Cathepsin B and cystatin C play an inflammatory role in gouty arthritis of the knee.
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.
Chu
Shu-chen
SC
Department of Food Science, Central Taiwan University of Science and Technology, Taichung 406, Taiwan.
Yang
Shun-fa
SF
Tzang
Bor-show
BS
Hsieh
Yih-shou
YS
Lue
Ko-huang
KH
Lu
Ko-hsiu
KH
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
D015415:Biomarkers; D055316:Cystatin C; D002401:Cathepsin B