The behaviour of collagen peptidase in the serum of different dermatoses.

In 150 patients with different dermatoses and 15 controls the activity of collagen peptidase in serum was determined. No relation to specific skin diseases was found. Negative findings were also observed in the group of collagenoses: only 4 of 14 patients with progressive systemic sclerosis showed an increase of this enzyme activity. These negative results seem noteworthy because it thus is demonstrated that alterations of collagen structure are not necessaryly associated with alterations of collagen peptidase activity.