Researchers Find Key Enzyme to Improve the Treatment of Eczema

The identification of a key enzyme in the development of eczema may lead to better treatment of the disorder, according a study in the Journal of Investigative Dermatology.

In those with eczema, also called atopic dermatitis, the protective barrier of the skin gets broken down, allowing the skin to become more vulnerable to entities from the external environment. This then leads to itching, inflammation, dryness, and further degradation of the protective barrier on the skin.

"The symptoms people often experience with eczema make them more likely to avoid going outside their homes or to work," said senior author David Granville, PhD, a professor in the University of British Columbia's (UBC) faculty of medicine and researcher at Vancouver Coastal Health Research Institute, in a press release. "It is estimated that the annual cost of eczema in North America is over $5.5 billion because of how it impacts people's health and well-being."

In the study, the researchers observed that a key enzyme called Granzyme B is associated with the itchiness and other severe symptoms for those with eczema. They discovered that Granzyme B cleaves through the proteins that connect cells, making it easier for allergens to penetrate, which subsequently results in a weakening of the skin barrier.

"Between cells in our skin are proteins that anchor them tightly together," Granville said in the press release. "In some inflammatory diseases, such as eczema, Granzyme B is secreted by cells and eats away at those proteins, causing these bonds to weaken and the skin to become further inflamed and itchy."

The researchers found that by either eliminating Granzyme B through genetic modification or inhibiting it with a topical gel, they could prevent damage to the skin barrier and significantly reduce the severity of eczema symptoms.

"Previous work had suggested that Granzyme B levels correlate with the degree of itchiness and disease severity in patients with atopic dermatitis; however, there was no evidence that this enzyme played any causative role," Granville said. "Our study provides evidence that topical drugs targeting Granzyme B could be used to treat patients with eczema and other forms of dermatitis."

Currently, corticosteroid creams are commonly prescribed to treat eczema in those with severe itching and rashes. However, this cream can also cause the skin to thin over time, which can lead to further damage and infection.

The study authors asserted that a gel or cream that specifically targets Granzyme B could reduce the severity of eczema and be safer for patients in the long term.

"A gel or cream that blocks Granzyme B could have fewer if any side-effects and circumvent the itch-scratch cycle, making flare-ups less pronounced," said lead author Chris Turner, PhD, a former UBC postdoctoral fellow in Granville's laboratory, in the press release.

Although a therapy that targets Granzyme B is not yet commercially available, the study authors said this treatment approach shows great promise.

REFERENCE

Researchers uncover novel approach for treating eczema. University of British Columbia; June 10, 2020. eurekalert.org/pub_releases/2020-06/uobc-run061020.php. Accessed August 19, 2020.