Nephritic syndrome is an inflammation of the kidneys that damages the kidney?s filtering mechanisms, called the glomeruli. It is also called rapidly progressive glomerulonephritis. Rapidly progressive nephritic syndrome is unusual, but may be more likely to affect people with autoimmune disorders. In many cases, the cause of rapidly progressive nephritic syndrome is unknown. In other cases, the cause appears to be a malfunction of the immune system, which could result from a virus or autoimmune disorder such as systemic lupus erythematosus. The immune system produces infection-fighting proteins, called antibodies, which attack the glomeruli. In some patients, these antibodies affect the kidneys and the lungs, causing a condition called Good pasture?s syndrome. Because the initial symptoms of rapidly progressive nephritic syndrome are so general, many patients are not diagnosed until their condition has progressed to kidney failure. For this reason, it is important to see your doctor whenever you have general symptoms such as fever, weakness, and fatigue for no apparent reason.