Anti-p200 pemphigoid

Anti-p200 pemphigoid is an autoimmune bullous disorder, first described in 1996. Clinically, it presents with tense blisters, erosions, crusts and erythematous macules/plaques, in addition to mucosal involvement in about 40% of cases, resembling bullous pemphigoid or the inflammatory variant of epidermolysis bullosa acquisita. As in other pemphigoid diseases, autoreactive IgG and/or C3 bind along the cutaneous basement membrane zone. Serum autoantibodies recognize a 200 kDa protein of the dermoepidermal junction that label the dermal side of human salt-split skin by indirect immunofluorescence microscopy. Subsequently, laminin γ1 has been described as a target antigen of anti-p200 pemphigoid. Laminin β4 has also recently been identified as a target antigen. A standardized, highly specific and sensitive detection system for serum anti-laminin β4 IgG is now widely available. This allows for the diagnosis of anti-p200 pemphigoid outside of specialized centres. Current in vitro and ex vivo data point to laminin β4 as the pathophysiologically relevant autoantigen, while in vivo data to clarify the functional relevance of anti-laminin β4 IgG are still lacking. Here, we summarize the current knowledge about the epidemiology, clinical presentation, diagnosis, target antigens, pathophysiology and treatment of this pemphigoid disease.