Table 3.

Difference in relapses between male CD4^–/– and CD8^–/– mice and their heterozygous littermates

Mouse type	Mean relapse* start†	Relapse incidence‡	Mean relative relapse§	Mice w/new inflammation¶
CD4+ (n = 4)	35	25%	33%	50%
CD4– (n = 5)	23	20%	10%	40%
P (no diff.)	0·10
CD8+ (n = 5)	21	80%	18%	60%
CD8– (n = 4)	35	25%	6.3%	25%
P (no diff.)	0·13	0·099		0·76

^*Increased swelling in a joint at least five days after amelioration was considered a relapse.

^†Average number of days after second reimmunization before relapses were observed.

^‡The frequency of mice with relapses.

^§The severity of the new inflammation compared to swelling before amelioration as outlined in Materials and Methods.

^¶The frequency of mice with swelling in previously unaffected joints.

The relapse start, relapse incidence and relative relapse do not differ significantly. The small delay in relapse start and lower relapse incidence in CD8^–/– may indicate an activating role for the CD8 molecule in CIA.