Neutral protease, collagenase and elastase activities in synovial fluids from arthritic patients

Neutral protease, collagenase and elastase activities were high in synovial fluids from inflammatory arthritic diseases such as gout, active rheumatoid arthritis and ankylosing spondylitis. The activities correlated well with biochemical parameters such as CRP, ESR and total protein. Values were much lower in a non-inflammatory fluid from a patient with osteoarthrosis. Treatment of fluids with trypsin released both collagenase and elastase. The fluids possessed reserve inhibitory action against these enzymes presumably due to plasma antiproteases being present. The collagenase present was found to possess a MW of 32,700 daltons.