Penile Calciphylaxis Obscured by Phimosis in an End-Stage Renal Disease Patient: A Case Report

Penile calciphylaxis is a rare and severe complication primarily observed in patients with end-stage renal disease (ESRD) undergoing dialysis. A 50-year-old man presented with severe penile pain and phimosis. He had a history of hypertension and diabetes mellitus for 10 years, complicated by ESRD and was awaiting a cadaveric kidney transplant. He was on cinacalcet therapy for tertiary hyperparathyroidism. The patient underwent circumcision at which discolouration and necrotic patches involving the glans penis were noted. The histological findings were consistent with calciphylaxis and suppurative inflammation. However, due to persistent severe pain and progressive gangrene, a partial penectomy was performed. This report demonstrates the importance of consideration of calciphylaxis in patients with ESRD when presenting with penile pain, even phimosis.

Vitamin K for Vascular Calcification in Kidney Patients: Still Alive and Kicking, but Still a Lot to Learn

Patients with chronic kidney disease (CKD) suffer disproportionately from a high burden of cardiovascular disease, which, despite recent scientific advances, remains partly understood. Vascular calcification (VC) is the result of an ongoing process of misplaced calcium in the inner and medial layers of the arteries, which has emerged as a critical contributor to cardiovascular events in CKD. Beyond its established role in blood clotting and bone health, vitamin K appears crucial in regulating VC via vitamin K-dependent proteins (VKDPs). Among these, the matrix Gla protein (MGP) serves as both a potent inhibitor of VC and a valuable biomarker (in its inactive form) for reflecting circulating vitamin K levels. CKD patients, especially in advanced stages, often present with vitamin K deficiency due to dietary restrictions, medications, and impaired intestinal absorption in the uremic environment. Epidemiological studies confirm a strong association between vitamin K levels, inactive MGP, and increased CVD risk across CKD stages. Based on the promising results of pre-clinical data, an increasing number of clinical trials have investigated the potential benefits of vitamin K supplementation to prevent, delay, or even reverse VC, but the results have remained inconsistent.

SNF472: a novel therapeutic agent for vascular calcification and calciphylaxis

Vascular calcification is a common complication in patients with chronic kidney disease (CKD) and is strongly associated with an increased risk of cardiovascular events and all-cause mortality. Calciphylaxis is a specific and life-threatening manifestation of vascular calcifications that usually affects individuals with advanced kidney function impairment or those undergoing dialysis. Currently, the treatment of vascular calcification and calciphylaxis in CKD lacks approved treatments and focuses on controlling risk factors. SNF472, the intravenous formulation of myo-inositol hexaphosphate, is a novel vascular calcification inhibitor currently undergoing phase 3 clinical trials, demonstrating its ability to directly inhibit the formation of calcium and phosphorus crystals, thereby blocking the production and deposition of ectopic calcium. The efficacy and safety of SNF472 in inhibiting vascular calcification have been confirmed in recent clinical studies. This review summarizes the results of studies related to SNF472 to provide a comprehensive overview of its mechanism of action, efficacy, safety, and ongoing clinical studies.

Calciphylaxis Episodes in the Australia and New Zealand Dialysis and Transplant Registry

Introduction

Calciphylaxis is a rare disorder associated with significant morbidity and mortality. Data registries are an invaluable source of information for rare diseases. We reviewed cases of calciphylaxis recorded in the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) and evaluated associations and outcomes of this condition.

Methods

Data was obtained on all cases of calciphylaxis reported between 2019 and 2022 in Australian and New Zealand patients on kidney replacement therapy (KRT). This cohort was compared to all patients in the registry who received KRT from 2019 to 2022 without an episode of calciphylaxis. Cox proportional hazards regression including a time-varying covariate for calciphylaxis episode was conducted for mortality with models restricted to patients on dialysis only.

Results

From 2019 to 2022, 333 patients had calciphylaxis episodes reported. Overall incidence rate for patients on dialysis was 4.5 (4.1-5.1) episodes per 1000 patient-years on dialysis. Median age was 63 (interquartile range [IQR]: 55-73) years, 54% were female, 66% had diabetes, 59% were obese (body mass index [BMI] ≥ 30 kg/m2) and 77% were receiving hemodialysis (HD) treatment. Compared to patients without calciphylaxis (n = 46,526), patients with calciphylaxis were more likely to be older, female, and have diabetes, greater BMI, coronary artery, and peripheral vascular disease. The median time to calciphylaxis was 3.2 (IQR: 0.9-6.7) years after KRT commencement. Half of the patients with calciphylaxis died by 12 months from diagnosis. Adjusted hazard ratio (HR) of mortality for patients on dialysis with calciphylaxis <1 year and 1 to 4 years after an episode was 5.8 (4.9-6.9) and 1.5 (1.0-2.1), respectively compared to patients on dialysis without calciphylaxis.

Conclusion

Calciphylaxis is a rare but life-threatening condition in people on KRT with the greatest mortality burden within 12 months of diagnosis.

