What does the abbreviation sle mean?

Systemic lupus. Sle stands for systemic lupus erythematosus. Sle is an autoimmune condition in which the body makes antibodies against different cells & tissues resulting in chronic inflammation. Systemic means body-wide, lupus (from the latin for wolf) is thought to represent skin ulcers common with this condition that "devour" the skin, and erythematosus means red, also in reference to the rash.