Serum autoantibody levels in MRL/lpr mice treated with 5.5 Gy × 2 + IBM.

The levels of anti-ssDNA Abs and RFs were measured 40 weeks after the treatment (striped bars). Sera from B6 (black bars) and nontreated MRL/lpr mice (white bars) at 20 weeks of age served as positive and negative controls, respectively. Results are expressed as the mean ± SD of 6 mice. Asterisks represent P values of treated versus nontreated MRL/lpr mice; *P < .01 and **P < .001.