EVOLUTION OF THE SEROLOGIC RESPONSE TO BORRELIA-BURGDORFERI IN TREATED PATIENTS WITH CULTURE-CONFIRMED ERYTHEMA MIGRANS

We investigated the appearance and evolution of immunoglobulin M (IgM) and IgG antibodies to Borrelia burgdorferi in 46 patients with cultur e-proven erythema migrans (EM), All patients received antimicrobial tr eatment and were prospectively evaluated for up to 1 year. A total of 257 serially collected serum samples were tested by commercial IgG-IgM enzyme-linked immunosorbent assay and separate IgM and IgG immunoblot s (IBs), At the baseline, 33% of the patients had a positive ELISA res ult and 43% of the patients had a positive IgM IB result by using the criteria of the Centers for Disease Control and Prevention-Association of State and Territorial Public Health Laboratory Directors for the i nterpretation of IB results. Positive serology at the baseline and the rate of seroconversion correlated directly with disease duration and/ or evidence of dissemination prior to treatment, At days 8 to 14 after the baseline, 91% of patients had a positive ELISA result and/or IgM IB result. Peak IgM antibody levels were seen at this time in patients with localized or disseminated disease, The most frequent IgM bands a t the baseline and the peak were of 24 kDa (OspC), 41 kDa, and 37 kDa. Although 89% of the patients developed IgG antibodies as determined a t a follow-up examination, only 22% were positive by the IgG IB criter ia of the Centers for Disease Control and Prevention-Association of St ate and Territorial Public Health Laboratory Directors, The persistenc e of antibodies was directly related to disease duration and/or dissem ination prior to treatment. Since IgM antibodies to the 24- and 41-kDa antigens remained detectable for long periods, 38% of IgM IBs were st ill positive at 1 year postbaseline. IgM to antigens of 39, 58, 60, 66 , or 93 kDa, conversely, were most often seen in sera obtained within 1 month postbaseline. Their presence may be of assistance in confirmin g a recent infection with B. burgdorferi in individuals living in area s where Lyme disease is endemic.