Do Your Genes Know What’s Making You Sick?

Tim Sweeney had been a surgeon for only one year, but he was already fed up with a seemingly unsolvable and dangerous problem. Many patients who underwent a major operation or trauma seemed unwell after, with a fever and a high heart rate. Many looked like they had a postoperative infection, though Sweeney knew the actual rate of those was just 5 to 10 percent. Doctors can give powerful medicine just in case, but that carries its own risks to the patient and contributes to the rise of drug-resistant pathogens. “You can’t just go around treating everyone with antibiotics,” Sweeney told me. “It’s bad for them and it’s bad for the system.”

This conundrum set Sweeney on a mission. In 2011, he joined the lab of Purvesh Khatri, a computational immunologist at Stanford, in hopes of developing a new kind of test that might help surgeons sort out which describing how the genes in our immune system behave in response to sepsis, the life-threatening condition that may result from an infection. A year later, the duo, along with a third partner, founded a company called Inflammatix, which became one of a growing number of start-ups trying to develop diagnostic tools that detect infection by measuring exactly this sort of activity.