Successful treatment of a patient with severe calcific uremic arteriolopathy (calciphylaxis) by etidronate disodium

Epidemiology and Treatment of Calcinosis Cutis: 13 Years of Experience

Background:

Calcinosis cutis is a rare condition associated with different diseases, which is difficult to manage.

Aims and Objectives:

In this retrospective study, the epidemiology of calcinosis cutis and the effectiveness of various treatment regimens in its management were assessed in a single center.

Materials and Methods:

The data of 34 patients suffering from calcinosis cutis (male:female = 12:22; mean age = 48.6 ± 18.6 years) treated at our department between 2003 and 2016 were analyzed retrospectively.

Results:

Dystrophic, idiopathic, metastatic subtype, and calciphylaxis occurred in 70.6%, 11.8%, 5.9%, and 11.8% of the cases, respectively. Underlying diseases of dystrophic calcinosis included autoimmune connective tissue disease, skin trauma, cutaneous neoplasm, and inherited disorder in 58.3%, 20.8%, 12.5%, and 8.3% of the cases, respectively. Extremities were most frequently affected (n = 18). In the management, diltiazem was most frequently used in monotherapy with partial response in five of eight cases. Other drugs in monotherapy or in combination were administered in single cases. Surgical treatment resulted in least partial response in all of the cases followed (n = 7).

Conclusion:

Dystrophic was the most common subtype and autoimmune connective tissue disease was the most frequent underlying disease. We conclude that lower doses of diltiazem have only partial efficiency, and surgical therapy is at least partially effective in localized calcinosis.

Calciphylaxis: Successful Management of a Rare Complication of Chronic Kidney Disease in Two Patients

Calciphylaxis, or calcification uremic arteriolopathy, is a rare disease thought to occur due to arteriolar calcifications of the dermis and is responsible for ischemia with cutaneous necrosis and painful panniculitis. Its mechanism remains poorly understood which makes its management challenging and difficult to standardize. We report our management of two patients diagnosed with calciphylaxis. In one patient, calciphylaxis was mentioned upon admission given the context of preexisting secondary hyperparathyroidism and the existence of multiple risk factors. In both patients, the diagnosis was confirmed histologically. Our two observations highlight the difficulty of the diagnosis and the complexity of the therapeutic management that has been personalized according to patient characteristics and clinical evolution. Several therapeutic means can be implemented once the diagnosis is made; nevertheless, its prognosis remains pejorative despite the therapeutic advances. Broad debridement, good phosphocalcic balance control, and the correction of the risk factors top the list of any therapeutic strategy. One of the major challenges of the therapy is normalizing the calcium-phosphate balance. Thus, Cinacalcet and sodium thiosulfate appear to be promising treatments.

Treatment of Calciphylaxis in CKD: A Systematic Review and Meta-analysis

BACKGROUND

Calciphylaxis is a life-threatening complication of chronic kidney disease (CKD). To inform clinical practice, we performed a systematic review of case reports, case series, and cohort studies to synthesize the available treatment modalities and outcomes of calciphylaxis in patients with CKD.

METHODS

Electronic databases were searched for studies that examined the uses of sodium thiosulfate, surgical parathyroidectomy, calcimimetics, hyperbaric oxygen therapy, and bisphosphonates for calciphylaxis in patients with CKD, including end-stage renal disease. For cohort studies, the results were synthesized quantitatively by performing random-effects model meta-analyses.

RESULTS

A total of 147 articles met the inclusion criteria and were included in the systematic review. There were 90 case reports (90 patients), 20 case series (423 patients), and 37 cohort studies (343 patients). In the pooled cohorts, case series, and case reports, 50.3% of patients received sodium thiosulfate, 28.7% underwent surgical parathyroidectomy, 25.3% received cinacalcet, 15.3% underwent hyperbaric oxygen therapy, and 5.9% received bisphosphonates. For the subset of cohort studies, by meta-analysis, the pooled risk ratio for mortality was not significantly different among patients who received sodium thiosulfate (pooled risk ratio [RR] 0.89; 95% confidence interval [CI] 0.71-1.12), cinacalcet (pooled RR 1.04; 95% CI 0.75-1.42), hyperbaric oxygen therapy (pooled RR 0.89; 95% CI 0.71-1.12), and bisphosphonates (pooled RR 0.77; 95% CI 0.44-1.32), and those who underwent surgical parathyroidectomy (pooled RR 0.88; 95% CI 0.69-1.13).

CONCLUSION

This systematic review found no significant clinical benefit of the 5 most frequently used treatment modalities for calciphylaxis in patients with CKD. Randomized controlled trials are needed to test the efficacy of these therapies.

