BMT as a treatment for EAE. (A) DA rats were irradiated on day 17 after immunization and received BM transplants of either DA (n = 6) or ACI (n = 6) origin. Controls were not irradiated and did not receive BM transplants (n = 10). Differences between the groups receiving BM transplants compared with the control were significant (cumulative score day 19 to 87 after immunization, P = .036, ANOVA). Rats were reimmunized for EAE on day 90. Rats receiving BM transplants had significantly lower disease scores upon reimmunization compared with controls not receiving transplants (P < .001, ANOVA). A second confirmatory experiment gave similar results (data not shown). (B) Rats were immunized on day 0 with MOG 1-125 and underwent transplantation on day 140 with BM of DA origin (n = 9) or did not receive BM transplants (n = 4). There was no effect of BMT at a late time point. Rats were then reimmunized on day 181 with MOG 1-125. After reimmunization only a slight exacerbation of disease was observed in the group receiving transplants compared with the group without BMT (cumulative score day 188 to 234 after immunization, P = .021, t test).