Friday, September 16, 2005

Dose of worms may ease asthma

ALLERGY-prone people are to be given an innovative therapy: hookworms that suck blood from their guts.

The idea is that the worms will prime their immune systems so they no longer react to grass pollen, cat dander and dust mites. A trial of 50 allergy sufferers in the UK run by David Pritchard and colleagues at the University of Nottingham will start within weeks, and if it works, researchers plan to see if the same trick can be used to treat asthma.

Like many parasites, the human hookworm, Necator americanus, has evolved ways to avoid being killed by the body's immune system. Although we don't know precisely how, it appears to promote multiplication of "regulatory T-cells". These in turn suppress other white blood cells that become overactive in people suffering allergies and asthma