A Heart of Stone: Cardiac Fibroblasts Turn to Bone in Calcified Hearts

The identity of the cells and molecular events driving deleterious calcification of heart muscle remains elusive. In this issue of Cell Stem Cell, Pillai et al. (2017) report that cardiac fibroblasts respond to injury by adopting an osteogenic cell fate and creating damaging calcific deposits, which can be prevented by inhibiting the activated mineralization process.

Adynamic bone disease: from bone to vessels in chronic kidney disease

Adynamic bone disease (ABD) is a well-recognized clinical entity in the complex chronic kidney disease (CKD)-mineral and bone disorder. Although the combination of low intact parathyroid hormone (PTH) and low bone alkaline phosphatase levels may be suggestive of ABD, the gold standard for precise diagnosis is histomorphometric analysis of tetracycline double-labeled bone biopsies. ABD essentially is characterized by low bone turnover, low bone volume, normal mineralization, and markedly decreased cellularity with minimal or no fibrosis. ABD is increasing in prevalence relative to other forms of renal osteodystrophy, and is becoming the most frequent type of bone lesion in some series. ABD develops in situations with reduced osteoanabolic stimulation caused by oversuppression of PTH, multifactorial skeletal resistance to PTH actions in uremia, and/or dysregulation of Wnt signaling. All may contribute not only to bone disease but also to the early vascular calcification processes observed in CKD. Various risk factors have been linked to ABD, including calcium loading, ageing, diabetes, hypogonadism, parathyroidectomy, peritoneal dialysis, and antiresorptive therapies, among others. The relationship between low PTH level, ABD, increased risk fracture, and vascular calcifications may at least partially explain the association of ABD with increased mortality rates. To achieve optimal bone and cardiovascular health, attention should be focused not only on classic control of secondary hyperparathyroidism but also on prevention of ABD, especially in the steadily growing proportions of diabetic, white, and elderly patients. Overcoming the insufficient osteoanabolic stimulation in ABD is the ultimate treatment goal.

Calciphylaxis in a patient affected by rheumatoid arthritis, chronic renal failure, and hyperparathyroidism: a case report

Calciphylaxis, or calcific uremic arteriolopathy, is the tissue and vascular calcification that occurs mainly in chronic kidney disease. However, it can be secondary to parathyroid dysfunction and it has been described in rheumatic patients. We present a case of calciphylaxis in a woman with inactive rheumatoid arthritis, acute renal failure, and hyperparathyroidism.

Calciphylaxis: risk factors, diagnosis, and treatment

Calciphylaxis is a rare but devastating condition that has continued to challenge the medical community since its early descriptions in the scientific literature many decades ago. It is predominantly seen in patients with chronic kidney failure treated with dialysis (uremic calciphylaxis) but is also described in patients with earlier stages of chronic kidney disease and with normal kidney function. In this review, we discuss the available medical literature regarding risk factors, diagnosis, and treatment of both uremic and nonuremic calciphylaxis. High-quality evidence for the evaluation and management of calciphylaxis is lacking at this time due to its rare incidence and poorly understood pathogenesis and the relative paucity of collaborative research efforts. We hereby provide a summary of recommendations developed by a multidisciplinary team for patients with calciphylaxis.

Vascular calcification and renal bone disorders

At the early stage of chronic kidney disease (CKD), the systemic mineral metabolism and bone composition start to change. This alteration is known as chronic kidney disease-mineral bone disorder (CKD-MBD). It is well known that the bone turnover disorder is the most common complication of CKD-MBD. Besides, CKD patients usually suffer from vascular calcification (VC), which is highly associated with mortality. Many factors regulate the VC mechanism, which include imbalances in serum calcium and phosphate, systemic inflammation, RANK/RANKL/OPG triad, aldosterone, microRNAs, osteogenic transdifferentiation, and effects of vitamins. These factors have roles in both promoting and inhibiting VC. Patients with CKD usually have bone turnover problems. Patients with high bone turnover have increase of calcium and phosphate release from the bone. By contrast, when bone turnover is low, serum calcium and phosphate levels are frequently maintained at high levels because the reservoir functions of bone decrease. Both of these conditions will increase the possibility of VC. In addition, the calcified vessel may secrete FGF23 and Wnt inhibitors such as sclerostin, DKK-1, and secreted frizzled-related protein to prevent further VC. However, all of them may fight back the inhibition of bone formation resulting in fragile bone. There are several ways to treat VC depending on the bone turnover status of the individual. The main goals of therapy are to maintain normal bone turnover and protect against VC.

Are there ways to attenuate arterial calcification and improve cardiovascular outcomes in chronic kidney disease?

