Aim: This study aimed to evaluate the performance characteristics of preliminary coagulation tests on the Sysmex CS-5100 coagulation autoanalyzer and compare it with the ACL Top 700 autoanalyzer. Both analyzers were assessed for their ability to measure prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, and D-dimer levels, using optical clot detection and immunological techniques.

Materials and Methods: Blood samples were analyzed on both platforms, and key performance metrics such as within-day and between-day imprecision, bias, and total error were evaluated following CLSI guidelines. Method comparison was conducted using Bland-Altman plots, Passing-Bablok regression, and correlation analyses.

Results: Our results demonstrated that both analyzers provided precise and reliable results for most parameters. However, significant differences were observed in D-dimer measurements, where the Sysmex CS-5100 consistently reported lower values compared to the ACL Top 700, particularly at higher concentrations. Despite these differences, no diagnostic discrepancies were found among patient samples, and strong correlations were observed for all other parameters.

Conclusion: The findings suggest that the Sysmex CS-5100 is a reliable alternative to the ACL Top 700, although further standardization, particularly for D-dimer measurements, may be needed to ensure consistency across platforms.