title: Cathepsin B and cystatin C play an inflammatory role in gouty arthritis of the knee.
abstract: BACKGROUND
  To relate the expression of the matrix degrading proteinase cathepsin B and its endogenous inhibitor cystatin C in the synovial fluid (SF) to the clinical and laboratory variables of joint inflammation in gouty arthritis of the knee.
  
  
  METHODS
  Thirty-nine SF samples were obtained from inflamed knees of patients with acute gout. The levels of cathepsin B, cystatin C, urokinase-type plasminogen activator (uPA), soluble uPA receptor (suPAR) and PA inhibitor type-1 (PAI-1), activities of matrix metalloproteinase-2 (MMP-2) and MMP-9, and cell counts as well as local arthritis activity scores (LAS) were examined.
  
  
  RESULTS
  The increases of cathepsin B levels correlated with increased leukocyte and neutrophil counts, latent MMP-9 (pro-MMP-9) activities, uPA, suPAR and PAI-1 levels, and uPA/PAI-1 ratios. Increased cystatin C levels corresponded closely with increased LAS, leukocyte and neutrophil counts, pro-MMP-9 activities, uPA, suPAR and PAI-1 levels, and uPA/PAI-1 ratios. Moreover, there was a correlation between cathepsin B and cystatin C levels.
  
  
  CONCLUSIONS
  These results show a high correlation between the cathepsin B/cystatin C system and markers of joint inflammation in acute gout of the knee, demonstrating the pathologic role of cathepsin B and cystatin C in inflammation.
authors.affiliation: Department of Food Science, Central Taiwan University of Science and Technology, Taichung 406, Taiwan.
authors.forename: Shu-chen
authors.initials: SC
authors.lastname: Chu
authors.forename: Shun-fa
authors.initials: SF
authors.lastname: Yang
authors.forename: Bor-show
authors.initials: BS
authors.lastname: Tzang
authors.forename: Yih-shou
authors.initials: YS
authors.lastname: Hsieh
authors.forename: Ko-huang
authors.initials: KH
authors.lastname: Lue
authors.forename: Ko-hsiu
authors.initials: KH
authors.lastname: Lu
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015210:Arthritis, Gouty / Q000473:pathology*; D015415:Biomarkers / Q000032:analysis; D002401:Cathepsin B / Q000032:analysis* / Q000502:physiology; D055316:Cystatin C / Q000032:analysis* / Q000502:physiology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000209:etiology*; D007719:Knee Joint / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D013582:Synovial Fluid / Q000737:chemistry; D055815:Young Adult
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D002401:Cathepsin B