The kidney can become involved in immune-mediated diseases through 3 mechanisms. It can be the primary target of antibody-mediated injury. Goodpasture syndrome, with antibodies directed at the glomerular basement membrane, is an example of this type. The kidney can be injured by immune complexes that are trapped in the kidney and cause local inflammation. Examples include systemic lupus erythematosus and IgA nephropathies. Finally, the kidney can be injured by immune responses initiated in other organs. In Wegener granulomatosis, inflammation begins in the airway but results in glomerulonephritis. Currently available therapies lack efficacy and specificity. New therapies based on pathophysiology are being developed in animal models.