Antidesmoplakin antibodies in pemphigus vulgaris

Authors

  • E. Cozzani,

    1. Di.S.E.M. Section of Dermatology, University of Genoa, Viale Benedetto XV 7, 16132 Genoa, Italy
      *Laboratory of Molecular and Cell Biology, Istituto Dermopatico dell'Immacolata IRCCS, Rome, Italy
    Search for more papers by this author
  • M.G. Dal Bello,

    1. Di.S.E.M. Section of Dermatology, University of Genoa, Viale Benedetto XV 7, 16132 Genoa, Italy
      *Laboratory of Molecular and Cell Biology, Istituto Dermopatico dell'Immacolata IRCCS, Rome, Italy
    Search for more papers by this author
  • A. Mastrogiacomo,

    1. Di.S.E.M. Section of Dermatology, University of Genoa, Viale Benedetto XV 7, 16132 Genoa, Italy
      *Laboratory of Molecular and Cell Biology, Istituto Dermopatico dell'Immacolata IRCCS, Rome, Italy
    Search for more papers by this author
  • M. Drosera,

    1. Di.S.E.M. Section of Dermatology, University of Genoa, Viale Benedetto XV 7, 16132 Genoa, Italy
      *Laboratory of Molecular and Cell Biology, Istituto Dermopatico dell'Immacolata IRCCS, Rome, Italy
    Search for more papers by this author
  • A. Parodi

    1. Di.S.E.M. Section of Dermatology, University of Genoa, Viale Benedetto XV 7, 16132 Genoa, Italy
      *Laboratory of Molecular and Cell Biology, Istituto Dermopatico dell'Immacolata IRCCS, Rome, Italy
    Search for more papers by this author

  • Conflicts of interest: None declared.

Aurora Parodi.
E-mail: aurora.parodi@unige.it

Summary

Background  Besides being present in paraneoplastic pemphigus (PNP), circulating antidesmoplakin (DP) antibodies have been found anecdotally in other bullous diseases, including pemphigus foliaceus and pemphigus vulgaris.

Objectives  To verify how frequent anti-DP antibodies are in pemphigus vulgaris.

Methods  We studied 48 sera from patients with proven pemphigus vulgaris (29 mucosal dominant pemphigus and 19 mucocutaneous pemphigus) by indirect immunofluorescence (IIF) with rat bladder epithelium (RBE) as a substrate and by immunoblotting (IB) on human keratinocyte cultures enriched in DP.

Results  Ten sera (21%) were positive in IIF on RBE. By IB, eight sera proved to have antibodies to both DP I (250 kDa) and DP II (210 kDa), one serum had antibodies directed to DP I only, and two sera to DP II only.

Conclusions  Our data confirm that RBE is not a specific IIF substrate for the serological diagnosis of PNP. It remains a sensitive and specific substrate for the detection of anti-DP antibodies, which, in patients with pemphigus vulgaris, are probably caused by an epitope-spreading phenomenon.

Ancillary