The risk of cardiovascular mortality among patients with end-stage renal disease is several times higher than general population. Arterial calcification, a marker of atherosclerosis and a predictor of cardiovascular mortality, is common in chronic kidney disease (CKD). The presence of traditional cardiovascular risk factors such as diabetes, hypertension, hyperlipidemia, and advanced age cannot fully explain the high prevalence of atherosclerosis and arterial calcification. Other factors specific to CKD such as hyperphosphatemia, excess of calcium, high dose active vitamin D and prolonged dialysis vintage play important roles in the development of arterial calcification. Due to the significant health risk, it is prudent to attempt to lower arterial calcification burden in CKD. Treatment of hyperlipidemia with statin has failed to lower atherosclerotic and arterial calcification burden. Data on diabetes and blood pressure controls as well as smoking cessation on cardiovascular outcomes in CKD population are limited. Currently available treatment options include non-calcium containing phosphate binders, low dose active vitamin D, calcimimetic agent and perhaps bisphosphonates, vitamin K and sodium thiosulfate. Preliminary data on bisphosphonates, vitamin K and sodium thiosulfate are encouraging but larger studies on efficacy and outcomes are needed.

Curious case of calciphylaxis leading to acute mitral regurgitation

Calciphylaxis is uncommon and typically seen in patients with end-stage renal disease. It has been defined as a vasculopathic disorder characterised by cutaneous ischaemia and necrosis due to calcification, intimal fibroplasia and thrombosis of pannicular arterioles. We present the case of a 74-year-old woman with chronic kidney disease stage III who developed calciphylaxis leading to mitral valve calcification, chordae tendineae rupture and acute mitral regurgitation. Although an alternative explanation can typically be found for non-uraemic calciphylaxis, her evaluation did not reveal any usual non-uraemic causes including elevated calcium-phosphorus product, hyperparathyroidism, or evidence of connective tissue disease. Her wounds improved with sodium thiosulfate, pamidronate, penicillin and hyperbaric oxygen therapies but she ultimately decompensated with the onset of acute mitral regurgitation attributed to rupture of a previously calcified chordae tendineae. This case highlights an unusual case of calciphylaxis without clear precipitant as well as a novel manifestation of the disease.

Extraosseous calcification in end-stage renal disease: from visceral organs to vasculature

In earlier days, periarticular accumulations of calcium phosphate causing tumor-like depositions were considered the result of passive precipitation and referred to as metastatic calcifications. From sophisticated computer tomographic studies and growing insight, we have learned that calcifications in the cardiovascular system are far more threatening and in fact one of the most important sequela of end-stage renal disease. The histologic characteristic of uremia-related calcification is arteriosclerosis of the media. In addition, there is atherosclerosis of the intima, due to the high prevalence of classic cardiovascular risk factors in renal disease. The two vascular features can frequently exist at different sites in the vasculature. Novel diagnostic techniques are helping to elucidate the pathogenetic mechanisms of active conversion of vascular smooth muscle cells to osteochondritic cells. Through this process, extensive calcification of the central and peripheral vasculature ensues, influenced by different promotors and inhibitors. Calciphylaxis is a special form of extraosseous calcification leading to skin necrosis. The factors that trigger the development of calciphylaxis are not completely understood, but this syndrome shares part of the pathophysiologic basis of extraosseous calcification in general. However, the therapeutic approach must be prompt and aggressive, because of the poor prognosis. Frequently, a fatal outcome cannot be avoided in calciphylaxis.

Bisphophonates in CKD patients with low bone mineral density

Patients with chronic kidney disease-mineral and bone disorder (CKD-MBD) have a high risk of bone fracture because of low bone mineral density and poor bone quality. Osteoporosis also features low bone mass, disarranged microarchitecture, and skeletal fragility, and differentiating between osteoporosis and CKD-MBD in low bone mineral density is a challenge and usually achieved by bone biopsy. Bisphosphonates can be safe and beneficial for patients with a glomerular filtration rate of 30 mL/min or higher, but prescribing bisphosphonates in advanced CKD requires caution because of the increased possibility of low bone turnover disorders such as osteomalacia, mixed uremic osteodystrophy, and adynamic bone, even aggravating hyperparathyroidism. Therefore, bone biopsy in advanced CKD is an important consideration before prescribing bisphosphonates. Treatment also may induce hypocalcemia in CKD patients with secondary hyperparathyroidism, but vitamin D supplementation may ameliorate this effect. Bisphosphonate treatment can improve both bone mineral density and vascular calcification, but the latter becomes more unlikely in patients with stage 3-4 CKD with vascular calcification but no decreased bone mineral density. Using bisphosphonates requires considerable caution in advanced CKD, and the lack of adequate clinical investigation necessitates more studies regarding its effects on these patients.

