Sevelamer reverses liver fibrosis by deactivation of hepatic stellate cells

Liver fibrosis is a chronic liver disease characterized by a progressive wound healing response caused by chronic liver injury. Currently, there are no approved clinical treatments for liver fibrosis. Sevelamer is used clinically to treat hyperphosphatemia and has shown potential therapeutic effects on liver diseases. However, there have been few studies evaluating the therapeutic effects of sevelamer on liver fibrosis, and the specific mechanisms are still unclear. In this study, we investigated the antifibrotic effects of sevelamer-induced low inorganic phosphate (Pi) stress in vitro and in vivo and analyzed the detailed mechanisms. We found that low Pi stress could inhibit the proliferation of activated hepatic stellate cells (HSCs) by promoting apoptosis, effectively suppressing the migration and epithelial-mesenchymal transition (EMT) of hepatic stellate cells. Additionally, low Pi stress significantly increased the antioxidant stress response. It is worth noting that low Pi stress indirectly inhibited the activation and migration of HSCs by suppressing transforming growth factor β (TGF-β) expression in macrophages. In a rat model of liver fibrosis, oral administration of sevelamer significantly decreased blood phosphorus levels, improved liver function, reduced liver inflammation, and increased the antioxidant stress response in the liver. Our study revealed that the key mechanism by which sevelamer inhibited liver fibrosis involved binding to gastrointestinal phosphate, resulting in a decrease in blood phosphorus levels, the downregulation of TGF-β expression in macrophages, and the inhibition of HSC migration and fibrosis-related protein expression. Therefore, our results suggest that sevelamer-induced low Pi stress can attenuate hepatic stellate cell activation and inhibit the progression of liver fibrosis, making it a potential option for the treatment of liver fibrosis and other refractory chronic liver diseases.

Meta-analysis of the efficacy and safety of sevelamer as hyperphosphatemia therapy for hemodialysis patients

This study was designed to examine the relative safety and efficacy of sevelamer in the treatment of chronic kidney disease (CKD) patients in comparison to placebo, calcium carbonate (CC), or lanthanum carbonate (LC). The PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases were searched for articles published through 18 June 2022. The quality of relevant studies was independently analyzed by two investigators who also extracted data from these manuscripts as per Cochrane Collaboration Handbook 5.3. The safety and efficacy of sevelamer as a treatment for hyperphosphatemia in CKD patients were then examined through a meta-analysis, with the primary patient-level outcomes of interest in this analysis being all-cause mortality and the incidence of gastrointestinal adverse effects. Vascular calcification score was also examined as an intermediate outcome, while serum biochemical parameters including levels of phosphate (P), calcium (Ca), intact parathyroid hormone (iPTH), lipids, C-reactive protein (CRP), or fibroblast growth factor-23 (FGF-23) were additionally assessed. In total, this meta-analysis incorporated data from 34 randomized controlled trials (RCTs) enrolling 2802 patients. Sevelamer was associated with reduced all-cause mortality (RR 0.28, CI 0.19 - 0.41, very low certainty) and Vessel calcification score (RR -0.58, CI -1.11 to -0.04, low certainty) and induced less hypercalcemia (MD -0.28, CI 0.40 to -0.16, low certainty) and hyperphosphatemia (MD -0.22, CI -0.32 to -0.13, low certainty) when compared with Ca-based binders in CKD5D individuals. No significant differences in gastrointestinal adverse events (GAEs) incidence were observed. These data suggest that sevelamer may represent a beneficial means of protecting CKD patients against death and vessel calcification when used to treat hyperphosphatemia, while we found no clinically important benefits in decreasing gastrointestinal adverse effects.

Canakinumab in addition to phosphate-binding and phosphaturia-inducing therapy were effective in achieving remission in a child with a large familial calcinotic tumour

We describe the clinical evolution of a patient with tumoral calcinosis due to a pathogenic variant in the GALNT3 gene presented with a large mass overlying her left hip associated complicated by inflammatory flares. Therapy (sevelamer, acetazolamide, and probenecid) was unsuccessful in preventing tumour surgeries, therefore, interleukin-1β monoclonal antibody therapy was added; this was successful in the prevention of tumour re-growth. This case highlights the importance of assessing and treating the inflammatory aspect of calcinotic tumour.

