Comparison of Rapid Centrifugation Technique with Conventional Centrifugation for Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT) Testing

Hematology and coagulation preanalytics for clinical chemists: Factors intrinsic to the sample and extrinsic to the patient

In hematology and coagulation, diligence in the preanalytical phase of testing is of critical importance to obtaining reliable test results. If the sample used for testing is unsuitable, even outstanding analytical procedures and technology cannot produce a clinically-reliable result. Therefore, the intent of this manuscript is to review preanalytical factors intrinsic to the sample that affect the hematology and coagulation testing. Factors intrinsic to the sample (excluding in vivo anomalies) can be controlled, theoretically, by phlebotomists (including nurses) and laboratorians in the preanalytical phase of testing. Furthermore, the management and prevention of such factors is highlighted. Erroneous control of preanalytical factors can produce laboratory errors.

Genetic Polymorphisms Associated with Prothrombin Time and Activated Partial Thromboplastin Time in Chinese Healthy Population

(1) Background: The purpose of this study was to evaluate the effect of gene polymorphisms on prothrombin time (PT) and activated partial thromboplastin time (APTT) in a healthy Chinese population. (2) Methods: A total of 403 healthy volunteers from a series of novel oral anticoagulants (NOACs) bioequivalence trials in China were included. Coagulation tests for PT and APTT were performed in the central lab at Peking University First Hospital. Whole-exome sequencing (WES) and genome-wide association analysis were performed. (3) Results: In the correlation analysis of PT, 105 SNPs from 84 genes reached the genome-wide significance threshold (p < 1 × 10−5). Zinc Finger Protein 594 (ZNF594) rs184838268 (p = 4.50 × 10−19) was most significantly related to PT, and Actinin Alpha 1 (ACTN1) was found to interact most with other candidate genes. Significant associations with previously reported candidate genes Aurora Kinase B (AURKB), Complement C5(C5), Clock Circadian Regulator (CLOCK), and Histone Deacetylase 9(HDAC9) were detected in our dataset (p < 1 × 10−5). PiggyBac Transposable Element Derived 2(PGBD2) rs75935520 (p = 4.49 × 10−6), Bromodomain Adjacent To Zinc Finger Domain 2A(BAZ2A) rs199970765 (p = 5.69 × 10−6) and Protogenin (PRTG) rs80064850 (p = 8.69 × 10−6) were significantly correlated with APTT (p < 1 × 10−5). The heritability values of PT and APTT were 0.83 and 0.64, respectively; (4) Conclusion: The PT and APTT of healthy populations are affected by genetic polymorphisms. ZNF594 and ACTN1 variants could be novel genetic markers of PT, while PRTG polymorphisms might be associated with APTT levels. The findings could be attributed to ethnic differences, and need further investigation.

Impact of centrifugation time and pneumatic tube transport on plasma concentrations of direct oral anticoagulants

INTRODUCTION

Rapid results are needed when plasma concentrations of direct oral anticoagulants (DOACs) are required in acute clinical settings. We evaluated the impact of centrifugation time and pneumatic tube transport on DOAC plasma concentrations with the overall aim of reducing turnaround time.

METHODS

Blood samples were spiked with rivaroxaban, apixaban or dabigatran in a low and a high concentration prior to centrifugation for 25 minutes (3163 g) or 5 minutes (3000 g) (n = 20 for each DOAC). Both samples spiked with DOACs (n = 20 for each DOAC) and patient samples (n = 25 in total) were transported manually or by pneumatic tube system samples.

RESULTS

For samples spiked with DOAC, statistically significant differences in DOAC plasma concentrations were found between centrifugation times for rivaroxaban in low (P < .05) and high (P < .05) concentrations. Relative bias was below 9% for all DOACs. Statistically significant differences were found between modes of transportation for rivaroxaban (P < .01) and dabigatran (P < .01) in high concentrations. Relative bias was 4%-23% for all DOACs. For patient samples, no statistically significant differences were found between modes of transportation, and relative bias was below 12% for all DOACs.

CONCLUSION

Minor, clinically insignificant, differences regarding centrifugation times were found in DOAC plasma concentrations. Importantly, no significant differences were found according to transportation modes for samples collected from patients. Although statistically significant differences were found depending on mode of transportation of spiked samples, relative bias was clinically acceptable. Thus, reduced centrifugation time and pneumatic tube transport should be considered to reduce turnaround time for rapid measurement of DOAC plasma concentrations.