Development and Characterization of Dual-Platform Lyophilized Plasma-Based Quality Control Materials for Hepatitis C Virus Antibody Testing.

Background/Objectives: Reliable quality control (QC) materials are essential for maintaining the analytical performance of hepatitis C virus (HCV) screening assays. Rapid diagnostic tests (RDTs) are widely used for point-of-care HCV screening; however, standardized plasma-based internal quality control (IQC) materials compatible with both rapid tests and automated immunoassays remain limited. This study aimed to develop and evaluate plasma-based QC materials applicable to multiple anti-HCV RDTs and automated immunoassays. Methods: QC materials were prepared from pooled HCV-positive plasma at strong-positive, weak-positive, and negative levels in liquid and lyophilized formats. Lyophilized preparations were produced with and without trehalose, while liquid samples were prepared with and without a stabilizer. Performance was evaluated using five anti-HCV RDT kits and the Elecsys Anti-HCV II automated immunoassay platform. Stability was assessed under accelerated temperature conditions (45 °C for 28 days) and long-term storage (2-8 °C and 20-30 °C for six months). Signal trends were analyzed using linear regression (p > 0.05), and homogeneity was evaluated using one-way analysis of variance and Cochran's C test. Results: All QC formulations demonstrated consistent qualitative reactivity across the evaluated RDT kits and stable responses on the automated immunoassay platform. Lyophilized plasma containing trehalose maintained stable cut-off index (COI) values during accelerated and long-term storage, with no significant time-dependent trends (p > 0.05). Conclusions: Trehalose-stabilized lyophilized materials demonstrated enhanced stability and acceptable homogeneity, supporting practical applicability under the tested storage conditions across the evaluated rapid tests, and within the evaluated moderate-to-high positive analytical ranges on the automated anti-HCV immunoassay platform.