ABSTRACT
This chapter reviews mechanisms of immune injury in the kidney, focusing on mediator systems of this immune injury. It provides a discussion of how immune deposits form, based primarily on their location within the glomerulus. The chapter focuses on the glomerulus since this is the usual site of immunologic disease in the kidney, but recent work has also shown that tubular-interstitial areas may also be sites of immunologic injury. Deposits in the subepithelial space are characteristic of human membranous nephropathy. Exogenous antigen may also bind to glomerular structures and initiate subepithelial deposit formation. The mesangium is made up of mesangial cells and matrix. It is separated from the systemic circulation only by the glomerular endothelial cell with its wide fenestrae. The antibodies are associated with an interstitial nephritis. Antibody alone may produce injury without involving any other mediators. The usual mechanism whereby immune deposits and antibody are thought to initiate injury is through the activation of the complement system.
