Cytoplasmic antigens
Approximately 85% of the RA-SFB expressed the FB marker prolyl-4-hydroxylase (Fig. 6M, and Tables 1 and 4), comparable with the expression in normal skin-FB (71%; Tables 1 and 4).
RA-SFB showed a similar percentage but a higher MFI for the cytoskeletal protein vimentin (Fig. 6I) than normal skin-FB (Fig. 6C and Table 4), although the MFI difference did not attain statistical significance.
A mean of approximately 45% and 50% of the cells, respectively (Table 4), expressed procollagen I (Fig. 6J) and procollagen III (Fig. 6K), as confirmed by double-staining (Fig. 6L). The percentage of cells expressing procollagen I and III was similar to that of normal skin-FB (68% and 55%, respectively; Table 4); however, the MFI for procollagen III was significantly higher in RA-SFB (26 versus 15; Table 4).