SATURDAY, OCTOBER 1, 2016

Researchers map elements of deadly immune storm caused by flu

Scientists mapped important elements of an immune overreaction that can kill patients with certain flu virus infections, according to a study recently published in Proceedings of the National Academy of Sciences.

Researchers with The Scripps Research Institute mapped the immune overreaction process, known as a cytokine storm, which is an overproduction of immune cells and their activating compounds. The lung inflammation and fluid buildup from a cytokine storm can result in respiratory distress and can be contaminated by a secondary bacterial pneumonia.

Cytokine storms are now seen as the likely cause of significant mortality during the 1918-20 Spanish flu epidemic that killed more than 50 million people worldwide. Immune overreaction may have also contributed to the recent H1N1 swine flu and H5N1 bird flu epidemics.

After mapping the cytokine storm, the researchers used a candidate drug compound to activate immune-damping receptors on endothelial cells lining blood vessels in the lungs to quiet the cytokine storm in mice and ferrets. The team found the compound prevented most of the typical mortality from H1N1 infection.

"We show that with this type of drug, we can quiet the storm enough to interfere with the virus-induced disease and lung injury, while still allowing the infected host to mount a sufficient immune response to eliminate the virus," John Teijaro, the first author of the study, said.

The drug, CYM5442, has been licensed to the pharmaceutical company Receptos. It is currently in Phase III clinical trials for treating relapsing-remitting multiple sclerosis and in Phase II trials for ulcerative colitis.