Model systems duplicating epidermolysis bullosa acquisita: a methodological review

Epidermolysis bullosa acquisita (EBA) is a chronic mucocutaneous autoimmune skin blistering disease, in which generation of autoantibodies to type VII collagen (COL7) is the key factor for pathogenesis. Much of this current understanding of EBA pathogenesis has been obtained through the development and further application of respective model systems. In vitro model systems of EBA duplicate neutrophil activation by immune complexes of COL7 and anti-COL7 antibodies. Blister induction by anti-COL7 antibodies can be reproduced ex vivo by incubation of cryosections of human skin with anti-COL7 antibodies and neutrophils. Furthermore, EBA can be induced in mice by transfer of human or rabbit anti-COL7 IgG into adult mice, or by immunization of susceptible mouse strains with an immunodominant fragment within the non-collagenous 1 domain of COL7. However, our understanding of EBA pathogenesis is largely limited to mechanisms in autoantibody-induced tissue injury. Furthermore, these model systems of EBA have not been used to a large extent to evaluate the potential of novel treatment options. To foster a broader use of these elaborate model systems to specifically address these open issues, this review focuses on a detailed description of model systems for EBA, which should allow for a broad use of these models. This will hopefully lead to a better understanding of EBA pathogenesis, as well to a benefit in patient care.