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Linear IgA disease with IgA antibodies directed against 200‐ and 280‐kDa epidermal antigens
Author(s) -
Fujimoto W.,
Ohtsu T.,
Toi Y.,
Nakanishi G.,
Arata J.
Publication year - 2000
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1046/j.1365-2133.2000.03553.x
Subject(s) - hemidesmosome , immunofluorescence , antigen , immunoperoxidase , autoantibody , pathology , lamina lucida , biology , antibody , dermoepidermal junction , basement membrane , histopathology , immunoelectron microscopy , direct fluorescent antibody , immunology , medicine , dermis , monoclonal antibody , ultrastructure , basal lamina
We report an 80‐year‐old man with the lamina lucida type of linear IgA disease, with IgA autoantibodies reactive with 200‐kDa and 280‐kDa epidermal proteins. The patient presented with widespread bullous lesions on his trunk and extremities without mucosal involvement. Histopathology of lesional skin showed a subepidermal blister with papillary microabscesses of neutrophils and a few eosinophils. Direct immunofluorescence microscopy of perilesional skin showed linear deposits of IgA and C3 at the basement membrane zone. The patient’s serum contained IgA autoantibodies that bound exclusively to the epidermal side of 1 mol L −1 NaCl split skin as determined by indirect immunofluorescence microscopy. Circulating IgA autoantibodies to 200‐ and 280‐kDa antigens were detected in the patient’s serum by immunoblot analysis using extracts from normal human epidermis and human epidermal keratinocytes. These two antibodies, eluted from individual nitrocellulose membranes, reacted with the epidermal side of 1 mol L −1 NaCl split skin on indirect immunofluorescence microscopy, and bound to hemidesmosomes as determined by immunoperoxidase electron microscopy. This observation suggests the presence of hitherto uncharacterized 200‐ and 280‐kDa hemidesmosomal proteins distinct from BPAG1, BPAG2 and β4 integrin as target antigens in linear IgA disease.