Comparative evaluation of adsorption with E. coli on ELISA tests for Lyme borreliosis

Objective. To evaluate prospectively in a clinical setting the use of a soluble fraction of E. coli to adsorb nonspecific antibodies which can cause false positive ELISA tests for Lyme borreliosis. Methods. The patient population tested was obtained from individuals referred to or initially presenting at a pediatric Lyme disease clinic in Wilmington, DE. Patients were followed for a minimum of 6 months subsequent to primary presentation at the clinic. Results. A total of 209 met criteria for study inclusion, 93 of whom were diagnosed as having Lyme borreliosis and 116 of whom had other diagnoses. Results of ELISA tests were compared with different diagnoses and, when available, ELISA results from commercial laboratories. Findings indicate that some commercial laboratories have excessively high rates of false positive results (> 90% of positives were found to be false positives). Conclusion. Adsorption with E. coli antigens effectively removed antibodies causing false positive results including those occurring at commercial laboratories and did not cause any significant reduction in assay sensitivity.