An important screening test for serum autoantibodies in pemphigoid diseases is indirect immunofluorescence on human salt-split skin. The majority of patients with pemphigoid diseases exhibit autoantibodies binding to the epidermal side of the artificial splits targeting mainly BP180, BP230 and α6β4 integrin. The remainder of patients (10%) with pemphigoid diseases display autoantibodies labelling the dermal side of the blister. The bullous pemphigoid (BP) is the  most frequent form of the bullous autoimmune dermatosis. The antibodies in the serum of bullous pemphigoid (BP) patients react with the 16th non-collagenous domain (NC16A) of BP180. Additionally, many antibodies of patients recognize epitopes on the BP180 ectodomain.

The diagnosis of these patients takes place in the autoimmune laboratory of the Department of Dermatology, Lübeck with the use of Western blot analysis. This test obtains a specificity of only 80%.

The project focuses on the preparation of four different fragments of the BP180 ectodomain and the investigation of the reactivity of autoantibodies in serum samples from bullous pemphigoid and mucous membrane pemphigoid patients with these fragments by Western blotting. The sensitivity and specificity of this method will be optimised to establish a useful test for routine examinations.