Acute respiratory distress syndrome (ARDS) is an often-fatal condition that can be caused by lethal pathogens such as H5N1 avian flu, SARS, anthrax, or chemical agents. In response to growing numbers of scares of avian flu and threats of SARS, an international team of scientists from Stockholm to Hong Kong has been researching underlying disease mechanisms for the past 5 years.

Acute respiratory distress syndrome is a severe, acute lung dysfunction to most or all of both lungs. It causes severe shortness of breath and often requires mechanical ventilation because of respiratory failure. Among patients infected with H5N1 bird flu, about 50% die of ARDS.

Lead by Josef Penninger and Yumiko Imai of the Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, the team of scientists has identified oxidative stress and innate immunity as a common susceptibility pathway that controls the severity of acute lung injury.

A press release from IMBA describes what the researchers have come up with.

Based on their findings, “the researchers can now outline a common molecular disease pathway: microbial or chemical lung pathogens trigger oxidative stress machinery. Oxidation products are interpreted as danger signals by the receptor TLR4. Subsequently, the body’s innate immune system is activated. This defense machinery in turn leads to a chain of reactions with severe and often fatal lung damage as a consequence.”

The findings are outlined in a paper published in Cell.