Impact of rapid centrifugation on routine coagulation assays in South Africa.
Author(s): Haripersadh R, Pillay D, Rapiti N
Publication: Afr J Lab Med, 2022, Vol. 11, Page 1901
PubMed ID: 36483324 PubMed Review Paper? No
Purpose of Paper
The purpose of this paper was to investigate the potential impacts of centrifugation speed and duration on coagulation by comparing prothrombin time (PT), thrombin time (TT), activated partial thromboplastin time (APTT), D-dimer, fibrinogen levels and platelet counts in case-matched plasma obtained by centrifugation at 4000 rpm for 10 min or 15 min, or at 5000 rpm for 5 min or 10 min.
Conclusion of Paper
While all plasma obtained using protocols A (4000 rpm for 15 min) and B (4000 rpm for 10 min) were considered platelet poor plasma (PPP), PPP was only obtained in 55% and 45% of specimens using protocol C (5000 rpm for 10 min) and protocol D (5000 rom for 5 min), respectively. Significant differences in mean PT, TT, and D-dimer were found when blood was centrifuged at 5000 rpm rather than 4000 rpm for 15 min, but significance depended on the duration of the spin and if the results obtained with the reference specimen (4000 rpm for 15 min) were normal or abnormal. APTT and fibrinogen in normal and abnormal specimens were comparable among plasma obtained using the four different centrifugation protocols. Strong correlations in PT, APTT and fibrinogen were very strongly correlated between plasma obtained with protocol A and the other 3 protocols (r>0.975) but poor correlations were observed for TT, D-dimer (r<0.975). None of the analytes evaluated were significantly affected when centrifugation duration was decreased from 15 min at 4000 rpm to 10 min at 4000 rpm.
Studies
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Study Purpose
The purpose of this study was to investigate the potential impacts of centrifugation speed and duration on coagulation by comparing prothrombin time (PT), thrombin time (TT), activated partial thromboplastin time (APTT), D-dimer, fibrinogen levels and platelet counts in case-matched plasma obtained by centrifugation at 4000 rpm for 15 min or 10 min, or at 5000 rpm for 10 min or 5 min. Tubes of sodium citrate blood from sixty volunteers (no diagnosis provided, 33 males and 27 females) were transported to the laboratory at room temperature. A tube of blood from each volunteer was centrifuged within 4 h of venipuncture using each of the four protocols: A.) 4000 rpm for 15 min, B.) 4000 rpm for 10 min, C.) 5000 rpm for 10 min and D.) 5000 rpm for 5 min. Centrifugation protocols A and B were conducted in a centrifuge which allowed direct placement of the blood tube in the rotor. In contrast centrifugation protocols C and D required the blood tubes to be placed inside a 50 mL falcon tube with cotton as a buffer. After centrifugation, plasma was transferred to empty tubes. PT, APTT, and TT as well as levels of fibrinogen and D-dimer were measured using a Sysmex CS5100 automated coagulation analyzer. Platelets were counted on a Sysmex XN 3000 Automated Hematology analyzer with a threshold of < 10 × 109 platelets/L platelet poor plasma. A threshold of r<0.975 was considered poorly correlated.
Summary of Findings:
While all plasma obtained using protocols A (4000 rpm for 15 min) and B (4000 rpm for 10 min) was considered platelet poor plasma (PPP), PPP was only obtained in 55% and 45% of specimens using protocol C (5000 rpm for 10 min) and protocol D (5000 rom for 5 min), respectively. Using plasma obtained with protocol A, a normal value for PT was obtained in 49 specimens, for APTT in 38 specimens, for TT in 46 specimens, for fibrinogen in 47 specimens, and for D-dimer in 19 specimens. Specimens with normal PT values using protocol A had shorter times when plasma was obtained by centrifugation protocol C or D (P=0.002 and P=0.005, respectively); however, no significant differences in PT were found among specimens with longer times and PT was very strongly correlated between plasma specimens obtained with protocol A and the remaining three centrifugation protocols (r≥0.99). TT in normal specimens was comparable among plasma obtained using the four different centrifugation protocols, but TT was shorter in abnormal specimens centrifuged using protocol D compared to protocol A (P=0.03), and correlations in TT between plasma obtained with protocol A and the other three protocols were lower than for other analytes (r=0.92-0.93). Plasma specimens with normal D-dimer values that were isolated using protocol A had higher levels than those obtained by centrifugation protocol C or D (P=0.04 and P=0.02, respectively), but no significant differences were found among specimens with abnormal D-dimer levels and D-dimer levels were poorly correlated between plasma obtained with protocol A and the other three protocols (r<0.975). APTT and fibrinogen levels were comparable among plasma obtained using the four different centrifugation protocols regardless of whether APPT and fibrinogen levels were normal or abnormal. APTT and fibrinogen levels were very strongly correlated between plasma obtained with protocol A and the other three protocols (r>0.975).
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Not specified
- Normal
Platform:
Analyte Technology Platform Peptide Hematology/ auto analyzer Morphology Hematology/ auto analyzer Cell count/volume Hematology/ auto analyzer Glycoprotein Hematology/ auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Centrifugation Multiple durations compared
Multiple speeds compared