Blistering in Bullous pemphigoid is because of antibodies against
**Core Concept**
Bullous pemphigoid is an autoimmune skin disease characterized by the formation of blisters. The pathogenesis involves the production of autoantibodies against components of the skin's basement membrane zone.
**Why the Correct Answer is Right**
In bullous pemphigoid, the autoantibodies target the hemidesmosomal components, specifically BP180 (collagen type XVII) and BP230. These antibodies trigger an inflammatory response, leading to the activation of complement and the release of various cytokines. The subsequent damage to the basement membrane zone results in the formation of blisters.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the autoantibodies in bullous pemphigoid are not primarily directed against laminin 332, which is a component of the basement membrane but is more relevant to epidermolysis bullosa acquisita.
**Option B:** This option is incorrect because desmogleins are the target antigens in pemphigus vulgaris, a different autoimmune skin disease characterized by the formation of intraepidermal blisters.
**Option C:** This option is incorrect because the autoantibodies in bullous pemphigoid do not primarily target type VII collagen, which is the main component of anchoring fibrils and is more relevant to dystrophic epidermolysis bullosa.
**Clinical Pearl / High-Yield Fact**
Bullous pemphigoid is often associated with other autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus, and may be triggered by the use of certain medications, including NSAIDs and diuretics.
**Correct Answer: D.**