.NET winform combobox

I have a winform with some comboboxes and datagrids with
datagridcomboboxcolums. I am binding these comboboxes with data from
the database table. Over time some of the items can be inactivated
from the list. The problem is that forms that items that are
inactivated already selected when they were active.
How can I display items that are inactivated, but prevent user from
selecting those items.
Thank you