Automated measurement of coagulation and fibrinolytic activation markers: Outcomes in coronavirus disease 2019 (COVID-19) patients

BACKGROUND: Severe coronavirus disease 2019 (COVID‐19) is characterized by marked hypoxaemia and lung oedema, often accompanied by disordered blood coagulation and fibrinolytic systems, endothelial damage and intravascular fibrin deposition. PATIENTS/METHODS: We present a retrospective observational study of 104 patients admitted to hospital with COVID‐19. Plasma samples were collected within 72 h of admission. In addition to routine coagulation and haematology testing, soluble thrombomodulin (sTM), thrombin‐antithrombin (TAT), tissue plasminogen activator‐plasminogen activator inhibitor 1 complex (tPAI‐C) and plasmin‐α2 antiplasmin complex (PIC) were performed by automated chemiluminescent enzyme immunoassays. RESULTS: Significantly higher levels of D‐dimer, TAT, sTM and tPAI‐C were observed in non‐survivors compared to survivors. To confirm which parameters were independent risk factors for mortality, multiple logistic regression was performed on D‐dimer, TAT. sTM, tPAI‐C and PIC data. Only increasing sTM was significantly associated with mortality, with an odds ratio of 1.065 for each 1.0 TU/mL increment (95% CI 1.025–1.115). CONCLUSIONS: Of the haemostatic variables measured, sTM, which can be rapidly assayed, is the best independent predictor of mortality in patients hospitalized with COVID‐19, and this suggests that endothelial dysfunction plays an important role in disease progression

Thawing times and haemostatic assessment of fresh frozen plasma thawed at 37°C and 45°C using water bath methods

BACKGROUND: The Barkey Plasmatherm (BP; Barkey GmbH & Co. KG) can thaw plasma at 37°C and 45°C. No studies have assessed thawing times or hemostatic qualities of plasma thawed at 45°C with BP. This study assessed fresh frozen plasma (FFP) thawing times with use of BP at 37°C and 45°C and Thermogenesis ThermoLine (TT; Helmer Scientific) at 37°C and compared the hemostatic quality of LG-Octaplas (Octapharma) with use of BP at 37°C and 45°C with TT at 37°C. STUDY DESIGN AND METHODS: The thawing time of FFP (pairs or fours) was assessed using BP at 37°C and 45°C (not prewarmed and prewarmed) and TT at 37°C. Hemostasis was assessed in LG-Octaplas at 5 minutes, 24 hours, 48 hours, and 120 hours after thawing with use of the three methods. RESULTS: Thawing time for two units was 13.44 minutes using TT, the same as using BP at 37°C (12.94 min not prewarmed; 12.20 min prewarmed) or 45°C (12.38 min not prewarmed), but longer than using BP prewarmed to 45°C (11.31 min, p < 0.001). Thawing time for four units was 13.41 minutes using TT, shorter than using BP at 37°C (17.19 min not prewarmed, 18.47 min prewarmed; both p < 0.001) or 45°C (15.03 min not prewarmed, p = 0.012; 15.22 min prewarmed, p = 0.004). There was no reduction in hemostatic markers in LG-Octaplas with use of BP at 37°C or 45°C compared to TT. CONCLUSION: BP is quicker than TT by 2 minutes when thawing two units of FFP if it is prewarmed to 45°C. BP is slower than TT by at least 2 minutes when thawing four units of FFP at 37o C. There was no significant difference in the hemostatic qualities of plasma whether thawed at 37°C or 45°C

International multicenter, multiplatform study to validate Taipan snake venom time as a lupus anticoagulant screening test with ecarin time as the confirmatory test: communication from the ISTH SSC subcommittee on Lupus Anticoagulant/Antiphospholipid antibodies

