Evaluation of two line immunoassays for the detection of Borrelia antibodies
Abstract number: R2287
Verstreken I., Appeltans T., Verhaegen J., Lagrou K.
Objectives: Lyme borreliosis is a multisystemic disease with diverse clinical manifestations transmitted to humans by ticks. Clinical diagnosis is difficult. In routine practice a two step test strategy is recommended for the diagnosis of the disease. Several confirmation tests are available. We evaluated the performance characteristics of two different line immunoassays.
Methods: 62 sera submitted to the Laboratory Medicine unit of the University Hospitals Leuven were analyzed for the presence of Borrelia IgM and IgG antibodies with two line immunoassays: recomLine Borrelia (Mikrogen) and Borrelia Europe LINE (VIROTECH) and with an immunoblot assay recomBlot Borrelia (Mikrogen) as reference method. All tests were performed on the auto LIA II instrument (Innogenetics). Sensitivity was evaluated on 33 preselected sera from patients with Lyme borreliosis based on clinical symptoms and the presence of Borrelia IgM and/or IgG with recomBlot Borrelia assay (8 erythema migrans, 10 arthritis, 15 neuroborreliosis). Specificity was evaluated on 29 sera (10 Epstein Barr virus IgM positive sera, 9 rheumatoid factor positive sera and 10 sera positive for rapid plasma reagin antibodies).
Results: Specificity of both IgM line assays was 89.7%. 2/29 false positive IgM results were from patients with a primary EBV infection. Cross reaction due to EBV infection can be detected by the Europe LINE assay due to the presence of the EBV-VCA gp125 antigen on the strip. One IgG positive result was obtained with both line assays. This was probably due to a previous Borrelia infection in a rheumatoid factor positive patient. Sensitivity for both line assays was 97% if we combine IgM and IgG test results. IgG were present in 7/8 (87.5%) of erythema migrans sera with both line assay compared to 1/8 (12.5%) sera that was IgG positive with the recomBlot assay.
Conclusion: The performance characteristics of the two Borrelia antibody confirmation line immunoassays, recomLine Borrelia and Borrelia Europe LINE, were very good and similar in this evaluation. From early stage sera it seems that the sensitivity of both IgG line assays is higher compared to the Mikrogen IgG recomBlot assay.
|Session name:||19th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Helsinki, Finland, 16 - 19 May 2009|
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