Good clot? Bad clot? Rheological and microstructural studies of abnormal blood clots from incipiency to breakdown

Lead Research Organisation: Swansea University
Department Name: Institute of Life Science Medical School

Abstract

Cardiovascular disease (CVD) and associated thrombotic disorders cause significant morbidity and mortality claiming 17.1 Million lives a year worldwide. CVD (including heart disease and stroke) accounts for around four out of ten of deaths in the UK. The incidence of CVD increases markedly with age and is often higher in socially deprived areas. In CVD, the processes of endothelial and vascular damage and activation of the coagulation cascade result in abnormal clots, often with excessively cross-linked fibrin networks. Such clots are often referred to as bad clots by the clinician. It has been claimed that tighter fibrin networks lead to a decreased ability of the body to effectively digest these clots (lysis). However, the relationships between whole blood clot microstructure and lysis remains contentious. This is in part due to the lack of rheological techniques to characterise clot microstructure and to appropriately measure clot lysis. The ability to characterise clot microstructure and measure clot lysis will form the basis of a new haemorheometrical device which can be used to diagnose disease states (such as CVD), to monitor anticoagulant therapy, to guide therapeutic interventions and to assess the efficiency of various drugs.This Application will address the hypothesis that measurement of incipient clot microstructure can provide the basis for a new biomarker of clot lysis. It is widely assumed that the incipient clot microstructure is a template for ensuing clot development, and will therefore ultimately control the accessibility of fibrinolytic agents that serve to lyse the clot. It is planned to test this hypothesis by conducting appropriate rheological measurements during whole blood coagulation. However, measurement of clot lysis has been complicated by the fact that it exists simultaneously with platelet mediated clot retraction which has the effect of the clot pulling away from the rheometer's measuring plates. A novel aspect of this work is to perform viscoelastic measurements of whole blood clots whilst maintaining a zero normal force between the rheometer's measuring plates. This has the desired effect that, during clot retraction, the fibrin network acts to pull the plates towards each other therefore facilitating appropriate viscoelastic measurements of the contracted clot. These measurements will allow a greater understanding of the relationships between clot microstructures and clot lysis. Overall, the ultimate goal of the research is to develop a new haemorheometrical tool which has the potential to be used in a clinical setting for patient benefit.

Planned Impact

Who might benefit from this research? How might they benefit from this research? A short term beneficiary of this research is industry (including medical diagnostic, bioengineering and pharmaceutical firms). The impact of the applicant's research has already been demonstrated at Swansea University in the form of a spin in medical device company, Haemair Ltd. and a collaborative project with Calon Cardio Technologies Ltd. It is envisaged that continued research within the area of haemorheology will attract further investment in these companies and the possibility of the formulation (spinning in or spinning out) of new companies who wish to make commercial use of this research leading to the the creation of jobs and wealth within the biomedical sector. Furthermore, the pharmaceutical industry may be interested in the potential of the Applicant's haemorheological techniques as a tool for measuring the efficiency of various clot busting drugs and anticoagulants. This may lead to investment in research and development at Swansea University by global companies. The ultimate beneficiary in the long term will be patients and the general public as the research develops into novel techniques used in hospitals for disease screening. These include members of the general public who may be at risk of cardiovascular disease due to various genetic factors (e.g. familial hypercholesterolemia) or patients who have had previous cardiovascular events (e.g. deep vein thrombosis, stroke, or a heart attack). Furthermore, the Applicant's research into haemorheological techniques has already shown significant potential as a tool for anticoagulant monitoring. This will have enormous benefit to patients undergoing anticoagulant therapy (e.g. warfarin) as they will have an more rigorous measure of their anticoagulant status allowing a more appropriate dose to be administered by the doctor. In addition to enhancing the quality of life, health and well being of the patient this work has wider implications in the economy and NHS. Costs associated with patients regularly visiting hospitals and clinics will be substantially reduced as technologies are geared more towards a near patient or point of care (POC) setting. The Applicant's research into haemorheological techniques lends itself to the possibility of a development of a POC device, saving time and costs for both the NHS and the patient.