Background Lupus anticoagulant (LA) assays are compromised in anticoagulated patients, and existing strategies to overcome the interferences have limitations. The prothrombin-activating Taipan snake venom time (TSVT) screening test and ecarin time (ET) confirmatory test are innately insensitive to vitamin K antagonists (VKA) and direct factor Xa inhibitors (DFXaI). Objectives Validate standardised TSVT/ET reagents for LA detection, in a multi-centre, multi-platform study. Patients/Methods Six centres from four countries analysed samples with TSVT/ET from 81 non-anticoagulated patients with LA, patients with established antiphospholipid syndrome (APS) and proven persistent LA who were either not anticoagulated (n=120) or were anticoagulated with VKAs (n=180) or DFXaIs (n=71). Additionally, 339 non-anticoagulated LA-negative patients, and 575 anticoagulated non-APS patients (172 VKA, 403 DFXaI) were tested. Anticoagulant spiking experiments were performed and 112 samples containing potential interferences (i.e. direct thrombin inhibitors) were tested. Results were evaluated against locally derived cut-offs. Imprecision was evaluated. Results Cut-offs were remarkably similar despite use of different analysers and donor populations. Cut-offs for TSVT ratio, ET ratio, percent correction and normalised TSVT ratio/ET ratio ranged between 1.08-1.10, 1.09-1.12, 9.3%-14.8% and 1.10-1.15 respectively. Coefficients of variation for TSVT and ET ratios were ≤5.0%. TSVT/ET exhibited sensitivity, specificity, negative and positive predictive values of 78.2%/95.0%/86.3%/91.5% respectively with established APS as the LA-positive population, and 86.9%/95.0%/76.8%/97.4% respectively with triple-positive APS. Interference was seen with direct thrombin inhibitors, unfractionated heparin and low molecular weight heparins, but not VKAs or DFXaIs. Conclusions TSVT/ET are validated for LA detection in non-anticoagulated patients and those on VKAs or DFXaIs

Renal transplant and hemostasis: early postoperative changes in recipients and donors

Background The benefit of administering pharmacologic thromboprophylaxis following renal transplantation remains uncertain. Objectives To compare hemostatic parameters before and after renal transplant surgery in both recipients and their donors at predetermined time points. Methods Blood samples were collected at baseline (T1), immediately after surgery (T2), and at 24 hours after surgery (T3) in both recipients and donors and at 72 (T4) and 120 hours (T5) from recipients only. Assays included in vitro thrombin generation, factor VIII (FVIIIc) activity, von Willebrand factor (VWF) antigen, D-dimer, antithrombin activity, prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin complexes, and plasminogen activator inhibitor-1 (PAI-1) antigen. Results Fifty-two patients (28 recipients and 24 donors) were enrolled. Both donors and recipients had increased FVIIIc, VWF, F1 + 2, D-dimer, and PAI immediately after surgery but reduced antithrombin. Mixed-model analysis showed that the magnitude of change over time (between T1 and T3) for FVIIIc (mean estimated difference [MED], 72; 95% CI, 41-102; P < .0001), VWF (MED, 89; 95% CI, 35-142; P = .001), F1 + 2 (MED, 283; 95% CI, 144-422; P < .0001), thrombin-antithrombin complexes (MED, 3.5; 95% CI, 1.9-5.1; P < .0001), D-dimer (MED, 2.2; 95% CI, 1.0-3.3; P < .0001), PAI-1 (MED, 9.2; 95% CI, 3.4-14.9; P = .002), and time to peak thrombin generation (MED, 1.5; 95% CI, 0.35-2.7; P = .01) was more significant in recipients than in donors. Conclusion Persistence of a hypercoagulable state was more prominent in recipients after 24 hours despite recovery in renal function and initiation of thromboprophylaxis

Activated Protein C Drives the Hyperfibrinolysis of Acute Traumatic Coagulopathy

National Institute for Health Research Programme Grant for Applied Research (RP-PG-0407-10036)

Lupus Anticoagulant and Abnormal Coagulation Tests in Patients with Covid-19

From New England Journal of Medicine, Bowles, L., Platton, S., Yartey, N., Dave, M., Lee, K., Hart, D.P., MacDonald, V., Green, L., Sivapalaratnam, S., Pasi, K.J. and MacCallum, P., Lupus Anticoagulant and Abnormal Coagulation Tests in Patients with Covid-19. New England Journal of Medicine DOI: 10.1056/NEJMc2013656. Copyright © 2020 Massachusetts Medical Society. Reprinted with permission.Letter to the edito

International consensus recommendations on the management of people with haemophilia B

