Hydroxychloroquine - what is lupus?

Systemic lupus erythematosus (SLE) is a chronic, inflammatory autoimmune disorder. It may affect the skin, joints, kidneys, and other organs.

SLE (lupus) is an autoimmune disease. This means there is a problem with the body's normal immune system response. Normally, the immune system helps protect the body from harmful substances. But in patients with an autoimmune disease, the immune system can't tell the difference between harmful substances and healthy ones. The result is an overactive immune response that attacks otherwise healthy cells and tissue. This leads to chronic (long-term) inflammation.

Please see link below for detailed information about Lupus.

http://www.drugs.com/enc/systemic-lupus-erythematosus.html