Immunoblotting analysis and complement binding capacity of bullous pemphingoid autoantibody / 대한피부과학회지

ABSTRACT

BACKGROUND: Bullous pemphigoid is a rare autoimmune bullous disease characterized by subepidermal bulla. The serum of these patients contains detectable autoantibodies which bind to the hemidesmosome of the basement membrane zone. It is well known that there are two bullous pemphigoid antigen molecules, 230KD and 170KD protein. Serum studies in Caucasian patients show that 70-80% of the patients recognize 230KD antigen while 10-30% recognize 170KD antigen, In contrast, in herpes gestationis, which is an autommune-mediated bullous disease of pregnancy, 90% of the patients recognize 170KD and 10% recognize 230KD antigen, The autoantibody of herpes gestationis(HG factor) has a strong complement binding capacity and it may share the same epitope as the antibody of bullous pemphigoid patients which recognize 170KD antigen. OBJECTIVE: The purpose of this study was to characterize the clinical and histological manifestations of Korean patients with bullous pemphigoid and to characterize the autoantibodies of Korean bullous pemphigoid patients by immunoblotting. We also wished to compare the characteristics of the antibodies with that of American bullous pemphigoid patients, and to elucidate the hypothesis that the bullous pemphigoid autoantibody against 170KD protein has the same strong complement binding capacity as the herpes gestationis autoantibody. MEHTODS We investigated the clinical and histological characteristics of 9 Korean patients and also performed a complement binding capacity and immunoblotting study on the sera of 9 Korean patients and 16 American patients. RESULTS: 1. Korean bullous pemphigoid patients clinically showed polymorphic skin eruption in addition to tense bullae. They frequently showed pruritic erythematous patches and urticarial plaques. Histologically, infiltration of subepidermal bullae with eosinophils, neutrophils and lymphocytes were observed in all patient's specimen, in which eosinophils were the most predominant cells, Uncommonly, eosinophilic spongiosis, vaculoar degeneration of basal cells were observed. These observations did not have any particular characteristics or racial differences compared to those patients reported in Western literature. 2. In the immunoblotting study of Korean bullous pemphigoid patients, 7 of 9 sera(785) recognized 230KD antigen and, also, 7 of 9 sera(78%)recognized 170KD antigen, In contrast, 15 of 16 American patients sera (94%) recognized 230KD antigen and 6 of 16 patients sera(38%) recognized 170KD antigen. The high incidence of the autoantibody against 170KD in Korean patients shows possible racial differences in autoantibody formation. 3. There was no relationship between the types of autoantibodies typed by immunoblotting and the complement binding capacity. In other words, autoantibodies against 170KD antigen do not carry the same potential as autoantibodies of herpes gestationis for the complement biding capacity, CONCLUSION: The above results suggest tha there may be racial difference in bullous pemphigoid autoantibodies between Korean bullous pemphigoid patients and American patients. In conclusion, We conclude that 170KD bullous pemphigoid antibodies do not always have the same strong complement binding as herpes gestationis antibody.