Women's Health

Postoperative delirium biomarker identified

An interdisciplinary team of HMS researchers at Beth Israel Deaconess Medical Center has identified a single protein present in the blood that is associated with increased risk of postoperative delirium. The finding sheds light on a potential pathophysiological mechanism underlying delirium and paves the way for a noninvasive, cost-effective test to guide prediction, diagnosis, and monitoring of delirium. Preoperative blood tests for these proteins could help physicians determine which patients are at higher risk for developing this form of confusion.

Delirium, a common syndrome among older adults, is a form of acute confusion that is characterized by poor attention, disorientation, impaired memory, delusions, and abrupt changes in mood and behavior, particularly in critically ill patients in the ICU, in older patients with multiple health issues, and in those who have recently undergone surgery. Patients who experience delirium are also at increased risk of long-term cognitive decline.

Despite its pervasiveness, delirium has remained a clinical diagnosis with no established diagnostic tests. The team notes that the discovery of a reliable biomarker could change that.

For the study, the researchers analyzed more than 1,300 proteins in blood samples from participants in the Successful Aging after Elective Surgery study, which investigates the long-term outcomes and novel risk factors for delirium after surgery or hospitalization in older adults. They found that a single protein, known as chitinase-3-like-protein-1, was present at higher concentrations in the blood both before and after surgery in patients who experienced delirium compared with patients who did not develop postoperative delirium. This protein is also linked to aging and age-related conditions, including Alzheimer’s disease, and plays a critical role in the body’s type 2 immune response.

In addition, the team found that patients who had high preoperative levels of the protein as well as high postoperative levels of an immune-related protein called interleukin-6 were at increased risk of delirium.

The findings add to other research that  suggests a link between delirium, aging, and Alzheimer’s disease.

Vasunilashorn SM et al., Journal of Gerontology: Medical Sciences, February 2021

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