Phosphate in Cardiovascular Disease: From New Insights Into Molecular Mechanisms to Clinical Implications

Hyperphosphatemia is a common feature in patients with impaired kidney function and is associated with increased risk of cardiovascular disease. This phenomenon extends to the general population, whereby elevations of serum phosphate within the normal range increase risk; however, the mechanism by which this occurs is multifaceted, and many aspects are poorly understood. Less than 1% of total body phosphate is found in the circulation and extracellular space, and its regulation involves multiple organ cross talk and hormones to coordinate absorption from the small intestine and excretion by the kidneys. For phosphate to be regulated, it must be sensed. While mostly enigmatic, various phosphate sensors have been elucidated in recent years. Phosphate in the circulation can be buffered, either through regulated exchange between extracellular and cellular spaces or through chelation by circulating proteins (ie, fetuin-A) to form calciprotein particles, which in themselves serve a function for bulk mineral transport and signaling. Either through direct signaling or through mediators like hormones, calciprotein particles, or calcifying extracellular vesicles, phosphate can induce various cardiovascular disease pathologies: most notably, ectopic cardiovascular calcification but also left ventricular hypertrophy, as well as bone and kidney diseases, which then propagate phosphate dysregulation further. Therapies targeting phosphate have mostly focused on intestinal binding, of which appreciation and understanding of paracellular transport has greatly advanced the field. However, pharmacotherapies that target cardiovascular consequences of phosphate directly, such as vascular calcification, are still an area of great unmet medical need.

Dermatological Manifestations in Patients With Chronic Kidney Disease: A Review

Chronic kidney disease (CKD) is a progressive disease and has multiple clinical manifestations; when CKD reaches the end stage, at least one cutaneous manifestation appears due to some increased toxin levels or a constant proinflammatory state. Nonspecific manifestations include pruritus, xerosis, pigmentation disorders, acquired ichthyosis, purpuric spots, and nail disorders. Some specific manifestations are bullous dermatoses, acquired perforating dermatoses (APD), eruptive xanthoma, access site infections, calcifying disorders, and nephrogenic systemic fibrosis (NSF). All these cutaneous changes negatively impact patients; early recognition and diagnosis of these dermatoses will make a difference in their quality of treatment. Exploring a patient's skin is fundamental to suspect some diseases and increased toxin levels; pruritus occurs when uremic toxins are raised, and nail disorders are associated with hypoalbuminemia. This review provides the clinician with information on the clinical manifestations that occur in CKD, including epidemiology, pathophysiology, clinical manifestations, diagnosis, histopathology, treatment, and life impact of the dermatoses in CKD.

Multimodality approach to treat calciphylaxis in end-stage kidney disease patients

A multimodality approach has been proposed as an effective treatment for calciphylaxis in patients with end-stage kidney disease. In this retrospective study, we report the cases of 12 end-stage kidney disease patients from l'Hôtel-Dieu de Québec hospital (Canada) who were diagnosed with calciphylaxis between 2004 and 2012 and treated with a multimodality clinical approach including sodium thiosulfate (STS). Statistical analyses were performed to evaluate the impacts of patients characteristics, the different interventions as well as therapy regimen on the therapeutic response. The majority of patients (n = 9) were hemodialyzed. The patients-associated comorbidities were consistent with previously reported risk factors for calciphylaxis: Diabetes (n = 11), calcium-based phosphate binders use (n = 10), warfarin use (n = 9), obesity (n = 7), female gender (n = 8) and intravenous iron use (n = 8). STS was given for a median duration of 81 days. 75% of the patients had a response (total or partial) including a complete response in 42% of patients. One-year mortality rate was low (25%). STS was used during a mean duration of 83.33 ± 41.52 days and with a total cumulating dose of 1129.00 ± 490.58 g. The recorded mean time before a complete response was 102.20 days (51-143). Pain improvement occurred after a mean time of 8.67 ± 10.06 days. None of the studied factors was statistically associated with a complete or a partial response to the multimodality approach. Although our data have a limited statistical power, they support treating calciphylaxis with a multimodality approach including STS as its effects are independent from important clinical variables.

Is Adynamic Bone Always a Disease? Lessons from Patients with Chronic Kidney Disease

Renal osteodystrophy (ROD) is a common complication of end-stage kidney disease that often starts early with loss of kidney function, and it is considered an integral part in management of patients with chronic kidney disease (CKD). Adynamic bone (ADB) is characterized by suppressed bone formation, low cellularity, and thin osteoid seams. There is accumulating evidence supporting increasing prevalence of ADB, particularly in early CKD. Contemporarily, it is not very clear whether it represents a true disease, an adaptive mechanism to prevent bone resorption, or just a transitional stage. Several co-players are incriminated in its pathogenesis, such as age, diabetes mellitus, malnutrition, uremic milieu, and iatrogenic factors. In the present review, we will discuss the up-to-date knowledge of the ADB and focus on its impact on bone health, fracture risk, vascular calcification, and long-term survival. Moreover, we will emphasize the proper preventive and management strategies of ADB that are pivotal issues in managing patients with CKD. It is still unclear whether ADB is always a pathologic condition or whether it can represent an adaptive process to suppress bone resorption and further bone loss. In this article, we tried to discuss this hard topic based on the available limited information in patients with CKD. More studies are needed to be able to clearly address this frequent ROD finding.

A systematic review of the efficacy and safety of anticoagulants in advanced chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) have an increased risk of venous thromboembolism (VTE) and atrial fibrillation (AF). Anticoagulants have not been studied in randomised controlled trials with CrCl < 30 ml/min. The objective of this review was to identify the impact of different anticoagulant strategies in patients with advanced CKD including dialysis.

