ANN ARBOR, Mich. – A respiratory virus common among infants and children during cold and flu season may become a threat to the old too, especially those who have survived sepsis.
A University of Michigan Health System study showed that following sepsis, a life-threatening blood infection, survivors may be more prone to respiratory viral infections, such as RSV, which can clog airways, cause wheezing and is a leading cause of bronchiolitis in infants.
The U-M study published in the November issue of Shock suggests a new threat for those recovering from severe sepsis.
“Prior research on survivors of sepsis have focused on secondary bacterial infections, however, recently we have identified that vulnerability of survivors of sepsis is not limited to bacterial infections, but also viral infections of the lung,” says study author Sumanta Mukherjee, Ph.D., an immunology expert in the U-M Department of Pathology.
For physicians, the findings highlight the potential for viral infections of the lung to complicate the recovery of patients suffering from severe sepsis.
Sepsis is a condition that’s becoming one to watch among the elderly, as hospitalizations for sepsis doubled in the U.S. from 2000-2008; a majority of them over age 65, according to federal figures.
Patients with sepsis are most often treated in intensive care units for the systemic inflammatory response that can damage organs and rapidly become life-threatening. Those who survive sepsis may develop an altered inflammatory response.
Using animal models, the authors revealed a propensity for survivors of sepsis to produce IL17, a type of immune signal molecule that can restrict immunity to some viral infections.
“Critical care physicians should be aware of RSV and other viral infections of the lung when managing the short-term and long-term care of patients diagnosed with severe sepsis,” says William F. Carson IV, Ph.D., a research investigator at the U-M Medical School.
Learning more about IL17 and offsetting its ability to worsen lung inflammation could lead to better treatments for patients suffering from viral infections such as RSV, authors say.
Additional authors: RM Allen, Nicholas W. Lukacs, Ph.D., Steve L. Kunkel, Ph.D., all of the University of Michigan Health System.
Reference: “STAT3-Mediated IL-17 Production by Post-septic T Cells exacerbates viral immunopathology of the lung,” Shock. November 2012, Vol. 38, Issue 5.
Funding: Supported by grants R01 AI073876 and R01 HL031237 from the National Institutes of Health.