Repurposing of sevelamer as a novel antidote against aluminum phosphide poisoning: An in vivo evaluation

Aluminum phosphide (AlP) is widely used for protecting grains from pests. AlP releases toxic phosphine gas (PH₃) while exposed to humidity. Poisoning with these tablets is dangerous and can cause death or serious injuries. Up to now, no definite antidote has been introduced for specific treatment of this poisoning. Sevelamer carbonate or sevelamer hydrochloride (Renagel) is a polymeric pharmaceutical prescribed for treating hyperphosphatemia in patients with chronic kidney disease. Sevelamer can bind with phosphate groups and act as an anion exchanger. Herein, sevelamer is repurposed as a potent antidote agent in phosphine gas poisoning. In vivo evaluation was conducted on male Sprague Dawley rats. The evaluation was conducted on three groups of animals: control, AlP-poisoned, and AlP-poisoned treated with sevelamer. Survival percentage, serum biomarkers level of organ injury, and ATP level were recorded. The results indicate a high survival rate in sevelamer-treated animals compared with the AlP-poisoned group (75% vs. 0% respectively, 48 h after poisoning). The analysis of serum markers of organ injury also showed that sevelamer could reduce toxicity and organ injury in poisoned animals. ATP level of separate organs showed that sevelamer treated groups were recovered. The results showed that sevelamer could be a potent antidote for managing aluminum phosphide poisoning. Moreover, a mechanism is suggested for the interaction of sevelamer with phosphine gas.

Exploring co-dispensed drug use in patients on sevelamer or polystyrene sulfonate to identify potential novel binding interactions: a cross sectional in silico study : Potential novel binding interactions with resins

Background Sevelamer and polystyrene sulfonate are used for treating hyperphosphatemia and hyperkalaemia in chronic kidney disease patients. Because of their binding properties, these resins potentially bind other drugs in the gastrointestinal tract, thereby decreasing their bioavailability and clinical effectiveness. Aim The aim of this study was to explore co-dispensed drug use in patients on sevelamer or polystyrene sulfonate to identify potential novel binding interactions. Method In this in silico study, the 100 drugs most frequently co-dispensed with sevelamer/polystyrene sulfonate in the period 2000-2018 were extracted from the University Groningen IADB.nl database. Drugs dispensed to < 5% of patients, drugs not orally administered, drugs administered once daily before bedtime and drugs for which information on binding interactions with sevelamer or polystyrene was already available were excluded. The likelihood of an interaction (yes or no) of the included drugs was assessed based on pKa- and Log P values. For sevelamer, drugs with a pKa (acid) between 1.5 and 7.4 and or a Log P value > 2.0 were identified as potential interacting drug. For polystyrene sulfonate, drugs with a pKa (base) > 1.5 were identified as potential interacting drug. Results Of the top 100 drugs most frequently co-dispensed with sevelamer/polystyrene sulfonate, 22 and 27 potentially clinically relevant new interacting drugs were identified for sevelamer and polystyrene sulfonate respectively. Conclusion Several potentially relevant novel binding interactions for sevelamer and polystyrene sulfonate were identified based on dispensing data and assessment of chemical properties for which further interaction research is warranted.

[Colonic Mass Secondary to Sevelamer-associated Rectal Ulcer]

The phosphorous balance is clinically important in increasing the long-term outcomes and preventing complications of end-stage renal disease. Sevelamer is a phosphate binder used widely to regulate hyperphosphatemia. On the other hand, gastrointestinal side effects increase with increasing sevelamer intake. A 29-year-old male with end-stage renal disease of IgA nephropathy on maintenance hemodialysis was admitted for diffuse alveolar bleeding and pneumonia. He presented with a low-grade fever and watery diarrhea tinged with blood. Initially, a Clostridioides difficile-associated diarrhea treatment was started with positive findings of Clostridioides difficile toxin and culture. Despite this, there was no improvement in the symptoms even with the appropriate antibiotic treatment. Computed tomography of the abdomen and pelvis revealed an occlusive mass in the rectum and secondary obstructive changes in the sigmoid colon. The initial suspicion was a malignancy or fungal infection. Sigmoidoscopy with a biopsy identified the mass as a lump of mucous material with the entire lumen covered with exudate. The subsequent histopathology examination revealed a colonic mucosal injury and characteristic "fish scale"-like sevelamer crystals in the exudate. The diagnosis of a sevelamer-induced rectal ulcer was made. We report this case of a sevelamer-associated rectal ulcer of the sigmoid.

Lower gastrointestinal bleeding in a patient receiving sevelamer: Case report

Phosphate binders such as sevelamer are widely used in patients with chronic kidney disease to lower serum phosphate levels. We present a case of a 67-year-old woman with lower gastrointestinal bleeding after 9 days of using sevelamer carbonate (Renvela^®). Sigmoidoscopy revealed multiple deep ulcers (diameter 10–15 mm) and mucosal oedema. Histologic examination showed deposition of sevelamer crystals in these rectal ulcers. We hypothesized that the lower gastrointestinal bleeding was caused by deposition of sevelamer crystals. After cessation of sevelamer, gastrointestinal bleeding stopped. Deposition of sevelamer crystals in the gastrointestinal tract is a rare complication of sevelamer therapy. There are only 17 other recorded cases of gastrointestinal deposition of sevelamer crystals. This adverse effect should be considered in all patients taking sevelamer who present with gastrointestinal symptoms, such as gastrointestinal bleeding and abdominal pain. When sevelamer is discontinued, symptoms and mucosal damage appear to revert.

