Autoimmune diseases in the kidney

The kidney, like most other organs, is a target of autoimmunity. This can happen as a consequence of systemic autoimmunity, such as systemic lupus erythematosus which causes nephritis in 35%-55% of the patients due to an abnormal inflammation in the glomerulus. In other instances, kidney disorders are caused by deposits of nonspecific autoantibodies in the glomerulus as in cases of antineutrophil cytoplasmic antibody, complement 3, and IgA glomerulopathies. The kidney is also the target of autoantibodies that attack specific cell types in the glomerulus. These include membranous nephropathy and glomerular basement membrane nephropathy. Besides these established autoimmune diseases, acute kidney injury and chronic kidney disease have autoimmune features and are increasingly being considered to have important autoimmune components. This chapter briefly summarizes the main autoimmune diseases of the kidney, treatments, and connections to the general concept of autoimmunity.