Rheumatoid arthritis (RA)

Rheumatoid arthritis (RA) is an inflammatory disease where the joints become stiff and swollen, and is associated with future joint destruction. This is caused by immune cells, which normally attack foreign organisms, instead react against the tissues in the joints, resulting in inflammation.

Symptoms 
The symptoms in patients with RA are very variable but due to the pain and the effects on the joints the disease often becomes obstructing. The therapies that patients receive are given to dampen the inflammation and relieve the pain and to diminish future joint destruction.

In some RA patients antibodies are formed that target collagen II, an important protein in joint cartilage. These antibodies drive the inflammation early in the disease and the highest amounts of collagen antibodies have been detected at the time of diagnosis, after which the levels decrease during the first year.

References (sources):  Uppsala University