New test in England aims to make blood transfusions safer
Genetic test to prevent immune system from attacking donated blood cells
England’s National Health Service (NHS) is introducing a new genetic test that seeks to make it safer for people with sickle cell disease and other blood disorders to receive transfusions.
“Thousands of people living with sickle cell disease and thalassaemia will be eligible for this new world-first blood test which is set to transform their care,” Health Minister Andrea Leadsom said in a press release. “This is a huge step forward in improving the quality of life for people who are living with these blood disorders.”
The NHS said it is the first healthcare system in the world to offer this new test, and the agency is encouraging patients in England to get this test done alongside their routine blood tests.
“The initiative will rely on patients attending hospital and having their blood sent to NHS Blood and Transplant for testing. We strongly encourage clinical and laboratory teams to work with patients to support this programme,” said Sara Trompeter, MD, a consultant hematologist at NHS Blood and Transplant.
17,000 people living with sickle cell disease in England
The NHS estimates there are about 17,000 people with sickle cell and 800 people with thalassemia living in England. Both disorders are caused by genetic mutations that cause abnormalities with hemoglobin — the protein inside red blood cells that is responsible for oxygen transport.
Transfusions “continue to be crucial in the treatment of sickle cell disorder,” said John James, chief executive of the Sickle Cell Society.
“With the introduction of this innovative test, we take a remarkable stride towards achieving better blood matches for all those living with the condition,” he said. “We urge individuals with sickle cell disorder to have the blood test as it will not only support more accurate treatment but also hold the potential to save more lives in the future.”
If I’d had this test several years ago before my transfusion, I might not have antibodies now.
Finding matching donor can be challenge for blood transfusions
Although blood transfusions can be life-saving, finding a matching donor can be challenging. The problem is the body’s immune system is hardwired to assume anything that isn’t part of the body is a hostile threat. If the immune system recognizes the donated blood cells as foreign, it will attack them, which can cause problematic side effects and reduce the efficacy of the transfusion.
That’s what happened to Ama Aryee, a 34-year-old science teacher living with sickle cell in Cheshunt in Hertfordshire. After receiving emergency blood transfusions for complications from pneumonia, Aryee developed antibodies against many common blood types. Now, if she needs a transfusion, there are only two to four units of blood in England that she can receive safely, according to the NHS.
“The doctors and laboratory team find it very difficult to find matching blood for me,” Aryee said. “It is a worry to know that if there was an emergency and I needed blood it would not be straightforward to find enough. I try not to dwell on it but it’s there in my mind. It’s a bit scary to think about future pregnancies or problems with sickle cell, I am well aware that there’s almost no blood I can receive at the moment.”
To prevent the immune system from attacking donated blood cells after a transfusion, transfused cells need to look similar enough to the patient’s own blood cells, so that the immune system won’t recognize them as foreign. This has traditionally been done through a relatively crude analyses of large protein markers on the surface of blood cells (that’s where the traditional blood-typing system of A, B, AB, and O comes from).
Test uses genetics to provide more precise matching of blood cell markers
The new test is basically a more detailed version of this type of testing, using genetics to provide more precise matching of different blood cell markers that the immune system might recognize.
“While blood matching for patients with inherited blood disorders, including sickle cell disease and transfusion-dependent thalassaemia is already done to a high standard, we can learn more and develop better blood matching further by using this exciting new world-leading test,” said Ryan Mullally, MD, a consultant hematologist at Whittington Health NHS Trust. “We are keen to raise awareness of it among patients and specialist medical and nursing teams involved in their care.”
Aryee “definitely” supports people getting their blood groups tested.
“If I’d had this test several years ago before my transfusion, I might not have antibodies now,” she said. “And if this new testing could help people like me receive blood again that would be wonderful.”