Immunopathological studies in pemphigus vulgaris, bullous pemphigoid and epidermolysis bullosa acquisita / 대한피부과학회지

ABSTRACT

Pemphgus vulgaris (PV), Bullus pemphigoid (BP), and Epidermolysis bullous acqusita (EBA) are autoimmune bullous dermatoses, characterized by circulating IgG autoantibodies. These antibodies react with antigens located at the intercellular substance (ICS) of epidermis, basement membrane zone (BMZ), and subepidermal anchoring fibril zone (AFZ), respectively. The subclass distribution of IgG autoantibodies, and the properties and degrees of complement fixing activities of these autoantibodies in each of the above diseases have not been well understood. Indirect immunofluorescence and in vitro complement stainings were performed for the titration of subclasses of IgG antibodies and for the immunofluorescence staining reactivities of complement components C3, C4, C5b-9, H, C4bp, and S. Each serum specimen from five cases of PV, five cases of BP. and three cases of EBA was tested. The findings of multistep technique with monoclonal and polyclonal antibodies are as follows All four subclasses of IgG antibodies were identified at the antigenic sites in these group, however there were some differences in the antibodies titers. In PV and BP the dominant subclass of highest antibody titer was IgG1 and/or IgG4. In EBA only IgG4 was dominant in all three cases. The results of complement component stainings, in most of the cases of PV, showed positive for C3 and C4 but were negative for the other components or inhibitor proteins at the ICS of epidermis. In BP most of the cases revealed positive staining reactivities at the BMZ for C3, C4, C5b-9, H, and C4bp-9 with no staining reactivities for the inhibitor proteins No significant relevancy was found between the titers of complement fixing IgG subclasses and the numbers of positive complement staining reactivities for complement components. The results suggest that the complement system may contribute more strongly to the formation of bullous lesions in BP and EBA than in PV.