BACKGROUND: Bullous pemphigoid (BP) is a subepidermal autoimmune blistering disease, which is characterized by blisters on the skin. Autoantibodies to components of the basement membrane zone are usually observed in the sera of patients with BP. Autoantibodies to the bullous pemphigoid antigens (BP Ag1, 230-kDa desmoplakin protein, and BP Ag2, 180-kDa hemidesmosomal protein) are present in the sera of BP patients. OBJECTIVE: The objective of this study was to report the influence of intravenous immunoglobulin (IVIg) therapy on autoantibody titres to BP Ag1 and BP Ag2. METHODS: In this prospective study, we measured autoantibody titres to both BP Ag1 and BP Ag2, in 10 patients with severe BP, over a period of 18 consecutive months on each patient, using an immunoblot assay. RESULTS: Prior to the initiation of IVIg therapy, the sera of nine patients demonstrated the presence of high autoantibody titres to both BP Ag1 and BP Ag2. One patient had autoantibodies to BP Ag1 only. A statistically significant decline in the autoantibody titres to both BP Ag1 and BP Ag2 was observed after 3 months of receiving the first cycle of IVIg therapy. This gradual decline in autoantibody titres continued until patients were observed to have non-detectable titres to BP Ag1 after 11 months and to BP Ag2 after 10 months of receiving IVIg therapy. Once patients achieved non-detectable titres, these patients were considered to be in a serological remission. This serological remission was sustained for an additional 7 months of observation. CONCLUSION: Autoantibody titres to BP Ag1 and BP Ag2 can be used to monitor the serological response to treatment in patients with BP. Patients with severe BP who are treated with IVIg therapy, as described in our protocol, achieve a long-term serological remission.