Abstract
BACKGROUND: Existing erythrocyte osmotic fragility test (EFT) methods are constrained by subjectivity, poor reproducibility, and lack of standardization, limiting their clinical utility in thalassemia screening. This study evaluates the RA-800 Plus, a novel fully automated EFT analyzer, as a scalable tool for thalassemia screening and aims to establish reference intervals for healthy individuals. By addressing the key limitations of manual EFTs, this work seeks to promote methodological innovation and enable standardized, high-throughput screening in diverse clinical settings. METHODS: EFTs were performed on 273 healthy adults via an RA-800 Plus analyzer. The light scattering turbidity method was employed to establish a reference interval within the normal range. The neonatal samples were tested in the same way to determine the newborn-specific range. Moreover, 97 samples underwent dual tests of RA-800 Plus analysis and the gold standard (genetic testing) to evaluate the diagnostic performance. A total of 103 pairs of samples were detected and compared via an automated system and the traditional manual direct colorimetric method, further verifying the consistency of the two methods. The effects of anticoagulant type, sample storage, and rewarming were also investigated. RESULTS: RA-800 Plus demonstrated high reliability, with minimal influence from anticoagulants and sample handling conditions. The analyzer showed an 84 % detection rate for β-thalassemia, indicating superior effectiveness for β-thalassemia screening. The test results were consistent with the manual method (Kappa ≥0.6). ROC curve analysis confirmed the suitability of both methods for thalassemia screening, with AUCs of 0.91 for β-thalassemia and 0.72 for α-thalassemia. CONCLUSIONS: The RA-800 Plus offers a fully automated, reliable, and clinically viable alternative for thalassemia screening, particularly for β-thalassemia. Its stability, accuracy, and ease of use make it a valuable tool for improving thalassemia diagnostics.