Painful skin ulcers in a hemodialysis patient

Calciphylaxis, also referred to as calcific uremic arteriolopathy, is a relatively rare but well described syndrome that occurs most commonly in patients with late stage CKD. It is characterized by very painful placques or subcutaneous nodules and violaceous, mottled skin lesions that may progress to nonhealing ulcers, tissue necrosis, and gangrene with a 1-year mortality rate >50%. The pathogenesis of calciphylaxis is poorly understood. Risk factors include female sex, obesity, hyperphosphatemia, hypercalcemia, hyperparathyroidism, longer dialysis vintage, hypercoagulable states, and use of calcium-containing phosphate binders and warfarin. Treatment strategies for calciphylaxis are limited by inadequate understanding of its pathophysiology. Therapy is generally focused on correcting disturbances of calcium, phosphorus, and parathyroid hormone metabolism. Additional therapy focuses on decreasing inflammation and on dissolution of tissue calcium deposits with sodium thiosulfate and/or bisphosphonates. Successful treatment generally results in improvement of pain and healing of the lesions within 2-4 weeks, but the disorder generally takes many months to completely resolve.

Update on cutaneous calciphylaxis

Calciphylaxis is a devastating disorder with a mortality rate of 80% due to sepsis and organ failure. Hallmarks of this rare disease are arteriolar media calcification, thrombotic cutaneous ischemia, and necrotic ulcerations. Different mechanisms of vascular calcification can lead to calciphylaxis. Early diagnosis by deep cutaneous ulcer biopsy is most important for prognosis. Here, dermatologists play a significant role although treatment usually needs an interdisciplinary approach. Surgical procedures had been the cornerstone of treatment in the past including parathyroidectomy, but recently new medical treatments emerged aiming to normalize disturbances of minerals to reduce the serum concentration of sodium phosphate and to prevent precipitation and calcification. Multimodal therapy is warranted but only aggressive surgical debridement of cutaneous ulcers has shown significant outcome improvement.

Extraskeletal benefits and risks of calcium, vitamin D and anti-osteoporosis medications

Drugs used for the prevention and the treatment of osteoporosis exert various favourable and unfavourable extra-skeletal effects whose importance is increasingly recognized notably for treatment selection.

INTRODUCTION

The therapeutic armamentarium for the prevention and the treatment of osteoporosis is increasingly large, and possible extra-skeletal effects of available drugs could influence the choice of a particular compound.

METHODS

The present document is the result of a national consensus, based on a systematic and critical review of the literature.

RESULTS

Observational research has suggested an inverse relationship between calcium intake and cardiovascular diseases, notably through an effect on blood pressure, but recent data suggest a possible deleterious effect of calcium supplements on cardiovascular risk. Many diverse studies have implicated vitamin D in the pathogenesis of clinically important non-skeletal functions or diseases, especially muscle function, cardiovascular disease, autoimmune diseases and common cancers. The possible effects of oral or intravenous bisphosphonates are well-known. They have been associated with an increased risk of oesophageal cancer or atrial fibrillation, but large-scale studies have not found any association with bisphosphonate use. Selective oestrogen receptor modulators have demonstrated favourable or unfavourable extra-skeletal effects that vary between compounds. Strontium ranelate has a limited number of non-skeletal effects. A reported increase in the risk of venous thromboembolism is not found in observational studies, and very rare cases of cutaneous hypersensitivity reactions have been reported. Denosumab has been introduced recently, and its extra-skeletal effects still have to be assessed.

CONCLUSION

Several non-skeletal effects of bone drugs are well demonstrated and influence treatment choices.

Evolution of treatment strategies for calciphylaxis

Treatment strategies for calciphylaxis are limited by inadequate understanding of its pathophysiology. Mortality reaches 80%, due to progressive skin ischemia, necrosis and infections. In addition to calcium and parathyroid disorders, hypercoagulability can have a role: primary thrombotic disorders as well as secondary, such as proposed warfarin procoagulant effects. Traditional care addresses the calcium-phosphate-PTH axis: minimizing calcium intake, calcimimetics, cautious vitamin D analogs, strict phosphate control, and surgical parathyroidectomy if necessary. Newer approaches focus on extraosseous mineralization: dissolution of calcium deposits, altering osteoprotegerin and NF-κB pathways, and treating macrophage or cytokine-mediated inflammation. Sodium thiosulfate has reported success, and is thought to be due to enhanced calcium solubility and dialysis clearance. Bisphosphonates may have efficacy by lowering bone turnover or a variety of vascular tissue mechanisms. The literature for both agents is very limited, and optimal dosing regimens remain unclear. Patients responsive to a medication will have decreasing pain in days and lesions beginning to heal within approximately 2 weeks. Due to high mortality, early use of combination therapy is advocated, although specific protocols have not been well established. The often dramatic improvements in case-based literature are very encouraging and will hopefully lead to more rigorous studies.

