Enzyme-linked immunosorbent assays were developed to detect immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies to Borrelia burgdorferi, the etiologic agent of Lyme disease. Of the 135 blood samples obtained during 1985-1986 from persons in Connecticut with erythema migrans or other clinical manifestations of this spirochetosis, 106 (79%) contained IgM antibody. In separate tests for IgG antibody, 106 (83%) of 128 specimens were considered positive. To assess the specificity of these assays, the authors analyzed sera from patients with other spirochetal infections or nonrelated diseases. Heterologous IgM antibody was detected in 32 (42%) of 77 samples, while cross-reactivity occurred in 17 (25%) of 69 sera screened for IgG antibody. Geometric mean titers for homologous reactions were usually twofold or more higher than those of heterologous reactions. Information on IgG antibody is particularly useful for serodiagnosis, but because of the cross-reactivity among Borrelia and Treponema, clinical data and the use of other serologic tests may be needed to separate Lyme disease from other spirochetal infections.
American Journal of Epidemiology
Am J Epidemiol. 1988 Apr;127(4):818-25