COMPARISON OF IMMUNODOT AND WESTERN-BLOT ASSAYS FOR DIAGNOSING LYME BORRELIOSIS

Two commercially available serologic tests for use in diagnosing Lyme borreliosis were evaluated by using a test panel comprised of sera fro m patients diagnosed with Lyme borreliosis, non-lyme disease controls, and healthy subjects. The test methods examined were a Western blot a ssay and an immunodot assay. The study was initiated to determine how the immunodot assay, which contains purified and recombinant proteins to those borrelial antigens recommended for immunoglobulin M (IgM) det ection in the Dearborn criteria, would compare with the Western blot a ssay as a confirmatory method for serologic diagnosis of Lyme borrelio sis. Results obtained showed that the two test methods performed compa rably for detecting IgG antibodies. For IgM antibody detection, the im munodot and Western blot assays had similar sensitivities; however, th e immunodot assay was more specific and had greater positive predictiv e value than the Western blot assay. The results obtained indicate tha t the immunodot assay performs as well as or better than the Western b lot assay for diagnosing Lyme borreliosis. Furthermore, because it use s a limited panel (n = 5) of antigens, the immunodot is easier to read and interpret than standard Western blots.