Until recently, the cause of most cases of membranous nephropathy was not known — termed idiopathic. But recent research has found evidence of autoimmune activity in a majority of cases studied. In autoimmune diseases, such as rheumatoid arthritis or lupus, your body's immune system mistakes some of your own tissues as foreign invaders and attacks them with autoantibodies. These autoantibodies are now thought to be the cause of the damage to the glomeruli in most cases of membranous nephropathy.

Sometimes membranous nephropathy is brought on by other causes, notably:

  • Infections (hepatitis B and C)
  • Certain medications (gold salts, nonsteroidal anti-inflammatory drugs)
  • Tumors (solid tumors and lymphomas)
Oct. 12, 2011