Comparison of SYSMEX CN-6000 and STAGO STA-R: Effects of hemolysis and lipemia.

Background: Routine coagulation testing is critical in diagnosing hemostatic disorders and monitoring anticoagulant therapy. The SYSMEX CN-6000 and STAGO STA-R analyzers utilise different clot detection methods, which may impact test results. This study evaluates the analytical performance of these two automated coagulation analysers and examines the effects of hemolysis and lipemia on routine coagulation tests.

Methods: Blood samples were collected from patients at Gaziantep University Şahinbey Research and Application Hospital and analysed for activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen (FBG), and D-dimer using both analysers. Precision, method comparison, and interference studies were conducted following CLSI guidelines. Hemolysis and lipemia were induced in vitro, and their effects on test results were evaluated based on Fraser's criteria.

Results: All precision study CV values were within the acceptable limits of biological variation. APTT results exhibited a significant systematic difference between analysers (r= 0.872), whereas PT (INR), FBG, and D-dimer showed strong correlations (r> 0.945). Hemolysis had a minimal impact at lower concentrations (<1 g/L). However, at 4 g/L, PT bias increased to 2.8% for the CN-6000 and 2.0% for the STA-R, with similar increases observed in APTT and FBG. Lipemia significantly affected CN-6000, which failed to produce PT results at triglyceride levels 14 mmol/L and APTT/FBG results at 28 mmol/L. In contrast, STA-R provided results with biases below 7.3% at all lipemia levels.

Conclusions: Both analysers demonstrated strong analytical performance, though methodological differences influenced APTT measurements. Hemolysis had a minor impact within Fraser's acceptable bias limits, whereas CN-6000 exhibited performance limitations in severely lipemic samples, necessitating preanalytical lipid-reducing strategies. These findings underscore the need for expanded reference range studies and optimised laboratory workflows to enhance coagulation testing reliability.