Search

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most frequent monogenic hereditary disease as well as the most studied inherited kidney disease. Two drugs have recently been authorized that can slow down the progression of the disease: Tolvaptan (vasopressin receptor antagonist) and Octreotide-LAR (long-acting somatostatin analogue); they both are able to reduce the activity of cyclic adenosine monophosphate (cAMP) and therefore have anti-proliferative and anti-secretory effects. This review analyzes the main trials published to date demonstrating the effects on disease progression in patients with ADPKD and illustrates the indications for identifying subjects eligible for therapy.

To identify early prognostic factors for idiopathic nephrotic syndrome (INS) in childhood.A retrospective analysis of 103 patients with INS at onset, all treated in a single center with the same induction protocol, was conducted. Minimum length of follow-up was 2 years; median length of follow-up was 43 months. Survival data were assessed with Cox-Mantel analysis. Predictive values were estimated with receiver operating characteristic curves.The median time of response to steroid therapy was 7 days. A significant association was found between the interval from onset of steroid therapy to remission and the risk of relapsing within 3 months after steroid therapy discontinuation (P.0001). A similar association was found between the time to achieve remission and the risk of developing frequent relapsing or steroid-dependent nephrotic syndrome (P.0001), the prescription of maintenance steroid therapy (P.003), and the prescription of all other non-steroid drugs (P.0001) during follow-up. Patients with non-relapsing and infrequent relapsing nephrotic syndrome had a median time to achieve remission7 days; in patients with frequent relapsing and steroid-dependent nephrotic syndrome, this median was7 days.The interval from onset of steroid therapy to remission is an accurate early prognostic factor in INS.

Background: The intact parathyroid hormone (PTH) assay evaluates levels of serum 1-84 PTH and other N-terminally truncated PTH fragments, mainly PTH "7-84." This PTH molecule has been found experimentally to interfere with biological activity of PTH 1-84, perhaps through its binding to the PTH receptor complex. Therefore, assuming that high levels of PTH 7-84 are a cause of bone resistance to PTH, it has been hypothesized that a decreased 1-84 to 7-84 PTH ratio caused by a relative increase in PTH 7-84 level might help in the noninvasive diagnosis of low-turnover osteodystrophy (LTO). Methods: This study was performed in 35 patients with chronic renal failure on hemodialysis therapy who underwent bone biopsy for a histological, histomorphometric, and histodynamic study. In addition, blood samples were obtained for intact PTH, 1-84 PTH, and total PTH assays. PTH 7-84 level was obtained from the difference between total and 1-84 PTH assay results. Results: Nine patients had LTO (8 patients, adynamic bone disease; 1 patient, osteomalacia), 12 patients had hyperparathyroidism (HP), and 14 patients had mixed osteodystrophy (MO). On average, 1-84 PTH levels were approximately 60% of mean values for intact PTH. The two assays were strictly correlated. Average 1-84 to 7-84 PTH ratios were 1.57 ± 0.85, 1.73 ± 1.31, and 1.95 ± 2.1 in the three histological groups (LTO, HP, and MO, respectively), with no significant difference. Conclusion: Contrary to previous expectations, results do not favor the hypothesis of a role of 7-84 PTH in bone resistance in renal osteodystrophy. The 1-84 to 7-84 PTH ratio is not a marker of LTO and is of no use in noninvasive histological diagnosis. © 2002 by the National Kidney Foundation, Inc.

