An international team of Canadian and Spanish scientists have found the first potential immunological clue of why some people develop severe pneumonia when infected by the pandemic H1N1 virus.
The study analyzed different levels of regulating molecules for 20 hospitalized patients, 15 outpatients and 15 control subjects in 10 Spanish hospitals during the first pandemic wave in July and August 2009. Researchers from the Hospital Clinico Universitario de Valladolid in Spain and the University Health Network found high levels of a molecule called interleukin 17 in the blood of severe H1N1 patients, and low levels in patients with the mild form of the disease.
Interleukin 17 is produced by the body and is important in the normal regulation of white blood cells which fight infection and disease. In certain circumstances, the molecule becomes "out of control", leading to inflammation and autoimmune diseases. The research paper titled, "Th1 and Th17 hypercytokinemia as early host response signature in severe pandemic influenza" is published in the December issue of the Journal of Critical Care.