Adult Respiratory Distress Syndrome (ARDS) is a
condition where the patient suffers from breathlessness, low blood oxygen
levels and lung inflammation that could progress to respiratory failure. It is
caused by a number of conditions like sepsis, bacterial pneumonia, severe trauma,
multiple transfusions, aspiration of gastric contents, drug overdosage and post
cardiopulmonary bypass surgery.
White blood cells, called neutrophils, accumulate in
the lungs during ARDS. They help to fight against infection, but could also
contribute to inflammatory damage in the lungs.
Different people are affected to variable extents by
ARDS. Certain factors like genetic,
environmental and complex demographic factors are known to be responsible for
this heterogenicity. Researchers now suggest that a variable expression of
interferon - stimulated genes (ISGs) could also be responsible for the variable
response in ARDS patients.
Viral infections result in an increased production
of interferons due to increased expression of interferon- stimulated genes
(ISG). Interferons are proteins that play an important role in the inflammatory
process. Researchers suggest that
increased expression of ISGs alters neutrophil functions and impairs their
ability to fight against bacterial infection. During this study, this
impaired defense was observed against Staphylococcal aureus but not Pseudomonas
with high ISGs post ARDS could be increasingly susceptible to infections caused
by S aureus bacteria. On the other hand, patients
with low expression of ISGs may be less susceptible to this infection. Thus, ISG expression could explain the
variability in patients suffering from ARDS -associated complications.
the already known genetic, environmental, and complex demographic factors,
increased ISG expression may also be responsible for the variability of
neutrophil response in ARDS.
1. Malcolm KC, Kret JE, Young RL, Poch KR, Caceres SM, et al. (2011)
Bacteria-Specific Neutrophil Dysfunction Associated with Interferon-Stimulated
Gene Expression in the Acute Respiratory Distress Syndrome. PLoS ONE 6(7):