Once-Overlooked Therapy Effectively Treats Genetically-Caused Emphysema

Once-Overlooked Therapy Effectively Treats Genetically-Caused Emphysema

What was once an overlooked treatment may soon be a well-accepted therapy for genetically-caused emphysema as a result of work conducted at Toronto Western Hospital. A study entitled “Intravenous Augmentation Treatment and Lung Density in Severe α1 Antitrypsin Deficiency (RAPID): A Randomised, Double-Blind, Placebo-Controlled Trial,” published in The Lancet, identified that intravenous α1 proteinase inhibitor (A1PI) is effective in slowing the progression of emphysema.

“Augmentation therapy not only preserves lung structure, but likely adds years of life,” said Dr. Kenneth Chapman, Director of the Asthma and Airways Centre at Toronto Western Hospital, in a news release. “Patients with this condition need access to timely diagnosis and treatments to ensure they receive the best possible care.”

The study evaluated 177 patients with severe α1 antitrypsin deficiency who were non-smokers. Patients were split into groups of A1PI treatment or placebo, and treatment last for two years. At baseline and points throughout the study, patients were evaluated for computed tomography (CT)-measured lung density at total lung capacity (TLC) and functional residual capacity (FRC). This metric provided a more sensitive indication of the efficacy of A1PI than spirometry, which is often used to measure the efficacy of lung disease treatments.

Annual rate of lung density loss at TLC was significantly less in the A1PI-treated patients. However, there was no difference between A1PI and placebo in terms of annual rate of lung density loss at FRC or in terms of adverse events. Since A1PI treatment slowed the progression of emphysema, Dr. Chapman believes that “We can now say with certainty that augmentation therapy is effective and should be given to patients with emphysema caused by this deficiency.”

Genetically-caused emphysema occurs in individuals even without exposure to tobacco smoke. It can result from a deficiency of α1 antitrypsin, which is a lung protecting protein synthesized in the liver. A genetic mutation causes the protein to build up in the liver rather than be distributed to the lungs. Treating patients with augmentation therapy infuses their body with α1 antitrypsin to increase the level in the lungs.

It is important to note that A1PI is not effective in patients with the more common forms of lung disease, such as chronic bronchitis, chronic obstructive pulmonary disease (COPD), or common emphysema. However, for individuals such as Ken Bee who have α1 antitrypsin deficiency, the therapy may be of great benefit and has been around for more than 25 years. “Without this treatment my symptoms would have progressed,” said Mr. Bee.

In the seven years since he was diagnosed with α1 antitrypsin deficiency and began treatment, his lung function has remained steady. “My hope is that more people will recognize the benefit it has to patients,” he concluded.

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