Detection of specific IgA antibodies in serum of patients with varicella and zoster infections.

A sensitive solid-phase, enzyme-linked immunosorbent assay (ELISA) was developed for detection of serum IgA antibodies to varicella-zoster virus (VZV). The antigen consisted of a sonically disrupted extract of VZV-infected human embryo cells. Rabbit antihuman IgA peroxidase conjugate was used to detect human IgA bound to viral antigens. In parallel, IgM and IgG antibodies to VZV were studied by ELISA and by an immunoperoxidase antibody to membrane antigen technique, respectively. VZV IgA antibodies were detected in high titers in all 5 varicella and 8 zoster patients. Specific VZV IgM antibodies were detected in all 5 varicella patients, but only in 2 of 8 zoster patients. No VZV IgA antibodies (less than 40) were detected in 50 healthy control sera. Neither were they found in paired sera of 5 patients with herpes simplex infections, 2 patients with Epstein-Barr virus infections, and 5 patients with human cytomegalovirus infections. The potential application of ELISA IgA techniques in serodiagnosis of both primary and reactivated VZV infections is discussed.