Proteinuria in childhood. Diagnostic and therapeutic approach

The excretion of a nearly protein-free urine is one of the most important tasks of human kidneys. To achieve this, the glomeruli of an adult human filter around 180 l of a nearly protein-free primary urine every day. Glomerular damage is the main cause of a substantial protein loss through the kidneys, called proteinuria and needs to be distinguished from damage to the tubular system; however, proteinuria is not only a marker of renal damage but also an independent risk factor for progression of chronic kidney disease and for the development of cardiovascular complications. The exact diagnosis and therapy of proteinuria during childhood and adolescence are therefore crucial, especially in patients suffering from chronic kidney disease. This article describes a structured diagnostic approach, to give insights into the underlying pathogenesis and current therapeutic approaches of proteinuria and to outline the importance of proteinuria in daily clinical routine