RESUMEN
Urinary excretion of lysozyme was investigated in a group of 66 patients with various renal diseases, nephrolitiasis and urinary tract infections. The results obtained demonstrate that the amount of the enzyme excreted is related to the entity of tubular damage whereas is not with glomerular damage. No correlation was found between lysozyme excretion neither to the degree of proteinuria neither to the amount of leukocytes and bacteria in the urine. In patients with urinary infections urinary lysozyme increases only when there is a tubular injury of some entity. In 90 pediatric patients with urinary infection and pyelonephritis lysozyme in the urine was found only in two cases. Therefore urinary lysozyme determination cannot be considered for the detection of early tubular injury and is not a helpful diagnostic tool in urinary tract infections.