Adhesive stripping to remove epidermis in junctional epidermolysis bullosa for revertant cell therapy.
Replacing mutant skin in epidermolysis bullosa (EB) by epithelial sheets of transduced autologous keratinocytes is the essential surgical step of ex vivo gene therapy. The same applies for revertant cell therapy in which epithelial sheets of revertant autologous keratinocytes are used. Revertant cells can be found in patches of normal skin in patients with junctional EB (JEB) due to revertant mosaicism caused by in vivo reversions. To develop a technique of adhesive tape stripping as a method for epidermis removal to prepare the acceptor site for revertant cell therapy in a patient with revertant mosaic JEB. We performed revertant cell therapy on a patient with mosaic type XVII collagen-deficient non-Herlitz JEB. Skin biopsies were taken from revertant skin on the wrist. Graft production took place on a 3T3-J2 feeder layer resulting in two 6 x 7 cm grafts. An innovative method that uses the pathological plane of least resistance of JEB skin was developed to prepare the acceptor site. A polyacrylate adhesive plaster was placed on the skin and then pulled off with the epidermis. The epidermis was easily removed with the plaster. The skin separated at the level of the lamina lucida, leaving a bloodless wound bed of naked lamina densa. Transplantation was successful; the acceptor site healed without scarring. However, blistering could be provoked. The functional repair was not achieved due to the low percentage of revertant cells in the graft. We conclude that adhesive stripping is a simple, effective and almost painless procedure for removing epidermis for ex vivo cell therapy in EB.