Serum COMP (S-COMP) at baseline and after 3 and 6 months in rheumatoid arthritis patients treated with infliximab. Serum COMP was lower than at baseline after 3 months (P < 0.001). The levels remained low after 6 months (P < 0.001 compared with baseline). For details, see text. COMP = cartilage oligomeric matrix protein (thrombospondin-5).