Publications

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Description The work conducted as a part of the grant contributed to the finding that the incipient (or "infant") blood clot is a microstuctural template for it's mature form. This has been widely assumed but has never been rigorously assessed, until now, using appropriate rheometrical techniques. The consequence of this finding, is that a biomarker of incipient clot formation (the fractal dimension) can be used to predict the the eventual structure of the fully formed clot and it's susceptibility to clot lysis (breakdown) which are important in understanding abnormal blood coagulation in various diseased states.

Furthermore, the research has led to the early stage of development of a novel biomarker to assess the lysis or breakdown of blood clots. This will open up new avenues for assessing thrombolytics (clot busting drugs) and understanding the pathophysiology of a wide range of disease such as Stroke and Deep Vein Thrombosis.
Exploitation Route The work has potential to form an apparatus for measuring the efficacy of thrombolytics (clot busting drugs) which are commonly used in patients. This apparatus will particularly appeal to drug companies and potentially attract industrial funding, or even spinning out a new company.
Furthermore, the clinical implications of this novel biomarker of lysis need to be exploited (by clinicians, research nurses and academics) for it's potential as (i) a biomarker of disease and (ii) therapeutic (anti-coagulant) and thrombolytic monitoring, in patients. The route for this is through the Haemostasis Biomedical Research Unit, a rheological laboratory based at an NHS Hospital.
Sectors Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology

 
Description The findings obtained from this research have contributed to the an award of a Haemostasis Biomedical Research Unit (by NISCHR), a unique laboratory based on site of the Accident and Emergency Department of an NHS hospital. This has led to a research culture embedded within a hospital environment, where academics liaise with clinicians and nurses.
First Year Of Impact 2011
Sector Healthcare
Impact Types Economic,Policy & public services

 
Description EPSRC Healthcare Impact Partnerships
Amount £922,580 (GBP)
Funding ID EP/L024799/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 05/2014 
End 04/2017
 
Description EPSRC Platform Grant
Amount £1,000,000 (GBP)
Funding ID EP/N013506/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 03/2016 
End 02/2021
 
Description NISCHR Haemostasis Biomedical Research Unit
Amount £1,450,000 (GBP)
Organisation Health and Care Research Wales 
Sector Public
Country United Kingdom
Start 09/2011 
End 03/2015
 
Title A new method for measuring whole blood clot lysis and it's response to therapeutic intervention 
Description Work conducted under an EPSRC First Grant award and an EPSRC Healthcare Impact Partnership has led to the development of advanced haemorheological techniques for measuring clot breakdown in response to therapy. The technique will be applied in an NHS setting to assess therapeutic intervention in patients with Venous Thromboembolism and Stroke. 
Type Of Material Technology assay or reagent 
Year Produced 2014 
Provided To Others? Yes  
Impact Uptake by clinicians and biomedical scienctists in an NHS laboratory setting. 
 
Description Collaboration in haemorheology with University of Cambridge 
Organisation University of Cambridge
Country United Kingdom 
Sector Academic/University 
PI Contribution Using microfluidic scale rheological analysis, we have shown that it is possible to differentiate between healthy and abnormal red blood cells. This has particular relevance for the development of biomarkers and associated tehcniques for the diagnosis of disease that manifest in red blood cells (e.g. Malaria, Sepsis)
Collaborator Contribution Dr Peter Bull, Department of Pathology, University of Cambridge, provides the necessary expertise and facilities for culturing malarial infected red blood cells.
Impact Paper and grant proposals in preparation. This is a mutidisciplinary collaboration between engineers and biologists.
Start Year 2017
 
