The serum levels of connective tissue growth factor in patients with rheumatoid arthritis. The serum concentration of connective tissue growth factor (CTGF) in patients with RA (n = 39), SLE and SS (n = 15) and normal healthy controls (n = 50) were measured using a sandwich ELISA (Figure 1A). Dotted line (Figure 1A) indicates the cut off point designed as the mean OD + 3 SD for normal sera. Value above the cut off point was defined as an elevated serum CTGF concentration. Comparison of the serum concentrations of CTGF between active (n = 20) and inactive (n = 19) RA patient was shown (Figure 1B). Comparison of the serum concentrations of CTGF between before and after Infliximab treatment was also shown (Figure 1C). The sera treated with infliximab (n = 10) were collected at post 24 hrs after the first administration. Bars in 1B and 1C indicate the SD.