The autoimmune diseases known as lupus are hard to diagnose, unpredictable and affect many more women than men, explains Upstate rheumatologist Hiroshi Kato, MD. Lupus causes the immune system to attack the body‘s healthy tissues and organs, and while its cause is unknown, it appears to involve both genetic factors and environmental triggers, Kato says. Close monitoring by a rheumatologist is usually necessary to help control the disease, he notes.