[Clinical implication of urine test for markers of endothelial dysfunction and angiogenesis factors in assessment of tubulointerstitial fibrosis in chronic glomerulonephritis].

Aim: To evaluate contribution of endothelial dysfunction and impairment of endothelial proliferation/ regeneration to mechanisms of development of tubulointerstitial fibrosis (TIF) in chronic glomerulonephritis (CGN) basing on urinary levels of markers of endothelial activation/impairment and angiogenesis factors.
Material and Methods: A total of 67 CGN patients entered the study: 19 patients with moderate urinary syndrome (group 1), 37 patients with nephrotic syndrome (group 2), 11 patients with nephrotic syndrome and persistent renal failure (RF). A control group consisted of 12 healthy subjects. The examination covered excretion with urine of Willebrand factor (WF), plasminogen activator inhibitor I (PAL-I), fibrin degradation products (FDP), vascular endothelial growth factor (VEGF). These values were compared with severity of fibrous changes in renal interstitium estimated by biopsy morphometry.
Results: CGN patients had signs of affection of parietal effects of vascular endothelium. In particular, increased excretion of functionally active WF, PAI-I and FDP correlating with activity/severity of CGN. The changes were especially noticeable in patients with progressive forms of CGN (with NS and RF). Patients with morphologically verified TIF (interstitial area more than 20%) excretion of endothelial dysfunction markers was higher than in CGN patients free of TIF In a progressive course of nephritis endothelial dysfunction deteriorates by endothelial proliferation/regeneration impairment as shown by reduced urinary excretion of angiogenic factor VEGF and parallel elevation of functionally active WF in urine of patients with severe forms of CGN. Combined contribution of endothelial dysfunction and angiogenesis impairment to mechanisms of TIF development is seen from these values relations with severity of creatinemia and fibrous alterations in tubulointerstitial tissues of the kidney.
Conclusion: The results point to participation of endothelium in mechanisms promoting development of TIF and RF in CGN both in terms of endothelial dysfunction and impairment of endothelial repair capacity. Clinicomorphological comparisons confirm the significance of WF, PAI-I and VEGF in assessment of local-renal endothelial changes and severity of fibrosis in renal tissue in CGN. Due to availability of the study material, perspectives of fibrogenesis monitoring in the kidneys with the tests appear which is essential for making prognosis and treatment policy in CGN patients.