Signalling and targeted therapy of inflammatory cells in epidermolysis bullosa acquisita

Pemphigoid diseases (PDs) are chronic and life-threatening autoimmune diseases of the skin and mucous membranes. PDs are characterized and caused by autoantibodies targeting components of the basement membrane. In the PD epidermolysis bullosa acquisita (EBA), the target autoantigen is type VII collagen. Current treatment options of PD, especially EBA, are limited and are mostly based on systemic immunosuppression. Animal models of PD have greatly advanced our understanding of PD pathogenesis. This has led to the identification of several novel therapeutic targets, including signalling molecules. Herein, the contribution of signalling molecules in the pathogenesis of the PD EBA and the effects of pharmacological targeting of these pathways are reviewed in detail. The p38 MAPK, ERK1/2, AKT, PI3Kβ, Hsp90, RORα, PDE4, Src kinases and CARD9 have been demonstrated to be critically involved in EBA pathogenesis. With the advent of new signal transduction inhibitors, we expect that the so far poor prognosis of EBA and other PD will improve significantly in the future.