Blood donors may pass on small risk of brain bleed to recipients

People who receive blood from a donor who later experiences more than one intracerebral haemorrhage – blood vessels rupturing in their brain – have a heightened risk of experiencing a brain haemorrhage themselves. Although the risk is very small, it suggests that intracerebral haemorrhages may have a transmissible cause.

These brain bleeds are commonly triggered by the accumulation of proteins called amyloid in the walls of the brain’s blood vessels. A few case …