Laboratory evaluation of the Coasys® Plus C coagulation analyzer

The Coasys® Plus C (Behnk Elektronik, distributed by Roche Diagnostics) is a coagulation analyzer for small to midsize clinical chemistry laboratories. We performed a laboratory evaluation.

After a familiarization period the dead volume, carry-over, capacity, within-assay reproducibility and imprecision were determined for the tests aPTT (STA APTT en STA Cephascreen), PT (STA Neoplastin Plus, STA Neoplastin R), INR (Hepato Quick), fibrinogen (STA Fibrinogen), antithrombin (Antithrombin III) and D-Dimer (Tina-quant D-Dimer Gen.2). A precision test and patient comparison with a STA-R Evolution® system were performed for aPTT (STA Cephascreen), PT (STA Neoplastin R), fibrinogen, antithrombin and D-Dimer.

No carry-over was detected. The analyzer performed on average 66 measurements per hour. Within-assay reproducibility (% with normal/abnormal/extreme result): STA APTT 2.4/1.7/2.7; aPTT Cephascreen 1.4/3.1/1.8; PT Neoplastin Plus 1.2/2.1/1.7; PT Neoplastin R 2.3/-/3.1; INR Hepato Quick 0.6/0.9/1.9; fibrinogen 4.8/3.0/4.5; antithrombin 1.3/4.1/3.8; D-Dimer 19.9/4.3/4.3. Total imprecision (% with control 1/control 2/human pooled plasma): STA APTT 3.1/1.4/2.1; APTT Cephascreen 2.3/2.6/2.0; PT Neoplastin Plus 3.3/1.3/4.1; PT Neoplastin R 3.7/4.0/3.5; INR Hepato Quick 1.5/4.3/1.4; fibrinogen 3.4/5.8/8.1; antithrombin 3.0/6.4/2.4; D-Dimer 4.6/2.2/30.3. The correlation between the Coasys® Plus C and the STA-R Evolution® was good for aPTT, PT, antithrombin and fibrinogen. Some differences were observed for extreme deviant results for fibrinogen. For the analysis of D-Dimer, no sufficient correlation was found between the two analyzers.

The Coasys® Plus C analyzer is fast, easy to handle and safe for the personnel. Its analytical performance makes it suitable for use in a clinical chemistry laboratory.