Flu Severity Predicted with Key Immune Response

St. Jude Children's Research Hospital scientists have conducted a study involving 84 individuals that had community-acquired influenza during the 2009-2010 and 2010-2011 flu seasons. The study is still underway, but the scientists have already identified a key immune response to the flu.

The immune response is believed to soon help doctors identify which newly diagnosed flu patients are likely to develop severe symptoms. It will also help explain why infants and toddlers have an increased risk for catching the flu. The study will appear in the upcoming issue of the American Journal of Respiratory and Critical Care Medicine.

Of the 84 participants in the study, ages ranged from 3-weeks-old to 71-years-old, including 41 infants and toddlers under the age of 23 months. Regardless of age, the patients who possessed elevated levels of three certain immune system regulators (cytokines) early in their infection were more likely to suffer severe symptoms of the flu.

These cytokines serve to help regulate inflammation driven by one's innate immune response. The response serves as the frontline of the body's defense against the flu and other viruses/illnesses until antibodies and T cells are ready to get in on the action and provide further help. The testing revealed that children possessed a more aggressive inflammatory response than adults, which was a surprise. Previous studies have shown that children typically have a weaker response, but St. Jude's study tested the cytokine levels in the blood, nose and sinuses of the participants, which was one of the first studies to do so.

Additionally, inking evidence between inflammatory cytokine levels and white blood cells called monocytes were among the study's findings. Monocytes have the ability to provide a variety of inflammatory responses based on cytokine secretion as well as other activities. While some of the monocytes' responses can be beneficial, others can be an impediment during the recovery process.

This study could provide useful and groundbreaking information for treating different types of flu patients, which is crucial since the virus is the leading cause of illness and death worldwide.

To read more about this study, visit this St. Jude Hospital article.