Vannina Seta1, Françoise Aucouturier2, Jonathan Bonnefoy3, Christelle Le Roux-Villet1, Valérie Pendaries4, Marina Alexandre1, Sabine Grootenboer-Mignot5, Michel Heller6, Nicole Lièvre6, Liliane Laroche1, Frédéric Caux1, Matthias Titeux3, Alain Hovnanian7, Catherine Prost-Squarcioni8. 1. Department of Dermatology, APHP, Avicenne Hospital, Bobigny, France. 2. Department of Immunology, Assistance Publique des Hôpitaux de Paris (APHP), Saint-Louis Hospital, Paris, France. 3. Institut National de la Santé et de la Recherche Médicale (INSERM), Unité Mixte de Recherche (UMR) 1163, Institut Imagine, Paris, France; Université Paris Descartes-Sorbonne Paris Cité, Paris, France. 4. INSERM, U563, Purpan Hospital, Toulouse, France. 5. Department of Immunology, APHP, Bichat Hospital, Paris, France. 6. Department of Histology, Unité de Formation et de Recherche (UFR) Léonard de Vinci, University Paris 13, Bobigny, France. 7. Institut National de la Santé et de la Recherche Médicale (INSERM), Unité Mixte de Recherche (UMR) 1163, Institut Imagine, Paris, France; Université Paris Descartes-Sorbonne Paris Cité, Paris, France; Department of Genetics, APHP, Necker-Enfants Malades Hospital, Paris, France. 8. Department of Dermatology, APHP, Avicenne Hospital, Bobigny, France; Department of Histology, Unité de Formation et de Recherche (UFR) Léonard de Vinci, University Paris 13, Bobigny, France; Department of Pathology, APHP, Avicenne Hospital, Bobigny, France. Electronic address: catherine.prost@aphp.fr.
Abstract
BACKGROUND: Serologic diagnosis of epidermolysis bullosa acquisita (EBA) relies on the detection of circulating autoantibodies to type VII collagen (C7). OBJECTIVE: We sought to compare the diagnostic performances of a commercialized enzyme-linked immunosorbent assay (ELISA) using C7 noncollagenous (NC) domains (C7-NC1/NC2 ELISA) and indirect immunofluorescence (IIF) biochip test on NC1-C7-expressing transfected cells (IIFT), with a full-length-C7 ELISA developed in our laboratory. METHODS: C7-NC1/NC2 ELISA, IIFT, and full-length-C7 ELISA were run on 77 nonselected consecutive EBA sera. RESULTS: C7-NC1/NC2 ELISA, IIFT, and full-length-C7 ELISA were positive, respectively, for: 30%, 27%, and 65% of the 77 sera; 43%, 32%, and 80% of 44 sera labeling the salt-split-skin (SSS) floor (F) by IIF (SSS/F(+)); 9%, 22%, and 47% of 32 SSS/F(-) sera; 28%, 28%, and 58% of classic EBA; 41%, 41%, and 82% of inflammatory EBA; and 18%, 0%, and 55% of mucous-membrane-predominant EBA. Significant differences for all sera were found between: the 2 ELISAs for the 77 sera, SSS/F(+) and SSS/F(-) sera, and IIFT versus full-length-C7 ELISA. LIMITATIONS: The retrospective design was a limitation. CONCLUSION: C7-NC1/NC2 ELISA and IIFT sensitivities for serologic diagnoses of EBA were low. Full-length-C7 ELISA was significantly more sensitive and could serve as a reference test.
BACKGROUND: Serologic diagnosis of epidermolysis bullosa acquisita (EBA) relies on the detection of circulating autoantibodies to type VII collagen (C7). OBJECTIVE: We sought to compare the diagnostic performances of a commercialized enzyme-linked immunosorbent assay (ELISA) using C7 noncollagenous (NC) domains (C7-NC1/NC2 ELISA) and indirect immunofluorescence (IIF) biochip test on NC1-C7-expressing transfected cells (IIFT), with a full-length-C7 ELISA developed in our laboratory. METHODS: C7-NC1/NC2 ELISA, IIFT, and full-length-C7 ELISA were run on 77 nonselected consecutive EBA sera. RESULTS: C7-NC1/NC2 ELISA, IIFT, and full-length-C7 ELISA were positive, respectively, for: 30%, 27%, and 65% of the 77 sera; 43%, 32%, and 80% of 44 sera labeling the salt-split-skin (SSS) floor (F) by IIF (SSS/F(+)); 9%, 22%, and 47% of 32 SSS/F(-) sera; 28%, 28%, and 58% of classic EBA; 41%, 41%, and 82% of inflammatory EBA; and 18%, 0%, and 55% of mucous-membrane-predominant EBA. Significant differences for all sera were found between: the 2 ELISAs for the 77 sera, SSS/F(+) and SSS/F(-) sera, and IIFT versus full-length-C7 ELISA. LIMITATIONS: The retrospective design was a limitation. CONCLUSION: C7-NC1/NC2 ELISA and IIFT sensitivities for serologic diagnoses of EBA were low. Full-length-C7 ELISA was significantly more sensitive and could serve as a reference test.