ISSN 2997-1036
International Journal of Hematology | Vol. 6, No. 1, January 2015 | pp. 1–8
DOI: 10.46882/2015/IJH/000061
Original Article
Title: Impact of pre-analytical storage duration and temperature variables on routine plasma coagulation screening assays
Names of Authors: A. I. Ibrahim¹, C. D. Balogun², E. O. Ojo³
Authors’ Affiliations: ¹Department of Haematology, Ahmadu Bello University, Zaria, Nigeria; ²Department of Medicine, University of Ilorin, Ilorin, Nigeria; ³Department of Chemical Pathology, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
Abstract: Delays in sample processing can alter coagulation test results, leading to erroneous clinical decisions. This prospective study evaluated the stability of prothrombin time and activated partial thromboplastin time in 100 healthy adult plasma samples stored under varying temperature conditions (4 °C and 25 °C) for up to 24 hours. Baseline assays were performed within 1 hour of venipuncture, and repeat testing was conducted at 2, 4, 8, 12, and 24 hours. Prothrombin time values remained stable for up to 24 hours across both storage temperatures, with a mean variation below 5.0% (P > 0.05). In contrast, activated partial thromboplastin time demonstrated significant prolongation when stored at 25 °C starting at 8 hours, increasing from a baseline mean of 32.4 ± 2.8 seconds to 38.6 ± 3.4 seconds at 12 hours (P < 0.01), primarily due to the rapid degradation of labile factor VIII. Storage at 4 °C preserved activated partial thromboplastin time stability for up to 12 hours. These findings demonstrate that while prothrombin time is relatively stable, plasma samples for activated partial thromboplastin time screening should be analyzed within 4 to 6 hours if kept at room temperature, or refrigerated to ensure diagnostic accuracy.
Keywords: Prothrombin time, activated partial thromboplastin time, sample stability, pre-analytical variables, coagulation assays
Manuscript Timeline: Received: October 10, 2014; Revised: November 18, 2014; Accepted: December 05, 2014; Published: January 14, 2015