Skin collagen biosynthesis in patients with rheumatoid arthritis treated with D-penicillamine.

Collagen biosynthesis was measured in skin biopsies taken from 13 patients with rheumatoid arthritis before and after at least 6 months' continuous treatment with D-penicillamine, 1.0 g/day. There was a significant 36% reduction in mean collagen biosynthesis (p less than 0.0125) as assayed by 14C-hydroxyproline formation from 14C-proline during 24 h of tissue culture. The changes in 14C-hydroxyproline formation were correlated with the total doses of D-penicillamine taken (r = 0.71, p less than 0.01) and the falls in ESR (r = 0.72, p less than 0.01). No significant change in general protein syntehsis was observed. 500 microgram/mlD-penicillamine added to skil cultures in vitro inhibited both collagen and general protein synthesis (p less than 0.01). It is suggested that the clinical improvement induced by D-penicillamine could reflect an inhibition of collagen proliferation in the synovium.