BACKGROUND: Changes in the concentration of extracellular matrix components in body fluids may reflect the degree of kidney fibrosis. The aim of our study was to evaluate fibronectin (FN) and type IV collagen (COL IV) concentrations in blood serum and urine, and to refer these values to immunoreactivity in renal biopsy material. MATERIAL/METHODS: Our research involved 37 children with glomerulonephritis (GN) aged 4-15 and 18 healthy children. The patients were divided into 3 groups according to the histopathological diagnosis of GN: I - minimal change GN (MCGN, n=17), II - lupus nephritis (LN, n=7), III - other types of GN (n=13). RESULTS: Significantly higher COL IV concentrations in serum and urine were noted in the patient group in comparison to the controls, but no differences in FN concentrations. The highest values of serum and urine COL IV were observed in the LN patients. Positive correlation was found between serum and urine COL IV and its renal content in the LN group. CONCLUSIONS: The results indicate that serum and urine COL IV rises in children with GN, above all in the course of LN. This also reflects changes in renal COL IV content.

Keywords: Collagen Type IV - blood, Collagen Type IV - urine, Fibronectins - urine