Calciphylaxis: a systematic review of existing and emerging therapies

Calciphylaxis, also known as calcific uremic arteriolopathy, is a cutaneous ischemic small vessel vasculopathy seen in 1 to 4% of patients with chronic kidney disease on hemodialysis. It is associated with extreme pain and a 60 to 80% mortality rate in the setting of few and frequently ineffective therapeutic options, although this may be changing based on reports of success with newer therapies.

Calciphylaxis: no longer rare; no longer calciphylaxis? A paradigm shift for wound, ostomy and continence nursing

This article challenges conventional wisdom that calciphylaxis is a rare condition. Rather, emerging evidence suggests that calciphylaxis is neither rare nor uncommon. In addition, the term calciphylaxis is questioned because misrepresents the underlying etiology of the condition. Multiple researchers and clinicians advocate abandoning the use of the term, but nursing literature has not yet followed suit. This article reviews the epidemiology, clinical manifestations, diagnosis, prevention, and treatment of this condition and associated wounds, and suggests areas for future research. The WOC nurse's role as an educator, leader, researcher, clinical expert, and patient advocate is summarized.

Treatment of severe metastatic calcification and calciphylaxis in dialysis patients

Metastatic calcification is a frequent complication encountered in patients undergoing maintenance dialysis and has a complex pathogenesis. It is often difficult to treat and is associated with high morbidity and mortality. Early recognition and prompt initiation of treatment is vital. Local wound care and aggressive metabolic control remain the cornerstones of the therapy. Various novel treatment strategies including sodium thiosulfate and hyperbaric oxygen therapy have been utilized and reviewed in this paper. The response rate to treatment is poor and prevention is the best approach.

Calcific uremic arteriolopathy: pathophysiology, reactive oxygen species and therapeutic approaches

Calcific uremic arteriolopathy (CUA)/calciphylaxis is an important cause of morbidity and mortality in patients with chronic kidney disease requiring renal replacement. Once thought to be rare, it is being increasingly recognized and reported on a global scale. The uremic milieu predisposes to multiple metabolic toxicities including increased levels of reactive oxygen species and inflammation. Increased oxidative stress and inflammation promote this arteriolopathy by adversely affecting endothelial function resulting in a prothrombotic milieu and significant remodeling effects on vascular smooth muscle cells. These arteriolar pathological effects include intimal hyperplasia, inflammation, endovascular fibrosis and vascular smooth muscle cell apoptosis and differentiation into bone forming osteoblast-like cells resulting in medial calcification. Systemic factors promoting this vascular condition include elevated calcium, parathyroid hormone and hyperphosphatemia with consequent increases in the calcium × phosphate product. The uremic milieu contributes to a marked increased in upstream reactive oxygen species—oxidative stress and subsequent downstream increased inflammation, in part, via activation of the nuclear transcription factor NFκB and associated downstream cytokine pathways. Consitutive anti-calcification proteins such as Fetuin-A and matrix GLA proteins and their signaling pathways may be decreased, which further contributes to medial vascular calcification. The resulting clinical entity is painful, debilitating and contributes to the excess morbidity and mortality associated with chronic kidney disease and end stage renal disease. These same histopathologic conditions also occur in patients without uremia and therefore, the term calcific obliterative arteriolopathy could be utilized in these conditions.

Unusual causes of cutaneous ulceration

Skin ulceration is a major source of morbidity and is often difficult to manage. Ulcers caused by an inflammatory cause or microvascular occlusion are particularly challenging in terms of diagnosis and treatment. The management of such ulcers requires careful assessment of associated systemic conditions and a thorough analysis of the ulcer's clinical and histologic findings. In this article, the authors discuss several examples of inflammatory ulcers and the approach to the diagnosis and treatment of these ulcers.

Recent progress in the treatment of vascular calcification

Vascular calcification is common in patients with advanced chronic kidney disease and is associated with poorer outcomes. Although the pathophysiology is not completely understood, it is clear that it is a multifactorial process involving altered mineral metabolism, as well as changes in systemic and local factors that can promote or inhibit vascular calcification, and all of these are potential therapeutic targets. Current therapy is closely linked to strategies for preventing disordered bone and mineral metabolism in advanced kidney disease and involves lowering the circulating levels of both phosphate and calcium. The efficacy of compounds that specifically target calcification, such as bisphosphonates and thiosulfate, has been shown in animals but only in small numbers of humans, and safety remains an issue. Additional therapies, such as pyrophosphate, vitamin K, and lowering of pH, are supported by animal studies, but are yet to be investigated clinically. As the mineral composition of vascular calcifications is the same as in bone, potential effects on bone must be addressed with any therapy for vascular calcification.

