[ADPKD treatment: Tolvaptan and Octreotide].

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.

[Renal manifestation of Autosomal Dominant Polycystic Kidney Disease].

Autosomal dominant polycystic kidney disease affects over 12 million people in the world and is the fourth cause of ESRD. It is the main monogenic kidney disease and causes the progressive formation of cysts leading to renal failure after a few decades. The main manifestations of the disease are observed even at a young age. The early sign of ADPKD is impaired urinary concentrating capacity, due to medullary alteration by cysts, and resistance to vasopressin. These anatomical alterations determine hyperfiltration, altered ammonium transport, nephrolithiasis, and, above all, hypertension even in pediatric age. Activation of the renin-angiotensin-aldosterone system has been shown responsible for the maintenance of high pressure values as well as the growth of cysts and renal fibrosis. Arterial hypertension would be responsible for ventricular hypertrophy. Many recent studies have confirmed the role of pressure control, especially if rigorous, in decreasing the progression of renal disease, and the use of ACE inhibitors seems to have higher efficacy than other antihypertensive drugs. The progression of renal disease is evidenced by the reduction of glomerular filtration which may be minimal in the early years, due to hyperfiltration, but, then, may even exceed 5 ml / min per year, especially when the total kidney volume (TKV) exceeds 1500 ml. In more rapid progression forms, ESRD may appear at about 55 years of age. The main risk factors are age, genetic mutation, familiarity with ESRD, macrohematuria episodes, and early onset hypertension. Some authors have proposed both genetic and clinical scores that can provide guidance on the probability of rapid progression. Other renal manifestations include kidney pain, nephrolithiasis, urinary tract infections and cyst hemorrhage. Renal cell carcinoma is a very rare event.

Continuous veno-venous hemofiltration using a phosphate-containing replacement fluid in the setting of regional citrate anticoagulation.

PURPOSE: The need for prolonged anticoagulation and the occurrence of hypophosphatemia are well known drawbacks of continuous renal replacement therapies (CRRT). The aim was to evaluate the effects on acid-base status and serum phosphate of a regional citrate anticoagulation (RCA) protocol for continuous veno-venous hemofiltration (CVVH) combining the use of citrate with a phosphate-containing replacement fluid. METHODS: In a small cohort of heart surgery patients undergoing CRRT for acute kidney injury, we adopted an RCA-CVVH protocol based on a commercially available citrate solution (18 mmol/l) combined with a recently introduced phosphate-containing replacement fluid (HCO3 -30 mmol/l, phosphate 1.2), aimed at preventing phosphate depletion. RESULTS: In 10 high bleeding-risk patients, the RCA-CVVH protocol provided an adequate circuit lifetime (46.8 ± 30.3 h) despite the adoption of a low citrate dose and a higher than usual target circuit Ca2+ (≤0.5 mmol/l). Acid-base status was adequately maintained without the need for additional interventions on RCA-CVVH parameters and without indirect sign of citrate accumulation [(pH 7.43 (7.41-7.47), bicarbonate 24.4 mmol/l (23.2-25.6), BE 0 (-1.5 to 1.1), calcium ratio 1.97 (1.82-2.01); median (IQR)]. Serum phosphate was steadily maintained in a narrow range throughout RCA-CVVH days [1.1 mmol/l (0.9-1.4)]. A low amount of phosphorus supplementation (0.9 ± 2 g/day) was required in only 30% of patients. CONCLUSIONS: Although needing further evaluation, the proposed RCA-CVVH protocol ensured a safe and effective RCA without electrolyte and/or acid-base derangements. CRRT-induced hypophosphatemia was prevented in most of the patients by the adoption of a phosphate-containing replacement solution, minimizing phosphate supplementation needs.

Continuous venovenous hemodiafiltration with a low citrate dose regional anticoagulation protocol and a phosphate-containing solution: effects on acid-base status and phosphate supplementation needs.

BACKGROUND: Recent guidelines suggest the adoption of regional citrate anticoagulation (RCA) as first choice CRRT anticoagulation modality in patients without contraindications for citrate. Regardless of the anticoagulation protocol, hypophosphatemia represents a potential drawback of CRRT which could be prevented by the adoption of phosphate-containing CRRT solutions. The aim was to evaluate the effects on acid-base status and phosphate supplementation needs of a new RCA protocol for Continuous Venovenous Hemodiafiltration (CVVHDF) combining the use of citrate with a phosphate-containing CRRT solution. METHODS: To refine our routine RCA-CVVH protocol (12 mmol/l citrate, HCO3- 32 mmol/l replacement fluid) (protocol A) and to prevent CRRT-related hypophosphatemia, we introduced a new RCA-CVVHDF protocol (protocol B) combining an 18 mmol/l citrate solution with a phosphate-containing dialysate/replacement fluid (HCO3- 30 mmol/l, Phosphate 1.2). A low citrate dose (2.5-3 mmol/l) and a higher than usual target circuit-Ca(2+) (≤ 0.5 mmol/l) have been adopted. RESULTS: Two historical groups of heart surgery patients (n = 40) underwent RCA-CRRT with protocol A (n = 20, 102 circuits, total running time 5283 hours) or protocol B (n = 20, 138 circuits, total running time 7308 hours). Despite higher circuit-Ca(2+) in protocol B (0.37 vs 0.42 mmol/l, p < 0.001), circuit life was comparable (51.8 ± 36.5 vs 53 ± 32.6 hours). Protocol A required additional bicarbonate supplementation (6 ± 6.4 mmol/h) in 90% of patients while protocol B ensured appropriate acid-base balance without additional interventions: pH 7.43 (7.40-7.46), Bicarbonate 25.3 (23.8-26.6) mmol/l, BE 0.9 (-0.8 to +2.4); median (IQR). No episodes of clinically relevant metabolic alkalosis, requiring modifications of RCA-CRRT settings, were observed. Phosphate supplementation was needed in all group A patients (3.4 ± 2.4 g/day) and in only 30% of group B patients (0.5 ± 1.5 g/day). Hypophosphatemia developed in 75% and 30% of group A and group B patients, respectively. Serum phosphate was significantly higher in protocol B patients (P < 0.001) and, differently to protocol A, appeared to be steadily maintained in near normal range (0.97-1.45 mmol/l, IQR). CONCLUSIONS: The proposed RCA-CVVHDF protocol ensured appropriate acid-base balance without additional interventions, providing prolonged filter life despite adoption of a higher target circuit-Ca(2+). The introduction of a phosphate-containing solution, in the setting of RCA, significantly reduced CRRT-related phosphate depletion.