High frequency of false positive IgM immunoblots for Borrelia burgdorferi in Clinical Practice.
ABSTRACT Clin Microbiol Infect ABSTRACT: Although it is known that two-tier serologic testing for Lyme disease may be associated with false positive results on the IgM immunoblot, this problem has never been systematically studied in the clinical practice setting. In a retrospective investigation of patients referred to the private adult practice of an Infectious Diseases physician for possible for Lyme disease, 50 of 182 patients (27.5%, 95% CI: 21.1-34.6) were found to have a false positive IgM immunoblot. 78.0% of these patients had received unnecessary antibiotic therapy. False positive results were not restricted to any single commercial laboratory. Research on alternative testing strategies that eliminate the IgM immunoblot entirely is warranted.
- SourceAvailable from: Diana Roen09/2013;
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ABSTRACT: Current serodiagnostic assays for Lyme disease are inadequate at detecting early infection due to poor sensitivity and non-specificity that arise from the use of whole bacteria or bacterial proteins as assay targets; both targets contain epitopes that are cross-reactive with epitopes found in antigens of other bacteria species. Tests utilizing peptides that containing individual epitopes highly-specific for Borrelia burgdorferi as diagnostic targets are an attractive alternative to current assays. Using an overlapping peptide library, we mapped linear epitopes in OspC, a critical virulence factor of B. burgdorferi required for mammalian infection, and confirmed the results by ELISA. We identified a highly conserved 20-amino acid peptide epitope, OspC1. Via ELISA, OspC1 detected specific IgM and/or IgG in 60 out of 98 serum samples (62.1%) obtained from patients with erythema migrans (early Lyme disease) at the time of their initial presentation. By comparison, the commercially available OspC peptide, PepC10, detected antibody in only 48 of 98 serum samples (49.0%). In addition, OspC1 generated fewer false positive results among negative healthy and disease (rheumatoid arthritis and RPR+) control populations compared to PepC10. Both highly specific and more sensitive than currently available OspC peptides, OspC1 could have value as a component of a multi-peptide Lyme disease serological assay with significantly improved capabilities for the diagnosis of early infection.Clinical and vaccine Immunology: CVI 01/2013; · 2.60 Impact Factor
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ABSTRACT: TO THE EDITOR: We believe the recent article by Maggi et al. (1) contains serious flaws in content and underlying message, including a poorly defined study population, lack of appropriate controls, improper use of the term bacteremia, and incongruent laboratory findings. Selection criteria were vague: the authors state only that participants were a "biased" collection of "patients selected by a rheumatologist," with no control population included for comparison. The diagnosis of Lyme disease and other previously diagnosed conditions was solely by self-report. Although blood samples were collected from every participant, the authors apparently neglected to perform standardized testing for Borrelia burgdorferi or other conditions.Emerging Infectious Diseases 11/2012; 18(11):1918-9. · 6.79 Impact Factor