Evaluation of the Epitogen Lyme Detect IgG ELISA: a novel peptide multiplexing approach

Lyme Borreliosis (LB), or Lyme disease, is a growing health concern caused by <i>Borrelia burgdorferi sensu lato</i> (Bbsl) bacteria transmitted through tick bites, and untreated cases can lead to severe health complications. Existing serology tests, while valuable, have low sensitivity in early infection stages where diagnosis is vital, interpretation variability, and false positives from cross-reactivity, while direct detection methods also suffer from low sensitivity, due to the inconsistent presence of Bbsl components in clinical samples. This study validated the diagnostic performance of the novel Epitogen Lyme Detect IgG enzyme-linked immunosorbent assay (ELISA) based on scaffold-displayed peptide antigens, using 120 specific immunodominant epitopes selected from 37 antigenic bacterial proteins corresponding to the main pathogenic Bbsl genospecies. Using 220 serum samples from Scottish patients with early, late, and disseminated LB, the assay's sensitivity was compared with that of the LIAISON Borrelia IgG CLIA, while specificity was assessed with 198 control samples, including healthy individuals and patients with diseases that are humorally similar. The Epitogen Lyme Detect IgG assay demonstrated comparable performance to the LIAISON Borrelia IgG in disseminated and late LB (Lyme neuroborreliosis, acrodermatitis chronica atrophicans, and Lyme arthritis). Notably, the Epitogen Lyme Detect IgG showed significantly higher sensitivity in patients with suspected erythema migrans, while maintaining high specificity. The Epitogen Lyme Detect IgG ELISA offers a promising advancement in LB diagnostics, demonstrating its potential for more accurate and timely diagnosis, particularly in the early stages of LB infection.IMPORTANCELyme Borreliosis (LB), caused by <i>Borrelia burgdorferi sensu lato</i> bacteria, poses significant health risks if undiagnosed or diagnosed late. Current diagnostic tests have limitations, especially in early-stage detection. This study validates the Epitogen Lyme Detect IgG enzyme-linked immunosorbent assay, demonstrating superior sensitivity in early LB detection while maintaining high specificity. The Epitogen Lyme Detect IgG comprises a suite of 120 immunodominant IgG epitopes/peptides from 37 bacterial antigens, covering the main LB-causing species: <i>Borrelia burgdorferi sensu stricto</i>, <i>Borrelia afzelii</i>, <i>Borrelia garinii</i>, and <i>Borrelia mayonii</i>. The novel design of multiplexing peptide antigens onto a scaffold to facilitate expression, correct folding, and orientation of the relevant peptides offers a promising advancement, potentially leading to more accurate and timely LB diagnoses and improving patient outcomes.