Post-surgery recovery rates, even from identical procedures, vary widely from patient to patient. Some feel better in a week. Others take a month to get back on their feet. And – until now, anyway – nobody has been able to accurately predict how quickly a given surgical patient will start feeling better. Docs don’t know what to tell the patient, and the patient doesn’t know what to tell loved ones or the boss.
Worldwide, hundreds of millions of surgeries are performed every year. Of those, tens of millions are major ones that trigger massive inflammatory reactions in patients’ bodies. As far as your immune system is concerned, there isn’t any difference between a surgical incision and a saber-tooth tiger attack.
In fact, that inflammatory response is a good thing whether the cut came from a surgical scalpel or a tiger’s tooth, because post-wound inflammation is an early component of the healing process. But when that inflammation hangs on for too long, it impedes rather than speeds healing. Timing is everything.
In a study just published in Science Translational Medicine, Stanford researchers under the direction of perioperative specialist Martin Angst, MD, and immunology techno-wizard Garry Nolan, PhD, have identified an “immune signature” common to all 32 patients they monitored before and after those patients had hip-replacement surgery. This may permit reasonable predictions of individual patients’ recovery rates.
In my news release on this study, I wrote:
The Stanford team observed what Angst called “a very well-orchestrated, cell-type- and time-specific pattern of immune response to surgery.” The pattern consisted of a sequence of coordinated rises and falls in numbers of diverse immune-cell types, along with various changes in activity within each cell type.
While this post-surgical signature showed up in every single patient, the magnitude of the various increases and decreases in cell numbers and activity varied from one patient to the next. One particular factor – changes, at one hour versus 24 hours post-surgery, in the activation states of key interacting proteins inside a small set of “first-responder” immune cells – accounted for 40-60 percent of the variation in the timing of these patients’ recovery.
That robust correlation dwarfs those observed in earlier studies of the immune-system/recovery connection – probably because such previous studies have tended to look at, for example, levels of one or another substance or cell type in a blood sample. The new method lets scientists simultaneously score dozens of identifying surface features and goings-on inside cells, one cell at a time.
The Stanford group is now hoping to identify a pre-operation immune signature that predicts the rate of recovery, according to Brice Gaudilierre, MD, PhD, the study’s lead author. That would let physicians and patients know who’d benefit from boosting their immune strength beforehand (there do appear to be some ways to do that), or from pre-surgery interventions such as physical therapy.
This discovery isn’t going to remain relevant only to planned operations. A better understanding, at the cellular and molecular level, of how immune response drives recovery from wounds may also help emergency clinicians tweak a victim’s immune system after an accident or a saber-tooth tiger attack.
Previously: Targeting stimulation of specific brain cells boosts stroke recovery in mice, A closer look at Stanford study on women and pain and New device identifies immune cells at an unprecedented level of detail, inside and out
Photo by yoppy