Name a degenerative joint disease in which the body's immune system mistakenly attacks its own tissue in the joint or organs.

Answer: Rheumatoid Arthritis

Explanation:

In patients suffering from rheumatoid arthritis, accumulation of urates occur in the joints due to the deficiency of a vital enzyme, as a result the immune system produces antibodies that attack these joints or organs where urates are found.

This eventually leads to inflammation & degeneration of the joints, characterized by painful swelling and stiffness