scholarly journals Polycystic Kidney Disease and the Vasopressin Pathway

2017 ◽  
Vol 70 (Suppl. 1) ◽  
pp. 43-50 ◽  
Author(s):  
Maatje D.A. van Gastel ◽  
Vicente E. Torres

Vasopressin, also known as arginine vasopressin or antidiuretic hormone, plays a pivotal role in maintaining body homeostasis. Increased vasopressin concentrations, measured by its surrogate copeptin, have been associated with disease severity as well as disease progression in polycystic kidney disease (PKD), and in experimental studies vasopressin has been shown to directly regulate cyst growth. Blocking vasopressin effects on the kidney via the vasopressin V2-receptor and lower circulating vasopressin concentration are potential treatment opportunities that have been the subject of study in PKD in recent years. Treatment with vasopressin V2-receptor antagonist tolvaptan has been shown to inhibit disease progression in experimental studies, as well as in a large randomized controlled trial involving 1,445 patients with autosomal dominant PKD, lowering total kidney volume growth from 5.5 to 2.8%, and the slope of the reciprocal of the serum creatinine level from -3.81 to -2.61 mg per mL-1/year. Alternatively, lowering circulating vasopressin could delay disease progression. Vasopressin is secreted in response to an increased plasma osmolality, which in turn is caused by a low fluid or high osmolar intake. Other lifestyle factors, like smoking, increase vasopressin concentration. Here, we provide a comprehensive review of the physiology as well as pathophysiology of vasopressin in PKD, the promising effects of tolvaptan treatment, and potential synergistic or additive treatments in combination with tolvaptan. In this study, we also review current evidence regarding the effect of influencing disease progression in PKD by lifestyle changes, especially by fluid intake.

2016 ◽  
Vol 101 (9) ◽  
pp. e2.58-e2 ◽  
Author(s):  
Kazeem Olalekan ◽  
Andy Fox ◽  
Rodney Gilbert

BackgroundUnlicensed medications are used all the time in the management of diseases in childhood. Tolvaptan (Jinarc®) is a vasopressin V2-receptor antagonist licensed for use to slow the progression of cyst development and renal insufficiency of ADPKD in adults with CKD stage 1 to 3 with evidence of rapidly progressing disease. Studies of animal models implicate the antidiuretic hormone arginine vasopressin and its messenger cyclic adenosine monophosphate (cAMP) as promoters of kidney-cyst cell proliferation and luminal fluid secretion. The suppression of vasopressin release by means of high water intake, genetic elimination of vasopressin, and vasopressin V2-receptor blockade all reduce the cyst burden and protect kidney function1 A Phase 3 trial showed that Tolvaptan, as compared with placebo, slowed down the increase in total kidney volume and decline in kidney function in adults (average 39 yrs) with ADPKD over a 3-year period.2 ADPKD is the most common form of polycystic kidney disease (PKD) typically late in onset and results from mutation of either of two genes: PKD1 and PKD2. Autosomal recessive polycystic kidney (ARPKD), the other form of PKD, is 20 times less common, presents primarily in infancy and childhood, is typically more severe, and commonly associated with hypertension. ARPKD results from mutation of PKHD1. In spite of these differences, there is growing evidence to suggest that ADPKD and ARPKD are more related than previously suspected.3 Bilineal inheritance of PKD1 abnormalities has been reported to cause extremely severe disease resembling ARPKD.4 The use of Tolvaptan in the management of PKD in children is therefore expected to become more important.AimTo describe the first known UK use of Tolvaptan in a neonate with severe ADPKD and the role of the hospital pharmacist in facilitating the use.MethodThe role descriptor of hospital pharmacists produced by the World Health Organisation (WHO) was adapted and used to map the pharmaceutical challenges of using Tolvaptan in this child. The descriptor include: (i) Promotion of rational prescribing of drugs, (ii) Use of specialist pharmacists networks to gain greater expertise; (iii) Monitor compliance and therapeutic response and report adverse drug reactions; (iv) ensure supply of high quality products; (v) partake in planning and implementation of clinical trials.ResultsThe use of Tolvaptan for indication other than hyponatraemia and other endocrine uses are not routinely commissioned by NHS England. In view of the exceptionality of this case – a severe neonatal form of ADPKD with estimated prevalence of the order of 1 in tens of millions, an Individual Funding Request (IFR) application was made and was approved. The application was supported by financial information provided by the hospital pharmacist who facilitated the application process. Using available information and formulation knowledge, a suspension was eventually recommended and was well tolerated. This resulted in approximately 85% reduction in the cost of treatment over six months. Tolvaptan produced the expected aquaresis and blood pressure reduction. Initial dose of 0.1 mg/kg/day was used and increased according to weight and clinical response. Initial monitoring parameters, which included 4 hourly blood pressure, urine and electrolytes and hepatic function, were recommended. Electrolyte supplements were adjusted accordingly. At 2-month review point, there was no oedema of leg and face but the kidneys were still enlarged. The long term effect on cyst burden and kidney function is being evaluated and will feed into the IFR process.ConclusionThe use of unlicensed medications in children poses a number of pharmaceutical challenges and can be managed through a multidisciplinary approach to treatment intervention. It also re-enforce the paediatric formulation challenge to pharmaceutical companies in which formulation needs are prioritised and existing data are better used to facilitate paediatric formulation development.


