Giant cell arteritis (also called arteritis temporalis) and polymalgia rheumatica are autoimmune diseases that occur predominantly, but not exclusively, in older people, usually well over 50 years of age. Their causes are still unknown. This leads to inflammatory changes in the large blood vessels (giant cell arteries) and the musculature (Polymyalgia rheumatica), which can be detected with modern imaging methods. Interestingly, the Polymyalgia rheumatica often occurs as an accompanying disease of giant cell arteritis, which is why both diseases are combined here. However, it is not clear what exactly links the two diseases.
Initial stage
Both diseases usually begin with unspecific symptoms such as fever, weight loss, night sweats and general discomfort. Sudden onset with loss of vision is rare, but not impossible.
In the further course
This can occur in the further course of the disease:
In many cases, blindness caused by occlusion of the blood vessels that supply the eye is the most serious complication of giant cell arteritis. This is to be regarded as one of the few rheumatological emergencies.
In a few cases, a constant high level of inflammatory activity in the large blood vessels (aorta/abdominal artery) can lead to destruction and instability of the vessel walls. During acute inflammation, but also years later, this can lead to tearing of the vessel walls (aortic dissection/neurysm) and therefore requires regular checks.
Polymyalgia rheumatica used to be a clinical diagnosis, characterized by the classic muscle pain of the pelvic and shoulder girdle. Laboratory tests were able to support the diagnosis. Today, ultrasound examinations are increasingly being used to help detect inflammatory activity in the musculoskeletal system.
The diagnosis of giant cell arteritis is more complex and depends on the symptoms. Since the complaints, with the exception of pelvic and shoulder girdle complaints, as they also occur in Polymalgia rheumatica, can also occur in many other diseases, including tumors and infections, giant cell arteritis is often primarily an exclusion diagnosis. However, new imaging methods (ultrasound, MRT, PET-CT) can immensely accelerate the diagnostic process today. In many cases, a biopsy of the temporal artery can definitively confirm the diagnosis.
Long-term glucocorticoid therapy ("cortisone") has so far been the most important pillar in the treatment of both diseases. As described above, patients take glucocorticoids for one or more years. Although glucocorticoids are well tolerated in many cases in the short term, many other problems occur during the long therapy periods, including osteoporosis, diabetes mellitus, high blood pressure, etc., which then have to be treated by rheumatologists.
Methotrexate, which has a very good effect on many other rheumatic diseases, has a much lower significance in giant cell arteritis and polymyalgia rheumatica and is used when glucocorticoid therapy does not respond sufficiently or cannot be further reduced.
We are currently placing great hope in the blockade of interleukin-6, an important inflammatory substance in both diseases. This therapy is currently only available in clinical studies (GiACTA study). The therapy is well established for other rheumatic diseases. If it proves to be effective in the studies, which can be assumed from the treatment of some cases, it would revolutionise the therapy of giant cell arteritis and significantly reduce the dose of glucocorticoids.
