Renal manifestations of systemic diseases.

During childhood, the kidney may be involved in several different systemic diseases including the vasculitic syndromes, collagen vascular diseases, and the thrombotic microangiopathic diseases. This article discusses three of the more common systemic disease including Henoch Schonlein Purpura (HSP), systemic lupus erythematosus (SLE), and the hemolytic uremic syndrome (HUS), which occur during childhood. Each of these diseases have important renal manifestations that may present with hematuria with or without proteinuria, hypertension, rapidly progressive glomerulonephritis, and/or with acute renal failure. The occurrence of these diseases during childhood raises lifelong concerns for the child's renal function. As in glomerulonephritis associated with SLE, reactivation of the underlying disease can result in additional renal injury, whereas late extrarenal and renal complications may be observed following HUS or nephritis associated with HSP. These diseases are not only an important cause of acquired chronic renal failure during childhood, but may also lead to end-stage renal disease or other complications that do not become apparent until adulthood. In each disease, we will review the clinical manifestations, the pathology, pathophysiology, and current management and therapy.