Erythema migrans and serodiagnosis by enzyme immunoassay and immunoblot with three borrelia species

There is wide divergence of opinion between physicians regarding the use of serological measures for the diagnosis and treatment of erythema migrans, the hallmark of Lyme borreliosis. We studied the outcome of an enzyme immun oassay and immunoblot (Western blot) used on the sera of patients who had s uffered tick bite and erythema migrans, and had been subsequently treated w ith various antibiotics. Ninety-nine consecutive patients presenting with erythema migrans after tic k bite were prospectively recruited at the outpatient department of two Vie nna City hospitals and at the consultation office for Lyme borreliosis of t he Institute of Hygiene, University Vienna. Blood samples were taken before antibiotic treatment and 3 and 6 months thereafter. Blood samples from 100 blood donors served as controls. Antibodies against Borrelia burgdorferi s ensu late were determined by enzyme immunoassay (IgG and IgM EIA) and by Ig G immunoblot. The latter was performed with isolates of B. afzelii (H2), B. burgdorferi sensu stricto (Le) and B. garinii (W) from Austrian patients. The 4 interpretation criteria for immunoblot results were: A (3 bands out o f 8), B (2 bands out of 9), C and D (1 band out of 6). In all patients, the erythema resolved within the treatment period. No comp lications secondary to the borrelia infection were registered. After treatm ent there was no significant change in titre, nor was there a difference in the immunoblot pattern between the first, second and third serum samples. Serum antibodies to B. burgdorferi were positive by EIA in 22.9% (IgG) and 2.5% (IgM). Immunoblot results differed by borrelia species and by the inte rpretation criteria, ranging between 8.3% (criterion A, strain Le) and 44.2 % (criterion D, strain H2). By EIA, control samples were IgG and IgM positi ve in 5% and 1%, respectively. Positive immunoblot results with strain H2 w ere found in 9%, 13%, 18%,and 20% by the criteria A through D, respectively . After antibiotic treatment of erythema migrans the immunological response a ppears to be abrogated. Thus, serological results are not supportive for th e diagnosis of erythema migrans, nor will they retrospectively prove succes sful antibiotic treatment of borrelia infection.