METHODS

We conducted a systematic review of randomized controlled trials and cohort studies, searching electronic databases from 1946 to 2022. Studies that evaluated both thrombotic and bleeding outcomes with anticoagulant use in CrCl < 50 ml/min were included.

RESULTS

Our initial search yielded 14,503 papers with 53 suitable for inclusion. RCTs comparing direct oral anticoagulants (DOACs) versus warfarin for patients with VTE and CrCl 30-50 ml/min found no difference in recurrent VTE events (RR 0.68(95% CI 0.42-1.11)) with reduced bleeding (RR 0.65 (95% CI 0.45-0.94)). Observational data in haemodialysis suggest lower risk of recurrent VTE and major bleeding with apixaban versus warfarin. Very few studies examining outcomes were available for therapeutic and prophylactic dose low molecular weight heparin for CrCl < 30 ml/min. Findings for patients with AF on dialysis were that warfarin or DOACs had a similar or higher risk of stroke compared to no anticoagulation. For patients with AF and CrCl < 30 ml/min not on dialysis, anticoagulation should be considered on an individual basis, with limited studies suggesting DOACs may have a preferable safety profile.

CONCLUSION

Further studies are still required, some ongoing, in patients with advanced CKD (CrCl < 30 ml/min) to identify the safest and most effective treatment options for VTE and AF.

Concurrent development of encapsulating peritoneal sclerosis and calciphylaxis in a patient with peritoneal dialysis for end-stage renal disease

Both encapsulating peritoneal sclerosis (EPS) and calciphylaxis are rare but severe complications involving patients with end-stage renal disease. In this report, we discuss a unique case of a 73-year-old female patient who had undergone 8 years of peritoneal dialysis for IgA nephropathy and concurrently developed these two synchronous complications within 3 months of each other. Diagnosis and management of both conditions were discussed in detail as well as the possible association between the two. With surgical treatment for EPS and measures to minimise bone mineral disorder abnormalities, both complications have been successfully managed to date.

The CALCIPHYX study: a randomized, double-blind, placebo-controlled, Phase 3 clinical trial of SNF472 for the treatment of calciphylaxis

Background

Calcific uraemic arteriolopathy (CUA; calciphylaxis) is a rare disease seen predominantly in patients receiving dialysis. Calciphylaxis is characterized by poorly healing or non-healing wounds, and is associated with mortality, substantial morbidity related to infection and typically severe pain. In an open-label Phase 2 clinical trial, SNF472, a selective inhibitor of vascular calcification, was well-tolerated and associated with improvement in wound healing, reduction of wound-related pain and improvement in wound-related quality of life (QoL). Those results informed the design of the CALCIPHYX trial, an ongoing, randomized, placebo-controlled, Phase 3 trial of SNF472 for treatment of calciphylaxis.

Methods

In CALCIPHYX, 66 patients receiving haemodialysis who have an ulcerated calciphylaxis lesion will be randomized 1:1 to double-blind SNF472 (7 mg/kg intravenously) or placebo three times weekly for 12 weeks (Part 1), then receive open-label SNF472 for 12 weeks (Part 2). All patients will receive stable background care, which may include pain medications and sodium thiosulphate, in accordance with the clinical practices of each site. A statistically significant difference between the SNF472 and placebo groups for improvement of either primary endpoint at Week 12 will demonstrate efficacy of SNF472: change in Bates-Jensen Wound Assessment Tool-CUA (a quantitative wound assessment tool for evaluating calciphylaxis lesions) or change in pain visual analogue scale score. Additional endpoints will address wound-related QoL, qualitative changes in wounds, wound size, analgesic use and safety.

Conclusions

This randomized, placebo-controlled Phase 3 clinical trial will examine the efficacy and safety of SNF472 in patients who have ulcerated calciphylaxis lesions. Patient recruitment is ongoing.

Calciphylaxis After Aortic Valve Replacement in a Patient with End-Stage Renal Disease

In this study, we report a case of a patient on dialysis who presented necrotic lesions on the legs and penile ulceration 7 years after a mechanical aortic valve replacement. The diagnosis of calciphylaxis was not confirmed even after skin biopsy, and multidisciplinary management was not initiated until the patient was admitted with septic shock. Cardiovascular surgeons should be aware of warfarin-induced calciphylaxis, whose pathophysiology differs from that of atherosclerosis. Considering poor long-term survival of dialysis patients, mechanical valves should be reserved only for those patients whose estimated survival is longer than the time taken for a biological valve to deteriorate.

Successful Treatment of Calciphylaxis in a Young Female With End-Stage Renal Disease on Peritoneal Dialysis With Parathyroidectomy, Intensification of Dialysis, and Sodium Thiosulphate-A Case Report and Literature Review

Calcific uremic arteriolopathy, commonly referred to as “calciphylaxis,” is a rare life-threatening condition observed in patients with chronic kidney disease and end-stage renal disease on dialysis. This results in necrotic, ischemic, tender dermal lesions anywhere in the body, but mainly on the abdominal wall and lower extremities, where subcutaneous tissue is abundant. Histologically, it is defined by calcification in dermal capillaries, arterioles, and subcutaneous adipose tissues. It can occur in all advanced stages of chronic kidney disease as well as end-stage renal disease patients on hemodialysis or peritoneal dialysis. Our case highlights a successful case of calciphylaxis in a young female patient who underwent parathyroidectomy and intensification of peritoneal dialysis regimen along with the infusion of sodium thiosulphate injection resulting in complete resolution of the lesion in 3 months. With limited evidence of treatment options and increased frequency of this condition in a dialysis patient, our case highlights the key aspects of calciphylaxis management in a young end-stage renal disease patient who didn’t need a change of dialysis modality. We also review the risk factors and current practiced management options of this condition in our article.