Multivalent cation and polycation polymer preparations influence pharmacokinetics of dolutegravir via chelation-type drug interactions

Dolutegravir (DTG) is an integrase inhibitor, whose gastrointestinal absorption is impaired by the formation of chelates with multivalent metal cation preparations. However, little is known regarding the interactions of DTG with preparations containing other multivalent metal cations or with polycation polymer preparations. This study examined how the pharmacokinetics of DTG are affected by co-administration with Al(OH)₃, LaCO₃, and the polycation polymers bixalomer (Bxl) and sevelamer (Svl). Prior to oral administration of DTG (5 mg/kg), rats were orally administered Al(OH)₃ (150 or 300 mg/kg), LaCO₃ (50 or 75 mg/kg), Bxl (250 or 500 mg/kg), or Svl (300 or 600 mg/kg). Serum concentrations of DTG were then measured over the next 24 h. Compared to the administration of DTG alone, its co-administration with Al(OH)₃, LaCO₃, Bxl, and Svl led to reduced serum concentration of DTG, and consequently, a significantly reduced area under the curve. These comparisons also revealed a considerable reduction in the maximum concentration, suggesting that the interactions of these agents with DTG in the intestinal tract inhibit absorption of DTG. The above results demonstrate that Al(OH)₃, LaCO₃, Bxl, and Svl affect the pharmacokinetics of DTG and indicate the need for caution when combining any of the above preparations with DTG.

Changes in oxidative nucleic acid modifications and inflammation following one-week treatment with the bile acid sequestrant sevelamer: Two randomised, placebo-controlled trials

AIMS

Sevelamer has been reported to have anti-oxidative and anti-inflammatory effects as well as effects on glycaemic control and plasma lipids. The aim of this study was to determine the effects of one-week treatment with sevelamer on oxidative nucleic acid modifications and inflammation markers.

METHODS

Two double-blinded studies including 30 patients with type 2 diabetes (T2D) and 20 healthy individuals were conducted. Participants were randomised to one week of treatment with sevelamer (1600 mg three times daily) or placebo. RNA and DNA oxidation, measured by urinary excretion of 8-oxo-7,8-dihydroguanosine(8-oxoGuo) and (8-oxo-7,8-dihydro-2'-deoxyguanosine(8-oxodG), and markers of inflammation were determined before and after the intervention.

RESULTS

In patients with T2D there was no significant placebo-corrected reduction in 8-oxoGuo or 8-oxodG. However, a reduction in 8-oxoGuo was observed within the group treated with sevelamer (∆8-oxoGuo/creatinine (median[IQR]): -0.04 [-0.24; 0.01] nmol/mmol, p = 0.02). A sevelamer-mediated reduction in interleukin-2 (p = 0.04) and a trend towards reduction in interleukin-6 (p = 0.053) were found in patients with T2D.

CONCLUSIONS

This study reveals a potential effect of sevelamer treatment on inflammation and possible oxidative RNA modifications. The potential protective effects of sevelamer in terms of cardiovascular disease in patients with T2D need further investigation.

Phosphate binders in chronic kidney disease: an updated narrative review of recent data

Chronic kidney disease (CKD) is frequently accompanied by hyperphosphatemia. High serum phosphate usually requires dietary measures, adequate dialysis prescription and/or phosphate binders. For this narrative review a PubMed searched was undertaken to identify new publications on phosphate binders that had been published between January 2015 and July 2019. The present review summarizes this most recent information on dietary measures and their problems in treating hyperphosphatemia in CKD patients, overall effects of phosphate binders on cardiovascular mortality and morbidity, adherence to phosphate binder therapy as well as new data on specific aspects of the various phosphate binders on the market: calcium-containing phosphate binders, polymeric phosphate binders (sevelamer, bixalomer, colestilan), magnesium-containing phosphate binders, lanthanum carbonate, ferric citrate, sucroferric oxyhydroxide, and new compounds in development, in particular drugs targeting intestinal phosphate transporters.

Sulfonic acid-functionalized polyallylamine (sevelamer) as an efficient reusable strong solid acid catalyst for the synthesis of xanthenes derivatives

Sevelamer (polyallyamine resin)-supported sulfonic acid (S-SO3H) has been prepared from the reaction of sevelamer with chlorosulfonic acid and characterized using FT-IR spectroscopy, scanning electronmicroscopy (SEM) and thermogravimetric analysis (TGA). The catalytic activity of S-SO3H was investigated in the synthesis of 1,8-dioxo-octahydroxanthene derivatives. All of the reactions were fast and gave excellent yields. The catalyst was easily recovered and reused for 5 runs without significant loss of its catalytic activity.

