Potential New Treatment Approach For Severe
Asthma
Potential new treatment approach for severe asthmaSeptember
15, 2005 Tumour necrosis factor (TNF alpha) as
a novel therapeutic target in symptomatic corticosteroid
dependent asthma Thorax 2005 Online First Researchers
have uncovered a potentially new treatment approach
for severe asthma, by blocking a powerful immune
system chemical, present in large amounts in patients
with the severe form of the disease, a small study
in Thorax reveals. Around one in 10 asthmatics
has the severe form of the disease, which frequently
requires progressively higher doses of steroids
in a bid to control symptoms.
Severe asthma is
also associated with a much higher risk of illness
and death than milder forms and accounts for almost
a third of health service costs for asthma The
research team investigated tumour necrosis factor
alpha (TNF alpha), which is found in a range of
chronic inflammatory conditions, including rheumatoid
arthritis, Crohn's disease, and psoriasis.
Included in the study were 26 healthy people,
67 mild asthmatics, and 51 severe asthmatics.
Bronchial fluid and lung tissue samples were
taken from the participants to discover their
levels of TNF alpha. Levels were significantly
higher in those with severe disease and concentrated
in one particular type of immune cell (mast cells)
which are recognised components of the inflammatory
reaction in asthma. TNF alpha levels were low
and similar in those with no asthma or who only
had mild symptoms. This suggests that the high
levels of TNF alpha in severe disease are characteristic
of more chronic disease that is resistant to steroid
treatment, rather than a feature of the disease
itself, say the authors.
Seventeen people with severe asthma who still
had symptoms, despite being treated with a range
of drugs, were also given 25 mg of a drug that
blocks TNF alpha production (etanercept) twice
weekly, injected below the skin for 12 weeks.
Fifteen completed the course. At the end of the
study period, these patients experienced a significant
improvement in symptoms and lung function. Two
patients were able to discontinue one of their
drugs. The treatment also curbed the inflammatory
reaction in the lungs, known as bronchial hyperresponsiveness.
And there were few side effects.
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