Asthma Cause Discovered

Researchers at Harvard Medical School have discovered that "a little-known group of natural killer cells" are the actual cause of asthma.

"These cells actually make up a small population of cells in our blood," [Dale Umetsu, a professor of pediatrics] points out. "But in the lungs of people with asthma, they apparently proliferate and overexpand. Novel drugs and other treatments would be aimed at reducing their numbers in the lungs, or preventing them from becoming activated."

That could be tricky. "We are working on ways to get at the natural killer T cells without knocking out helper T cells, which are involved in many different kinds of protective responses."