Researchers, including one of Indian-origin, have identified a set of 11 genes that could act as markers to quickly and accurately diagnose patients with sepsis, a whole-body inflammation syndrome which is the leading cause of hospital deaths in the US.
Sepsis occurs when the immune system wildly overreacts to the presence of infectious pathogens. Majority of sepsis cases are caused by bacterial rather than viral infections and are best treated with antibiotics.
But antibiotics are unhelpful - and can be counterproductive - when a patient has an outwardly similar but infection-free syndrome called sterile inflammation, an intense, systemic inflammatory response to traumatic injuries, surgery, blood clots or other noninfectious causes.
"It's critical for clinicians to diagnose sepsis accurately and quickly, because the risk of death from this condition increases with every passing hour it goes untreated," said Purvesh Khatri, assistant professor of biomedical informatics research at Stanford University School of Medicine.
In practice, distinguishing sepsis from sterile inflammation is a toss-up. Right now, the only diagnostics that can help do this are too slow or too inaccurate, or both, Khatri said.
"We think we've got the makings of a diagnostic blood test that will allow clinicians to distinguish between these two types of inflammation," Khatri said.
Khatri and colleagues found a gene-activation pattern that distinguishes septic from sterile systemic inflammation.
"We thought there might be some genes that the body turns on specifically in response to infection, and after sifting through a huge amount of data we found them," said lead author Timothy Sweeney, a postdoctoral scholar now doing a residency in general surgery at Stanford.
Researchers analysed a number of publicly available data sets containing results of studies that had assessed activity levels for the entire human genome in sepsis cases, as well as in cases of sterile inflammation.
In all, they looked at more than 2,900 blood samples from nearly 1,600 patients in 27 different data sets containing medical information on diverse patient groups - suffering from sterile inflammation or sepsis, including patients who already had sepsis when first admitted to the hospital as well as patients who were diagnosed with it later - in addition to healthy control subjects.
Researchers found 11 genes as likely sepsis markers. They confirmed this 11-gene signature in an additional 18 cohorts comprising more than 1,800 patient samples.
"We were able to identify a slight bump in activity of these 11 genes in patients two to five days prior to their clinical diagnosis," said Khatri.
That could mean getting an earlier diagnosis than can be achieved with current approaches, he said.
