According to an article in the New Scientist (10/8/19 No 3242) some scientists think Porphyromonas Gingivalis (a bacterium) may be partly to blame for a wide range of inflammatory diseases such as Altzheimer's and heart disease. P.gingivalis is present in gum tissue and passes from there into the blood stream. Once in the blood the p.gingivalis changes its surface proteins so it can hide inside white blood cells of the immune system and can also enter cells lining arteries.
Is it possible for this infection of the arterial wall to precipitate the formation of granulomatous tissue, such as the giant cells seen at biopsy? I am sure this has all been well researched but it's worth asking the question.
Some years ago I could hardly walk downstairs in the morning and was diagnosed with PMR and treated with prednisolone. A year later I was symptom free and no longer taking the steroids. Then the symptoms returned and this time I asked to be tested for Lyme, was found to be positive and two months of Doxycycline was the only treatment required. (My wife has GCA). The disease is caused by borrellia, a bacterium, but I find it interesting that it can mimic PMR.
Back in the 1980's a researcher by the name of Marshall infected himself with Helicobactor Pylori and was able to demonstrate that stomach ulcers were caused by bacteria as opposed to spicy foods and stress. Prior to that it was thought bacteria could not survive the acidity of the stomach and few people thought they could be associated with stomach ulcers.
Seemingly more and more illness, especially those affecting older people, are being investigated for a bacterial component. It just makes you wonder if bacteria, such as P.gingivalis could be associated with PMR and GCA. Unlikely, but ........ !!!!!
(Unfortunately p.gingivalis is not susceptible to antibiotic treatment but there are drugs being developed that may "deactivate" it).