Researchers identify a new set of immune cells linked to bacterial sepsis

Sepsis is a life-threatening immune response to infection that can lead to tissue damage, organ failure and amputation. It is fatal in up to 34% of cases and is the most expensive medical condition to treat in the United States. Early detection has been particularly challenging in sepsis, because it’s still not clear what triggers it and it does not always present the same way.

In a recent study, MGH investigators used single cell RNA sequencing to compare samples from hospitalized patients with early sepsis and a control group who had infections without sepsis. By doing so, the team identified a new subset of immune cells that are significantly expanded in patients with sepsis, as well as two genes that together serve as a biomarker for sepsis. The team is not yet sure if the newly discovered immune cells contribute to the onset of sepsis or are a byproduct of it.

“Not only might this be a way to monitor patients with known infections to predict which of them will develop sepsis, but it could also lead to medications that interfere with the dysbiosis and thereby treat sepsis more effectively than we currently do,” says Marcia Goldberg, MD, of the MGH Infectious Diseases Division and the Broad Institute. Goldberg led the study along with Nir Hacohen, PhD, Michael Filbin, MD, and Miguel Reyes, from the Broad Institute.

The team is currently seeking funding for a larger study. “We can dig deeper once we look at more patients,” says Goldberg.

Study finds brains of young men with autism have lower levels of a protein connected to inflammation and metabolism

MGH investigators have used advanced imaging technology to show, for the first time, that the brains of young men with autism spectrum disorder have low levels of a protein that appears to play a role in inflammation
and metabolism.

While the cause of autism is still unknown, growing evidence has linked the disorder to neuroinflammation – inflammation of the brain tissue.

The study team compared the brains of 15 young adult males with autism – of varying symptom intensity – to 18 control subjects who were similar in age. Going into the study, investigators thought they would see increased levels of translocator protein (TSPO) in patients with autism, as TSPO has previously been connected to neuroinflammation. To their surprise, however, the opposite occurred.

The scans showed that the subjects with autism had lower levels of TSPO than healthy subjects and that those with the lowest levels also demonstrated the most severe symptoms. The brain regions where the low TSPO levels were found have previously been linked to autism and are believed to regulate brain functions related to the processing of emotions, interpreting facial expressions, empathy and relating to others.

“Our study has generated new hypotheses that now need to be investigated,” says Nicole Zurcher, PhD, of the Martinos Center for Biomedical Imaging, who led the study along with Jacob Hooker, PhD, director of Radiochemistry at the Martinos Center.