Background. Numerous growth factors and cytokines are known to modulate bone turnover. An important, recently discovered complex involved in osteoclastogenesis is the osteoprotegerinuosteoprotegerin-ligand (OPGuOPGL) cytokine complex, which is produced by osteoblasts. Many factors, including parathyroid hormone (PTH), appear to affect bone turnover through this pathway. In this disorder, the role of the OPGu OPGL system in the pathogenesis of renal osteodystrophy, a disease with either low or high bone turnover, has not been investigated so far. Methods. Thirty-nine chronic haemodialysis patients had bone biopsies, including histomorphometric and histodynamic examinations. In addition, the following serum biochemistry parameters were measured: serum OPG, intact PTH, PTH 1–84, total PTH, osteocalcin, total and bone alkaline phosphatases, 25-hydroxycholecalciferol and 1,25-dihydroxycholecalciferol. Results. On average, serum OPG levels were above the normal range. They were lower in adynamic bone disease (ABD) patients, than in patients with predominant hyperparathyroidism (HP) or mixed osteodystrophy (MO). Significant negative correlations were found between serum OPG and PTH levels, and between serum OPG and parameters of bone resorption (ESuBS) and bone formation (ObSuBS and BFRuBS) in HP and MO patients with PTH values O1000 pguml. For intact PTH levels O300 pguml, serum OPG was significantly lower in the group with ABD than in those with HP or MO (P-0.05). Conclusion. In renal osteodystrophy the OPGuOPGL system is involved in the regulation of bone turnover induced by PTH. The determination of serum OPG levels could be of use in the diagnosis of low turnover bone disease, at least in association with PTH levels O300 pguml.

Background Renal artery stenosis (RAS) is a known cause of hypertension and ischemic nephropathy. Stenting of the artery is a valid approach, in spite of cases of unexpected adverse evolution of renal function. Methods In this study, 27 patients with unilateral RAS were subjected to stenting and followed for a period of one year, while 19 patients were observed while on medical treatment only. The group of 27 patients, 67.33 ± 6.8 years of age, creatinine of 2.15 ± 0.9 mg/dl, following stenting, were followed at intervals with biochemical tests, renal scintigraphy and doppler ultrasonography. The control group (70.0 ± 6.1 years, creatinine 1.99 ± 0.7 mg/dl) was also followed for one year. Result One year after stenting mean creatinine clearance (Ccr) increased from 36.07 ± 17.2 to 40.4 ± 21.6 ml/min (NS). Arterial BP, decreased after 1,3,6, and 12 months (p < 0.05). The number of antihypertensive drugs also decreased (p < 0.05). A significant increase in proteinuria was also observed. In the control group both Ccr, BP and proteinuria did not show significant changes. Based on renal scintigraphy and Ccr at subsequent times, it was possibile to evaluate the timecourse of renal function in both kidneys of the stented patients. In the stented kidneys Ccr increased significantly. On the controlateral kidney a decrease of renal function (p < 0.05) was observed. Resistance index appeared to be a risk factor of the functional outcome. Conclusions Stenting of RAS due to atherosclerosis is followed by stabilization or improvement of Ccr, mainly at the stented kidney, while contralateral renal function showed a decrease.

Background Atherosclerotic ischemic renal disease is a frequent cause of end-stage renal failure leading to dialysis among the elderly; Its prevalence is inferred from autopsy or retrospective arteriographic studies. This study has been conducted on 269 subjects over 50 with hypertension and/or CRF, unrelated to other known causes of renal disease. Methods All 269 patients were studied either by color-flow duplex sonography (n = 238) or by renal scintigraphy (n = 224), and 199 of the 269 patients were evaluated using both of these techniques. 40 patients, found to have renal artery stenosis (RAS), were subjected to 3D-contrast enhancement Magnetic Resonance Angiography (MRA) and/or Selective Angiography (SA). An additional 23 cases, negative both to scintigraphy and to ultrasound study, underwent renal angiography (MRA and/or SA). Results Color-duplex sonography, carried out in 238 patients, revealed 49 cases of RAS. MR or SA was carried out in 35 of these 49 patients, and confirmed the diagnosis in 33. Color-duplex sonography showed a PPV value of 94.3% and NPV of 87.0% while renal scintigraphy, carried out in 224 patients, had a PPV of 72.2% and a NPV of 29.4%. Patients with RAS showed a higher degree of renal insufficiency compared to non stenotic patients while there were no differences in proteinuria. RAS, based on color-duplex sonography studies, was present in 11% of patients in the age group 50–59, 18% in the 60–69 and 23% at age 70 and above. Conclusions A relatively large percentage of the elderly population with renal insufficiency and/or hypertension is affected by RAS and is at risk of developing end-stage renal failure. Color-duplex ultrasonography is a valid routine method of investigation of population at risk for renal artery stenosis.