Effects of preanalytical frozen storage time and temperature on screening coagulation tests and factors VIII and IX activity.
Author(s): Zhao Y, Feng G, Zhang J, Gong R, Cai C, Feng L
Publication: Sci Rep, 2017, Vol. 7, Page 12179
PubMed ID: 28939816 PubMed Review Paper? No
Purpose of Paper
This paper investigated the effects of frozen storage temperature and duration on coagulation testing in plasma specimens. Differences in results based on analyzer used were also examined.
Conclusion of Paper
Prothrombin time (PT), thrombin time (TT), international normalized ratio (INR), activated partial thromboplastin time (APTT), Factor (F)VIII-C, and FIX-C levels were significantly affected by storage at -20 or -80˚C, but fibrinogen levels were generally stable. Storage at -20˚C resulted in clinically relevant changes (>10%) in APTT and FVIII-C after more than 15 days and in PT, INR, and FIX-C after more than 1 month. Clinically significant effects of storage at -80˚C were limited to FVIII-C and FIX-C when stored for more than 1 month and APTT after more than 6 months. No clinically significant effects of storage on TT or fibrinogen were observed. Importantly, stability times were consistent between analyzers.
Studies
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Study Purpose
This study investigated the effects of frozen storage temperature and duration on coagulation testing in plasma specimens. Differences in results based on analyzer used were also examined. Blood was collected by venipuncture in sodium citrate tubes following a 12 h fast from 144 asymptomatic patients. Plasma was obtained by centrifugation at 3000 x g and specimens were aliquoted. Specimens from 36 patients were processed as one of four groups: 1) frozen and stored at -20˚C and analyzed using the CA7000 system, 2) frozen and stored at -80˚C and analyzed using the CA7000 system, 3) frozen and stored at -20˚C and analyzed using the CS5100 system, or 4) frozen and stored at -80˚C and analyzed using the CS5100 system. One specimen from each patient was analyzed immediately after collection and additional aliquots were tested after 15 days, 1 month, 3 months, 6 months, and 1 year. Specimens were thawed in a 37˚C water bath for 10 min, inverted six times, and analyzed within 30 min of thawing. Clinical significance was defined as a change of more than 10%.
Summary of Findings:
Significant increases in PT, TT, INR, APTT, FVIII-C, and FIX-C were observed after 15 days at -20˚C and at -80˚C, depending on analyzer used and after 1 month, regardless of analyzer. Clinically significant increases (>10%) in PT and INR were only observed after storage at -20˚C for more than 1 month and were not observed at -80˚C for up to 1 year of storage. Clinically significant increases in APTT were observed after storage at -20˚C for more than 15 days or -80˚C for more than 6 months, regardless of analyzer used. Clinically significant decreases of FVIII-C and FIX-C were observed after storage for more than 1 month at -80˚C or after storage at -20˚C for more than 15 days and 1 month, respectively. Although TT increased with storage at either temperature, no clinically significant effects were observed. Fibrinogen levels were relatively stable over the course of 1 year of storage with only small (<1%) changes observed during storage at either temperature. Importantly, stability times were consistent between analyzers.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Not specified
Platform:
Analyte Technology Platform Glycoprotein Hematology/ auto analyzer Morphology Hematology/ auto analyzer Protein Hematology/ auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage temperature -20˚C
-80˚C
Storage Storage duration 0 days
15 days
1 month
3 months
6 months
1 year
Hematology/ auto analyzer Specific Technology platform CA7000
CS5100