title: Analysis of serum IgG subclasses in Churg-Strauss syndrome--the meaning of elevated serum levels of IgG4.
abstract: OBJECTIVE
  Mikulicz's disease (MD) is characterized by symmetrical and persistent enlargement of the lacrimal and salivary glands. Recently it has been categorized as an 'Ig (immunoglobulin) G4-related disease.' It presents with elevated serum levels of IgG4 and abundant infiltration of IgG4-bearing plasmacytes in involved organs. Allergic symptoms are often observed in patients with IgG4-related disease. On the other hand, allergic diseases are often complicated with Churg-Strauss syndrome (CSS). Here we focused on CSS and analyzed the relation of IgG4 in its pathogenesis.
  
  
  METHODS
  We analyzed five patients (2 men and 3 women) with CSS and 51 patients (20 men and 31 women) with MD who presented at Sapporo Medical University Hospital since 2001. We measured the serum concentrations of IgG subclasses in the patients with MD and CSS, and evaluated renal specimens from CSS patients, staining them for anti-IgG4 antibody.
  
  
  RESULTS
  We surprisingly found elevated serum levels of IgG4 not only in MD but also in CSS patients. The renal specimens in CSS patients revealed the infiltration of IgG4-positive plasmacytes.
  
  
  CONCLUSIONS
  IgG4-bearing plasmacytes may be involved in the pathogenesis of CSS, and it is possible that an allergic reaction plays an important role in the pathogenesis of IgG4-related disease.
authors.affiliation: The First Department of Internal Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan. mocha@cocoa.plala.or.jp
authors.forename: Motohisa
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takahashi
authors.forename: Chisako
authors.initials: C
authors.lastname: Suzuki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tabeya
authors.forename: Mikiko
authors.initials: M
authors.lastname: Ohara
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Naishiro
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Kohzoh
authors.initials: K
authors.lastname: Imai
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Shinomura
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015267:Churg-Strauss Syndrome / Q000175:diagnosis* / Q000276:immunology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood* / Q000145:classification*; D008297:Male; D008875:Middle Aged; D008882:Mikulicz' Disease / Q000175:diagnosis / Q000276:immunology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007074:Immunoglobulin G