ACQUIRED SUBEPIDERMAL BULLOUS DISEASES ASSOCIATED WITH PSORIASIS - A CLINICAL, IMMUNOPATHOLOGICAL AND IMMUNOGENETIC STUDY

Clinical, immunopathological and immunogenetic studies of four patient s with a subepidermal bullous disease associated with psoriasis were c arried out td determine the true nature of the blistering disease and to investigate further the relationship between psoriasis and acquired subepidermal bullous diseases, Autoantibodies in all four patients bo und to the epidermal side of salt-split skin by indirect immunofluores cence and detected the major bullous pemphigoid (BP) antigens by immun oblotting, One had additional IgA autoantibodies binding an epidermal polypeptide of 270/280 kDa and another had circulating IgG autoantibod ies which detected both BP and epidermolysis bullosa acquisita (EBA) a ntigens. All patients had active psoriasis at the onset of the bullous disease, Three patients were being treated with tar when blisters dev eloped: one patient also received UVB radiation and experienced a rela pse after exposure to sunlight, HI,A phenotypes in three patients were determined. All the patients responded well to methotrexate, These fi ndings demonstrate that BP is the subepidermal bullous disease most as sociated with psoriasis, Changes at the basement membrane zone in psor iasis may be responsible for the heterogeneous antibody response and m ay trigger the bullous disease, as may antipsoriatic treatment includi ng tar and UV radiation, However, common immunogenetic mechanisms may play a crucial part in this disease association.