Linear Peptide Epitopes Derived from ErpP, p35, and FlaB in the Serodiagnosis of Lyme Disease.

Lyme disease is the most common vector-borne disease in the northern hemisphere. Current serodiagnostics are insensitive in early infection. Sensitivity in these seroassays is compromised by the necessity to preserve specificity in the presence of cross-reactive epitopes in target antigens. We evaluated the efficacy of using synthetic peptides containing epitopes unique to as antigen targets in a Lyme disease seroassay. We performed linear B cell epitope mapping of the proteins p35 (BBH32) and ErpP to identify unique epitopes. We generated peptides containing these newly identified linear epitope sequences along with previously identified epitopes from the antigens FlaB and VlsE and evaluated their diagnostic capabilities via ELISA using large serum sets. Single-epitope peptides, while specific, demonstrated insufficient sensitivity. However, when epitopes from FlaB, ErpP, or p35 were combined in tandem with an epitope from VlsE, the sensitivity of the assay was significantly increased without compromising specificity. The identification of additional unique epitopes from other antigens and the further development of a combined multi-peptide-based assay for the laboratory diagnosis of Lyme disease offers a way to address the poor specificity associated with the use of whole protein antigen targets and thus significantly improve the laboratory diagnosis of Lyme disease.