Events on 27 September 2023

If you're interested in blood groups, blood group serology, transfusion or just want to know "what the hell is Kell?" then this talk is for you...

This presentation on the Kell Blood group system will cover the following;

An entertaining overview of the Kell blood group system
Structure, function and molecular background of the most well-known Kell blood group system antigens
Clinical significance of antibodies to Kell blood group system antigens
The association with the Kx blood group system
Interesting facts about the lesser known Kell Blood group system antigens

Help, nothing compatible

Who lives in a papaya under the sea? SpongeBob Alloadsorption Pants! A Transfusion Laboratory Perspective of AIHA

Explanation of the various serological and molecular techniques that are available to identify novel blood groups. Discussing how these cases may present within the hospital and RCI labortories through to publication and ratification at the International Society of Blood Transfusion.

Join some of our panel members for our lunchtime session where we will be hosting an antibody workshop. Looking at different types of antibodies and how to positively identify or eliminate any suspected clincially significant antibodies, whilst testing your knowledge and skills.

The aim is to make the session fun and interactive, focusing on some top tips for solving those antibody mysteries.

In 2022 the unthinkable happened - NHSBT was forced to declare an Amber Alert for red cells in England. But does that tell the whole story? This presentation will briefly examine the build-up to the shortage declaration but also consider its impact, provide evidence of the response within hospitals and consider the opportunities for future change in practices.

CRYOSTAT 2 trial

The idea of generating blood cells in vitro for transfusion is not new but only now we are reaching the point where the concept is reaching clinical trials. In vitro derived blood cells (namely platelets and red cells at this stage) are complementary to blood donor-derived products but with distinct advantages: biological safety, more resilient supply line and potentially less immunogenicity.

We have developed a forward programming approach relying on the overexpression of transcription factors in pluripotent stem cells to produce the platelet mother cells, the megakaryocytes, conferring added efficiency and purity to the culture system. The challenges that remain to be addressed are related to transition to GMP production, optimising platelet release in the culture and quality control of the final product. The power of genome editing has also allowed us to explore the production of platelets with added clinical benefit (immune silent, added thrombotic potential).

Red cell production from primary CD34+ progenitors has been demonstrated in academic laboratories about a decade ago. We are now mid-way through a first in human study to look at the potential of using in vitro derived red cells for transfusion. One of the main benefits would be a potentially longer survival of the manufactured red cells in the circulation than their donor-derived counterpart. This would allow spacing out transfusion intervals for patients on chronic transfusion programme, thereby reducing iron overload.

Coagulation tests can be confusing, but correct interpretation is crucial to guide transfusion of blood products and haemostatic agents. Advantages and limitations of these tests will be discussed, using a variety of examples to demonstrate potential pitfalls.

Learning outcomes:

Understand appropriate use and limitations of coagulation tests
Interpretation of abnormal results
How results can guide transfusion of blood products
Recognise alternatives to blood products for haemostatic support

Postpartum haemorrhage is caused by obstetric complications but may be exacerbated by haemostatic impairment. It is a common observation that placental abruption and amniotic fluid embolism are associated with a severe and early coagulopathy characterised by hypofibrinogenaemia and increased fibrinolysis.

In Cardiff, a programme of research has been undertaken investigating the early detection and replacement of fibrinogen based on viscoelastic haemostatic assays. This culminated in the development of a care bundle for postpartum haemorrhage called the Obstetric Bleeding Strategy for Wales (OBS Cymru). Introduction of the OBS Cymru intervention across Wales resulted in fewer women experiencing massive postpartum haemorrhage (defined as >2500 mL) and decreased need for blood transfusion. The intervention is being investigated further in a NIHR supported study.

At term, women have increased levels of procoagulant clotting factors and reduced anticoagulants leading to a prothrombotic state. Our study confirmed these findings and demonstrated significantly raised thrombin generation. We identified two main types of coagulopathy; a dilutional coagulopathy with coagulation factors and platelets falling progressively with bleed size. However, clinically significant reductions in clotting factors were not seen until bleeds of 3000-4000 mL had occurred due to the high starting levels. Despite this, thrombin generation did not decrease due to increased levels of factor VIII during bleeds. Similar dilution-related falls were seen with fibrinogen levels. The exception was factor XIII which falls at term and decreases further with bleed size. The clinical significance of this finding has not been investigated but could suggest a role for cryoprecipitate.

In a subgroup of women we identified an early and severe consumptive coagulopathy caused by hyperfibrinolysis with very high D-dimer and plasmin/antiplasmin complexes which we termed acute obstetric coagulopathy (AOC). In addition, women with AOC had low levels of fibrinogen and evidence of an acquired dysfibrinogenaemia demonstrated by a reduced Clauss/antigenic ratio. The coagulopathy caused depletion of factor V and factor VIII but other clotting factors and thrombin generation was preserved. An increase in activated protein C was observed but no increase in soluble thrombomodulin demonstrating similarities and differences to trauma-induced coagulopathy.

AOC occurred in about 1/1000 deliveries and was associated with a high rate of fetal and neonatal deaths. It was most commonly associated with placental abruption but occurred with all underlying causes of postpartum haemorrhage.