Print Overview Kidney cross section Enlarge image Close Kidney cross section Kidney cross section The kidneys remove waste and extra fluid from the blood through filtering units called nephrons. Each nephron contains a filter, called a glomerulus. Each filter has tiny blood vessels called capillaries. When blood flows into a glomerulus, tiny bits, called molecules, of water, minerals and nutrients, and wastes pass through the capillary walls. Large molecules, such as proteins and red blood cells, do not. The part that's filtered then passes into another part of the nephron called the tubule. The water, nutrients and minerals the body needs are sent back to the bloodstream. The extra water and waste become urine that flows to the bladder. Lupus nephritis is a problem that occurs often in people who have systemic lupus erythematosus, also called lupus. Lupus is a disease in which the body's immune system attacks its own cells and organs, called autoimmune disease. Lupus causes the immune system to make proteins called autoantibodies. These proteins attack tissues and organs in the body, including the kidneys. Lupus nephritis occurs when lupus autoantibodies affect parts of the kidneys that filter out waste. This causes swelling and irritation of the kidneys, called inflammation. It might lead to blood in the urine, protein in the urine, high blood pressure, kidneys that don't work well or even kidney failure.Products & ServicesA Book: Mayo Clinic Family Health BookNewsletter: Mayo Clinic Health Letter — Digital EditionShow more products from Mayo Clinic SymptomsSigns and symptoms of lupus nephritis include: Blood in the urine. Urine that foams because of too much protein. High blood pressure. Swelling in the legs, ankles or feet and sometimes in the hands and face. High levels of a waste product called creatinine in the blood. Request an appointment CausesAs many as half of adults with systemic lupus get lupus nephritis. Systemic lupus causes the body's immune system to damage the kidneys. Then the kidneys can't filter out waste as they should. How kidneys work Show transcript for video How kidneys work One of the important jobs of the kidneys is to clean the blood. As blood moves through the body, it picks up extra fluid, chemicals and waste. The kidneys separate this material from the blood. It's carried out of the body in urine. If the kidneys are unable to do this and the condition is untreated, serious health problems result, with eventual loss of life. Risk factorsThe only known risk factors for lupus nephritis are: Being male. Women are more likely to get lupus, but men get lupus nephritis more than women do. Race or ethnicity. Black people, Hispanic people and Asian Americans are more likely to have lupus nephritis than are whites. ComplicationsLupus nephritis can cause: Hypertension. Kidney failure. A higher risk of getting cancer, especially one that starts in the cells of the immune system, called B-cell lymphoma. A higher risk of heart and blood vessel problems. By Mayo Clinic Staff Lupus nephritis care at Mayo Clinic Request an appointment Diagnosis & treatment March 28, 2024 Print Show references Lupus and kidney disease (Lupus nephritis). National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/kidney-disease/lupus-nephritis. Accessed April 17, 2023. AskMayoExpert. Lupus nephritis. Mayo Clinic; 2021. Bomback AS, et al. Lupus nephritis: Diagnosis and classification. https://www.uptodate.com/contents/search. Accessed April 17, 2023. Davidson A, et al. Lupus nephritis: Challenges and progress. Current Opinion in Rheumatology. 2019; doi:10.1097/BOR.0000000000000642. Falk RJ, et al. Lupus nephritis: Initial and subsequent therapy for focal or diffuse lupus nephritis. https://www.uptodate.com/contents/search. Accessed April 17, 2023. Gasparotto M, et al. Lupus nephritis: Clinical presentations and outcomes in the 21st century. Rheumatology. 2020; doi:10.1093/rheumatology/keaa381. Ami T. Allscripts EPSi. Mayo Clinic, Rochester, Minn. May 3, 2023. Ami T. Allscripts EPSi. Mayo Clinic, Rochester, Minn. May 3, 2023. Mejia-Vilet JM, et al. The lupus nephritis management renaissance. Kidney International. 2022; doi:10.1016/j.kint.2021.09.012. Related News from Mayo Clinic Steroid dosage risks and benefits when managing lupus nephritis Aug. 28, 2024, 04:00 p.m. CDT Products & Services A Book: Mayo Clinic Family Health Book Newsletter: Mayo Clinic Health Letter — Digital Edition Show more products and services from Mayo Clinic Lupus nephritisSymptoms&causesDiagnosis&treatmentDoctors&departmentsCare atMayoClinic Advertisement Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. 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