Key clinical point: Patients with psoriatic arthritis (PsA) had higher levels of cathepsins G and K in the serum and synovial fluid than patients with gonarthrosis or control individuals having no physical findings related to their internal organs, skin, or joints.
Major finding: Cathepsin G and cathepsin K levels in the serum ( P < .01) and synovial fluid ( P < .02) were significantly higher in the PsA group than in the gonarthrosis or control group. Serum cathepsin G levels > 6 ng/mL and serum cathepsin K levels > 0.86 ng/mL showed 100% diagnostic accuracy in distinguishing patients with PsA from control individuals and patients with gonarthrosis, respectively, whereas synovial fluid cathepsin G levels > 2 ng/mL showed 100% accuracy in distinguishing PsA from gonarthrosis.
Study details: This retrospective case-control study included 156 patients having PsA with synovial effusion, 50 patients with gonarthrosis, and 30 control individuals.
Disclosures: This study did not receive any external funding. The authors declared no conflicts of interest.
Source: Popova-Belova SD et al. Serum and synovial levels of cathepsin G and cathepsin K in patients with psoriatic arthritis and their correlation with disease activity indices. Diagnostics (Basel). 2023;13(20):3250 (Oct 19). doi: 10.3390/diagnostics13203250