A systematic review of the economic evaluations of non-calcium-containing phosphate binders, sevelamer and Lanthanum, in end-stage renal disease patients with hyperphosphatemia

INTRODUCTION

End-stage renal disease is associated with significant comorbidity and mortality. Among its implications, hyperphosphatemia constitutes a consistent and independent risk factor. The use of benchmark treatment, low-cost calcium-based binders declined due to a potential calcification effect on coronary arteries.

AREAS COVERED

Given the increasing prevalence of end-stage renal disease and the high cost of hyperphosphatemia's new primary modality, the non-calcium based phosphate binders, we set-off to systematically assess the economic evaluations of non-calcium containing phosphate binders, sevelamer and lanthanum. The study was performed based on a systematic review of the economic evaluations of sevelamer and lanthanum. The cost-effectiveness profile of the two non-calcium-containing Phosphate Binders compared to calcium-based phosphate binders depends on several factors such as future dialysis costs, utility values, age, survival, and phosphorus levels.

EXPERT OPINION

The comparison between the two agents is rather inconclusive; nevertheless, current review suggests that non-calcium-based phosphate binders may yield a positive cost-effectiveness ratio in patients with inadequate phosphorus management and patient with longer life-expectancy. It is crucial that the literature is endowed with more data, specifically on survival, future dialysis costs, and calcification.

Linkage of Fibroblast Growth Factor 23 and Phosphate in Serum: Phosphate and Fibroblast Growth Factor 23 Reduction by Increasing Dose of Sevelamer

Background

High serum phosphate and fibroblast growth factor-23 (FGF-23) levels are well-recognized independent risk factors of mortality and morbidity in patients with chronic kidney diseases (CKDs). Sevelamer, as a phosphate chelating agent, reduces serum phosphate and FGF-23 levels produced by bone osteocytes. This study aimed to determine the best dose at which sevelamer could successfully reduce serum phosphate and FGF-23 levels in rat models of adenine-induced CKD.

Methods

CKD was induced using adenine. Healthy and CKD-induced rats were divided into 6 groups as follows: healthy controls; CKD controls; rats treated with 1%, 2%, and 3% sevelamer for CKDs; and healthy rats administered 3% sevelamer. Biochemical factors and serum FGF-23 levels were measured using spectrophotometry and enzyme-linked immunosorbent assay methods.

Results

Serum phosphate levels were best decreased in rats receiving 3% sevelamer in their diet (5.91±1.48 mg/dL vs. 8.09±1.70 mg/dL, P<0.05) compared with the CKD control rats. A dose-dependent decrease in serum FGF-23 levels was observed, and the most significant results were obtained in rats receiving 3% sevelamer compared with the CKD control rats (142.60±83.95 pg/mL vs. 297.15±131.10 pg/mL, P<0.01).

Conclusions

Higher sevelamer doses significantly reduced serum phosphate and FGF-23 levels in adenine-induced CKD rats.

Influence of Carnicor, Venofer, and Sevelamer on the levels of genotoxic damage in end-stage renal disease patients

End-stage renal disease (ESRD) patients present high levels of phosphorus and calcium products in serum, which contribute to the development of vascular calcification and cardiovascular disease, and to low iron stores and carnitine deficiency. For these reasons, ESRD patients are generally supplemented with different medicines. Some of the most common treatments include the use of Carnicor, Venofer, and Sevelamer drugs. Carnicor is used as a source of L-carnitine, acting as antioxidant and neuroprotector. Venofer is used to reduce the deficit of iron. Sevelamer is used to treat hyperphosphatemia. To determine the potential harmful genotoxic effects of these drugs, a group of 214 patients included in a hemodialysis program with different intakes of Carnicor, Venofer, and Sevelamer were evaluated. The levels of basal and oxidative DNA damage, as well as chromosomal damage, were measured in all individuals using the comet and the micronucleus assays, respectively. Our results indicate that Carnicor administration was associated with low but significant increases in the frequency of basal DNA damage and micronuclei. Environ. Mol. Mutagen. 59:302-311, 2018. © 2018 Wiley Periodicals, Inc.

Sevelamer-Induced Gastrointestinal Injury Presenting as Gastroenteritis

End-stage renal disease (ESRD) is a common disease encountered in clinical practice and is associated with increasing metabolic derangements through disease progression. Phosphate retention is one of the most common derangements and is associated with increased mortality. Hyperphosphatemia becomes increasingly prevalent as glomerular filtration rate decreases. Non-calcium phosphate-binding resins and dietary phosphate restriction are the mainstays for managing hyperphosphatemia in patients with ESRD. Sevelamer carbonate is the most frequently used non-calcium phosphate binder in the US due to ease of administration and an excellent safety profile. However, there is increasing recognition of gastrointestinal injury associated with medication use. Here we report a case of an 81-year-old male with biopsy-proven gastrointestinal mucosal injury secondary to sevelamer carbonate administration.

