Use of Western Blot and Enzyme-Linked Immunosorbent Assays to Assist in the Diagnosis of Lyme Disease

Abstract

Without evidence of erythema chronicum migrans, diagnostic confirmation of Lyme disease may be difficult, particularly if there are conflicting laboratory results. Often, for families and physicians, the clinical dilemma is whether fatigue, arthritis/arthralgias, a positive enzyme-linked immunosorbent assay (ELISA), and tick exposure, but no evidence of erythema chronicum migrans, are sufficient to diagnose and treat Lyme disease. Patients with discordant ELISA and Western blot (WB) assay results for Borrelia burgdorferi were studied to determine whether there was sufficient clinical evidence to support a diagnosis of Lyme disease. Of 650 consecutive sera analyzed by ELISA in a laboratory within a 1-year period, 77 were subsequently tested by WB. The clinical data from these patients were then analyzed. The study population was divided into three groups: group 1 (positive ELISA, positive WB), group 2 (positive ELISA, negative WB), and group 3 (negative ELISA, negative WB). Findings included the following: (1) Patients with a strong clinical history of Lyme disease were usually positive by both WB and ELISA (group 1). (2) All patients with erythema chronicum migrans had both positive WB and ELISA tests. (3) Ninety-one percent of group 2 had a rheumatic or inflammatory condition other than Lyme disease. (4) A definite response to antibiotics occurred in 75% of patients wherein both ELISA and WB were positive but in only 11% of cases with a positive ELISA but a negative WB. (5) History of tick exposure and degree of fever were not significantly different among the three serologic groups, and thus they were not diagnostically helpful.(ABSTRACT TRUNCATED AT 250 WORDS)