WESTERN-BLOT AS A TOOL IN THE DIAGNOSIS OF LYME BORRELIOSIS

Borrelia burgdorferi is the causative agent of Lyme borreliosis, a mul tisystem disorder, which can mimic numerous immune disorders and infla mmatory diseases. Laboratory diagnosis of Borrelia infection relies on immunodiagnostic assays, which, however, are hampered by unsatisfacto ry specificity. The Westem blot technique.has been employed to analyze the humoral immune response in Lyme borreliosis and is used as a sero diagnostic confirmation test. The most important immunodominant protei ns of Borrelia burgdorferi are the 94 kDa, 60 kDa, 41 kDa (flagellin), 34 kDa (Osp B), 31 kDa (Osp A), 30 kDa, 21 kDa (Osp C), and 17/18 kDa proteins. Whereas the 60 kDa, 41 kDa, and 34 kDa constituents reveal a marked cross-antigenicity with other spirochetes and even more dista ntly related bacteria, antibodies against the 94 kDa, 31 kDa and 21 kD a proteins are largely species-specific. The early immune response in Lyme borreliosis is triggered mainly by the flagellin. In the later st age a wide range of immunogenic proteins is involved, with the 94 kDa antigen being the best marker for late immune response. If the Westem blot is used for diagnostic purposes the differences between early and late-stage immunogenicity of Borrelia proteins must be taken into acc ount. Interpretation criteria for blot positivity in early-stage borre liosis are primarily based on the presence of the 21 kDa band and the semiquantitatively recorded intensity of the 41 kDa band. In the diagn osis of late-stage infection, blot positivity relies on the presence o f the 94 kDa, 39 kDa, 31 kDa, 30 kDa and 21 kDa bands.