Prevalence of serum IgG and IgM antibodies against Epstein-Barr virus capsid antigen in Indian patients with respiratory tract carcinomas.

Antibodies against Epstein-Barr virus capsid antigen (EBV-VCA) were measured in sera of Indian patients with respiratory tract carcinomas (lung, larynx, laryngopharynx, nasopharynx) using a commercial enzyme linked immunosorbent assay (ELISA) kit. Nineteen out of thirty-three (19/33) lung cancer, 12/22 laryngeal cancer, 11/16 laryngopharyngeal cancer, 6/9 nasopharyngeal carcinoma cases and 3/29 matched controls were positive for IgG antibody to VCA. None were positive for the IgM antibody to VCA. The antibody positivity was evaluated on the basis of immune status ratio (ISR) of the sera as described in the manual of the kit. Prevalence of the antibody was more pronounced among smokers with laryngeal and laryngopharyngeal carcinoma than among lung cancer cases. The results indicated that the antibody positivity rate among the patients declined with the advanced stages of the diseases. Serum IgG and IgM levels were raised in the patients who were tested positive for the viral antibody.