Figure 1

FMS-related tyrosine kinase 3 ligand levels in rheumatoid arthritis serum, synovial fluid and synovial tissue are significantly elevated. (A) FMS-related tyrosine kinase 3 ligand (Flt3L) serum levels (S) were increased in rheumatoid arthritis (RA; n = 9) compared with healthy individuals (HI; n = 19) (P = 0.0027). (B) Flt3L serum levels were elevated in RA synovial fluid (SF) compared with paired serum (n = 9) (P = 0.0019 (C). Gene expression analysis by quantitative polymerase chain reaction showed increased Flt3L expression in RA synovial tissue (ST; n = 22) compared with gout ST (n = 12) (P = 0.0450). Each data point represents a single subject. Results presented as mean ± standard error of the mean mRNA expression of Flt3L relative to GAPDH. *P <0.05, **P <0.01.