Thaindian News

Washington, May 5 (IANS) Flu virus can cripple the immune systems of otherwise healthy individuals, triggering infections like pneumonia, even as swine flu continues unabated.
Kathleen Sullivan, study co-author, who heads the allergy and immunology division at the Children’s Hospital of Philadelphia, said: “We have a very limited understanding of why some people who get influenza simply have a bad cold and other people become very sick and even die.”

The results of this study give us a much better sense of the mechanisms underlying bacterial infections arising on top of the viral infection, she added.

Sullivan and colleagues recruited paediatric patients with severe influenza and examined the level of cytokines, which serve as the first line initiators of immune response, in the blood plasma.

Although they found elevated levels of cytokines, they also found a decreased response of toll-like receptors, which activate immune cell responses as a result of invading microbes.

This suggests that the diminished response of these receptors may be responsible for the paralysis of the immune system, leading to secondary bacterial infections, said a Children’s Hospital release.

“Despite major medical advances since the devastating flu outbreak of 1918 and 1919, influenza virus infection remains a very serious threat,” said John Wherry, deputy editor of the Journal of Leukocyte Biology, which published the study.

“The current swine flu outbreak is a grim reminder of this fact. The work by Dr. Sullivan and colleagues brings us a step closer to understanding exactly what goes wrong in some people who get the flu, so, ultimately, physicians can develop more effective treatment strategies,” Wherry added.