Sensitive and specific assays for routine serological diagnosis of epidermolysis bullosa acquisita - 09/02/13
Abstract |
Background |
Epidermolysis bullosa acquisita (EBA) is a severe autoimmune subepidermal blistering disease characterized by autoantibodies against the N-terminal collagenous domain (NC1) of type VII collagen (Col VII).
Objective |
Development of reliable assays for the detection of anti-Col VII-NC1 antibodies.
Methods |
NC1 was expressed in human HEK293 cells and used as target antigen in an enzyme-linked immunosorbent assay (ELISA) and in an immunofluorescence assay (IFA). These two assays were probed in a large cohort of patients with EBA (n = 73), bullous pemphigoid (BP, n = 72), anti-p200 pemphigoid (n = 24), anti-laminin 332 mucous membrane pemphigoid (MMP, n = 15), pemphigus vulgaris (PV, n = 24), and healthy control subjects (n = 254).
Results |
The cut-off for the ELISA was optimized for accuracy by receiver-operating characteristics (area under the curve [AUC] = 0.9952). IgG reactivity against NC1 was detected in 69 of 73 EBA (94.5%) and 5 control sera (2 healthy controls and 3 BP patients), resulting in a specificity of 98.7%. The IFA showed a sensitivity of 91.8% and specificity of 99.8%. Reproducibility of the ELISA was demonstrated by an intra-class correlation coefficient of 0.97. IgG subclass analyses by ELISA revealed IgG1, IgG2, IgG3, and IgG4 anti-NC1 reactivity in 83.6%, 85.3%, 37.7%, and 83.6% of EBA sera, respectively.
Limitations |
The novel assays were not evaluated prospectively and their use in monitoring serum levels during the disease course was not tested.
Conclusion |
The two assays are highly specific and sensitive to diagnose EBA. Their diagnostic competence was demonstrated in a large cohort of well-characterized EBA sera.
Le texte complet de cet article est disponible en PDF.Key words : autoantibody, ELISA, immunofluorescence, type VII collagen
Abbreviations used : BP, Col VII, DEJ, EBA, ELISA, IF, NC1, PBS
Plan
Drs Komorowski and Müller contributed equally and are listed in alphabetical order. |
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Funding sources: This work was supported by the Schleswig-Holstein Cluster of Excellence in Inflammation Research (DFG EXC 306/1) to E.S., D.Z., and R.L and the Graduiertenkolleg “Modulation of Autoimmunity” (GRK 1727/1) to A.V. |
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Disclosure: Drs Probst and Stõcker are employees and shareholders of EUROIMMUN AG. Dr Komorowski is an employee of EUROIMMUN AG. |
Vol 68 - N° 3
P. e89-e95 - mars 2013 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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