Jingcheng Zhao, MD PhD’s Post

Excited to share our latest paper, published today in JAMA. We show evidence of possible transmission of a factor causing intracerebral hemorrhages through blood transfusion. Using nationwide registers and blood bank data in Sweden and Denmark, we show that among approximately 1M patients who underwent transfusions, the risk of an intracerebral hemorrhage increases approximately from 1.5% to almost 4% over 30 years among patients transfused with blood from blood donors that later developed multiple intracerebral hemorrhages - compared to blood from donors that did not develop intracerebral hemorrhages. This exploratory study was based on the biological premise that cerebral amyloid angiopathy (CAA), a disease characterized by beta-amyloid deposition in brain blood vessels and the second most common cause of intracerebral hemorrhage, may be transmissible. Previous studies have shown that CAA can be transferrable in humans through the injection of contaminated cadaveric pituitary hormone and dura mater grafts. Intracerebral hemorrhage was a very rare event and we do not currently see a need for a policy change nor do we wish to discourage otherwise indicated blood transfusion. However, more research is needed to explore the possible underlying mechanisms. Thanks to Principal Investigator Gustaf Edgren, and our collaborators, especially Klaus Rostgaard and Henrik Hjalgrim who replicated the analyses in Denmark. Links in the comments below.