I'm pretty sure that underline will not be added as it is normally implies that it's a link. And really, italics and underline are basically the same thing, except underlining is a lot more deceptive.
However, you can always put it in an underlining generator like Sciz did. They work horribly though. It barely underlines the word, examples shown in the comment section. (It's really inaccurate underlining, Sciz and Sempi and whoever else didn't do that inaccurate underlining purposely.)
Hope I helped. :)