[Calciphylaxis. A less well-known, clinically relevant disease]

Calciphylaxis is a rare disease which has been increasingly reported in recent decades and has consequently shifted into the focus of clinical and scientific research. The clinical picture is characterized by extensive ischemic ulcerations of the skin and subcutis. Histologically, the small vessels in these lesions show prominent calcifications. Due to the extensive areas of ulceration and necrosis as well as frequently present comorbidities, patients with calciphylaxis are prone to infection and sepsis. In this work, we describe the case of a female kidney-transplant patient with vasculitis who, despite good graft function, developed a fulminant calciphylaxis of both thighs 4 years post transplantation and died of septic complications. The differential diagnoses as well as clinical procedures are described in detail in the case history. In the discussion, we give an overview of the current state of knowledge regarding the etiopathogenesis, risk factors, diagnostic measures and clinical management of calciphylaxis.

Calcific uremic arteriolopathy: contemporary pharmacotherapy

Calcific uremic arteriolopathy (CUA) is a poorly understood disease affecting 4% to 5% of the patients with end-stage renal disease. Strategies aimed at prompt identification and diagnosis, such as use of plain radiographs, bone scans, and transcutaneous oxygen saturation tension, may lead to earlier initiation of treatment. Early treatment should focus on preventing progression into overt ulceration, which significantly raises the likelihood of infection, amputation, and death. Several agents, including sodium thiosulfate, bisphosphonates, cinacalcet, and tissue plasminogen activator, have been used in the treatment of CUA with varying effects; however, there has been no consensus on an optimal treatment option. The lack of randomized trials comparing treatment options and a potential bias with respect to publication of case reports hinders the ability to choose the most effective agent in the treatment of CUA. Future insights into the molecular basis of vascular calcification may help determine new therapeutic targets.

Possible role of hypercoagulability in calciphylaxis: review of the literature

BACKGROUND

The role of a hypercoagulable state in the pathogenesis of calciphylaxis has yet to be determined.

OBJECTIVE

We sought to find evidence of an association between hypercoagulability and calciphylaxis.

METHODS

We reviewed the primary literature for review articles, studies, and case reports that discussed or demonstrated a possible relationship between calciphylaxis and a hypercoagulable state.

RESULTS

Review of the primary literature showed that in cases of calciphylaxis with reported levels of protein C and S, 38% of the patients had decreased protein C levels and 43% had decreased levels of protein S. From review of case reports, 3 cases of improvement of skin lesions with low molecular weight heparin treatment, and a fourth case of healing of skin lesions with tissue plasminogen activator treatment, were found. Calciphylaxis was also found in a patient with antiphospholipid antibody syndrome, and a patient with cryofibrinogenemia had clinical and histologic findings consistent with possible calciphylaxis.

LIMITATIONS

A limited number of reports were available for review.

CONCLUSION

Our review of the literature found sufficient evidence to suggest a possible role of a hypercoagulable state in the pathogenesis of calciphylaxis. A prospective study with serial testing of all relevant clotting factors in patients with calciphylaxis is needed to more definitively establish this role.

[Calciphylaxis in dialysis patients: To recognize and treat it as soon as possible]

Calciphylaxis (CPX) or calcific uraemic arteriolopathy is a rare life-threatening complication, affecting mainly dialysis patients. The condition is characterized by calcifications and thrombosis of the small cutaneous vessels and small vessels in the fat tissue, resulting in the development of necrotizing and non-healing ulcers. The development of these lesions leads to poor outcomes owing to infectious complications and some frequently associated unfavourable medical conditions: obesity, diabetes, and peripheral vascular disease. We report the case of six patients with different clinical forms of CPX in the past 10 years with favourable outcomes observed in five of the six patients. The diagnosis was based on clinical presentation: bilateral and hyperalgesic necrotic lesions along with a history of mineral metabolism disorder or warfarin use. The therapeutic strategy included the following: daily dialysis, hyperbaric oxygen therapy, treatment of limb artery stenosis, maintenance of the optimal haemodynamic stability, delivery of cutaneous care, administration of analgesics and antibiotics, warfarin and calcium cessation, and additional therapy with cinacalcet or parathyroidectomy and therapy with bisphosphonates or sodium thiosulphate. Healing was observed in five out of six CPX patients by using this strategy that should be rapidly employed in order to decrease the necrotizing areas that result in poor outcomes. Prevention includes identification of at-risk patients in order to optimize the treatment of the identified risk factors for CPX.

