IgA pemphigus--occurrence of anti-desmocollin 1 and anti-desmoglein 1 antibody reactivity in an individual patient.
BACKGROUND
IgA pemphigus is a rare pustular autoimmune disease with exclusive IgA anti-keratinocyte cell surface antibody reactivity. Two subtypes have been discerned: in the subcorneal pustular dermatosis type, desmocollin 1 has been identified as a targeted autoantigen, while in few cases of the intraepidermal neutrophilic type, IgA anti-desmoglein 1 or IgA anti-desmoglein 3 reactivity has been demonstrated.


METHODS
A 48-year-old white male presented with generalized large confluent pustules. Skin pathology was assessed by histology and direct immunofluorescence analysis. IgG/IgA autoantibodies against desmoglein 1/3 and desmocollin 1 were measured by ELISA and indirect immunofluorescence using desmocollin 1 cDNA-transfected COS7 cells, respectively.


RESULTS
Histopathology revealed subcorneal pustules and direct immunofluorescence microscopy exclusively showed in vivo bound IgA with an intercellular pattern in the epidermis. Desmocollin 1 was identified as a target of IgA autoantibodies by indirect immunofluorescence microscopy utilizing desmocollin 1 cDNA-transfected COS7 cells. In addition, IgA anti-desmoglein 1 reactivity was demonstrated by ELISA. Neither IgA anti-desmoglein 3 nor IgG anti-desmoglein 1/3 autoantibodies were present.


CONCLUSIONS
Both desmocollin 1 and desmoglein 1 were autoantigens in this patient with IgA pemphigus and a distinct clinical presentation. To our knowledge, this is the first IgA pemphigus case with dual autoantibody reactivity.
Kopp
Tamara
T
Division of Immunology, Allergy and Infectious Diseases, Department of Dermatology, Medical University of Vienna, Vienna General Hospital, Austria.
Sitaru
Cassian
C
Pieczkowski
Friederike
F
Schneeberger
Achim
A
Födinger
Dagmar
D
Zillikens
Detlef
D
Stingl
Georg
G
Karlhofer
Franz M
FM
D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000627:therapeutic use; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001323:Autoantibodies / Q000032:analysis / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D002435:Cefamandole / Q000008:administration & dosage / Q000627:therapeutic use; D003622:Dapsone / Q000008:administration & dosage / Q000627:therapeutic use; D051187:Desmocollins / Q000276:immunology*; D051183:Desmoglein 1 / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009824:Ointments; D010392:Pemphigus / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D012867:Skin / Q000473:pathology; D013411:Sulfadiazine / Q000008:administration & dosage / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000893:Anti-Inflammatory Agents; D001323:Autoantibodies; D001324:Autoantigens; D051187:Desmocollins; D051183:Desmoglein 1; D007070:Immunoglobulin A; D009824:Ointments; D013411:Sulfadiazine; D002435:Cefamandole; D003622:Dapsone