Novel Epstein-Barr virus immunoglobulin G-based approach for the specific detection of nasopharyngeal carcinoma.
OBJECTIVE
This study was designed to find a reliable Epstein-Barr virus (EBV) immunoglobulin (Ig) G-based diagnostic/screening test for nasopharyngeal carcinoma (NPC) able to demarcate between the NPC-related seropositivity of EBV IgG antibodies and that of other head and neck cancer (HNCA) and control groups. The NPC-associated immunosuppression affects EBV IgA much more than IgG, leading to inconsistent detection of NPC using EBV IgA antibodies.


METHODS
One hundred twenty-two HNCA patients, 42 NPC, 66 laryngeal carcinoma, and 14 hypopharyngeal carcinoma and 3 groups of 100 control subjects were enrolled in this study. Enzyme-linked immunosorbent assay (ELISA) was used to find a specific cutoff value for the NPC-related seropositivity of EBV IgG antibodies.


RESULTS
NPC group showed higher serum level of EBV IgG antibodies than control and other HNCA groups (P < .05). However, the traditional cutoff value, mean + 2 SDs of control subjects, failed to demarcate the seropositives of NPC patients from those of healthy population (P > .05). The new cutoff value, mean + 2 SDs of the seropositives group of control subjects who had already been grouped by the traditional cutoff value, proved successful. It succeeded to demarcate between the NPC-related EBV IgG seropositivity and that issued from the persistent, latent, or reactivated EBV infection in the population (P < .05). The sensitivity/specificity of NPC detection by the new cutoff-based ELISA kit, 76.19% and 86%, was close or higher than that of EBV IgA antibodies.


CONCLUSIONS
EBV IgG-based ELISA could be used for the diagnosis of NPC using a new cutoff threshold that excludes the population baseline of EBV IgG seropositivity.
Abdulamir
Ahmed S
AS
Microbiology Research Department, University Putra Malaysia, Serdang, Malaysia. ahmsah73@yahoo.com
Hafidh
Rand R
RR
Abu Bakar
Fatimah
F
Abbas
Kassim
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies / Q000032:analysis; D002277:Carcinoma; D004797:Enzyme-Linked Immunosorbent Assay; D020031:Epstein-Barr Virus Infections / Q000276:immunology; D005260:Female; D006258:Head and Neck Neoplasms / Q000276:immunology; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology*; D007822:Laryngeal Neoplasms / Q000276:immunology; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis / Q000276:immunology; D012680:Sensitivity and Specificity
D000906:Antibodies; D007074:Immunoglobulin G