WESTERN-BLOT BAND INTENSITY ANALYSIS - APPLICATION TO THE DIAGNOSIS OF LYME ARTHRITIS

Objective. To determine the usefulness of quantitative band-intensity analysis of Western blots for the diagnosis of Lyme arthritis. Methods . IgG Western blots for antibodies to Borrelia burgdorferi were perfor med on sera from 39 patients with Lyme arthritis, 30 patients with syp hilis, 50 patients with connective tissue diseases, and 10 healthy ind ividuals. Band positions and band intensities were calculated using a computerized image analysis system. Results. Lyme arthritis patients h ad more bands and higher-intensity bands than did non-lyme patients. T he presence of at least 2 bands of moderate to high intensity (>40 opt ical units) or at least 5 bands of lower intensity (>20 optical units) was over 90% sensitive and 100% specific for the diagnosis of Lyme ar thritis. A 60-kd band was present in all Lyme arthritis patients. The presence of an 83-, 39-, 21-, or 18-kd band was highly specific for Ly me arthritis. Conclusion. Band intensity analysis increases the object ivity and accuracy of Western blot interpretation for the diagnosis of Lyme arthritis.