Evaluation of a New Multiparametric Microspot Array for Serodiagnosis of Lyme Borreliosis.

BACKGROUND Laboratory diagnosis of Lyme borreliosis follows a two-step algorithm, starting with a screening assay with maximum sensitivity followed by a confirmatory assay of positive results with respect to specificity. Line immunoassays with single recombinant antigen lines are the established confirmatory test method, although result interpretation is not standardized. The present study evaluates suitability of the multiplex test SeraSpot Anti-Borrelia IgG/IgM (SeraSpot) as confirmatory test in serodiagnosis of Lyme disease. METHODS For this retrospective study, serum samples from patients with suspicion of Lyme borreliosis were analyzed. For determination of specificity, blood donor samples as well as rheumatoid factor (RF), ANA, and EBV positive sera were investigated. The SeraSpot IgG/IgM results were compared with the recomBead Borrelia IgG/IgM (recomBead) test as alternative multiplex-based method. RESULTS In comparison to the recomBead test the sensitivity of SeraSpot was determined 95% for IgG/IgM detection. The analysis of blood donors revealed a specificity of ≥ 96.0% for SeraSpot IgG/IgM and of 97.3% for recomBead IgG/IgM. RF positive samples tested negative by both assays (specificity of 100%). ANA and EBV antibody positive samples resulted in specificities of 90% (SeraSpo IgG/IgM) and ≥ 94% (recomBead IgG/IgM) and ≥ 91% (SeraSpot IgG/IgM) and ≥ 91% (recomBead IgG/IgM). The intra- and interassay coefficient of variation (CV) and the lot-to-lot reproducibility of the SeraSpot assay ranged between 1 - 9% for the different Borrelia IgG and IgM antigens. Potentially interfering substances (bilirubin F, bilirubin C, hemoglobin, lipid factor, and rheumatoid factor) did not influence the SeraSpot assays. CONCLUSIONS Our evaluation data confirm that new multiplex assay generations such as SeraSpot Anti-Borrelia IgG/IgM are reliable and robust test systems suitable for application as confirmatory tests for serodiagnosis of Lyme borreliosis.