Blood platelets disinfected to death
If blood becomes too thin, a transfusion with blood platelets may be necessary – but potential pathogenic agents must first be rendered harmless. The substances used for this unfortunately also destroy the blood platelets themselves, as shown in the findings of research at LiU and several European and Canadian universities.
In contrast to other donated blood products, the blood platelets – the particles that inhibit blood loss and heal wounds in blood vessel walls and other tissues – must be stored at room temperature as they do not tolerate the cold. This entails a risk that pathogens such as bacteria and viruses develop and follow the platelets into the patient’s blood system. The consequence can be blood poisoning, in the worst case leading to death.
There are two methods that can reduce the risk of infection: simple gamma irradiation or irradiation in combination with treatment with chemical substances. The treatment inactivates the pathogenic agents by cross-linking to their nucleic acids (DNA and RNA).
“The problem is also that the blood platelets have nucleic acids that are very important for their wound healing abilities and communication with other cells. If they are eradicated it can damage the blood cells and lead to more severe bleeding for the patient,” says Majid Osman, researcher in clinical chemistry at Linköping University and hospital chemist at the University Hospital.
Dr Osman is lead author of the study, which was published in the scientific journal Platelets. The major part of the chemical analyses was carried out at his laboratory in Linköping, while the blood platelets were prepared by a research colleague in Germany, where they were subjected to a number of different treatments. The ones that were treated by the two inactivated substances available on the market, Intercept and Mirasol, aggregated badly, which worsened wound healing. Intercept eradicated the nucleic acids of the platelets, causing them to become overactive and reduced in volume. Gamma radiation, on the other hand, had no damaging effects on the blood platelets.
“Our recommendation to blood centres is not to use any of the substances, only irradiation treatment,” says Majid Osman.
This method is used, for example, at the University Hospital in Linköping, where there have been no cases of infection related to transfusion of blood platelets.
The research group’s findings are not without controversy. The FDA in the United States is currently dealing with applications from the companies behind the two commercially available preparations, Intercept and Mirasol, previously approved by the EU.
“We have been subjected to pressure, and studies with conflicting findings were rapidly published. But our study is the only one which is completely independent of commercial interests,” says Dr Osman.
Article: Effects of pathogen reduction systems on platelet microRNAs, mRNAs, activation, and function by A.M. Osman, W.E. Hitzler, C.U. Meyer, P. Landry, Aurélie Corduan, B. Laffont, E. Boilard, P. Hellstern, E.C. Vamvakas and P. Provost. Platelets, online 21 April 2014. (doi:10.3109/09537104.2014.898178)
Top picture: Blood platelets stuck to vessels, spreading and attaching itself to others to heal an injury. Photo taken by Lars Faxälv with an electron microscope.
Photo of Mr Osman: Göran Billeson
Last updated: 2014-07-02