Calcific Uremic Arteriolopathy: Pathophysiology, Reactive Oxygen Species and Therapeutic Approaches

Calcific uremic arteriolopathy (CUA)/calciphylaxis is an important cause of morbidity and mortality in patients with chronic kidney disease requiring renal replacement. Once thought to be rare, it is being increasingly recognized and reported on a global scale. The uremic milieu predisposes to multiple metabolic toxicities including increased levels of reactive oxygen species and inflammation. Increased oxidative stress and inflammation promote this arteriolopathy by adversely affecting endothelial function resulting in a prothrombotic milieu and significant remodeling effects on vascular smooth muscle cells. These arteriolar pathological effects include intimal hyperplasia, inflammation, endovascular fibrosis and vascular smooth muscle cell apoptosis and differentiation into bone forming osteoblast-like cells resulting in medial calcification. Systemic factors promoting this vascular condition include elevated calcium, parathyroid hormone and hyperphosphatemia with consequent increases in the calcium × phosphate product. The uremic milieu contributes to a marked increased in upstream reactive oxygen species—oxidative stress and subsequent downstream increased inflammation, in part, via activation of the nuclear transcription factor NFκB and associated downstream cytokine pathways. Consitutive anti-calcification proteins such as Fetuin-A and matrix GLA proteins and their signaling pathways may be decreased, which further contributes to medial vascular calcification. The resulting clinical entity is painful, debilitating and contributes to the excess morbidity and mortality associated with chronic kidney disease and end stage renal disease. These same histopathologic conditions also occur in patients without uremia and therefore, the term calcific obliterative arteriolopathy could be utilized in these conditions.

A 44 year-old lady with chronic renal disease and intractable ulcers: a case report

Calciphylaxis is a rare but potentially fatal condition occurring in patients with end stage renal disease on dialysis. Due to interplay of various factors, disturbances occur in the metabolism of calcium and phosphate leading to calcification within the vessel walls. The net result is tissue ischemia and necrosis. Clinically this presents as painful non-healing skin ulcers, which contribute to significant morbidity and mortality due to septic progression of the lesion. In this case report, we highlight the rapidly progressive nature of this disease, its etiopathogenesis and the role of early diagnosis in preventing life-threatening complications.

The calcimimetic AMG 641 accelerates regression of extraosseous calcification in uremic rats

The purpose of the present study was to test the hypothesis that extraskeletal calcification regresses in uremic rats after reduction in phosphorus intake and treatment with calcimimetics. Extraosseous calcification was induced in five to six nephrectomized rats fed a high-phosphorus (1.2%) diet who received calcitriol (80 ng/kg ip) every other day for a period of 14 days. Next, dietary phosphorus was reduced to 0.6%, and rats were treated with vehicle ( n = 20), calcitriol [80 ng/kg ip/48 h ( n = 20)], or the calcimimetic AMG 641 [1.5 mg/kg sc/48 h ( n = 20)]. Aortic and soft-tissue calcium and phosphorus content was evaluated after 14 and 28 days. At 28 days, reduction of phosphorus intake resulted in a significant decrease in tissue mineral content in vehicle- and AMG 641-treated rats but not in rats receiving calcitriol. Aortic calcium and phosphorus was lower in rats treated with AMG 641 (96.7 ± 26.4 mg/g) than in rats receiving vehicle (178.3 ± 38.6 mg/g). An infiltrate of phagocytic cells expressing the calcium-sensing receptor was identified in areas surrounding foci of calcification. Additional studies in parathyroidectomized rats demonstrated that AMG 641 increased the urinary excretion of calcium (6.2 ± 0.6 vs. 3.1 ± 0.5 mg/day, vehicle) ( P < 0.001). In conclusion, experimentally induced extraosseous calcification in uremic rats can be partially resolved by reducing phosphorus intake; the addition of calcimimetics may accelerate the regression process through mechanisms potentially involving a direct stimulatory effect on mineral phagocytic cells plus an increase in urinary calcium excretion.

Effects of calcimimetics on extraskeletal calcifications in chronic kidney disease

While the precise mechanisms of vascular calcification (VC) in chronic kidney disease (CKD) remain to be elucidated, there is a close association between VC and secondary hyperparathyroidism (HPT). The elevations in calcium, phosphorus, the Ca x P product, and parathyroid hormone (PTH) observed in patients with CKD and secondary HPT have been associated with VC and increased risk of cardiovascular morbidity and mortality. We have investigated the development of extraskeletal calcification in uremic rats with secondary HPT treated with vitamin D derivatives (calcitriol or paricalcitol), calcimimetics (R-568 or AMG 641), or the combination of both types drugs. Treatment with calcitriol resulted in a significant increase in the extraosseous calcium and phosphorus content and high mortality. By contrast, treatment with calcimimetics, which provided a better control of plasma PTH levels, did not result in extraskeletal mineral accumulation and did not cause mortality. More important, when added to calcitriol, calcimimetics prevented the development of VC and reduced mortality. Paricalcitol administration to uremic rats resulted in calcification levels and mortality rates that were lower than in rats treated with calcitriol but higher than in rats treated with calcimimetics. The mechanism(s) of action responsible for the anticalcification effect of calcimimetics are likely related to the fact that these drugs can control PTH levels without increasing the plasma Ca x P product. In addition calcimimetic activation of vascular calcium-sensing receptor may also modulate the expression of proteins that prevent the development of VC, like matrix Gla protein.

