Urinary fibronectin as an indicator of fibrosing in the kidney in nephritis

Aim, To investigate clinicomorphological relationships between elevated uri nary excretion of fibronectin (FN) and development of fibrosis in the kidne y in patients with lupus nephritis (LN) and chronic glomerulonephritis (CGN ). Materials and methods, Urinary FN excretion was measured at radial immunodi ffusion in 54 LN patients. Of them, 15 patients had inactive LN, 39 patient s had active LN varying in clinical forms. Urinary FN was also measured by passive hemagglutination in 36 CGN patients (II inactive CGN and 25 active CGN cases). Biopsy specimens were obtained from 49 patients with active nep hritis (43 with CGN and 6 with LN). FN deposits were studied immunohistoche mically and morphometrically with determination of relative fibrosis area. Results, Urinary FN excretion in patients with nephritis war higher than in healthy controls. In active CCN and LN the levels of FN were significantly higher than in inactive CGN and LN. The highest FN urinary concentrations were registered in patients with severe CGN and LN, especially in the prese nce of renal failure and arterial hypertension. Among them, the highest ind ividual values were observed in patients with rapidly progressive nephritis . No positive correlations were found between the degree of the urinary FN excretion increment and degree of proteinuria. This suggests local-renal or igin of most urinary FN. Morphologically, FN deposits were revealed in 73% of the biopsies. In most of the patients with severe nephritis both in CGN find LN there was a diffuse distribution of FN in the glomerules and inters titium. A correlation,vith a morphological nephritis type was absent, but e xisted between FN presence in the renal biopsies and relative area of inter stitium (fibrosis). Conclusion. FN excreted in high amounts with wine in nephritis originates f rom the kidneys and reflects severity of fibrogenesis in the kidney.