Quantification of the synthesis of antibodies against Borrelia burgdorferi-specific antigens within the central nervous system by chemiluminescent and enzyme immunoassay
Abstract number: P2142
Lange P., Spreer A., Nau R.
Objectives: Diagnosis of central nervous system (CNS) involvement of infections by Borrelia burgdorferi sensu lato may be difficult when the clinical syndrome is atypical or when the interval between infection and cerebrospinal fluid (CSF) analysis is long. Diagnostic analysis of the CSF is complicated by antigenetic heterogeneity of Borrelia burgdorferi strains and differences in antigen compositions of diagnostic tests. This study compared the ability of chemiluminescent (CLIA) and enzyme immunoassay (EIA) to detect antibody synthesis directed against Borrelia burgdorferi sensu lato within the CNS.
Methods: Antibodies against Borrelia burgdorferi in CSF and serum pairs from 90 patients were quantified by CLIA (LIAISON BORRELIA, Diasorin, Saluggia, Italy) or by EIA (in-house method using ENZYGNOST Lyme Link VlsE plates, Dade Behring, Schwalbach, Germany). The Borrelia-specific IgG and IgM antibody index (AIIgG, AIIgM) was calculated: (Borrelia-specific Ig in CSF/Borrelia-specific Ig in serum)/(total Ig in CSF//total Ig in serum).
Results: In 47 cases, an elevated AI either for IgG or IgM or both suggesting Borrelia-specific antibody synthesis within the CNS was detected both by CLIA and EIA. The absolute AI values, however, showed considerable deviation among both methods. In 39 cases, AIIgG and AIIgM were normal or the Borrelia-specific CSF antibody concentration of IgG, IgM or both was below the quantification limit. In 3 cases, EIA detected IgG or IgM synthesis in CSF, whereas the AIs determined by CLIA were normal. In one case, AIIgM determined by CLIA was elevated, but below the detection limit when measured by EIA.
When Borrelia-specific IgG and IgM were analysed separately, the rate of incongruent results between the two methods was higher. In 29 cases, AIIgG was normal as determined by EIA, but not measurable by IML. In 5 cases with normal AIIgG determined by EIA, CLIA yielded implausibly low AIIgG (<0.5). In 11 cases, AIIgM was not detectable by EIA, but elevated when measured by CLIA.
Conclusion: CLIA was more sensitive than EIA in detecting Borrelia-specific IgM synthesis. EIA was more sensitive to detect Borrelia-specific IgG in CSF of patients with an elevated or normal AIIgG.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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