A semi-quantitative scale was used to estimate the degree of TUNEL staining in synovial tissue sections. Investigators blindly reviewed primarily two areas: synovial lining and subsynovial regions. The extent of staining in these areas was scored on a scale of 0 to 4 as follows: 0, negative; 1+, rare positive apoptotic bodies; 2+, scattered clusters of positive apoptotic bodies; 3+, moderate staining; and 4+, extensive staining. Student's t test was used for a statistical analysis. rTRAIL, recombinant TRAIL protein.