The forms in reviewboard.admin.forms use ugettext (as _(...)) for the form fields, which means they're not localized at page render time. To fix this, I updated the _ alias to be for ugettext_lazy instead of ugettext and imported ugettext.

I compared translations in the webpage with django's translation log (reviewboard/locale/it_IT/LC_MESSAGES/django.po:msgstr), and ensured translations from the log are also visible in the webpage.