IL2 induced a dose-dependent increase in the proportion of Treg cells , significant at all doses compared with placebo ( placebo mean increase 0.5 % [ SD 0.4 ] ; 0.33 MIU 2.8 % [ 1.2 ] , p = 0.0039 ; 1 MIU 3.9 % [ 1.8 ] , p = 0.0039 ; 3 MIU 4.8 % [ 1.9 ] p = 0.0039 ) .