2018 ◽  
Vol 48 (1) ◽  
pp. 67-78 ◽  
Author(s):  
Riccardo Magistroni ◽  
Cristiana Corsi ◽  
Teresa Martí ◽  
Roser Torra

Background: Autosomal dominant polycystic kidney disease (ADPKD) is the commonest inherited renal disorder; it is defined by progressive renal cyst formation and subsequent renal enlargement that leads to end-stage renal disease. Until recently, only symptomatic treatments for ADPKD existed. However, therapies that address the underlying pathophysiology of ADPKD are now available and accurate identification of the rate of disease progression is essential. Summary: Published data on the different imaging modalities for measuring kidney and cyst volumes in ADPKD are reviewed. The advantages and drawbacks of the different techniques for calculating kidney volume from renal imaging are also examined, including the use of manual planimetry, stereology, and the ellipsoid equation, as well as the prospect of semi- and fully automatic techniques. The translation of these approaches into clinical practice and their role in informing treatment decisions is discussed. Key Messages: These new therapies require the accurate monitoring of disease progression, which along with diagnosis and prognosis, relies on the effective use of renal imaging techniques. There is growing support for the use of total kidney volume as a measure of cyst burden and as a prognostic predictor of renal function in ADPKD, showing promise as a marker of disease progression.


2019 ◽  
Vol 49 (6) ◽  
pp. 487-493 ◽  
Author(s):  
Xiaofang Wang ◽  
Megan M. Constans ◽  
Fouad T. Chebib ◽  
Vicente E. Torres ◽  
Lorenzo Pellegrini

Background: Vasopressin V2 receptor inhibition is a clinically validated mechanism of action in the treatment of autosomal dominant polycystic kidney disease (ADPKD). In this study, the effect of lixivaptan, a potent, selective vasopressin V2 antagonist, was evaluated in PCK rats, a validated animal model of PKD. Methods: Four-week old PCK rats were fed rodent chow with 0.5% lixivaptan (low dose) or 1% lixivaptan (high dose), or chow only (control) for 8 weeks. Urine output was measured at weeks 7 and 10 of age. Animals were killed at 12 weeks of age; kidneys and livers were collected, weighted, and analyzed for cyclic adenosine 3′,5′-monophosphate (cAMP) levels and cystic burden and fibrosis; serum creatinine and sodium were measured. Results: Consistent with the development of a polycystic kidney phenotype, control PCK rats showed enlarged kidneys, extensive cyst formation, and early signs of serum creatinine elevation at 12 weeks of age. Compared to controls, PCK rats treated with low-dose lixivaptan showed a 26% reduction in % kidney weight/body weight (p < 0.01); a 54% reduction in kidney cystic score (p < 0.001), a histomorphometric measure of cystic burden; a 23% reduction in kidney cAMP levels (p < 0.05), a biochemical marker of disease; and a 13% reduction in plasma creatinine (p < 0.001), indicating preserved renal function. These reductions were associated with 3-fold increases in 24-h urine output, demonstrating the potent aquaretic effect of lixivaptan. The fact that the high dose was less efficacious than the low dose is discussed. Conclusions: These results provide the first evidence of the potential utility of lixivaptan for the treatment of ADPKD.


