Small fragments of DNA, known as cell-free DNA, offer invaluable clues into what’s happening in the body at any given time. And fortunately, these fragments can be recovered from a simple blood sample, a technology which researchers refer to as ‘liquid biopsies’.
In a new study from researchers at the Centre for Human Genetics, the team investigated liquid biopsies from people with sepsis. They found that people with sepsis had over 40 times more cell-free DNA in their blood compared to healthy people. Their data indicates that this is caused by the liver not clearing out this DNA during illness.
Exploring further, the researchers used advanced techniques to understand how cell-free DNA is cut and disposed of, as well as which tissues it comes from. For example, using molecular marks on the DNA allowed them to identify which organs it came from. Doing so confirmed that the cell-free DNA had been floating around in the blood for longer than usual, likely a result of the liver not clearing it.
The team also confirmed that cell-free DNA contains pieces of DNA from bacteria, which means that it could help professionals to detect infections more precisely in the future.
All things considered, these findings could pave the way to faster and more precise diagnostics going forward.
Dr Kiki Cano-Gamez, Postdoctoral Researcher at the Centre for Human Genetics and co-lead author on the study, said: ‘We’ve known for a long time that sepsis patients have a lot of extra DNA in their blood. However, it’s not clear why, and there are many theories about this. This study brings us one step closer to answering this question: it may be caused by the liver. We hope our study will unlock the potential to develop new diagnostics and tests that can help sepsis patients in the future.’
Read the full paper on the Cell Genomics website online: https://doi.org/10.1016/j.xgen.2025.100971