High free and latent collagenase activity in psoriatic arthritis synovial fluids

Collagenase activity has been studied intensively in SF from OA and RA patients. Less is known about collagenolytic activity in PsA SF. Therefore we examined collagenolytic activity in crude and trypsin treated SF as well as the alpha 1-antitrypsin and alpha 2-macroglobulin concentrations in 50 patients suffering from OA (n = 13), RA (n = 17), and PsA (n = 20). Free collagenolytic activity was low in the crude OA SF (1.80 +/- 1.35 micrograms released collagen/min/ml SF) and almost equally low in RA SF (2.35 +/- 1.80 micrograms released collagen/min/ml SF; P > 0.3). The PsA SF, however, exhibited a significantly higher free collagenolytic activity (5.63 +/- 5.69 micrograms released collagen/min/ml SF; P < 0.05 in comparison to OA and RA SF). The treatment of the SF with trypsin further activated collagenolytic activity in each group (OA 2.17 +/- 1.35 micrograms released collagen/min/ml SF; RA 6.48 +/- 6.73 micrograms released collagen/min/ml SF; PsA 11.24 +/- 5.02 micrograms released collagen/min/ml SF) and yielded significant differences between OA and RA, OA and PsA, and RA and PsA SF (P < 0.05). Concomitantly with the collagenolytic activity, the alpha 1-antitrypsin and alpha 2-macroglobulin concentrations of the SF were measured. In SF from patients with PsA (172.9 +/- 69.4 mg/100 ml) and RA (190.6 +/- 64.7 mg/100 ml) the alpha 1-antitrypsin was significantly higher than in those from OA SF (106.1 +/- 39.2 mg/100 ml).(ABSTRACT TRUNCATED AT 250 WORDS)