Dec. 21, 2009 -- A new type of gene therapy may help stop the progression of
emphysema in young people who
have an inherited form of the deadly disease.
Researchers say previous attempts to correct the gene mutation that
predisposes young people to emphysema have failed to achieve lasting
But a new study shows a different approach that targets cells known as
alveolar macrophages to deliver the gene therapy to the lungs of mice with this form
of inherited emphysema was successful in treating the condition for two
Emphysema is a progressive lung disease that causes
severe shortness of breath. There is no cure for the disease.
People born with a genetic mutation that causes a deficiency in alpha-1
antitrypsin are predisposed to an early form of emphysema as well as cirrhosis
of the liver.
Researchers say this single gene defect makes the condition an ideal
candidate for gene therapy, which would replace the defective gene with a
normal one. But the problem until now has been finding the right cell in which
to transfer the gene and deliver it to the lung.
In the study, published in the Journal of Clinical Investigation,
researchers developed a system to target alveolar macrophage (AM) cells within
the lungs of mice with alpha-1 antitrypsin deficiency. AM cells play a key role
in the development of emphysema.
The results showed a single treatment of the gene therapy successfully
delivered healthy human alpha-1 antitrypsin genes to 70% of the AM cells in the
"The lung macrophages carrying the therapeutic gene survived in the lungs'
air sacks for the two-year lifetime of the treated mice," says researcher
Darrell Kotton, MD, associate professor of medicine and pathology at the Boston
University School of Medicine, in a news release.
As a result, researchers say the symptoms and progression of emphysema in
mice that received the gene therapy were significantly improved compared with