Immune System Response to Acute Brain Hemorrhage Characterized

A team of researchers from Yale and MIT used RNA-sequencing, to find out that CD14+ macrophages and neutrophils change rapidly in the brain over the first few days after the hemorrhage. They were also able to find signatures in the macrophages that were consistent in patients with good recovery. Their findings were published in Science Immunology. 

"Our goal was to find out, for the first time, how certain key cells of the immune system are activated when they enter the brain after a hemorrhage and how this may shift over the first week. This is a critical time for our patients," said Lauren Sansing, lead researcher.

The team used detailed patient outcome measures collected by a clinical trial to identify key molecular circuits within CD14 macrophages that correlated with good neurological outcomes. Michael Askenase, adds  "We found that these cells preferentially use glycolytic metabolism to generate a key anti-inflammatory lipid known as prostaglandin E2 that, if it activates the right receptor, may have broad pro-recovery effects not only on neighboring immune cells, but also on brain-resident neurons and glia."

The study serves as a model for future studies to leverage a brain hemorrhage clinical trial to gain significant insight into the fundamental mechanisms of the disease and provide a more targeted approach to treating ICH.