Avidity determination of Borrelia burgdorferi-specific IgG antibodies in Lyme disease

The avidity indices of Borrelia burgdorferi-specific IgG antibodies were es timated using ELISA in sera from patients with different stages of Lyme dis ease. In addition, sera from healthy students with proof of borrelial-speci fic IgG antibodies from standard serology were tested. Low avidity indices were detected predominantly in sera from patients with early-stage Lyme dis ease [erythema migrans (EM); n = 25]. High avidity indices were found in he althy students (n=72) and in most of the patients with neuroborrellosis (NB ; n=44) and chronic late-stage Lyme disease [acrodermatitis chronica atroph icans (ACA); n = 36]. In conclusion, early-stage Lyme disease (EM) could be differentiated from advanced and chronic stages (NB, ACA) and from "seropo sitive" healthy persons using avidity determination in the majority of pati ents in this study.