Sensitivity of different assays for the serological diagnosis of epidermolysis bullosa acquisita: analysis of a cohort of 24 Italian patients
Article first published online: 6 MAR 2013
© 2013 The Authors Journal of the European Academy of Dermatology and Venereology © 2013 European Academy of Dermatology and Venereology
Journal of the European Academy of Dermatology and Venereology
Volume 28, Issue 4, pages 483–490, April 2014
How to Cite
Calabresi, V., Sinistro, A., Cozzani, E., Cerasaro, C., Lolicato, F., Muscianese, M., Parodi, A., Didona, B., Zambruno, G. and Di Zenzo, G. (2014), Sensitivity of different assays for the serological diagnosis of epidermolysis bullosa acquisita: analysis of a cohort of 24 Italian patients. Journal of the European Academy of Dermatology and Venereology, 28: 483–490. doi: 10.1111/jdv.12129
- Conflict of interest
- Conflict of interest
- None declared.
- Funding sources
- The study was funded by the Italian Ministry of Health.
- Issue published online: 18 MAR 2014
- Article first published online: 6 MAR 2013
- Manuscript Accepted: 4 FEB 2013
- Manuscript Received: 10 SEP 2012
- Italian Ministry of Health
Epidermolysis bullosa acquisita (EBA) is an autoimmune blistering disease characterized by tissue-bound and circulating autoantibodies to the dermal-epidermal junction. The autoantibody target is type VII collagen (Col VII) which is involved in dermal-epidermal adhesion. Diagnosis is made by clinical and histopathological findings, linear deposition of autoantibodies at the dermal-epidermal junction detected by direct immunofluorescence, and binding to the dermal side of salt-split skin by indirect immunofluorescence (IIF). However, the detection of specific anti-Col VII reactivity has an important confirmatory value.
The humoral immune response in EBA sera was analysed by (i) IIF on human skin, (ii) a commercial Col VII ELISA, and (iii) immunoblotting on Col VII produced by an epithelial cell line.
The aim of this study was to compare the sensitivity of different approaches for the serological diagnosis of EBA.
The vast majority of EBA sera (79.2%) bound to the Col VII non-collagenous domains by a commercial ELISA, while a small proportion of patients (12.5%) exclusively reacted to the collagenous domain by immunoblotting. Of note, the autoantibodies reactivity to Col VII was more frequently detected by IB (91.7%) than by IIF (83.3%) and ELISA (79.2%). Interestingly, 2 out of 24 sera recognized Col VII epitopes undetectable in the native secreted protein but present in the context of extracellular matrix proteins, as assessed by immunomapping on Col VII-deficient skin.
Our findings show that the use of multiple assays allows to improve diagnostic performance. An algorithm for efficient serological diagnosis of EBA is proposed.