title: Clinicopathologic features of IgG/IgA pemphigus in comparison with classic (IgG) and IgA pemphigus.
abstract: BACKGROUND
  The pemphigus group is characterized by the presence of circulating immunoglobulins against desmosomes. IgG/IgA pemphigus is defined by the presence of IgG and IgA cell surface deposits upon direct immunofluorescence (DIF) and/or circulating IgG and IgA autoantibodies upon indirect immunofluorescence. Previous reports of patients with IgG/IgA pemphigus are sparse. Whether IgG/IgA pemphigus is best classified as a subtype of IgG (classic) pemphigus or IgA pemphigus, or as a distinct entity, has yet to be determined.
  
  
  OBJECTIVE
  We compared the features of patients with IgG/IgA pemphigus to those of IgG pemphigus and IgA pemphigus.
  
  
  METHODS
  Retrospective clinicopathologic study of patients with IgG, IgG/IgA, and IgA pemphigus evaluated at our clinic (1993-2013).
  
  
  RESULTS
  We included 26, 13, and seven patients with IgG, IgG/IgA, and IgA pemphigus, respectively. Patients with IgG/IgA pemphigus did not differ significantly from patients with IgG pemphigus in terms of clinical and microscopic features, DIF findings, anti-desmoglein antibody values, and treatments required. However, patients with IgG/IgA pemphigus were significantly different from patients with IgA pemphigus regarding intertriginous distribution (P = 0.038) and pustular lesions (P < 0.001), acantholysis (P = 0.043), and presence of intercellular C3 deposits on DIF (P < 0.001).
  
  
  CONCLUSIONS
  Comparative clinicopathologic data imply that IgG/IgA pemphigus may best be regarded as a variant of IgG pemphigus and distinct from IgA pemphigus.
authors.affiliation: Mayo Clinic, Rochester, MN, USA.
authors.forename: Siavash
authors.initials: S
authors.lastname: Toosi
authors.affiliation: Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ, USA.
authors.forename: Jeffrey W
authors.identifier: http://orcid.org/0000-0001-7817-7760
authors.initials: JW
authors.lastname: Collins
authors.affiliation: Mayo Clinic, Rochester, MN, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Lohse
authors.affiliation: Mayo Clinic, Rochester, MN, USA.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Wolz
authors.affiliation: Mayo Clinic, Rochester, MN, USA.
authors.forename: Carilyn N
authors.initials: CN
authors.lastname: Wieland
authors.affiliation: Mayo Clinic, Rochester, MN, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Camilleri
authors.affiliation: Mayo Clinic, Rochester, MN, USA.
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Bruce
authors.affiliation: Mayo Clinic, Rochester, MN, USA.
authors.forename: Marian T
authors.initials: MT
authors.lastname: McEvoy
authors.affiliation: Mayo Clinic, Rochester, MN, USA.
authors.forename: Julia S
authors.initials: JS
authors.lastname: Lehman
mesh_terms: D000051:Acantholysis / Q000209:etiology; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D003176:Complement C3 / Q000032:analysis; D051182:Desmogleins / Q000276:immunology; D005260:Female; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D007074:Immunoglobulin G / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D010392:Pemphigus / Q000150:complications / Q000276:immunology / Q000378:metabolism* / Q000473:pathology*; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D003176:Complement C3; D051182:Desmogleins; D007070:Immunoglobulin A; D007074:Immunoglobulin G