A systematic review on the efficacy and safety of PA21 versus sevelamer in dialysis patients

AIM

To evaluate the efficacy and safety of PA21 versus sevelamer in dialysis patients.

METHODS

We searched Medline, Embase, Science Citation Index, Cochrane Central Register of Controlled Trials, and Clinical Trial Registries for randomized controlled trials comparing PA21 and sevelamer in dialysis patients.

RESULTS

Four studies were included. Compared with sevelamer group, PA21 needed fewer mean daily number of tablets (WMD, - 7.97 pill; 95% CI, - 11.28 to - 4.65, p < 0.00001), developed fewer all adverse events (RR = 1.05; 95% CI, 1.00 to 1.11, p = 0.05), and developed fewer gastrointestinal adverse events (RR = 1.32; 95% CI, 1.15 to 1.53, p = 0.0001). There was no significant difference in serum phosphorus between two groups (WMD, - 0.07 mmol/L; 95% CI, - 0.15 to 0.02, p = 0.12). As for serum calcium, there was also no significant difference between two groups (WMD, 0.27 mmol/L; 95% CI, - 0.63 to 1.17, p = 0.55).

CONCLUSION

PA21 can effectively control serum phosphorus with lower pill burden and less side effects than sevelamer. PA21 might be another valuable choice for dialysis patients with hyperphosphatemia when patients are unable to tolerate sevelamer.

Plasma p-cresol lowering effect of sevelamer in non-dialysis CKD patients: evidence from a randomized controlled trial

BACKGROUND

The accumulation of p-cresol, a metabolic product of aromatic amino acids generated by intestinal microbiome, increases the cardiovascular risk in chronic kidney disease (CKD) patients. Therefore, therapeutic strategies to reduce plasma p-cresol levels are highly demanded. It has been reported that the phosphate binder sevelamer (SEV) sequesters p-cresol in vitro, while in vivo studies on dialysis patients showed controversial results. Aim of our study was to evaluate the effect of SEV on p-cresol levels in non-dialysis CKD patients.

METHODS

This was a single-blind, randomized placebo-controlled trial (Registration number NCT02199444) carried on 69 CKD patients (stage 3-5, not on dialysis), randomly assigned (1:1) to receive either SEV or placebo for 3 months. Total p-cresol serum levels were evaluated at baseline (T0), and 1 (T1) and 3 months (T3) after treatment start. The primary end-point was to evaluate the effect of SEV on p-cresol levels.

RESULTS

Compared to baseline (T0, 7.4 ± 2.7 mg/mL), p-cresol mean concentration was significantly reduced in SEV patients after one (- 2.06 mg/mL, 95% CI - 2.62 to - 1.50 mg/mL; p < 0.001) and 3 months of treatment (- 3.97 mg/mL, 95% CI - 4.53 to - 3.41 mg/mL; p < 0.001); no change of plasma p-cresol concentration was recorded in placebo-treated patients. Moreover, P and LDL values were reduced after 3 months of treatment by SEV but not placebo.

CONCLUSIONS

In conclusion, our study represents the first evidence that SEV is effective in reducing p-cresol levels in CKD patients in conservative treatment, and confirms its beneficial effects on inflammation and lipid pattern.

Initiation of Sevelamer and Mortality among Hemodialysis Patients Treated with Calcium-Based Phosphate Binders

BACKGROUND AND OBJECTIVES

Prior studies have shown that sevelamer attenuates progression of arterial calcification and may reduce the risk of death compared with calcium-based phosphate binders. In clinical practice, however, sevelamer is used not only as an alternative but also as an add-on therapy in patients already being treated with calcium-based phosphate binders. We analyzed the Dialysis Outcomes and Practice Patterns Study (DOPPS) data to test the hypothesis that the initiation of sevelamer is associated with improved survival in patients on hemodialysis treated with calcium-based phosphate binders.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We included 12,564 patients from DOPPS phase 3 and phase 4 (2005-2011) who were prescribed calcium-based phosphate binders at baseline or before sevelamer treatment. Mortality risk was assessed using a sequential stratification method to identify as-yet-untreated patients who were appropriately matched to the newly treated patients on the basis of their risk of death.

