Abstract
The rate of seroconversion before treatment and antibody kinetics after treatment were analyzed and possible interpretations of serologic findings was proposed. Serum samples from 219 patients with Erythema migrans were tested by ELISA for antibodies against B. burgdorferi. Twenty-eight (28 %) to 55 % of the patients showed isolated IgM antibody response, 3–5 % showed isolated IgG response, 6–16 % showed concomitant IgM and IgG responses, and 24–63 % tested seronegative depending on number of days passed after the onset of Lyme borreliosis. One year after treatment, 38 % of the patients still had IgG response and 10% had IgM antibodies against B. burgdorferi. Furthermore, 4 of 106 seronegative patients revealed IgM response three months after treatment despite lack of signs or symptoms of active Lyme borreliosis. We concluded that persistence of antibody response is not indicative of treatment failure, although regular clinical and laboratory examinations, including PCR, should follow successful treatment.