Fig. 2

Mechanical allodynia and thermal hyperalgesia in ACIA and control-treated mice. Paw withdrawal thresholds (a) and latencies (b) were determined for both hind paws at the time points indicated using von Frey filaments (a) and the Hargreaves test (b), respectively. ACIA mice were immunized with s.c. mBSA and bovine collagen II, and arthritis was induced by i.a. mBSA in the ipsilateral joint (open squares), PBS was injected into the contralateral joint (black squares). Control animals only received s.c. adjuvant and i.a. mBSA (open circles) or PBS contralaterally (black circles). Data are represented as means ± SEM. Statistical analysis was performed using the two-way RM ANOVA and Bonferroni’s multiple comparison tests followed by a Bonferroni correction comparing ACIA ipsi- vs. contralateral thresholds (*P < 0.05, **P < 0.01, ***P < 0.001) and non-immunized ipsi- vs. non-immunized contralateral thresholds (#P < 0.05, ##P < 0.01, ###P < 0.001), N = 8. Inflammation scores of immunized, non-immunized, and CD8⁺-depleted mice were correlated with thermal paw withdrawal latencies (c) and mechanical paw withdrawal thresholds (d) using the Spearman correlation. Paw withdrawal latency was inversely correlated with inflammation scores (Spearman r = −0.6, P < 0.01, N = 24), no correlation was found for paw withdrawal thresholds and inflammation scores