RESULTS

Of 12,564 patients, 2606 were subsequently treated with sevelamer hydrochloride or sevelamer carbonate. After beginning sevelamer therapy, mean serum phosphorus levels decreased by 0.3 mg/dl in the first 4 months and gradually decreased thereafter. We matched 2501 treated patients with at least one as-yet-untreated patient. Patients treated with sevelamer had a 14% lower risk for mortality compared with as-yet-untreated patients (hazard ratio, 0.86; 95% confidence interval, 0.76 to 0.97). Similar results were observed in the sensitivity analyses when changing the matching calipers or the treated and as-yet-untreated ratios, and by using propensity score matching.

CONCLUSIONS

The use of sevelamer as an add-on or alternative therapy to calcium-based phosphate binders is associated with improved survival in patients on maintenance hemodialysis.

Effects of phosphate binders on the gastrointestinal absorption of arsenate and of an SGLT2 inhibitor drug on the urinary excretion of arsenite in mice

Arsenate (As^V) and arsenite (As^III) are typical sources of acute and chronic arsenic poisoning. Therefore, reducing inner exposure to these arsenicals is a rational objective. Because As^V mimics phosphate, phosphate binder drugs may decrease the intestinal As^V absorption. Indeed, lanthanum and aluminium salts and sevelamer removed As^V from solution in vitro, especially at acidic pH. In mice gavaged with As^V, lanthanum chloride, lanthanum carbonate and aluminium hydroxide given orally also lowered the urinary excretion and tissue levels of As^V and its metabolites, indicating that they decreased the gastrointestinal As^V absorption. As some glucose transporters may carry As^III, the effect of the SGLT2 inhibitor dapagliflozin was investigated in As^III-injected mice. While producing extreme glucosuria, dapagliflozin barely affected the urinary excretion and tissue concentrations of As^III and its metabolites. Thus, phosphate binders (especially lanthanum compounds) can reduce the gastrointestinal absorption of As^V; however, SGLT2 inhibition cannot diminish the renal reabsorption of As^III.

Clinical features of CKD-MBD in Japan: cohort studies and registry

Randomized controlled trials (RCTs) are essential for evidence-based medicine; however, cohort studies and registries provide an important information about risk factors and, hence, shed light on the target of laboratory parameters. The uniqueness of the current Japanese CKD-MBD guidelines lies in the lower target range of intact parathyroid hormone levels than those used in other countries, which is based on analyses of the nationwide Japan Renal Data Registry. Cohort studies were also useful in exploring risk factors of renal outcome in predialysis patients. It was revealed that low vitamin D status (very prevalent in Japan) and high fibroblast growth factor 23 (FGF23) levels predict poor renal outcome. The reported association of FGF23 levels with left ventricular hypertrophy (LVH) and heart failure observed in cohort studies may support the idea of adding the 4th component of CKD-MBD, namely, "LVH" to the three original components. When it is not feasible to conduct RCTs regarding intervention, we have no choice but to rely on observational studies with sophisticated analysis methods, such as facility-level analysis and marginal structural model minimizing indication bias. Observational studies conducted in Japan revealed that the side effects of medications for CKD-MBD, resultant compliance, and effective doses in terms of hard outcome in Japanese patients were found to be different from those in other countries. For example, the MBD-5D study confirmed the benefit of cinacalcet in terms of mortality despite its median dose of only 25 mg/day. These data are very helpful for future guidelines specific to Japanese patients with CKD.

Can Intestinal Phosphate Binding or Inhibition of Hydroxyapatite Growth in the Vascular Wall Halt the Progression of Established Aortic Calcification in Chronic Kidney Disease?

Vascular calcification significantly contributes to mortality in chronic kidney disease (CKD) patients. Sevelamer and pyrophosphate (PPi) have proven to be effective in preventing vascular calcification, the former by controlling intestinal phosphate absorption, the latter by directly interfering with the hydroxyapatite crystal formation. Since most patients present with established vascular calcification, it is important to evaluate whether these compounds may also halt or reverse the progression of preexisting vascular calcification. CKD and vascular calcification were induced in male Wistar rats by a 0.75 % adenine low protein diet for 4 weeks. Treatment with PPi (30 or 120 µmol/kg/day), sevelamer carbonate (1500 mg/kg/day) or vehicle was started at the time point at which vascular calcification was present and continued for 3 weeks. Hyperphosphatemia and vascular calcification developed prior to treatment. A significant progression of aortic calcification in vehicle-treated rats with CKD was observed over the final 3-week period. Sevelamer treatment significantly reduced further progression of aortic calcification as compared to the vehicle control. No such an effect was seen for either PPi dose. Sevelamer but not PPi treatment resulted in an increase in both osteoblast and osteoid perimeter. Our study shows that sevelamer was able to reduce the progression of moderate to severe preexisting aortic calcification in a CKD rat model. Higher doses of PPi may be required to induce a similar reduction of severe established arterial calcification in this CKD model.

Vascular calcification: When should we interfere in chronic kidney disease patients and how?

