title: Serum adenosine deaminase activity in systemic sclerosis (scleroderma) and related disorders.
abstract: BACKGROUND
  Adenosine deaminase (ADA) activity in serum is mainly derived from T lymphocytes.
  
  
  OBJECTIVE
  Our purpose was to clarify the significance of ADA activity in systemic sclerosis (PSS) and related disorders.
  
  
  METHODS
  ADA activity was determined with an enzymatic method in 34 patients with PSS, 4 with mixed connective tissue disease (MCTD), 6 with dermatomyositis (DM), 11 with localized scleroderma (LS), and 13 with other collagen diseases.
  
  
  RESULTS
  Serum ADA activity was elevated over the mean (+2 standard deviations) of the control in 85% of the patients with PSS, all with MCTD, 83% of those with DM, and 82% of those with LS. The mean values in 10 PSS patients with anti-topoisomerase I antibodies, 14 patients with anti-RNP antibodies, 12 patients with anticentromere antibodies (ACAs), and 5 patients without antinuclear antibodies (ANAs) were 26.1, 24.9, 22.6, and 16.8 IU/L, respectively. In most cases, except for ACA-positive patients, serum ADA activity changed almost in parallel with ANA titers.
  
  
  CONCLUSIONS
  These results support the notion that T cells are involved in the pathogenesis of PSS and related disorders.
authors.affiliation: Department of Dermatology, Yokohama City University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sasaki
authors.forename: H
authors.initials: H
authors.lastname: Nakajima
mesh_terms: D000243:Adenosine Deaminase / Q000097:blood*; D000328:Adult; D000974:Antibodies, Antinuclear / Q000032:analysis; D003095:Collagen Diseases / Q000201:enzymology*; D003882:Dermatomyositis / Q000201:enzymology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008947:Mixed Connective Tissue Disease / Q000201:enzymology; D012595:Scleroderma, Systemic / Q000201:enzymology* / Q000276:immunology; D013601:T-Lymphocytes / Q000201:enzymology / Q000276:immunology
chemical_list: D000974:Antibodies, Antinuclear; D000243:Adenosine Deaminase