Autoinflammatory vs autoimmune?

According to Claude AI app...
Yes, that's a fair and accurate characterization.
PMR is classified as an inflammatory rheumatic disease, but it doesn't fit neatly into either classic category:
Not clearly autoimmune: It lacks the specific autoantibodies that define classic autoimmune diseases (like rheumatoid factor or anti-CCP in rheumatoid arthritis). No consistent autoantigen has been identified.
Autoinflammatory features: PMR shows strong involvement of the innate immune system — elevated inflammatory cytokines (especially IL-6), a robust acute-phase response (high ESR/CRP), and a good response to glucocorticoids, all of which look more "autoinflammatory" than autoimmune.
But not purely autoinflammatory either: Unlike monogenic autoinflammatory syndromes (e.g., familial Mediterranean fever), PMR doesn't have a clear genetic mutation in innate immune pathways, and there's some evidence of adaptive immune (T-cell) involvement too.
So most current rheumatology literature describes PMR as occupying an intermediate or overlapping space — an immune-mediated inflammatory condition with a predominantly innate/cytokine-driven profile, without the autoantibody signature of classic autoimmune disease. It's also closely linked to giant cell arteritis, which shares this same ambiguous classification.

First, if you are going to quote something you found on the internet, please share the source with your audience. Without the source it is a guessing game on the reliability and applicability of the information. Your material sounds valid - however all information needs to be understood in context to be fully understood for applicability.
It is important to remember at all times that PMR is a default Dx. This means if it is not other things they test for then they default to PMR if you have certain symptoms and respond well to steroids. There is no definitive test to prove you have PMR. That being true it is impossible to say that PMR is a single medical problem. It could be a compound problem that needs to be peeled apart and treated individually. Even complicating it more - your version of PMR and my version of PMR may have similar characteristics but may not have the same root cause and thus may respond to identical treatments differently. PMR is complex mainly because it is not well understood.

There actually is a definitive test for both PMR and GCA (Giant Cell Arterits). It's called "Color Doppler Ultrasound," "Doppler Power Ultrasound," or "Musculoskeletal Ultrasound." They use it on your shoulders for PMR, and your head/temples and other spots to check for GCA.
They can see if there is fluid in the subacromial Bursa and other indicators of PMR in the shoulders.
I'm not sure what they look for to confirm GCA, but I got checked for GCA at same time as shoulders for PMR.
It's different from a standard Ultrasound machine from what I understand.
I'm not sure if they're easy to get in rural areas, but hopefully should be in many areas. It gave me definitive answers re having PMR and not having GCA.
Hope this information will help anyone who would like a definitive test.
Only wish none of us needed or wanted confirmation!!
Blessings to all of us

Just added 9/8/26:
Also, recently saw something re PET scans for confirming PMR.
https://www.sciencedirect.com/science/article/pii/S0001299826000772
I saw other links as well. It seems hopeful more awareness and methods of confirming PMR may be coming.
Wish no one needed them.
Blessings.

@jabrown0407
First of all, yes you are right in saying I should have provided sources. There were so many and so complicated/extensive . I am a bit of a newbie to this type of social media posting... so I hesitated to include. them.

secondly as later posts suggest there is beginning to be some types of tests that can indicate PMR more clearly. But yes, they appear to be not readily available and among Family physicians it is considered to be a diagnosis of exclusion.

It is a Dx of exclusion among Rheumy's as well. They have imaging tests but those are not conclusive by any means. They tried to tell me the pain in my right shoulder was PMR. I told them it was a pressure pain like something was pushing on my joint. My shoulder surgeon aspirated 3 vials of inflammation (yellowish liquid) from that shoulder. Pain gone! Nothing could be seen in the imaging in my left shoulder and no pain there either.
Until they find the cause they cannot develop a test and without a test it is a default Dx.