Clinical, Cosmetic and Investigational Dermatology (Apr 2022)
A Probing of the Issue of Detecting IgG, IgG4 and IgA Antibodies to Laminin 332 Epitopes in Mucous Membrane Pemphigoid: A Clinical-Laboratory Experience of a Single Central European University Dermatology Department
Abstract
Justyna Gornowicz-Porowska,1 Magdalena Jałowska,2 Agnieszka Seraszek-Jaros,3 Monika Bowszyc-Dmochowska,4 Elżbieta Kaczmarek,3 Marian Dmochowski2 1Department and Division of Practical Cosmetology and Skin Diseases Prophylaxis, Poznan University of Medical Sciences, Poznan, Poland; 2Autoimmune Blistering Dermatoses Section, Department of Dermatology, Poznan University of Medical Sciences, Poznan, Poland; 3Department of Bioinformatics and Computational Biology, Poznan University of Medical Sciences, Poznan, Poland; 4Cutaneous Histopathology and Immunopathology Section, Department of Dermatology, Poznan University of Medical Sciences, Poznan, PolandCorrespondence: Marian Dmochowski, Autoimmune Blistering Dermatoses Section, Department of Dermatology, Poznan University of Medical Sciences, Poznan, Poland, Tel +48 61 8691319, Email [email protected]: Mucous membrane pemphigoid (MMP) is a very rare autoimmune bullous disease, affecting predominantly the mucosae and characterized by autoantibodies to the epithelial basement membrane components. Laminin 332 (Ln-332) is one of the most probable antigens with association with malignancy. The laboratory diagnosis of Ln-332-mediated autoimmunity is troublesome. The aim here was to comparatively examine IgG, IgG4, and IgA autoantibodies specific to α 3, β 3 or γ 2 subunits of Ln-322 in MMP patients using the BIOCHIP mosaic-based indirect immunofluorescence technique (IIF).Patients and Methods: Sera from 15 MMP patients were studied. BIOCHIP mosaic-based Ln-332 IIF, direct immunofluorescence, ELISA tests for anti-BP180/BP20 IgG antibodies and statistical analyses were performed.Results: Of all the 15 sera examined for IgG4 antibodies, only 1 (6.67%) reacted with the α 3 chain, 0 with the β 3 chain, and 0 with the γ 2 chain. No positive reactivity was seen with the IgG and IgA antibodies. BIOCHIP mosaic-based IIF with Ln-332 showed 100% sensitivity, 8% specificity, 21% positive predictive value, and 100% negative predictive value in relation to the diagnostic gold standard of DIF. The concomitant malignancies were revealed in three cases.Conclusion: The detection of antibodies to Ln-332 chains is occasional in Polish MMP sufferers. Still, the evaluation of IgG4 antibodies in MMP can reduce the false-negative results.Keywords: mucous membrane pemphigoid, laminin 332, immunologic test
