Decreased urinary excretion of vascular endothelial growth factor in idiopathic membranous glomerulonephritis.

BACKGROUND: Membranous glomerulonephritis (MGN) has, for unknown reasons, an unpredictable and highly variable clinical course. Vascular endothelial growth factor (VEGF) enhances endothelial cell proliferation, angiogenesis, microvascular permeability, and monocyte chemotaxis, and it activates proteinases. In normal kidneys, it is predominantly expressed by glomerular podocytes, where its physiological function and role in development of renal diseases are obscure. This study was designed to evaluate the urinary excretion of VEGF in MGN compared with several other glomerular disease and to asses its relationships to the clinical activity of MGN. METHODS: Urinary VEGF was studied during renal biopsy using a sandwich enzyme immunoassay from 30 patients with idiopathic MGN, 8 with minimal change glomerulonephritis, 10 with focal segmental glomerulosclerosis (FSGS), 8 with necrotizing glomerulonephritis associated with systemic vasculitis, and 12 with diabetic nephropathy. In addition, 33 healthy controls were examined. Fifteen patients with MGN were re-evaluated 12 months later, and the evolution of proteinuria was compared with changes in urinary VEGF excretion. RESULTS: In healthy control subjects, urinary VEGF excretion was 68 +/- 10 (95% CI, 49 to 88) ng/mmol creatinine (UCr). In MGN, the excretion was decreased to 16 +/- 3 (CI, 10 to 23) ng/mmol crea (P < 0.0001, ANOVA), whereas in minimal change glomerulonephritis and diabetic nephropathy, it was unchanged [55 +/- 14 (CI, 24 to 86) and 101 +/- 25 (CI, 45 to 156) ng/mmol UCr, respectively, P = NS]. In vasculitis and FSGS patients, the excretion was higher than normal [184 +/- 68 (CI, 24 to 344), P = 0.01, and 160 +/- 29 (CI 95 to 226), P = 0.002 ng/mmol UCr, respectively]. The excretion did not correlate with serum VEGF, renal function, or proteinuria. In the follow-up of 15 patients, improving MGN (decreasing proteinuria) was associated with increasing VEGF excretion, while persistent disease (no change or increase of proteinuria) was associated with constantly low urinary VEGF excretion. The change in urinary protein excretion over one year correlated inversely with the change in urinary VEGF (r = -0.57, P = 0.026). CONCLUSIONS: MGN is associated with decreased urinary VEGF compared with normal subjects, which is in contrast with other proteinuric diseases. Moreover, decreasing clinical activity (proteinuria) is accompanied by increasing VEGF excretion. Urinary VEGF may serve as an indicator of activity of MGN.

Peritoneal dialysis access: prospective randomized comparison of the Swan neck and Tenckhoff catheters.

OBJECTIVE: To examine the impact of peritoneal catheter configuration on mechanical complications, catheter survival, probability of episodes of peritonitis, and probability of exit-site infections associated with the use of catheters for continuous ambulatory peritoneal dialysis (CAPD). DESIGN: Prospective randomized trial. SETTING: CAPD unit in one university hospital, serving a population of 1.2 million. PATIENTS: Forty consecutive patients requiring their first dialysis catheter for future CAPD were randomized to receive either a two-cuff permanently bent Swan neck catheter or a two-cuff straight Tenckhoff catheter. The skin exit was downward-directed in the Swan neck group and upward-directed in the Tenckhoff group. RESULTS: Dialysate leak, catheter migration, or tunnel infection did not occur in any of the patients. Three outer cuff extrusions needing cuff shaving occurred, all in the Tenckhoff group (p = 0.1). No significant differences could be demonstrated in catheter survival at 2 years, probability of episodes of peritonitis, or probability of exit-site infections. CONCLUSION: Catheter configuration did not influence the catheter-related mechanical or infectious complications, and equally good results were obtained with both catheter types studied.

Catheter configuration and outcome in patients on continuous ambulatory peritoneal dialysis: a prospective comparison of two catheters.

OBJECTIVE: To examine the impact of peritoneal catheter configuration on mechanical complications, catheter survival, probability of episodes of peritonitis, and probability of exit-site infections associated with the use of catheters for continuous ambulatory peritoneal dialysis (CAPD). DESIGN: Prospective randomized trial. SETTING: CAPD unit in one university hospital. PATIENTS: Forty consecutive patients requiring a dialysis catheter for future CAPD were randomized to receive either a single-cuff straight Tenckhoff catheter or a permanently bent single-cuff Swan neck catheter. The skin exit was upward-directed in the Tenckhoff group and downward-directed in the Swan neck group. RESULTS: Dialysate leak occurred in one patient and symptomatic catheter tip migration in 3 patients with the Tenckhoff catheter but in none with the single-cuff Swan neck catheter (p = 0.5, p = 0.12). No significant differences in catheter survival at 2 years, probability of episodes of peritonitis, or probability of exit-site infections could be demonstrated. CONCLUSION: Catheter configuration did not influence the catheter-related mechanical or infectious complications. We were unable to demonstrate any advantage of the newer, permanently bent single-cuff Swan neck catheter over the conventional straight type.