Serum samples from persons with
Lyme borreliosis, periodontitis, or acute necrotizing ulcerative gingivitis were analyzed by an enzyme-linked immunosorbent assay (ELISA) with and without adsorption and amplification procedures. When biotin and streptavidin reagents were used as an amplification procedure in ELISA without the use of commercially prepared sorbent (Treponema phagedenis biotype Reiter), sensitivity increased. Of the 85 serum samples collected from persons with erythema migrans but no detectable antibodies to Borrelia burgdorferi by standard ELISA, 17 (20%) were reactive after amplification. Adsorption of serum samples with a 1:10 dilution of T. phagedenis biotype Reiter sorbent used in conjunction with amplified ELISA also improved the sensitivity of this method. However, cross-reactivity could not be completely eliminated. An adsorbed-amplified ELISA may be helpful in the diagnosis of
Lyme borreliosis in the laboratory, particularly during early weeks of infection, when antibodies to B. burgdorferi can be present at a low concentration.