Influence of Plasma Interferences on Screening Coagulogram and Performance Evaluation of the Automated Coagulation Analyzer Sysmex® CS-2100i

Background: Plasma interference is a problem for coagulation analyzers using a photo-optical detection method. Sysmex® CS-2100i is a fully-automated coagulation analyzer which has been developed to reduce this problem. Objective: To evaluate the influence of interferences on prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen analyzed by Sysmex® CS-2100i. The performance of this analyzer was also assessed in this study. Methods: Pooled plasma samples spiked with interfering substances including hemoglobin, bilirubin and lipid were used in the interference study. Real patients’ samples with these interferences were also tested. Control materials and pooled samples were used for precision, comparison, and carryover studies. Results: The PT, APTT, and fibrinogen could be analyzed in both plasma samples with interference added and real abnormal patients’ plasma samples. The deviation of PT, APTT, and fibrinogen levels was not obvious, except for an upward trend of fibrinogen level with increased hemoglobin. The highest % CV of PT, APTT, and fibrinogen were 1.24, 3.18, and 4.31, respectively for within-run and 2.32, 2.11, and 6.06, respectively for between-run precision analysis. The correlation coefficients of PT, APTT, and fibrinogen between Sysmex® CS-2100i and Sysmex® CA-1500 were 0.99, 0.99, and 0.98 with intra-class correlation coefficients of 0.99, 0.99, and 0.98 respectively. No significant carryover of specimen was observed. Conclusion: Sysmex® CS-2100i could analyze both samples with artificial interfering substance added and real abnormal patients’ samples. This machine also had an acceptable performance by our evaluation