Kidney360 ◽  
2021 ◽  
pp. 10.34067/KID.0004292021
Author(s):  
Brian E. Jones ◽  
Yaman G. Mkhaimer ◽  
Laureano J. Rangel ◽  
Maroun Chedid ◽  
Phillip J. Schulte ◽  
...  

Background: Autosomal dominant polycystic kidney disease (ADPKD) has phenotypic variability only partially explained by established biomarkers that do not readily assess pathologically important factors of inflammation and kidney fibrosis. We evaluated asymptomatic pyuria, a surrogate marker of inflammation, as a biomarker for disease progression. Methods: We performed a retrospective cohort study of adult patients with ADPKD. Patients were divided into asymptomatic pyuria (AP) and no pyuria (NP) groups. We evaluated the effect of pyuria on kidney function and kidney volume. Longitudinal models evaluating kidney function and kidney volume rate of change with respect to incidences of asymptomatic pyuria were created. Results: There were 687 included patients (347 AP, 340 NP). The AP group had more female (65.1% vs 49.4%). Median age at kidney failure was 86 and 80 years in NP and AP groups, respectively (Log-rank, p=0.49) for patients with Mayo Imaging Class (MIC)1A-1B as compared to 59 and 55 years for patients with MIC1C-1D-1E (Log-rank, p=0.02). Compared to NP group, the rate of kidney function (ml/min/1.73m2/year) decline shifted significantly after detection of asymptomatic pyuria in models including all patients (-1.48, p<0.001), MIC 1A-B patients (-1.79 , p<0.001), MIC 1C-1D-1E patients (-1.18, p<0.001), and PKD1 patients (-1.04, p<0.001). Models evaluating kidney volume rate of growth showed no change after incidence of asymptomatic pyuria as compared to NP group. Conclusions: Asymptomatic pyuria is associated with kidney failure and faster kidney function decline irrespective of the ADPKD gene, cystic burden, and cystic growth. These results support asymptomatic pyuria as an enriching prognostic biomarker for the rate of disease progression.-


2020 ◽  
Vol 51 (6) ◽  
pp. 473-479
Author(s):  
Benjamin R. Griffin ◽  
Zhiying You ◽  
Lama Noureddine ◽  
Berenice Gitomer ◽  
Loni Perrenoud ◽  
...  

Background: Cyst compression of renal tubules plays a role in the progression of autosomal dominant polycystic kidney disease (ADPKD) and may induce expression of kidney injury molecule-1 (KIM-1). Whether urinary KIM-1 indexed for creatinine (uKIM-1/Cr) is a prognostic marker of disease progression in ADPKD is unknown.In this secondary analysis of a prospective cohort study, we sought to determine whether patients with high as opposed to low uKIM-1/CR at baseline had greater rates of eGFR loss and height-adjusted total kidney volume (HtTKV) increase. Methods: Baseline uKIM-1/Cr values were obtained from 754 participants in Halt Progression of Polycystic Kidney Disease (HALT-PKD) studies A (early ADPKD) and B (late ADPKD). The predictor was uKIM-1/Cr, which was dichotomized by a median value of 0.2417 pg/g, and the primary outcomes were measured longitudinally over time. Mixed-effects linear models were used in the analysis to calculate the annual slope of change in eGFR and HtTKV. Results: Patients with high uKIM-1/Cr (above the median) had an annual decline in eGFR that was 0.47 mL/min greater than that in those with low uKIM-1/Cr (p = 0.0015) after adjustment for all considered covariates. This association was seen in study B patients alone (0.45 mL/min; p = 0.009), but not in study A patients alone (0.42 mL/min; p = 0.06). High baseline uKIM-1/Cr was associated with higher HtTKV in the baseline cross-sectional analysis compared to low uKIM-1/Cr (p = 0.02), but there was no difference between the groups in the mixed-effects model annual slopes. Conclusion: Elevated baseline uKIM-1/Cr is associated with a greater decline in eGFR over time. Further research is needed to determine whether uKIM-1/Cr improves risk stratification in patients with ADPKD.


Sign in / Sign up

Export Citation Format

Share Document