A Scoping Review of Alternative Anticoagulation Strategies for Hemodialysis Patients with a Mechanical Heart Valve

INTRODUCTION

Patients with end-stage renal disease (ESRD) have high rates of cardiac valvulopathy but can develop contraindications for vitamin K antagonist (VKA) therapy. We explored the evidence for alternative anticoagulation strategies in patients with ESRD with a contraindication for VKA therapy.

METHODS

A scoping review was completed, searching MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Conference abstracts from inception to March 30, 2021. The study population was patients with ESRD who were on VKA therapy and developed a contraindication to VKA therapy use. All data regarding studies, patient characteristics, anticoagulation strategy, and clinical outcomes were summarized.

RESULTS

Twenty-three articles met inclusion criteria. These articles included 57 patients. Contraindications to VKA therapy included calcific uremic arteriolopathy (CUA) (n = 55) and warfarin-induced skin necrosis (n = 2). All studies were either case reports or case series. There were 10 anticoagulation strategies identified. Continuation of VKA therapy was associated with increased death and decreased rates of CUA resolution (80.0% and 10.0%, respectively), compared to apixaban (24.0% and 70.8%), subcutaneous (SC) low-molecular-weight heparin (LMWH) (14.3%, 85.7%), and SC unfractionated heparin (0.0%, 100.0%). While only 5 patient cases were reported with mechanical heart valves, SC LMWH use has been reported in this context with good outcomes.

CONCLUSIONS

In patients with ESRD who develop a contraindication to VKA therapy, several alternative anticoagulation strategies have been reported with superior outcomes to VKA continuation. While outcomes appear superior to continuation of VKA therapy, more data are required before definitive recommendations can be made for the patient with ESRD and a mechanical heart valve.

Nonuremic Calciphylaxis Associated With Hypercalcemia and Rheumatologic Diseases

Calcific uremic arteriolopathy, termed calciphylaxis, was previously considered a condition that developed mostly in patients requiring dialysis. It has now been described in kidney transplant patients, in advanced chronic kidney disease (CKD) patients not requiring dialysis, and in individuals with maintained kidney function. We describe an individual with CKD stage 3b with hypercalcemia who presented with features highly specific for calciphylaxis based on results of a skin biopsy. The condition has high morbidity and mortality, and thus prompts immediate cessation of the offending agents or treatment of the cause. The following case and literature review demonstrates a need for a detailed assessment of patients’ risks and exposures and expanding the differential diagnosis to include calciphylaxis in nonuremic patients with necrotic ulcers with a plan for early imaging and possible biopsy.

Hepatic and Vascular Vitamin K Status in Patients with High Cardiovascular Risk

Vitamin K dependent proteins (VKDP), such as hepatic coagulation factors and vascular matrix Gla protein (MGP), play key roles in maintaining physiological functions. Vitamin K deficiency results in inactive VKDP and is strongly linked to vascular calcification (VC), one of the major risk factors for cardiovascular morbidity and mortality. In this study we investigated how two vitamin K surrogate markers, dephosphorylated-undercarboxylated MGP (dp-ucMGP) and protein induced by vitamin K absence II (PIVKA-II), reflect vitamin K status in patients on hemodialysis or with calcific uremic arteriolopathy (CUA) and patients with atrial fibrillation or aortic valve stenosis. Through inter- and intra-cohort comparisons, we assessed the influence of vitamin K antagonist (VKA) use, vitamin K supplementation and disease etiology on vitamin K status, as well as the correlation between both markers. Overall, VKA therapy was associated with 8.5-fold higher PIVKA-II (0.25 to 2.03 AU/mL) and 3-fold higher dp-ucMGP (843 to 2642 pM) levels. In the absence of VKA use, non-renal patients with established VC have dp-ucMGP levels similar to controls (460 vs. 380 pM), while in HD and CUA patients, levels were strongly elevated (977 pM). Vitamin K supplementation significantly reduced dp-ucMGP levels within 12 months (440 to 221 pM). Overall, PIVKA-II and dp-ucMGP showed only weak correlation (r2 ≤ 0.26) and distinct distribution pattern in renal and non-renal patients. In conclusion, VKA use exacerbated vitamin K deficiency across all etiologies, while vitamin K supplementation resulted in a vascular VKDP status better than that of the general population. Weak correlation of vitamin K biomarkers calls for thoughtful selection lead by the research question. Vitamin K status in non-renal deficient patients was not anomalous and may question the role of vitamin K deficiency in the pathogenesis of VC in these patients.

