Detection of specific Iga antibodies to varicella zoster virus in serum of patients with ramsay hunt syndrome

Varicella zoster virus (VZV)–specific IgG and IgA antibody titers were determined in serial serum samples of 23 patients with Ramsay Hunt syndrome by the immunoperoxidase assay. Varicella zoster virus–specific IgG antibodies were found in the first serum samples of all the patients. In 80% of 20 patients in whom a serum sample was available within 5 days after the onset of the disease, VZV-specific IgA antibodies were detected. The second serum sample was VZV-specific IgA–positive in all of the patients. While all the healthy age- and sex-matched control subjects had VZV-specific IgG antibodies, VZV-specific IgA antibodies were detected in a low titer (dilution = 2) in only three of the subjects. By using VZV-specific IgA antibody titers of ≥ 2 and ≥ 4 by the immunoperoxidase assay as a “cutoff” for younger and older patients with Ramsay Hunt syndrome, respectively, an early diagnosis of the disease can be obtained in 89% of the younger and in 64% of the older patients by a single serum sample.