Subclass distribution of the serum and intrathecal IgG antibody response in varicella-zoster virus infections.

The subclass distribution of the varicella-zoster virus (VZV)-specific IgG antibody response was studied in serum samples from 22 patients with primary varicella and 34 with recurrent VZV infections and in cerebrospinal fluid (CSF) samples from 22 patients with recurrent infection who presented with symptoms of aseptic meningitis. IgG1 and 3 were the dominant subclasses among patients with primary and recurrent infections; IgG1 was also prevalent in the CSF samples. The VZV IgG subclass distribution patterns did not allow differentiation between primary and recurrent infections. However, seroconversions for IgG2, 3, or 4 were observed among patients with recurrences who were negative for specific IgM, suggesting that qualitative tests for serum IgG subclass antibody could be helpful for diagnosis in such cases. Herpes simplex virus-specific IgG was found in CSF samples from several patients with meningitis. The results suggest that calculation of the antibody to albumin index is better than IgG subclass antibody assays for discriminating the causative agent in these cases.