Leveraging Homomultivalent Epitope Presentation for Enhanced Diagnostic Accuracy

Presented on the 27th University of the Philippines College of Medicine Student Research Forum on 3 March 2026.Abstract:There is a critical need for synthetic peptide-based serologic assays that exploit avidity to replace whole antigens, providing low-cost diagnostics for resource-limited settings. This study evaluates the diagnostic accuracy of a polymeric peptide-based ELISA (S559).Methodology:The study utilized IEDB retrieval and SPPS LC-MS for peptide synthesis, followed by a polymerization process. The assay was validated using 1,222 clinical cases and 218 controls.Key Findings:The polymerized form of S559 showed a 2.18-fold avidity gain compared to the depolymerized form Kdapp of 29.26 nM-1 vs. 63.76 nM-1.Using a post hoc threshold (Youden J), the assay achieved a sensitivity of 95.01% and a specificity of 100.00%.The Area Under the Receiver Operating Characteristic (AUROC) curve was 96.59%.Conclusion:Homomultivalent epitope presentation using polymeric S559 allows for a highly specific immunoassay suitable for diagnosing infection, confirming vaccination status, and conducting population surveillance. Funding: Department of Science and Technology - Philippine Council for Health Research and Development (DOST-PCHRD).Affiliations: University of the Philippines Manila; National Institutes of Health, Manila.Patent Info: Application filed c/o UPM-TTBDO, 23 December 2025.Journal Status: Submitted to Current Protein & Peptide Science.