Test Details: The LE cell test is used to diagnose an autoimmune disease called Systemic Lupus Erythematosus (SLE). SLE is a chronic autoimmune disease in which the body’s immune system attacks healthy cells and the characteristic symptoms include severe fatigue, joint inflammation, joint pain, rashes on the nose and cheeks-known as the butterfly rash. This test is recommended when the patient presents with such symptoms and SLE is suspected.