2012 Volume 122 Issue 8 Pages 2097-2104
A 79-year-old Japanese male presented with bilateral post-auricular blisters, which had appeared several days before the first examination. On histopathological examination, HE staining revealed subepidermal blisters, and direct immunofluorescence detected deposits of IgG and C3 in the basement membrane zone. Indirect immunofluorescence revealed linear IgG anti-basement membrane zone antibodies, which reacted with the dermal side of 1M salt-split skin. Immunoblotting revealed that IgG reacted with α3, β3 and γ2 subunits of purified human laminin 332. These findings led us to a diagnosis of anti-laminin 332 mucous membrane pemphigoid. The patient was treated with prednisolone 60 mg/day and diaminodiphenyl sulfone 75 mg/day, which did not alleviate the disease. Therefore, 400 mg/kg/day high dose immunoglobulin therapy was then prescribed for 5 days, resulting in rapid improvement of the lesions. When the immunological analyses were repeated after alleviation of the lesions, indirect immunofluorescence detected no IgG anti-basement membrane zone antibodies. Immunoblotting using purified laminin 332 revealed that IgG was still positive for γ2, but not for α3 and β3 subunits, suggesting that the α3 and β3 subunits were the pathogenic antigens in this patient.