Secondary Hyperparathyroidism in Chronic Kidney Disease: Pathophysiology and Management

Serum calcium concentration is the main determinant of parathyroid hormone (PTH) release. Defect in the activation of vitamin D in the kidneys due to chronic kidney disease (CKD) leads to hypocalcemia and hyperphosphatemia, resulting in a compensatory increase in parathyroid gland cellularity and parathyroid hormone production and causing secondary hyperparathyroidism (SHP). Correction and maintenance of normal serum calcium and phosphate are essential to preventing SHP, hungry bone disease, cardiovascular events, and anemia development. Understanding the pathophysiology of PTH and possible therapeutic agents can reduce the development and associated complications of SHP in patients with CKD. Medical interventions to control serum calcium, phosphate, and PTH such as vitamin D analogs, calcium receptor blockers, and parathyroidectomy are needed in some CKD patients. In this review, we discuss the pathophysiology, clinical presentation, and management of SHP in CKD patients.

Non-Uremic Calciphylaxis: An Unexpected Complication With Recombinant Human Parathyroid Hormone

Calciphylaxis is a rare syndrome of calcific microvascular occlusion, whereas non-uremic calciphylaxis (NUC) is a subset of this disease in which renal impairment is not observed. Recombinant human parathyroid hormone (rhPTH) (1-84) is a medication approved for the management of hypocalcemia in patients with hypoparathyroidism. We present a case report of a 38-year-old woman with postoperative hypoparathyroidism treated with rhPTH who subsequently developed calciphylactic lesions on her abdomen. Multidisciplinary interventions included intravenous and intralesional sodium thiosulfate therapy, laboratory monitoring, dermatological wound care, and pain management. Calciphylaxis can rarely be precipitated by rhPTH due to its effect on calcium and phosphorus balance even in the setting of normal renal function. The use of calcium and calcitriol supplementation, complicated by factors such as female sex and obesity, may have contributed in this patient’s case. Hence, regular follow-up with tapering off of calcium and calcitriol supplementation is important in patients receiving rhPTH.

[Interdisciplinary aspects of oral anticoagulation with NOACs in atrial fibrillation]

Stroke prophylaxis with non-vitamin K-dependent oral anticoagulants (NOAKs) in patients with non-valvular atrial fibrillation (nvVHF) is now firmly established in routine clinical practice. The definition of nvVHF includes the absence of a mechanical heart valve and AF not associated with moderate- or high-grade mitral valve stenosis. The management of oral anticoagulation (OAC) requires a high degree of interdisciplinarity. Not least for this reason, uncertainties are repeatedly observed in practice, which can have far-reaching consequences for the individual patient. For this reason, a committee consisting of representatives from general medicine, geriatrics, cardiology, nephrology and neurology has gathered to identify aspects of practical relevance from the various disciplines and to jointly develop practical guidelines to improve therapy safety for patients in everyday life.

Old and New Drugs for the Management of Bone Disorders in CKD

Disturbances in mineral and bone metabolism are common in patients with chronic kidney disease (CKD), especially those undergoing dialysis. Renal osteodystrophy, which describes an alteration of bone morphology, is an important component of this systemic disorder and may explain the elevated risk of fracture which adversely affects morbidity and mortality. The most common form of renal osteodystrophy is high-turnover bone disease (osteitis fibrosa), which is induced by secondary hyperparathyroidism (SHPT). During the past decade, there has been considerable advances in the management of SHPT, with the introduction of the calcimimetic agents, the optimized use of nutritional and active vitamin D, and the accumulated experience with surgical parathyroidectomy. Studies supported that these advances could translate into improvement of renal bone disease and fracture prevention, as well as decreasing the risk of cardiovascular events and mortality. In this review, we summarize the available clinical evidence on the effect of old and new drugs on bone disorders in patients with CKD.

Multiple extremity necrosis in fatal calciphylaxis: Case report

INTRODUCTION

The clinical impact of vascular calcification is well established in the context of cardiovascular morbidity and mortality, but other clinical syndromes, such as calciphylaxis, although less frequent, have a significant impact on chronic kidney disease.

METHODS

Case report of a 27-year-old woman, who had complained of bilateral pain in her toes for 3 days, with the presence of small necrotic areas in the referred sites. She had a history of type 1 diabetes (25 years ago), with chronic kidney disease, on peritoneal dialysis, in addition to rheumatoid arthritis. She was admitted to the hospital, which preceded the current condition, due to exacerbation of rheumatoid arthritis, evolving with intracardiac thrombus due to venous catheter complications, when she started using warfarin. Ischemia progressed to her feet, causing the need for bilateral amputations. Her chirodactyls were also affected. Thrombophilia, vasculitis, endocarditis or other embolic sources were investigated and discarded. Her pathology report evidenced skin necrosis and superficial soft parts with recent arterial thrombosis, and Monckeberg's medial calcification. We started treatment with bisphosphonate and sodium thiosulfate, conversion to hemodialysis and replacement of warfarin with unfractionated heparin. Despite all the therapy, the patient died after four months of evolution.

DISCUSSION

Calciphylaxis is a rare microvasculature calcification syndrome that results in severe ischemic injuries. It has pathogenesis related to the mineral and bone disorder of chronic kidney disease combined with the imbalance between promoters and inhibitors of vascular calcification, with particular importance to vitamin K antagonism.

CONCLUSION

The preventive strategy is fundamental, since the therapy is complex with poorly validated effectiveness.