Chronic kidney disease (CKD) patients are endangered with the highest mortality rate compared to other chronic diseases. Cardiovascular events account for up to 60% of the fatalities. Cardiovascular calcifications affect most of the CKD patients. Most of this calcification is related to disturbed renal phosphate handling. Fibroblast growth factor 23 and klotho deficiency were incriminated in the pathogenesis of vascular calcification through different mechanisms including their effects on endothelium and arterial wall smooth muscle cells. In addition, deficient klotho gene expression, a constant feature of CKD, promotes vascular pathology and shares in progression of the CKD. The role of gut in the etio-pathogenesis of systemic inflammation and vascular calcification is a newly discovered mechanism. This review will cover the medical history, prevalence, pathogenesis, clinical relevance, different tools used to diagnose, the ideal timing to prevent or to withhold the progression of vascular calcification and the different medications and medical procedures that can help to prolong the survival of CKD patients.

Crystal-Associated Colitis with Ulceration Leading to Hematochezia and Abdominal Pain

Lower GI bleeding is a common cause for hospitalization in adults. Medication-associated mucosal injury is an important clinical entity that can result in significant morbidity and mortality. We present the case of a 45-year-old woman with a 3-month history of intermittent abdominal cramping and rectal bleeding. Her medical history was extensive and included end-stage renal disease and a remote history of endometrial carcinoma that was treated with radiation. Initial workup was concerning for ischemic and radiation colitis, however, histology was most consistent with acute inflammation and ulceration associated with crystal fragments. Sevelamer and cholestyramine are commonly used ion-exchange resins that have been associated with mucosal damage. Both medications were discontinued and her symptoms resolved. Our case highlights an underrecognized but important cause of hematochezia.

Incremental cost-utility of sevelamer relative to calcium carbonate for treatment of hyperphosphatemia among pre-dialysis chronic kidney disease patients

BACKGROUND

Sevelamer is an alternative to calcium carbonate for the treatment of hyperphosphatemia among non-dialysis dependent patients with chronic kidney disease (CKD). Although some studies show that it may reduce mortality and delay the onset of dialysis when compared to calcium carbonate, it is also significantly more expensive. Prior studies looking at the incremental cost-effectiveness of sevelamer versus calcium carbonate in pre-dialysis patients are based on data from a single clinical trial. The goal of our study is to use a wider range of clinical data to achieve a more contemporary and robust cost-effectiveness analysis.

METHODS

We used a Markov model to estimate the lifetime costs and quality-adjusted life years (QALYs) gained for treatment with sevelamer versus calcium carbonate. The model simulated transitions among three health states (CKD not requiring dialysis, end-stage renal disease, and death). Data on transition probabilities and utilities were obtained from the published literature. Costs were calculated from a third party payer perspective and included medication, hospitalization, and dialysis. Sensitivity analyses were also run to encompass a wide range of assumptions about the dose, costs, and effectiveness of sevelamer.

RESULTS

Over a lifetime, the average cost per patient treated with sevelamer is S$180,724. The estimated cost for patients treated with calcium carbonate is S$152,988. A patient treated with sevelamer gains, on average, 6.34 QALYs relative to no treatment, whereas a patient taking calcium carbonate gains 5.81 QALYs. Therefore, sevelamer produces an incremental cost-effectiveness ratio (ICER) of S$51,756 per QALY gained relative to calcium carbonate.

CONCLUSION

Based on established benchmarks for cost-effectiveness, sevelamer is cost effective relative to calcium carbonate for the treatment of hyperphosphatemia among patients with chronic kidney disease initially not on dialysis.

Factors associated with serum fetuin-A concentrations after long-term use of different phosphate binders in hemodialysis patients

Background

Fetuin-A is known as a circulating inhibitor of vascular calcification. Factors associated with serum fetuin-A concentrations after long-term use of different phosphate binders in hemodialysis patients is still uncertain.

Methods

In the post-hoc study, we analyzed serum fetuin-A and biochemical factors (Ca, P, i-PTH, hsCRP, TG, LDL-C) in 50 hemodialysis patients, who completed a 48-week, open-Label, controlled randomized parallel-group study. 23 patients received sevelamer and 27 patients received calcium carbonate.

Results

After the 48-week treatment, the sevelamer group had less serum calcium increment, less iPTH decrement, more ALK-P increment, more hsCRP decrement and more LDL-C decrement. There was no significant difference in the serum fetuin-A decrement between two groups. Decreased serum fetuin-A levels were found after 48-week treatment in both groups: from 210.61 (104.73) to 153.85 (38.64) ug/dl, P = 0.003 in sevelamer group, from 203.95 (107.87) to 170.90 (58.02) ug/mL, P =0.002 in calcium group. The decrement in serum fetuin-A (Δfetuin-A) levels was associated with ΔCa (ρ = - 0.230, P = 0.040), ΔiPTH (ρ = 0.306, P = 0.031) and Δalbumin (ρ = 0.408, P = 0.003), not associated with sevelamer use, ΔP and ΔhsCRP.

