Diagnosis of Lyme neuroborreliosis with antibodies to recombinant proteins DbpA, BBK32, and OspC, and VlsE IR₆ peptide

Abstract.

Three recombinant antigens, decorin binding protein A (DbpA), BBK32, and outer surface protein C (OspC), and IR₆ peptide of borrelial VlsE protein, were evaluated for the diagnosis of neuroborreliosis (NB), using cerebrospinal fluid (CSF) and serum samples from 89 patients. Their performances in enzyme-linked immunosorbent assay (ELISA) were compared with that of commercial flagella antigen. IgG ELISAs were performed with three variants of each recombinant antigen originating from Borrelia burgdorferi sensu stricto, B. afzelii and B. garinii, and with the IR₆ peptide. IgM antibodies were analysed against OspC and flagella. Of the patients whose CSF contained elevated anti-flagella IgG antibodies, 93% were positive for at least three of the new antigens. Of those with negative or borderline CSF anti-flagella antibodies, 51% were positive for three new antigens. Antibodies to BBK32 were detectable mainly in early disease. Antibodies to DbpA and IR₆ were observed in early and late NB. The use of the new antigens at presentation of the disease improved the laboratory diagnosis of NB. In IgG ELISAs, the diagnostic sensitivity of assays with the new antigens was between 75 and 88%, but was only 52% with the flagella antigen. The discriminatory power between patient and control samples appeared better in the CSF than in the serum. We suggest that assessment of CSF antibodies to at least two antigens, using either flagella and one of the new antigens or two of the new antigens, would improve the current diagnostic yield of NB.