What is an autoimmune disease?

The immune system usually makes antibodies to destroy foreign pathogens that may harm the body. However, in autoimmune disease, the body produces antibodies that recognise the body's own cells or enzymes as foreign, therefore these autoimmune antibodies attack and destroy the person's own cells. This leads to autoimmune disease such as systemic lupus erythematosus (SLE) and rheumatoid arthritis. The causes of autoimmune disease vary greatly depending on the specific disease.