An immunoperoxidase assay for the detection of specific IgA antibody in Epstein-Barr virus infections.

A technique using indirect immunoperoxidase antibody was developed for the detection of specific serum IgA antibody to Epstein-Barr virus capsid antigen and early antigen. The IgA technique was compared with an immunofluorescence antibody method. Epstein-Barr virus IgA antibody against viral capsid antigen was detected in all nine patients with Epstein-Barr virus associated undifferentiated nasopharyngeal carcinoma, in 13 (72.2%) of 18 patients with infectious mononucleosis, in 21 (28.3%) of 74 patients with acute lymphoblastic leukaemia, and in six (20%) of 30 patients who had recently had kidney transplants. Epstein-Barr virus IgA antibody against viral capsid antigen was also detected in four (10%) of 40 healthy subjects, but it was not found in any of 20 cord blood samples. Epstein-Barr virus IgA antibody to early antigen was detected in six (66.6%) patients with nasopharyngeal carcinoma and in two (2.7%) patients with acute lymphoblastic leukaemia. The immunoperoxidase assay for Epstein-Barr virus specific IgA was simple, reliable, and rapid and correlated well (r = 0.94) with the immunofluorescence antibody technique.