Effect of transportation and freeze-thaw procedure on hemostatic tests

Objective: Coagulation tests are sensitive to pre-analytical variables. The aim of our study is to identify the effect of transportation and freeze-thaw status on for Factor VIII, Factor IX, Anti-thrombin III, Protein S, Protein C, Prothrombin time (PT) and Activated partial thromboplastin time (aPTT). Materials and methods: The study was performed on 102 plasma samples obtained from 34 healthy volunteers. The samples were divided into three groups. Group A was analyzed whereas group B, C were frozen at -20 degrees C. After 24 h, group B and C were transported for 2 h. Following the transfer, group B was analyzed and C was frozen at -20 degrees C. After 24 h, group C was analyzed. Analyses of samples were performed in Thrombolyzer-XRM for PT, aPTT, Factor VIII, Factor IX, Anti-thrombin III, Protein C and Protein S. Results: There were significant variations for PT, aPTT, Protein S, Factor VIII and Factor IX for group A&B and A&C comparisons in different stability criteria approaches. In significant change limit and percentage change calculations Protein S, Factor VIII and IX showed significant differences. For acceptable change limit approach, aPTT and Factor IX showed significant changes. Conclusion: Laboratories should take precautions for transportation and freeze-thaw cycles to prevent inaccurate results.