Clinical evaluation of guidelines and two-test approach for Lyme disease

Objective. The diagnosis of Lyme disease should be based on objective clini cal signs and symptoms. In a clinical study, we have evaluated whether the recommended two-step approach for serodiagnosis of Lyme disease is useful i n daily clinical practice and can influence clinical decision making. Methods. The signs and symptoms of patients with ongoing musculoskeletal co mplaints, assumed by their referring physician or themselves to be attribut able to active or chronic Lyme disease, and of patients diagnosed as having Lyme disease, were evaluated. On the basis of clinical evaluation only, pa tients were classified into three groups: previous Lyme disease, active Lym e disease and no Lyme disease. Antibodies to Borrelia burgdorferi were dete rmined by means of an enzyme-linked immunosorbent assay (ELISA), followed, when positive, by immunoblotting. Results. One hundred and three patients (41 males and 62 females, mean age 48.7 yr) participated in the study. Of the 49 patients classified as previo us Lyme disease, 25 (51%) had antibodies to B. burgdorferi. All 10 patients with active Lyme disease had positive antibodies and 12 of the 44 patients (27%) classified as no Lyme disease had positive antibodies. No statistica lly significant differences were found between the percentage of positive i mmunoblots from patients with previous Lyme disease (72%) and patients with active Lyme disease (100%). In the group of no Lyme disease, five out of 1 2 patients had a negative immunoblot. Concerning serological testing, immun oblotting could have added additional information. However, immunoblotting did not influence clinical decision making in this group of patients. Conclusion. Immunoblotting did not influence clinical decision making for t he 47 patients with antibodies to B. burgdorferi in this study.