Pediatric nephrotic syndrome: from the simple to the complex.

Remarkable advances have been made in the past decade in understanding the pathophysiology of idiopathic nephrotic syndrome. Although the initiating events leading to the onset of proteinuria still are not well defined, it has become increasingly clear that many glomerular diseases can be classified as podocytopathies, with injury to the podocyte playing a major role in the development and progression of disease. A complex interaction of immune system mediators, slit diaphragm signal transduction, podocyte injury and conformational change, and mediators of apoptosis and fibrosis determine the extent and nature of proteinuria and progression of glomerulosclerosis. New insights into the pathogenesis of idiopathic nephrotic syndrome likely will lead to innovative therapies and new approaches to management and prevention.