A Novel 105-kDa Lamina Lucida Autoantigen: Association with Bullous Pemphigoid

A patient with both bullous pemphigoid and epidermolysis bullosa acquisita: an example of intermolecular epitope spreading

“…Patients have been reported with concurrent BP and pemphigus foliaceus 21 and with antibodies to a 105-kd antigen. 22,23 Chronic inflammatory disorders of the skin including psoriasis, 24,25 dermatitis herpetiformis, 26,27 lichen planus, 28-32 and discoid lupus erythematosus 33 have also all been reported in conjunction with BP. None of these reports, however, have documented autoantibodies developing against a second distinct autoantigen as reported here.…”

Autoantibodies in anti‐p200 pemphigoid stain skin lacking laminin 5 and type VII collagen

“…Antibodies to p105 and to laminin 5 are usually not detected by immunoblot analysis of dermal extracts. The most sensitive detection system for autoantibodies to p105 is immunoblotting of cellular extracts of keratinocytes and fibroblasts 21,28 . Antibodies to the laminin 5 subunits are demonstrated by immunoblotting of this protein purified from the extracellular matrix of cultured keratinocytes or by immunoprecipitation of radiolabelled keratinocytes 17,26 , 29,30 .…”

“…The most sensitive detection system for autoantibodies to p105 is immunoblotting of cellular extracts of keratinocytes and fibroblasts. 21,28 Antibodies to the laminin 5 subunits are demonstrated by immunoblotting of this protein purified from the extracellular matrix of cultured keratinocytes or by immunoprecipitation of radiolabelled keratinocytes. 17,26,29,30 We previously demonstrated that anti-p200 antibodies do not react with p105 extracted from fibroblasts or with purified laminin 5 by immunoblot analysis.…”

An extract of cultured A431 cells contains major tissue antigens of autoimmune bullous diseases

“…It appears that none of the culture extracts of epidermal cells, which are generally used, contains all the epidermal/DEJ autoantigens involved in AIBDs, and the diagnosis of these diseases currently requires use of a number of different antigenic extracts. 6,9–13 The current study shows that an extract of cultured A431 cells 14 provides a source of all relevant antigens, and therefore contributes a reliable and labour‐saving substrate for immunoblot diagnosis of AIBDs.…”