A Comparative Study for the Titer of IgG Autoantibodies in the Serum and Urine of Patients with Bullous Pemphigoid, Epidermolysis Bullosa Acqusita, and Pemphigus / 대한피부과학회지

ABSTRACT

BACKGROUND: The immunoglobulins can be detected in the urine in normal people without any renal disease. According to recent articles, it is known that autoantibodies of IgG, which share the identical antigenic specificities with the serum autoantibodies, targeting some nuclear antigens and cutaneous basement membrane zone antigens could be detected in the urine in patients with systemic lupus erythematosus and autoimmune bullous diseases. OBJECTIVE: We examined the urine for the detection of autoantibodies in patients with autoimmune bullous diseases and compared the titers of IgG autoantibodies in the serum and urine in each patient. Patients and METHODS: Nine patients were included in this study. They were 3 patient-groups of bullous pemphigoid(BP), epidermolysis bullosa acqusita(EBA), and pemphigus foliaceus(PF). Each group consisted of 3 patients having circulating autoantibodies in the serum. For a semi-quantitation of the IgG autoantibodies in the serum and urine specimens in each group, the indirect immuno fluorescence(IIF) examinations were performed. RESULTS: Seven out of nine patients showed positive results of autoantibodies in urine specimen. In the BP and EBA group, IgG autoantibodies were detected in the urine of all six patients at low titers. In the PF group, one out of three patients showed IgG autoantibodies in the urine. The high antibody titers in the sera roughly correlated with the positivity/titer of the urine IgG autoantibodies. CONCLUSION: The IIF examination of the urine could be tried for a diagnosis of autoimmune bullous diseases in some patients with active autoimmune bullous dermatoses, espacially in cases with certain difficulties in collecting serum samples.