Physicians could determine how long it will take a patient to recover from surgery by looking at the activity in a small set of immune cells right after the procedure.
Today, people who undergo surgery have no idea whether it will take days or months to recover and doctors have no way of telling them, this new finding could change that, the Stanford University School of Medicine reported.
To make their findings researchers looked at blood samples taken from middle-aged to older patients undergoing hip-replacement procedures. The team used technology called single-cell mass cytometry to look at a wide variety of biochemical features both inside and outside of immune cells, allowing researchers to determine their activity levels.
"We learned that within the first 24 hours after surgery you can find strong clues in blood that reveal what shape a particular patient is going to be in two weeks later," said senior co-author of the study Dr. Martin Angst, professor of anesthesiology, pain and perioperative medicine.
The finding could lead to the development of a personalized diagnostic blood test that would predict recovery after major surgery. This test could help physicians decide whether or not to put a patient on enhanced recovery-optimizing regimens following surgery. If the molecular function is understood at an even deeper level researchers could even learn to manipulate the immune system to help the body recover more quickly.
In the study the team analyzed blood samples from 32 patients between the ages of 50 and 80 who were undergoing hip-replacement surgery. The samples were drawn one hour before surgery, 24 and 72 hours after the procedure, and four to six weeks after surgery. The patients were also asked to fill out a questionnaire that assessed their degree of pain and fatigue every three days for six weeks.
The team identified a pattern of rises and falls in numbers of diverse immune cell types and changes in activity following surgery.
"Amazingly, this post-surgical signature showed up in every single patient," Angst said, but the magnitude of the responses varied among the patients. Change in the activation states of key interacting proteins at one hour and 24 hours after surgery were found to account for between 40 and 60 percent of the variation of recovery time among patients.
In the future the researchers hope to identify pre-operation immune signatures that could predict a patient's recovery rate.
"If we could predict recovery time before surgery even took place," said postdoctoral scholar Dr. Brice Gaudilliere, now a clinical instructor in anesthesia. "We might be able to see who'd benefit from boosting their immune strength beforehand, or from pre-surgery interventions such as physical therapy. It might even help us decide when or if a patient should have surgery."
The findings were published Sept. 24 in the journal Science Translational Medicine.
