Simplified method for the interpretation of immunoblots for Lyme borreliosis.

Interpretation of immunoblot results for Lyme borreliosis remains an area of controversy. This study was undertaken to devise a simple method which incorporated distinctions between specific and non-specific bands. A numerical value was assigned to bands reflecting their relative importance. This scheme was evaluated with sera from 61 forestry workers, which were previously tested by immunoblotting and interpreted subjectively. These results were reported as five separate categories representing levels of reactivity. A total of 72% (44) of sera fell into the same categories as they were originally reported. The method was also assessed with 40 sera routinely submitted for Lyme borreliosis serology. These were interpreted by two members of staff without previous experience of immunoblotting. Their results gave 80% and 72.5% agreement with those of an experienced person used to reading immunoblots for Lyme borreliosis.