Significance of Specific Epstein-Barr Virus IgA and Elevated IgG Antibodies to Viral Capsid Antigens in Nasopharyngeal Carcinoma Patients

The feasibility of using elevated Epstein‐Barr virus (EBV) specific‐IgG antiviral capsid antigen (VCA) and IgA anti‐VCA antibody levels as an aid in diagnosis of nasopharyngeal carcinoma (NPC) was analyzed by determination of serum anti‐body titers to EBV in 54 NPC patients, 114 healthy blood donors, and 40 family members by the immunoperoxidase assay (IPA). No significant difference was found in the prevalence rate of EBV IgG anti‐VCA antibodies (titer ≥20) between the patient group and the control and family groups (100% vs 92% and 90%, respectively). The prevalence rate of elevated EBV IgG anti‐VCA titers (≥ 80, ≥ 160, ≥ 320, and≥ 640) was significantly higher in the NPC patients than in controls. For example, at an IgG titer of ≥320, the prevalence rate was 82% in the NPC patient group and 1.7% in the controls (P