title: Autoantibodies against calpastatin in sera from patients with systemic sclerosis.
abstract: OBJECTIVE
  To determine the prevalence and clinical correlation of anti-calpastatin antibodies in patients with systemic sclerosis (SSc).
  
  
  METHODS
  Serum samples from patients with limited cutaneous SSc (lSSc; n=36), diffuse cutaneous SSc (dSSc; n=27), and healthy control subjects (n=29) were examined by an ELISA using human recombinant calpastatin as antigens.
  
  
  RESULTS
  IgG anti-calpastatin antibodies were positive in 15 (24%) of 63 patients with SSc, which was similar to the frequency of IgM anti-calpastatin antibody positivity (14/63, 22%). The presence of anticentromere antibodies was associated with the presence of IgG and/or IgM anti-calpastatin antibodies. The patients with SSc positive for IgG anti-calpastatin antibodies had significantly higher erythrocyte sedimentation rates (ESR) compared with those negative for IgG anti-calpastatin antibodies. Furthermore, the levels of IgG anti-calpastatin antibodies correlated positively with the levels of ESR. The patients with dSSc positive for IgM anti-calpastatin antibodies had significantly higher frequency of inflammatory joint and muscle involvement compared with those negative for IgM anti-calpastatin antibodies. Four (80%) of 5 patients with dSSc with both joint and muscle involvement produced IgM anti-calpastatin antibodies.
  
  
  CONCLUSIONS
  The presence of anti-calpastatin antibodies may be a clue to mechanisms of the inflammatory change occurring in SSc. Furthermore, the presence of anti-calpastatin antibodies could be a novel and useful serologic tool for recognizing patients with dSSc with inflammatory joint and muscle involvement.
authors.affiliation: Department of Dermatology, Kanazawa University School of Medicine, Ishikawa, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: M
authors.initials: M
authors.lastname: Hasegawa
authors.forename: T
authors.initials: T
authors.lastname: Nagaoka
authors.forename: Y
authors.initials: Y
authors.lastname: Takamatsu
authors.forename: N
authors.initials: N
authors.lastname: Yazawa
authors.forename: H
authors.initials: H
authors.lastname: Ihn
authors.forename: K
authors.initials: K
authors.lastname: Kikuchi
authors.forename: K
authors.initials: K
authors.lastname: Takehara
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000276:immunology; D000918:Antibody Specificity / Q000502:physiology; D001323:Autoantibodies / Q000032:analysis*; D001799:Blood Sedimentation; D002135:Calcium-Binding Proteins / Q000276:immunology*; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012594:Scleroderma, Localized / Q000097:blood / Q000276:immunology / Q000503:physiopathology; D012595:Scleroderma, Systemic / Q000097:blood / Q000276:immunology* / Q000503:physiopathology
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D002135:Calcium-Binding Proteins; D007074:Immunoglobulin G; C033668:calpastatin