Severe Asthma Patients Often Unresponsive to Conventional Treatments, Scientists Investigate Why

Patients with the most severe form of asthma produce special substances in their airways when they take medicine during an asthma attack that's blocking the treatment from working.

A EurekAlert! report specified that in the study, Rutgers researchers, in collaboration with scientists at Genetech, a member of the Roche Group, said two different so-called growth factors, naturally arising substances that stimulate cell proliferation, activate in the airways of severe asthma patients as they breathe in corticosteroids used as an emergency treatment during an asthma attack.

The finding was made as the study authors examined an enduring mystery in asthma treatment. In relation to their investigation, the study investigators asked why some patients suffering the most from the disease frequently have the least success with conventional rescue treatments.

Out of over 25 million people in the United States who have asthma, between five percent and 10 percent are suffering from severe asthma, the American Lung Association reported.

Corticosteroids Don't Work in People with Severe Asthma

Essentially the corticosteroids used to lessen swelling and irritation in people's airways with moderate asthma frequently fail to work in those with severe asthma. Patients with severe asthma have more frequent breathing problems than others.

In their study published in Science Translational Medicine, the authors found that inhaled steroids in severe asthma patients promote the secretion of growth factors known as the fibroblast growth factor or FGF and granulocytic colony-forming growth factor or G-CSF, in airway lining cells identified as the epithelium.

Reynold Panettieri Jr., the author of the study and a professor of medicine at Rutgers Robert Wood Johnson Medical School and vice-chancellor of Clinical and Translational Science, believes this response explains why patients with severe asthma are unresponsive to such conventional treatment.

Growth Factors

The researchers compared samples of bronchial airway epithelial cells or BAECs that had been exposed to inhaled corticosteroids and collected from three groups, including those with severe asthma, moderate asthma, and healthy volunteers.

By carrying out a genetic assessment to identify what genes had been turned on in the BAECs, the scientists found that the FGF and G-CSF growth factors had been expressed only in the cells of patients with severe asthma.

According to Panettieri, growth factors are essential for regulating various cellular processes. In the case of an asthma attack in patients with severe asthma, the growth factors identified in the cells lining the major connecting airways are working directly against the action of the corticosteroids.

The study findings have suggested different cellular pathways work in the severe asthma patients' cells, specifically those involved in inflammation.

Unresponsive to Conventional Treatment

A similar Medical Xpress report specified that here is how the study investigators envision a new medicine may work: In a study in rodent models, scientists discovered if they blocked the cascade of chemicals that ultimately triggers the growth factors to be secreted, corticosteroids are effectively reversed airway inflammation and even prevented scarring of tissue.

Panettieri also explained that their study had uncovered potential mechanisms to explain why patients with severe asthma are not responsive to conventional treatment.

He added if they could uncover new approaches to therapy that directly affect that mechanism, they may be able to restore sensitivity to the steroid and enhance outcomes.

Related information about asthma is shown on Osmosis' YouTube video below:

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