Conclusion

After long-term sevelamer or calcium carbonate treatment, both groups of maintenance HD patients had lower serum fetuin-A levels. Serum levels of increased calcium, decreased iPTH and decreased albumin were associated with the serum fetuin-A decrement.

Sevelamer is an Effective Drug in Treating Hyperphosphatemia Due to Tumor Lysis Syndrome in Children: A Developing World Experience

We report here a study on efficacy of sevelamer hydrochloride in treating hyperphosphatemia due to tumor lysis syndrome (TLS) in a developing world setting. Twenty one children with hyperphosphatemia due to TLS were included. All received hyper-hydration, allopurinol and sevelamer. Efficacy was assessed by decrease in serum phosphate level, calcium-phosphate product and TLS score as per Cairo Bishop definition. Four children who underwent dialysis were excluded from analysis. Among the remaining 17 patients with hyperphosphatemia, laboratory TLS was recorded in 15 patients and clinical TLS in five. Sevelamer was given according to weight, most often 400 mg twice to thrice daily. Mean phosphatemia decreased from 8.3 ± 3.0 to 6.7 ± 2.1 mg/dl within 24 h of starting sevelamer (p = 0.02), 6.0 ± 2.1 mg/dl at 48 h, 4.9 ± 1.5 mg/dl at 72 h and 4.39 ± 1.7 mg/dl at 96 h. TLS was corrected in 72 h in 14 patients, 96 h in 1 and 120 h in another patient. Mean calcium-phosphate product decreased from 63.0 ± 14.0 to 49.2 ± 9.7 mg/dl (p = 0.002) at 24 h, 46.1 ± 17.0 mg/dl at 48 h and 39.7 ± 13.5 mg/dl at 72 h. There was no mortality due to hyperphosphatemia. Sevelamer is efficacious in children with malignancy-associated hyperphosphatemia in the developing world.

Use of sevelamer in chronic kidney disease: beyond phosphorus control

Sevelamer is a non-calcium phosphate binder used in advanced chronic kidney disease (CKD) and in dialysis for hyperphosphataemia control. Several experimental, observational studies and clinical trials have shown that sevelamer has pleiotropic effects, beyond hyperphosphataemia control, including actions on inflammation, oxidative stress, lipid profile and atherogenesis, vascular calcification, endothelial dysfunction and the reduction of several uremic toxins. This is the biological basis for its global effect on cardiovascular morbidity and mortality in patients with chronic kidney disease. This review focuses on these pleiotropic actions of sevelamer and their impact on cardiovascular health, with the experience published after more than ten years of clinical expertise.

Alternative use of cross-linked polyallylamine (known as Sevelamer pharmaceutical compound) as biosorbent

In this study, an alternative use of Sevelamer carbonate (SEV, a cross-linked polyallylamine which is a widely known pharmaceutical compound) was suggested. The existence of primary and secondary amino groups (with different ratios) in its molecule increases its adsorption potential and use as biosorbent material. SEV was tested as biosorbent material aiming the removal of heavy metals and dyes from simulated effluents. As heavy metals and dyes, hexavalent chromium (Cr(VI)) and Remazol Brilliant Blue RN (RB) were used, respectively. A full adsorption study was done confirming the strong adsorption capability of SEV. The maximum theoretical adsorption capacity (Qm) was 772 and 485mg/g for single-component solutions of RB and Cr(VI), respectively; the respective values for binary mixtures of the same concentration (200mg/L) were 445 and 309mg/g respectively (calculated after fitting to Langmuir-Freundlich isotherm model at 25°C). The same experiments were also done at increasing temperatures (45 and 65°C) concluding thermodynamic remarks (ΔH(0)>0; ΔG(0)<0; ΔS(0)>0). The effect of contact time was analyzed running kinetic adsorption experiments and fitting them to pseudo-second order kinetic equation. The reusability was evaluated completing successfully 20 cycles of reuse (adsorption/desorption). The adsorption mechanism among SEV molecules and Cr(VI) or/and RB was clarified using FTIR spectroscopy before and after adsorption in line with a detailed theoretical modeling which provided important calculations. SEV was also characterized using swelling experiments, BET, SEM, XRD, TGA techniques.

Lower gastrointestinal bleeding: Association with Sevelamer use

Stercoral ulceration results from impaction of hard fecal mass on the colonic wall and is a relatively unknown cause of lower gastrointestinal bleeding. In this report, we describe a case of lower gastrointestinal bleeding due to stercoral ulceration resulting from Sevelamer, a drug which is commonly associated with constipation.