Excessive Platelet Sterilization Potentially Dangerous

Chemical processes used to sterilize blood products could lead to serious health issues in transfusion recipients, according to a new study.

Researchers at Linköping University (Sweden), Université Laval (Québec, Canada), and other institutions documented the effects of pathogen reduction (PR) systems on microRNA and mRNA levels in platelets stored in the blood bank, and assessed their impact on platelet activation and function. The researchers compared the two standard PR methods, gamma irradiation alone or irradiation in combination with chemical substances that inactivate pathogenic agents by cross-linking to their nucleic acids (DNA and RNA).

The researchers found that unlike platelets subjected to gamma irradiation or stored in additive solution, the ones that were treated by the two PR systems available on the market, Intercept and Mirasol, aggregated badly, which worsened wound healing. Intercept also 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. PR neither affected platelet microRNA synthesis or function, nor induced cross-linking of microRNA-sized endogenous platelet RNA species. The study was published early online on April 21, 2014, in Platelets.

“The processes that are used target the genetic material of pathogenic organisms; they were developed more than 20 years ago, before we understood the importance of the genetic material contained in platelets,” said corresponding author Patrick Provost, MD, of Université Laval. “These treatments activate blood platelets, triggering the release of RNA. The platelets end up depleted of RNA, so once transfused, they're unable to do what they normally would.”

“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,” added lead author clinical biochemist Abdimajid Osman, PhD, a researcher in Linköping University. “If they are eradicated it can damage the blood cells and lead to more severe bleeding for the patient. Our recommendation to blood centers is not to use any of the substances, only irradiation treatment.”

The function of platelets goes far beyond their role in blood coagulation and wound healing. They contain up to a third of the human genome in the form of ribonucleic acid (RNA), allowing them to synthesize over 1,000 proteins essential to the normal functioning of the human body. In contrast to other donated blood products, blood platelets 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.

Related Links:
Linköping University
Université Laval