Skin problems in chronic kidney disease

Skin disorders associated with chronic kidney disease (CKD) can markedly affect a patient's quality of life and can negatively impact their mental and physical health. Uremic pruritus, which is frequently encountered in patients with CKD, is considered to be an inflammatory systemic disease rather than a local skin disorder. Biomarkers of inflammation are increased in patients with uremic pruritus and an imbalance of the endogenous opioidergic system might be involved in the complex pathogenesis of the disease. Treatment options for uremic pruritus include emollients, topical capsaicin cream, ultraviolet B phototherapy, gabapentin, oral activated charcoal and nalfurafine, a kappa-opioid-receptor agonist. Calcific uremic arteriolopathy is triggered by an imbalance of promoters and inhibitors of vascular calcification, caused by the inflammatory changes that occur in uremia. Promising therapeutic strategies for calcific uremic arteriolopathy include bisphosphonates and intravenous sodium thiosulfate. Nephrogenic systemic fibrosis is a devastating condition associated with the use of gadolinium-based contrast agents in patients with CKD. At present, no therapies are available for this complication. Preventive measures include use of iodine-based contrast agents, particularly in patients with CKD stage 4 and 5. If gadolinium contrast is necessary, administration of low volumes of the more stable macrocyclic ionic types of gadolinium-based contrast agent is advocated. Hemodialysis following gadolinium exposure might offer benefits but evidence is lacking.

Calcific uraemic arteriolopathy: an update

PURPOSE OF REVIEW

Calcific uraemic arteriolopathy (CUA) or calciphylaxis is a rare but important cause of morbidity and mortality in patients with chronic kidney disease. The prevalence of CUA is increasing in patients with renal failure, and the condition is also being recognized in nonuraemic patients.

RECENT FINDINGS

There has been increasing understanding of the molecular basis of vascular calcification, in particular on the important role of the uraemic microenvironment in the factors implicated in the differentiation of vascular smooth muscle cells into osteoblasts. New options for treatment of hyperphosphataemia and secondary hyperparathyroidism in patients with chronic kidney disease have become available in the last few years and these have begun to be used in patients with CUA. These include bisphosphonates, newer noncalcium/nonaluminium-containing phosphate binders and case reports of use of cinacalcet. Other treatments for CUA that are not targeted directly at calcium/phosphate homeostasis include hyperbaric oxygen and the antioxidant cation chelator sodium thiosulphate.

SUMMARY

Clinicians managing patients with CUA should consider a combination approach of treating deranged calcium/phosphate with newer therapeutic agents and promoting wound healing with other older modalities such as hyperbaric oxygen and sodium thiosulphate infusions. Randomized controlled trials for treatments in CUA are still lacking.

Calciphylaxis

Calciphylaxis is defined by the presence of calcium deposits within the wall of small and medium-sized vessels. It is classically considered a life-threatening disease in patients with end-stage renal disease under dialysis. Clinically, it is characterized by the presence of painful plaques surrounded by a reticulate purpura that progresses to nonhealing ulcers, predominately in the lower limbs. It is associated with elevated parathyroid hormone levels and a dysregulation of the calcium/phosphate metabolism. In the absence of renal disease, normal parathyroid hormone levels, and calcium/phosphorus product, a good prognosis and the observation of similar calcium deposits associated with different conditions or even an epiphenomenon in diseases with well-known diagnosis leads one to consider the term calciphylaxis controversial.

Bisphosphonates in chronic kidney disease; balancing potential benefits and adverse effects on bone and soft tissue

Cardiovascular disease is highly prevalent in chronic kidney disease (CKD) and is often associated with increased vascular stiffness and calcification. Recent studies have suggested a complex interaction between vascular calcification and abnormalities of bone and mineral metabolism, with an inverse relationship between arterial calcification and bone mineral density (BMD). Although osteoporosis is recognized and treated in CKD 1 to 3, the interpretation of BMD levels in the osteoporotic range is controversial in CKD 4, 5, and 5D when renal osteodystrophy is generally present. In addition, there is a paucity of data for patients with CKD mineral and bone disorder (MBD), because studies using bisphosphonates in postmenopausal and glucocorticoid-induced osteoporosis have generally excluded patients with significant CKD. For these patients, treatment of low BMD using standard therapies for osteoporosis is not without potential for harm due to the possibility of worsening low bone turnover, osteomalacia, mixed uraemic osteodystrophy, and of exacerbated hyperparathyroidism; and bisphosphonates should only be used selectively and with caution. Some experimental and clinical studies have also suggested that bisphosphonates may reduce progression of extra-osseous calcification and inhibit the development of atherosclerosis. The authors review the potential benefits and risks associated with bisphosphonate use for bone protection in CKD, and assess their effect on vascular calcification and atherosclerosis.