(a and b) Kinetics of the accumulated clinical EAMG incidence (a) and mean clinical score (b) in DQ6, DQ8, DR3, and DQ8×DR3 F1 transgenic mice. DQ6 mice’s mean clinical scores (severity) were significantly lower than those of DQ8 and DR3 (from day 42 to the end of the experiment) and DQ8×DR3 F1 mice (from day 20 to the end of the experiment) after a second H-AChR immunization. P < 0.05, Student’s t test. In Fisher’s exact probability test, the difference in the clinical incidence between DQ8 and DQ6, and DR3 and DQ6 was significant at P = 0.060. (c and d) Clinical EAMG incidence (c) and mean clinical score (d) of DQ8 and DQ8×DQ6 F1 transgenic mice.