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. (J Am Acad Dermatol 2013;68:e89-95.)
Original language | English |
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Pages (from-to) | E89-E95 |
Number of pages | 7 |
Journal | Journal of the American Academy of Dermatology |
Volume | 68 |
Issue number | 3 |
DOIs | |
Publication status | Published - Mar-2013 |
Keywords
- autoantibody
- ELISA
- immunofluorescence
- type VII collagen
- NONCOLLAGENOUS NC1 DOMAIN
- 3 STRUCTURAL DOMAINS
- VII COLLAGEN
- CARBOXYL-TERMINUS
- ANCHORING FIBRILS
- PEPTIDE SEQUENCES
- AUTOANTIBODIES
- DISEASE
- ANTIGEN
- EPITOPE