Evaluation of the automated coagulation analyzer SYSMEX CA 6000

Abstract

In the present study the coagulation analyzer SYSMEX CA 6000 (TOA Medical Electronics Co., Kobe, Japan), an analyzer equipped with a photooptical clot detection unit and a cap-piercing system, was evaluated with respect to its technical characteristics in the determination of standard coagulation tests (prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, and antithrombin) and in the determination of coagulation single factor activities. In the normal and in the pathological range the intraassay coefficients of variation (CV) and interassay CV for most parameters were below 5% (exceptions: intraassay CV 5.4% for prolonged thrombin time; intraassay CV 9.26% and interassay CV 10.7% for decreased antithrombin; interassay CV 5.62% for fibrinogen in the normal range, intraassay CV 10.1% for fibrinogen greater than 7.0 g/L; intraassay CV 6.36% and interassay CV 11.7% for decreased fibrinogen; interassay CV 11.6% for prolonged activated partial thromboplastin time; interassay CV 6.12% for decreased factor VII). Interference studies with lipemic, icteric, and hemolytic samples showed just minor influences of these abnormal sample characteristics on prothrombin time, activated partial thromboplastin time, fibrinogen, and antithrombin measurements when compared to the results obtained by using mechanical clot detection (STA, Stago Diagnostica, Asnieres-Sur-Seine, France). No carryover was detected in alternating measurements of heparinized (3 U/mL unfractionated heparin) and normal plasma samples. Measurement of the activities of clotting factors V, VII, VIII, and IX showed a good correlation (r=0.993 to r=0.977) between SYSMEX CA 6000 and STA. Our results demonstrate that using SYSMEX CA 6000 analyzer basal routine coagulation testing as well as specialized tests for single factor activities can be performed with satisfactory precision; in particular, the cap-piercing system has no negative effect on the performance of the analyzer.