Check box for each comment: "Is this an actionable item?" Checking the box means it is actionable.
There would also be options to highlight each comment based on it's status. A red highlighted comment would mean the comment has not been addressed. A green highlighted comment would mean the comment has been addressed.
We have a number of examples in documentation WIKIs where we ask someone to add some information to a WIKI. The check box and color coding would help identify the actionable items and their statuses without having to fully read through a long WIKI.