Lupus is a type of inflammatory disease which primarily affects the organs of the body. These organs, most commonly the kidneys, heart, brain, and lungs, are negatively affected because the immune system of the body attacks and causes swelling.The immune system is intended to help protect the body.upus is a type of inflammatory disease which primarily affects the organs of the body. These organs, most commonly the kidneys, heart, brain, and lungs, are negatively affected because the immune system of the body attacks and causes swelling.