Bid-deficient mice develop a sustained and prolonged edema of the ankles following transfer of K/BxN serum. Pooled serum (300 μl) from K/BxN mice was injected intra-peritoneally (IP) into Bid-/- (n = 32) and wild-type (Wt) (n = 42) mice. Ankle joints were examined for arthritis by measuring two perpendicular diameters of both joints (anterior-posterior; medio-lateral) by calipers. The change in (Δ) ankle circumference at each time point is defined as the difference between the ankle circumference and the measurement at day 0. values represent the mean ± standard error of ankles/time point, which were compared by Student's t-test to Wt mice under parallel conditions. The asterisk denotes p < 0.002 compared to Wt under parallel conditions.