Frequency of IgA Antibodies in Pemphigus, Bullous Pemphigoid and Mucous Membrane Pemphigoid
Alexander Zink, Anna Gensbaur, Michael Zirbs, Florian Seifert, Isabel Leon Suarez, Vagkan Mourantchanian, Stephan Weidinger, Martin Mempel, Johannes Ring, Markus Ollert
Circulatingand bound IgA antibodies can be found in the autoimmune blisteringdiseases, but their prevalence, clinical relevance and target antigensremain unknown. Thirty-two patients with pemphigus, 73 with bullouspemphigoid and 28 with mucous membrane pemphigoid were studiedretrospectively. Direct immunofluorescence (DIF) analysis of IgG, IgA,IgM and C3 was carried out for all cases. Sera were studied by standardindirect immunofluorescence, indirect immunofluorescence on salt-splitskin, immunoblotting for bullous pemphigoid and mucous membranepemphigoid and ELISA for pemphigus. With DIF, we found IgAautoantibodies in 22 of all 133 cases. Circulating IgA antibodies toskin were detected in 2 of 3 IgA-DIF-positive patients with pemphigus,in 3 of 6 with bullous pemphigoid, and in 6 of 13 with mucous membranepemphigoid. We confirm that the IgA reactivity is more frequentlyassociated with mucous membrane involvement, especially in caseswithout critical involvement (5/8). The role of IgA and its antigenicspecificity in these diseases remain unclear.