Reduced suppressive potential of bone marrow-derived mensenchymal stem cells of patients with ankylosing spondylitis. (A1) Absorbance of mixed peripheral blood mononuclear cells (PBMCs) at 5 days (0.194 ± 0.038) was significantly higher than the value at 0 days (0.104 ± 0.023) (*P < 0.001), showing the significant mixed PBMC reaction. (A2), (A3) Compared with healthy donor (HD)-bone marrow-derived mensenchymal stem cells (BMSCs), the decreased percentage inhibition of ankylosing spondylitis (AS)-BMSCs on two-way mixed peripheral blood mononuclear cell reaction (MLR) at different ratios showed that suppressive potentials of AS-BMSCs were reduced (% inhibition reduced, *P < 0.001). (B1) PBMCs derived from a healthy volunteer could proliferate significantly the presence of phytohemagglutinin (PHA) in vitro (P < 0.001). (B2), (B3) Percentage inhibition of AS-BMSCs on PBMC proliferation induced by PHA was significantly lower than the values of HD-BMSCs at varied BMSC:PBMC ratios of 1:20, 1:10, 1:5, 1:2 and 1:1 (% inhibition reduced, *P < 0.001). Data expressed as mean ± standard deviation of triplicates of three separate experiments. (A2), (B2) and (A3), (B3) were performed by MTT assay and 3H-TdR assay respectively. There were no statistically significant differences of suppressive potentials between (A2), (A3) HLA-B27-negative healthy donor (HD1)-BMSCs and (B2), (B3) HLA-B27-positive healthy donor (HD2)-BMSCs. OD, optical density.
Wu et al. Arthritis Research & Therapy 2011 13:R29 doi:10.1186/ar3257