I didn't know there was an Autoimmune Registry. However polymyalgia rheumatica is not found through their opening page search although it is on the list as a vascular disease, as is giant cell arteritis. Maybe their search function is as useful as HU's (used to be)? Or maybe they just haven't got any research in their database yet?
( autoimmuneregistry.org/auto... ).
Interesting, considering this, which implies an effort to keep up to date: