Gel-Based Gene Therapy: A Promising Treatment for Epidermolysis Bullosa

ADITI MADHUSUDAN – For those with epidermolysis bullosa, a rare genetic disorder of the skin, a simple rub on the back can erupt in painful blisters and wounds to the area. The condition, also known as “butterfly disease,” is characterized by fragile skin that blisters easily due to minor mechanical stress. The disease is generally discovered in patients at birth or infancy and can vary in severity. Although blisters due to the epidermolysis bullosa are usually seen on the hands or feet, they can appear anywhere on the body. In some cases, blisters appear in uncomfortable areas, such as the mouth, esophagus, intestines, and bladder. In situations where internal organs and tissue are affected, the disease can be life-threatening. 

Epidermolysis bullosa has different causes and manifestations within the body and is categorized into various subtypes. There are three main types of epidermolysis bullosa: epidermolysis bullosa simplex (EBS), junctional epidermolysis bullosa (JEB), and dystrophic epidermolysis bullosa (DEB) . EBS is generally a dominantly-inherited form of the disease that involves the formation of blisters in the epidermis, which arise due to issues with the genes for Keratins 5 and 14 and plectin. JEB is a recessively-inherited form of the disease that can potentially be fatal as it affects genes Laminin 322, plectin, and α6β4 integrin. Lastly, DEB may either be recessively or dominantly inherited due to issues in the gene for Type VII collagen. 

Although there is no cure for epidermolysis bullosa, a gel-based gene therapy is currently in clinical trials and shows potential. A group of researchers from Stanford tested participants with recessive DEB unable to synthesize Type VII collagen. The gel-based therapy developed by the researchers consists of a modified inactive form of the herpes simplex virus which delivers two copies of the gene to make Type II collagen to host cells.The results of the trial, published in Nature Medicine, show that when the gel and a placebo gel were applied to different wounds for each participant over a period of 25 days, there was great variability in the rates at which wounds treated with the placebo healed and reemerged. On the other hand, almost all wounds treated with the gel therapy closed within a period of 3 months after the treatment. From biopsies, the scientists were able to confirm that the participants who received the gel were able to make collagen VII in their skin cells from as early as nine days after the beginning of treatment and up to three months afterward. Although larger studies are underway to determine the efficacy of this treatment, the gel therapy shows great promise in treating this rare disorder.

Copy Editor: Akshay Nair

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https://news.yale.edu/2020/12/11/research-findings-offer-hope-treatment-inflammatory-skin-condition