IL@ induced a dose-dependent increase in the proportion of Treg cells , significant at all doses compared with placebo ( placebo mean increase @ % -LSB- SD @ -RSB- ; @ MIU @ % -LSB- @ -RSB- , p = @ ; @ MIU @ % -LSB- @ -RSB- , p = @ ; @ MIU @ % -LSB- @ -RSB- p = @ ) .