New-onset acute rapidly deteriorating case of calciphylaxis after open heart surgery: a case report

Background 

Calciphylaxis is a rare life-threatening condition that is characterized by calcification of small blood vessels and soft tissues. This condition is classically described in uraemic patients with end-stage renal failure who are on dialysis or had previous renal transplant. It has also been reported in non-uraemic patients and those who are on warfarin therapy. It is typically associated with high calcium/phosphorus product. Patients classically present with painful skin lesion that evolve into painful ulcers. There are multiple risk factors that were reported to trigger or worsen calciphylaxis. Treatment is a multidisciplinary approach that involves elimination of risk factors, wound management, pain control, and optimization of calcium/phosphorus metabolism. Reported mortality rates are very high especially in the uraemic group.

Case summary 

Here we present a case of a patient, who is on chronic renal dialysis for stage renal failure, who underwent mechanical mitral valve replacement and tricuspid valve repair. In the perioperative period, she was exposed to multiple risk factors that are known to potentially trigger prophylaxis. In the early postoperative period, she developed new-onset rapidly deteriorating skin lesions and the histopathological diagnosis confirmed calciphylaxis. Her treatment plan included pain control, frequent wound care, and optimization of nutritional and metabolic status.

Discussion 

Calciphylaxis is a very serious condition that is usually associated with poor outcome. In this case, we discuss the unusual presentation of this condition with particular emphasis on the multiple perioperative risk factors that can potentially trigger the onset of calciphylaxis in postoperative cardiac patients. We also discuss the epidemiology, pathogenesis, diagnosis, histopathological findings, and different lines of treatment of this serious condition and the potential preventative strategies.

Risk factors for calciphylaxis in Chinese hemodialysis patients: a matched case-control study

Introduction

Calciphylaxis is a rare but potentially fatal disease commonly occurred in dialysis patients. Despite some previous studies on risk factors for calciphylaxis, there is still a lack of data from Chinese population.

Methods

The retrospective matched case–control study about calciphylaxis was performed in Zhongda Hospital affiliated to Southeast University. The case group involved 20 hemodialysis patients who were newly diagnosed with calciphylaxis from October 2017 to December 2018. The 40 noncalciphylaxis patients undergoing dialysis with the same age and duration of dialysis were randomly selected as controls.

Results

Most of calciphylaxis patients were male and elderly, while overweight people were more susceptible to the disease. Although incidence of secondary hyperparathyroidism was higher in calciphylaxis patients, the differences in duration of elevated serum intact parathyroid hormone (iPTH) and its highest value did not reach statistical significance compared with controls. No significant difference in warfarin therapy was discernible between two groups. The univariate regression analysis indicated that male, score of use of activated vitamin D and its analogues, corrected serum calcium level, serum phosphate, Ca × P product, iPTH, albumin, and alkaline phosphatase (ALP) level were significantly associated with calciphylaxis. Elevated levels of serum phosphate (OR 4.584, p = 0.027) and ALP (OR 1.179, p = 0.036), decreased level of serum albumin (OR 1.330, p = 0.013) were independent risk factors after multivariate analysis.

Conclusion

This is the first report of risk factors associated with calciphylaxis in China. Increased levels of serum phosphate and ALP, decreased level of serum albumin were vital high-risk factors for calciphylaxis in Chinese hemodialysis population.

Calciphylaxis in end-stage kidney disease: outcome data from the United Kingdom Calciphylaxis Study

BACKGROUND AND AIMS

Calciphylaxis is a rare condition associated with very high mortality in patients with end-stage kidney disease. Data from country-based registries have been an invaluable resource for a better understanding of the natural history and management for this condition. This study aimed to investigate the current management strategies and outcomes of patients enrolled in the United Kingdom Calciphylaxis study (UKCS).

METHODS

The study was conducted on 89 patients registered in the UKCS since 2012. The initial analysis included a description of the baseline characteristics, management strategies and outcomes on follow-up until May 2020. Further analysis included a comparison of the mortality outcome of the UKCS patients who were receiving haemodialysis with a propensity score matched cohort of haemodialysis patients from the Chronic Renal Insufficiency Standards Implementation Study- Haemodialysis (CRISIS-HD).

RESULTS

Median age of the cohort was 59 years, with a predominance of females (61%) and Caucasian (95%) ethnicity. About 54% of the patients were diabetic and 70% were receiving haemodialysis at study entry. The skin lesions were mostly distributed in the lower extremities (48%). Sodium thiosulphate and calcimimetic were the most widely used management strategies. The mortality rate was 72 deaths per hundred patient-years (50 deaths observed in 69.5 patient years). Complete wound healing was noted in 17% and bacteraemia was reported in 26% of patients. In a comparative analysis of the matched haemodialysis patients, the presence of calciphylaxis in 62 patients showed a strong association with all-cause mortality (HR 6.96; p < 0.001), with annual mortality 67% versus 10.2% in haemodialysis patients without calciphylaxis.

CONCLUSIONS

This UK wide study strengthens the evidence that calciphylaxis is a strong and independent risk factor associated with all-cause mortality; no significant benefit was shown with any individual treatment modality. Until further evidence becomes available, a multifaceted approach would be the appropriate treatment strategy in the management of this extremely serious condition.

