Lupus nephritis is a type of kidney inflammation. It's a common complication in people who have systemic lupus erythematosus — more commonly known as lupus.
Lupus is an autoimmune disease in which your immune system produces proteins called autoantibodies that attack your own tissues and organs.
Lupus nephritis occurs when lupus autoantibodies affect structures in your kidneys that filter out waste. This causes kidney inflammation and may lead to blood in the urine (hematuria), protein in the urine (proteinuria), high blood pressure, impaired kidney function or even kidney failure.
Lupus nephritis care at Mayo Clinic