Haemophilia B is a rare X-linked genetic deficiency of coagulation factor IX (FIX) that, if untreated, can cause recurrent and disabling bleeding, potentially leading to severe arthropathy and/or life-threatening haemorrhage. Recent decades have brought significant improvements in haemophilia B management, including the advent of recombinant FIX and extended half-life FIX. This therapeutic landscape continues to evolve with several non-factor replacement therapies and gene therapies under investigation. Given the rarity of haemophilia B, the evidence base and clinical experience on which to establish clinical guidelines are relatively sparse and are further challenged by features that are distinct from haemophilia A, precluding extrapolation of existing haemophilia A guidelines. Due to the paucity of formal haemophilia B-specific clinical guidance, an international Author Group was convened to develop a clinical practice framework. The group comprised 15 haematology specialists from Europe, Australia, Japan, Latin America and North America, covering adult and paediatric haematology, laboratory medicine and biomedical science. A hybrid approach combining a systematic review of haemophilia B literature with discussion of clinical experience utilized a modified Delphi format to develop a comprehensive set of clinical recommendations. This approach resulted in 29 recommendations for the clinical management of haemophilia B across five topics, including product treatment choice, therapeutic agent laboratory monitoring, pharmacokinetics considerations, inhibitor management and preparing for gene therapy. It is anticipated that this clinical practice framework will complement existing guidelines in the management of people with haemophilia B in routine clinical practice and could be adapted and applied across different regions and countries

2021 Update of the International Council for Standardization in Haematology Recommendations for Laboratory Measurement of Direct Oral Anticoagulants

International audienceIn 2018, the International Council for Standardization in Haematology (ICSH) published a consensus document providing guidance for laboratories on measuring direct oral anticoagulants (DOACs). Since that publication, several significant changes related to DOACs have occurred, including the approval of a new DOAC by the Food and Drug Administration, betrixaban, and a specific DOAC reversal agent intended for use when the reversal of anticoagulation with apixaban or rivaroxaban is needed due to life-threatening or uncontrolled bleeding, andexanet alfa. In addition, this ICSH Working Party recognized areas where additional information was warranted, including patient population considerations and updates in point-of-care testing. The information in this manuscript supplements our previous ICSH DOAC laboratory guidance document. The recommendations provided are based on (1) information from peer-reviewed publications about laboratory measurement of DOACs, (2) contributing author's personal experience/expert opinion and (3) good laboratory practice

COVID-19: Rapid antigen detection for SARS-CoV-2 by lateral flow assay: A national systematic evaluation of sensitivity and specificity for mass-testing

Background Lateral flow device (LFD) viral antigen immunoassays have been developed around the world as diagnostic tests for SARS-CoV-2 infection. They have been proposed to deliver an infrastructure-light, cost-economical solution giving results within half an hour. Methods LFDs were initially reviewed by a Department of Health and Social Care team, part of the UK government, from which 64 were selected for further evaluation from 1st August to 15th December 2020. Standardised laboratory evaluations, and for those that met the published criteria, field testing in the Falcon-C19 research study and UK pilots were performed (UK COVID-19 testing centres, hospital, schools, armed forces). Findings 4/64 LFDs so far have desirable performance characteristics (orient Gene, Deepblue, Abbott and Innova SARS-CoV-2 Antigen Rapid Qualitative Test). All these LFDs have a viral antigen detection of >90% at 100,000 RNA copies/ml. 8951 Innova LFD tests were performed with a kit failure rate of 5.6% (502/8951, 95% CI: 5.1–6.1), false positive rate of 0.32% (22/6954, 95% CI: 0.20–0.48). Viral antigen detection/sensitivity across the sampling cohort when performed by laboratory scientists was 78.8% (156/198, 95% CI 72.4–84.3). Interpretation Our results suggest LFDs have promising performance characteristics for mass population testing and can be used to identify infectious positive individuals. The Innova LFD shows good viral antigen detection/sensitivity with excellent specificity, although kit failure rates and the impact of training are potential issues. These results support the expanded evaluation of LFDs, and assessment of greater access to testing on COVID-19 transmission. Funding Department of Health and Social Care. University of Oxford. Public Health England Porton Down, Manchester University NHS Foundation Trust, National Institute of Health Research