Surgical Management of Secondary Hyperparathyroidism

Secondary hyperparathyroidism (SHPT) affects a majority of patients with chronic kidney disease (CKD) of stage 3 or worse. Despite the development of calcimimetics and their effectiveness in treating SHPT, many patients continue to fail medical management and should be referred to a parathyroid surgeon. In this narrative review, we summarize the indications for surgical referral, preoperative planning, intraoperative strategies to guide resection, and postoperative management. In the absence of universal guidelines, it can be difficult to determine when it is appropriate to make this referral. The majority of studies evaluating parathyroidectomy (PTX) for SHPT use the criteria of parathyroid hormone level (PTH) >800 pg/ml with hypercalcemia and/or hyperphosphatemia, which may be accompanied by symptoms such as bone pain and pruritis that can improve after surgery. Although the reported utility of the various imaging modalities (i.e., 99m-technetium-sestamibi scintigraphy with computed tomography [SPECT/CT], CT, or ultrasound) is highly variable in SHPT, SPECT/CT appears to be the most sensitive. Intraoperatively, PTH monitoring is effective in predicting long-term cure of SHPT but not in predicting hypoparathyroidism. Ectopic and supernumerary parathyroid glands are common in these patients and are often implicated in persistent or recurrent disease. Postoperatively, patients are at risk of severe hypocalcemia and hungry bone syndrome requiring close monitoring and replenishment.

Warfarin-Induced Calciphylaxis in a COVID-19 Patient

Calciphylaxis is a rare but highly fatal vascular calcification disorder with a predilection for patients with end stage renal disease (ESRD). The pathogenesis of calciphylaxis is unknown, however, several risk factors have been identified such as hypercalcemia, hyperphosphatemia, hyperparathyroidism, low serum albumin, and history of warfarin therapy. This article presents a case of calciphylaxis induced by warfarin in a COVID-19 patient.

Management of Cutaneous Calciphylaxis

Calciphylaxis is a deadly, painful disease with a 1-year mortality of up to 50%. The disease is commonly associated with patients with end-stage kidney disease (ESKD), but it can manifest in non-uremic patients as well. In patients who are undergoing dialysis, the incidence of calciphylaxis can range from 0.04% to 4%. The progressive arterial calcification seen in calciphylaxis can affect multiple body organs, including the skin, brain, lungs, and muscle. In cutaneous calciphylaxis, painful and non-healing nodules, plaques, and ulcers may appear, increasing morbidity for patients. Diagnosis can be difficult, and the condition can clinically appear similar to other dermatological diseases, especially in non-uremic patients. Currently, skin biopsy with histological analysis is the most reliable method to help diagnose the condition. In certain cases, the use of medical imaging may be helpful. Treatment of pain in this condition can be difficult and should be multimodal and include wound care as well as modification of risk factors. Analgesic options include opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), as well as analgesic options that are targeted for specific patients. There are currently multiple clinical trials underway that are studying targeted therapies for this condition.

The Role of Sclerostin in Bone and Ectopic Calcification

Sclerostin, a 22-kDa glycoprotein that is mainly secreted by the osteocytes, is a soluble inhibitor of canonical Wnt signaling. Therefore, when present at increased concentrations, it leads to an increased bone resorption and decreased bone formation. Serum sclerostin levels are known to be increased in the elderly and in patients with chronic kidney disease. In these patient populations, there is a high incidence of ectopic cardiovascular calcification. These calcifications are strongly associated with cardiovascular morbidity and mortality. Although data are still controversial, it is likely that there is a link between ectopic calcification and serum sclerostin levels. The main question, however, remains whether sclerostin exerts either a protective or deleterious role in the ectopic calcification process.

Calciphylaxis epidemiology, risk factors, treatment and survival among French chronic kidney disease patients: a case-control study

Background

Calcific Uremic Arteriolopathy (CUA) is a rare disease, causing painful skin ulcers in patients with end stage renal disease. Recommendations for CUA management and treatment are lacking.

Methods

We conducted a retrospective cohort study on CUA cases identified in western France, in order to describe its management and outcome in average clinical practices. Selection was based on the Hayashi diagnosis criteria (2013) extended to patients with eGFR < 30 mL/min/1.73m². Dialyzed CUA cases were compared with 2 controls, matched for age, gender, region of treatment and time period.

Results

Eighty-nine CUA cases were identified between 2006 and 2016, including 19 non dialyzed and 70 dialyzed patients. Females with obesity (55.1%) were predominant. Bone mineral disease abnormalities, inflammation and malnutrition (weight loss, serum albumin decrease) preceded CUA onset for 6 months. The multimodal treatment strategy included wound care (98.9%), antibiotherapy (77.5%), discontinuation of Vitamin K antagonists (VKA) (70.8%) and intravenous sodium thiosulfate (65.2%). 40.4% of the patients died within the year after lesion onset, mainly under palliative care. Surgical debridement, distal CUA, localization to the lower limbs and non calcium-based phosphate binders were associated with better survival. Risks factors of developing CUA among dialysis patients were obesity, VKA, weight loss, serum albumin decrease or high serum phosphate in the 6 months before lesion onset.

Conclusion

CUA involved mainly obese patients under VKA. Malnutrition and inflammation preceded the onset of skin lesions and could be warning signs among dialysis patients at risk.

Trial registration

ClinicalTrials.gov identifier NCT02854046, registered August 3, 2016.

