New genetic blood test could be 'lifesaver'

An international team of researchers has developed a new genetic test to determine blood type. The 'Bloodchip' will ensure a much closer match between blood donors and recipients than existing tests, say the BloodGen team, which includes scientists from the UK, Germany, Sweden, Spain, the Czech Republic and the Netherlands. A spokeswoman for the UK's National Blood Service said that the Bloodchip could be 'a lifesaver' for people who need regular transfusions - those with conditions such as heamophilia, sickle cell anaemia, leukaemia or thalassaemia.

Current 'serological' tests check to see if a person is blood type A, B, AB or O, and also look at whether they are rhesus positive or rhesus negative. This usually allows the blood type of the donated blood to be sufficiently matched to that of the recipient, preventing any potentially dangerous immune reactions against blood of the wrong type. However, people who need to have frequent blood transfusions can sometimes develop reactions against other blood cell markers, which are not routinely checked.

The new test looks at up to nine other blood type variations, including the Duffy system - blood can either be Duffy A or Duffy B. The Bloodchip can detect up to 116 different DNA 'profiles' associated with blood groups, once all the different variations are taken into account. It is currently the focus of a large-scale EU preclinical trial, involving 3,000 blood samples from healthy people, in order to gain European health and safety approval.

Professor Neil Avent, director of the University of West England's Centre for Research in Biomedicine, who helped develop the test, told BBC News online that 'there is a significant section of the population that suffer serious illness and side effects after receiving multiple transfusions of blood that is not a perfect match', adding 'these patients over time develop antibodies that reject imperfectly matched blood transfusions, a process known as alloimmunisation, which can lead to serious illness and life-threatening side effects. Bloodchip has been developed with these communities in mind'.

Professor Marion Scott, director of research at the National Blood Service said that the Bloodchip test would be of 'enormous benefit' in ensuring people affected by conditions such as sickle cell disease and thalassaemias receive perfectly matched blood, 'to enable them to better manage their conditions'. The new test, which cost £2 million to develop, will be manufactured by Progenika Biopharma in Spain.