Description Collaboration with Penn Medicine and Children's Hospital of Philadelphia 
Organisation Children's Hospital of Philadelphia
Country United States 
Sector Hospitals 
PI Contribution We have set up a joint rheology laboratory based at Penn Medicine in order to advance knowledge in areas of mechanical and microstructural aspects of blood coagulation. The laboratory is used by members of the Penn Medicine team, under our guidance, and it provides a base for our group to carry out research at one of the leading Medical Schools in the USA.
Collaborator Contribution Our collaborators at Penn Medicine and the Children's Hospital of Philadelphia (CHOP) have provided particular expertise in imaging studies in order to carry out our research projects. Our postdoctoral researchers and postgraduate students often visit each department to access state of the art equipment and to be trained in highly specialised techniques such as Scanning Electron Microscopy and Spinning Disk Confocal Microscopy for the imaging of blood clots. Furthermore, our collaborator at CHOP regularly supplies reagents necessary for a project that is investigating the use of rheometry for monitoring adverse reactions to heparin anticoagulant therapy.
Impact A landmark paper as a result of this collaboration has been published in British Journal of Haematology (DOI 10.1111/bjh.13173). This paper reports the first study of our rheological biomarker (df) in a study of anti-coagulated patients. The results show df is the only biomarker available with the ability to detect abnormal clotting in Venous Thrombo-Embolism patients whom appear fully anticoagulated by warfarin in terms of their INR (International Normalised Ratio). Professor Rhodri Williams and Dr Karl Hawkins led on the rheological aspects of the work, and Professor Adrian Evans and Professor John Weisel led on the clinical aspects, in particular the understanding and significance of altered clot structure in disease.
Start Year 2007
 
Description Collaboration with Penn Medicine and Children's Hospital of Philadelphia 
Organisation University of Pennsylvania
Department Perelman School of Medicine
Country United States 
Sector Academic/University 
PI Contribution We have set up a joint rheology laboratory based at Penn Medicine in order to advance knowledge in areas of mechanical and microstructural aspects of blood coagulation. The laboratory is used by members of the Penn Medicine team, under our guidance, and it provides a base for our group to carry out research at one of the leading Medical Schools in the USA.
Collaborator Contribution Our collaborators at Penn Medicine and the Children's Hospital of Philadelphia (CHOP) have provided particular expertise in imaging studies in order to carry out our research projects. Our postdoctoral researchers and postgraduate students often visit each department to access state of the art equipment and to be trained in highly specialised techniques such as Scanning Electron Microscopy and Spinning Disk Confocal Microscopy for the imaging of blood clots. Furthermore, our collaborator at CHOP regularly supplies reagents necessary for a project that is investigating the use of rheometry for monitoring adverse reactions to heparin anticoagulant therapy.
Impact A landmark paper as a result of this collaboration has been published in British Journal of Haematology (DOI 10.1111/bjh.13173). This paper reports the first study of our rheological biomarker (df) in a study of anti-coagulated patients. The results show df is the only biomarker available with the ability to detect abnormal clotting in Venous Thrombo-Embolism patients whom appear fully anticoagulated by warfarin in terms of their INR (International Normalised Ratio). Professor Rhodri Williams and Dr Karl Hawkins led on the rheological aspects of the work, and Professor Adrian Evans and Professor John Weisel led on the clinical aspects, in particular the understanding and significance of altered clot structure in disease.
Start Year 2007
 
Description Clot Busters, World Thrombosis Day Charity Event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact To mark World Thrombosis Day in 2016, Swansea University's EPSRC Healthcare Impact Partnership for new Blood Clotting Diagnostics and Management held an event at Swansea University's Bay Campus, where they attempted to break a Guinness World Record for the "Most hits of a person with water balloons in three minutes by a team". The Event was arranged in collaboration with the charity, Thrombosis UK, to raise awareness of Thrombosis and gained widespread media coverage including being featured in the World Thombosis Day Impact report.
Year(s) Of Engagement Activity 2016
URL http://www.thrombosis-charity.org.uk/downloads/Swansea-WTD-event.pdf
 
Description Invited Seminar at Penn Medicine 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Health professionals
Results and Impact The seminar stimulated several interesting discussions, some of which were continued outside of the seminar and have now led to some early collaborative studies (e.g. Collaboration with Doug Cines and Lubica Rauova of CHOP).

Following my talk, and through conversations at conferences and meetings, I have noticed a definite increase in awareness of our work in particular by clinicians working in the field of Hematology.
Year(s) Of Engagement Activity 2013