Fig. 2

ECP treatment efficiently reverses arthritis progression. Spleen cells from arthritic mice were submitted to psoralen + UVA irradiation, resulting in their rapid apoptosis. a Representative flow cytometry profile of cells 5 h after ivPUVA treatment of the cells. Live cells are defined as AnnV negative 7-AAD negative cells. b Mean and standard deviation of 5 samples from 5 different arthritic mice spleen cells. Statistical differences between treated and untreated mice were determined by Mann and Whitney test (“*” means p < 0.05). c Mice with established arthritis were injected (green dotted lines) or not (red plain lines) 3 times (arrows) with ivPUVA spleen cells taken from arthritic mice. Each curve represents the relative clinical score of one mouse. d Mean and standard error of the mean (SEM) of relative clinical score in 13 mice per group from two different experiments. The two curves represent the calculated nonlinear regression, second order polynomial equations and are statistically different (comparison of polynomial coefficients) for untreated (black squares) and treated (white circles) mice, reflecting the different overall clinical course in treated versus untreated mice. Bayesian analysis using a Baranyi model also indicated that the two curves were different (Bayes factor > 1000)