Sensitive and specific assays for routine serological diagnosis of epidermolysis bullosa acquisita

Lars Komorowski, Ralf Mueller, Artem Vorobyev, Christian Probst, Andreas Recke, Marcel F. Jonkman, Takashi Hashimoto, Soo-Chan Kim, Richard Groves, Ralf J. Ludwig, Detlef Zillikens, Winfried Stoecker, Enno Schmidt*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

54 Citations (Scopus)

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 languageEnglish
Pages (from-to)E89-E95
Number of pages7
JournalJournal of the American Academy of Dermatology
Volume68
Issue number3
DOIs
Publication statusPublished - 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

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