REACTIVITIES IN THE SERA OF PATIENTS WITH DIFFERENT EBV-ASSOCIATED DISEASES/

gp350 of Epstein-Barr virus (EBV) induces a strong immune response in EBV-infected individuals, but relatively little is known about the cli nical relevance of this response in patients with different EBV-associ ated malignancies and other diseases. Using our gp350 expressing cell clones, we studied gp350-specific humoral immune responses in the sera of individuals with nasopharyngeal carcinoma (NPC), chronic symptomat ic EBV infection (CEI), Hodgkin's disease (HD), acute infectious monon ucleosis (IM) and healthy EBV-seropositive individuals (HI). The titre s of antibody-dependent cellular cytotoxicity (ADCC) antibodies were h ighest in HI followed by CEI, HD and NPC. EBV-neutralizing (NA) and gp 350-specific IgG antibody profiles in these conditions were: CEI > HI > NPC > HD, whereas IgA titres were the highest in NPC sera followed b y CEI and HD. The sera from IM patients were found to be negative for gp350-specific ADCC and IgA activities. Sera from HI were also negativ e for gp350-specific IgA. A significant positive correlation was found between serum gp350 IgA and viral capsid antigen IgA and a significan t negative one between IgM and ADCC titres. High IgA titres were also found in CEI and EBV-genome positive HD in addition to NPC. Importantl y, gp350-specific IgA titres were of prognostic value in NPC patients. Our data provide new insights about the clinical relevance of gp350-s pecific immune responses in these diseases. Int. J. Cancer (Pred, Onco l.) 79:481-486, 1998. (C) 1998 Wiley-Liss, Inc.