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Background: The recommendation for coagulation blood samples is to centrifuge at 4000 revolutions per minute (rpm) for 15 min to produce platelet-poor plasma before analysis. Rapid centrifugation, defined as centrifuging samples at higher speeds for shorter durations, could potentially reduce turn-around times (TAT), provided sample integrity is maintained. Objective: This study assessed the impact of rapid centrifugation on routine coagulation assay results. Methods: Blood samples were collected from volunteers at Inkosi Albert Luthuli Central Hospital and King Edward VIII Hospital, Durban, KwaZulu-Natal, South Africa, from September to November 2021. Samples were centrifuged using Method A, the current standard (4000 rpm/15 min), Method B (4000 rpm/10 min), Method C (5000 rpm/10 min) and Method D (5000 rpm/5 min). Platelet count, prothrombin time, activated partial thromboplastin time, thrombin time (TT), fibrinogen and D-dimer levels were analysed and results from Methods B, C and D compared to reference Method A. Results: Platelet-poor plasma was obtained from all samples (n = 60) using Methods A and B, and from 33/60 (55%) samples using Methods C and D. Differences between Method A and Methods C and D for normal prothrombin time, normal D-dimer and abnormal TT results were statistically significant. Prothrombin time results correlated strongly across all methods, while TT and D-dimer results correlated poorly. Activated partial thromboplastin time and fibrinogen results showed no significant differences across all methods. Conclusion: Rapid centrifugation at 4000 rpm/10 min (Method B) showed results consistent with the reference method. This method could potentially reduce the overall TAT for routine coagulation assays. [ABSTRACT FROM AUTHOR]

Introduction: Disseminated intravascular coagulation (DIC) is a feared complication of various systemic illnesses. We aimed to evaluate the laboratory requesting practices of clinicians, especially concerning the laboratory parameters, included in the International Society of Thrombosis and Haemostasis (ISTH) DIC score. Methods: A retrospective descriptive study was performed and included data from DIC screen requests analysed at Universitas National Health Laboratory Service (NHLS) laboratory, Bloemfontein, South Africa, for one calendar year. Laboratory request forms were analysed, recording the pretest diagnosis and whether the diagnosis was associated with DIC. Parameters of the DIC screen, prothrombin time, activated partial thromboplastin time, thrombin time, d‐dimer and fibrinogen were used to calculate the ITSH DIC score and diagnose heparin contamination. The platelet count, currently not part of the DIC screen test set, was also recorded. Results: A total of 778 DIC screen requests were processed. One hundred and eighty‐three requests were excluded due to laboratory‐defined rejection criteria, heparin contamination or for lacking an ISTH score parameter. Of the remaining 595 complete requests, 283 (47.7%) were laboratory‐defined overt DIC. The pretest diagnosis was not predictive of either a positive or negative finding of overt DIC. The contribution of fibrinogen to assigning overt DIC was questionable. Conclusion: The number of DIC screen requests received highlights the need for laboratory evidence of DIC. To improve laboratory DIC testing, the authors suggest critical evaluation of the contribution of the pretest diagnosis and fibrinogen in a prospective study and adding the platelet count in our local DIC test set. [ABSTRACT FROM AUTHOR]

The article presents a study that evaluates the diagnostic utility of individual parameters in the disseminated intravascular coagulation (DIC) panel in the National Health Laboratory Service laboratory. It mentions parameters with statistically significant predictive values for the presence of an underlying DIC include platelet count, D-dimers, antithrombin and prolonged activated partial thromboplastin time. The study concludes that only 10 percent of patients had low fibrinogen levels.

Objective: To document the routine haemostatic variables of a group of San relocated from Namibia to South Africa., Design: Cross-sectional study done in two stages., Setting: Schmidtsdrif military camp in late 1990 and early 1991., Subjects: Healthy adult San volunteers: 31 males and 54 females from the Vasakela and Barakwena groups in 1990; 135 males from the Vasakela group in 1991. The subjects were all soldiers or their dependants., Main Outcome Measures: The following tests were performed: activated partial thromboplastin time, prothrombin time, thrombin time, fibrinogen and coagulation factors V, VII, VIII, IX, X, XI and XII. The results were compared with a Western population reference group (N = 50)., Main Results: Almost all the haemostatic variables were statistically significantly lower than those of the reference group. The mean derived fibrinogen concentration in the plasma in the first stage of the study (1990) was significantly higher, but this reverted to normal during the second stage (1991), perhaps reflecting a general improvement in health., Conclusions: Even though the San are one of the best studied groups of indigenous people, this is the first published report on their haemostatic condition. The generally lower levels of haemostatic variables may reflect the lower prevalence of cardiovascular disease in the San. The population needs to be followed up as they westernise.

Using surface immunofluorescence isolate-specific antigens were detected on the membrane of erythrocytes infected with Babesia parasites. In addition, the strains reacted differently with Plasmagel in that the European isolate (B.c. canis) could be purified on Plasmagel effectively, whereas infected erythrocytes of the South-African isolate (B.c. rossi) could not. Experimental infection of dogs with Babesia canis isolates from geographically different areas revealed different pathology. The European isolate obtained from France exhibited transient parasitaemia, usually below 1%, associated with low PCV values and congestion of internal organs. Clinical disease was correlated with an effect on the coagulation system, and not with peripheral parasitaemia. Infection of dogs with South-African-derived isolate induced high parasitaemia usually much higher than 1%, which required chemotherapeutic treatment. In these animals clinical disease was correlated with peripheral parasitaemia and not with parameters of the coagulation system. The results show that the etiology of disease caused by these isolates of B.c. canis and B.c. rossi is different. This might have implications for the development of vaccines against these infections.