THE DETECTION OF INTRATHECAL SYNTHESIS OF ANTI-HERPES SIMPLEX IGG ANTIBODIES - COMPARISON BETWEEN AN ANTIGEN-MEDIATED IMMUNOBLOTTING TECHNIQUE AND ANTIBODY INDEX CALCULATIONS

The detection of intrathecal antibody synthesis was compared by the ca lculation of antibody indices (Al) derived from ELISA techniques with the detection of virus-specific oligoclonal IgGs by an antigen-mediate d capillary blot technique. Twenty-seven paired serum and cerebrospina l fluid (CSF) samples were examined from 15 immunocompetent patients w ith herpes simplex virus encephalitis (HSE) diagnosed by PCR on early CSF samples. These techniques were also applied to paired samples from 20 multiple sclerosis (MS) patients, 10 patients with other inflammat ory neurological diseases and 10 patients with non inflammatory neurol ogical disorders. There was a good correlation between the results obt ained by Al and those obtained by immunoblotting, especially in HSE (2 discordant results out of 27). Discrepancies were more frequent (25%) in MS patients where a ''polyspecific'' reaction characterized by low affinity antibodies is known to occur. Some of the discrepancies coul d, in part, be due to serological cross-reaction with varicella tester virus. (C) 1997 Wiley-Liss, Inc.