What is the autoantibody target in bullous pemphigoid?

In bullous pemphigoid, the autoantibody target is the hemidesmosomes, which are structures that attach the basal layer of the epidermis to the underlying dermis. The primary autoantibodies in this condition are directed against proteins in the hemidesmosome complex, specifically BP180 (also known as type XVII collagen) and BP230. These proteins play a crucial role in maintaining the integrity of the skin's epithelium.

When these autoantibodies bind to their targets, it triggers an inflammatory response that leads to the separation of the epidermis from the dermis, resulting in the formation of blisters. This autoimmune reaction is distinct from other conditions such as pemphigus vulgaris, where the autoantibodies target desmogleins, proteins involved in the adhesion between keratinocytes. Therefore, recognizing hemidesmosomes as the target of the immune response highlights the distinct pathophysiology of bullous pemphigoid compared to other blistering skin disorders.