Recombinant multiepitope proteins for hepatitis C virus diagnosis: Systematic review

Hepatitis C virus (HCV) infection remains as major global health concern given the more than 50 million chronic cases recorded and the significant barriers to its early diagnosis, mainly in low-resource settings. Conventional serological assays rely on recombinant or synthetic antigens accounting for higher production costs and for limiting diagnostic accessibility. Recombinant multiepitope proteins have emerged as promising alternative for incorporating conserved antigenic regions from multiple HCV proteins, such as Core, NS3, NS4 and NS5, into a single construct capable of broadly detecting anti-HCV antibodies across different genotypes. The aim of this systematic review is to assess studies that have designed, expressed, purified and validated multiepitope constructs for HCV serodiagnosis. A search was made in PubMed, Scopus, LILACS and ISI Web of Science databases and it led to ten eligible articles. Most proteins were expressed in Escherichia coli by using pET-based vectors; they were first purified through affinity or ion-exchange chromatography. Diagnostic assessments employed ELISA, immunoblot, dot blot and rapid lateral-flow platforms, and used human serum or plasma samples provided by different geographical regions. Multiepitope antigens recorded high diagnostic performance across studies: sensitivity ranged from 91% to 100% and specificity ranged from 95% to 100%. These numbers are often comparable to, or surpass, commercial assays. The strategic conserved epitopes and rational design approach selection, including computational epitope prediction and flexible linker insertion, were key elements to improve antigenicity and assay robustness. Despite the promising results, further multicenter validation and standardized production workflows are still needed. Overall, recombinant multiepitope proteins represented an efficient, low-cost and scalable diagnostic strategy assumingly enhancing global HCV detection efforts and supporting progress toward WHO's 2030 elimination goals.