Why does flu trigger asthma?
Influenza activates a newly recognized group of immune cells called natural helper cells.
Washington: When asthmatic children are infected with flu, they often land in the hospital gasping for air.
Researchers from Children`s Hospital in Boston have found a previously unknown biological pathway explaining why influenza induces asthma attacks.
Studies in a mouse model reveal that influenza activates a newly recognized group of immune cells called natural helper cells, reports the journal Nature Immunology.
If activation of these cells, or their asthma-inducing secretions, could be blocked, asthmatic children could be more effectively protected when they get the flu and possibly other viral infections, says senior investigator Dale Umetsu, immunologist at the Children`s Hospital.
Although most asthma is allergic in nature, attacks triggered by viral infection tend to be what put children in the hospital, reflecting the fact that this type of asthma isn`t well controlled by existing drugs, according to a Children`s Hospital statement.
"Virtually 100 percent of asthmatics get worse with a viral infection," says Umetsu. "We really didn`t know how that happened, but now we have an explanation, at least for influenza."