Fig. 1

PDPN and CD248 markers identify specific fibroblast subsets localized to distinct anatomical compartments in the inflammatory synovium. a Representative confocal images of synovial biopsy tissue from healthy and rheumatoid arthritis (RA) synovium. Expression of podoplanin (PDPN) and CD248 is shown in healthy (normal) compared to rheumatoid synovium. b Quantification of marker expression in synovial tissue of patients with RA compared to normal controls. Data are expressed as median and interquartile range for CD248 (p = 0.65 by Mann-Whitney U test; n = 7 normal; n = 19 RA) and for PDPN (*p = 0.0013 by Mann-Whitney U test; n = 7 normal; n = 20 RA). c High magnification confocal images of rheumatoid synovium showing the lining (R1) versus sub-lining (R2) layer interface and expression of cell surface markers. Scale bars = 100 μm. PDI protein disulfide isomerase, UA unit area, VCAM-1 vascular adhesion molecule-1