Systemic LE (SLE) is an autoimmune disorder. During this disease, the system of the body mistakenly attacks healthy tissue. It can affect the skin, joints, kidneys, brain, and other organs. The precise explanation for SLE isn't known, but several factors are related to the disease like Genetics. The disease isn't linked to a particular gene, but people with lupus often have relations with other autoimmune conditions, Environment. Environmental triggers can include, Sex and hormones.Systemic LE (SLE) is an autoimmune disorder. During this disease, the system of the body mistakenly attacks healthy tissue. It can affect the skin, joints, kidneys, brain, and other organs. The precise explanation for SLE isn't known, but several factors are related to the disease like Genetics.