Comparative evaluation between Geenius™ dual-path migration immunochromatography platform and Western blot HIV-1 for confirmatory assays in the Brazilian population

Abstract

Human immunodeficiency virus (HIV) diagnosis requires both screening and confirmatory assays to accurately differentiate antigen and antibody reactivity. The Western blot (WB) method has long been considered the gold standard for confirming HIV infection. However, due to its labor-intensive workflow and technical complexity, the WB has become challenging for many clinical laboratories. Therefore, newer diagnostic techniques, such as the Dual-Path Platform (DPP) lateral flow immunochromatography assays, have been developed and approved by regulatory agencies. Automated interpretation of DPP enhances analytical sensitivity by minimizing subjectivity and allowing detection of faint bands, reducing the probability of false-negative results. This study compared the performance of the WB and DPP as confirmatory methods following chemiluminescent immunoassay (CLIA) screening. All samples were previously screened using CLIA and subsequently analyzed by both WB and DPP assays. Samples yielding borderline CLIA results underwent additional testing by RT-qPCR. The DPP platform demonstrated high concordance with the WB assay, achieving an agreement rate of 97.2 % and a kappa index of 93.9 %, indicating excellent predictive performance. Borderline results were confirmed as reactive by both DPP and RT-qPCR but remained indeterminate by WB. Although complete agreement between both confirmatory methods was not achieved, no clinically significant discrepancies were observed, suggesting that such variations did not impact patient outcomes. Despite the WB remaining as a reference confirmatory method for HIV diagnosis, the DPP method offers substantial advantages, including shorter turnaround time, greater operational simplicity, and automated digital documentation, making it a practical alternative for routine use in high-throughput or resource-limited laboratory settings.