Calciphylaxis in a Patient on Home Hemodialysis

Calciphylaxis is a rare and severe complication characterized by calcification of arterioles and capillaries in the dermis and subcutaneous adipose tissue that leads to ischemia, necrosis, and painful skin lesions in patients with end-stage renal disease (ESRD). It is also known as calcific uremic arteriolopathy. Calciphylaxis occurs most commonly with the ESRD with skin ulceration as a predominant presenting feature. Calcium-phosphorus dysregulation in dialysis patients are traditionally considered as a risk factor for the development of calciphylaxis. The involvement of an integrated interdisciplinary and multifaceted approach is key to the success of the calciphylaxis treatment. We present a case of a 51-year-old female with ESRD on home hemodialysis who developed calciphylaxis, which was successfully managed with increasing dialysis prescription, diligent wound care, and sodium thiosulfate infusion. Management of calciphylaxis in a patient receiving home hemodialysis has never been reported as per the review of the literature. Calciphylaxis is a sporadic disease, frequently encountered in the patients undergoing hemodialysis and carries a very grave prognosis. Current treatment is rarely effective, so preventive strategies play an important role by modifying the risk factors that promote the development of calciphylaxis.

Multidisciplinary management of calciphylaxis: a series of 5 patients at a single facility

Calciphylaxis is a rare and severe disease that manifests with painful skin ulceration and necrosis. Herein, we report five patients of hemodialysis patients with skin biopsy-proven calciphylaxis at a single facility. One patient had undergone parathyroidectomy (PTx) due to severe secondary hyperparathyroidism, four had been treated with vitamin D receptor activators, and two were on warfarin therapy. All patients had hyperphosphatemia, and one had hypercalcemia. The intact parathyroid hormone level at diagnosis was 2 pg/ml in the patient after PTx, while three patients were within the target range. The average period after diagnosis of calciphylaxis was 2 months. Skin lesions were present on the thighs and lower legs in two patients, and on the dorsum of the foot in one patient. In skin biopsy, calcification was found in the arteriolar media in four patients, and calcium (Ca) was deposited in the dermal lesion in one patient. All patients received local cures, surgical debridement, antibiotics to control infectious diseases, and strict control of serum Ca and phosphate. Calcimimetics were used in all patients except one who had undergone PTx one month before, sodium thiosulfate was used in 4 patients, and low Ca dialysate was used in three patients. The average follow-up period was 7.4 months. Four patients were cured, and one died due to infection. We suggest that multidisciplinary management for infectious diseases, surgical debridement, strict control of mineral and bone markers from the early stage, and elimination of risk factors may improve the course of calciphylaxis, which is a life-threatening disease.

On the role of skin biopsy in the diagnosis of calcific uremic arteriolopathy: a case-based discussion

Calciphylaxis is a rare disease characterized by ectopic calcification of skin arterioles resulting in ischemia, thrombosis and necrosis. Since end stage renal disease patients are those mainly affected, the term calcific uremic arteriolopathy (CUA) is also suggested. Early clinical manifestations are subtle, while overt necrotic ulcers may quickly spread and become infected so as to result in ominous outcome. Diagnosis might not be easy due to the number of other ischemic and non-ischemic skin lesions observed in uraemia. Skin biopsy, has been proposed as the diagnostic test and is often considered, but not systematically performed due to the hypothetical risk of further spreading of the lesions. Such ambiguity could be responsible for misdiagnosis or underdiagnosis. We review here five consecutive cases recorded in our Unit, all submitted to skin biopsy but with inconsistent results which generated some clinical frustration. Thus, we decided to carefully re-evaluate all of them together with pathologists and dermatologists. However, even after this ex-post discussion, we could not reach a complete agreement on the final diagnosis. In the meanwhile, papers were published in the literature that started to shed some light on the role of skin biopsy in the diagnosis of CUA.

Improvement in wound healing, pain, and quality of life after 12 weeks of SNF472 treatment: a phase 2 open-label study of patients with calciphylaxis

BACKGROUND

Calciphylaxis in end-stage renal disease is characterized by painful necrotic skin ulcers and high mortality. There are no approved therapies. SNF472, an intravenous formulation of myo-inositol hexaphosphate, inhibits the formation and growth of hydroxyapatite crystals, the final common pathway in the pathogenesis of vascular calcification.

METHODS

In this open-label, single-arm study, calciphylaxis patients on thrice-weekly hemodialysis and standard care, received intravenous SNF472 3 times per week for 12 weeks. The primary endpoint was wound healing assessed using the quantitative Bates-Jensen Wound Assessment Tool (BWAT). Pain visual analog scale (VAS), quality of life (wound-QoL), and qualitative wound image review were secondary endpoints. Quantitative changes from baseline were analyzed by paired t-tests using multiple imputation to account for missing observations.

RESULTS

Fourteen patients received SNF472. Improvements from baseline to week 12 were observed for mean BWAT score (- 8.1; P < 0.001), pain VAS (- 23.6 mm; P = 0.015) and wound-QoL global score (- 0.90; P = 0.003). Of the 9 patients with ulcerated lesions at baseline who completed treatment, wound image review showed improvement for 7. SNF472 was well tolerated with no serious treatment-related adverse events. The most common adverse events were infections which occur frequently in patients on hemodialysis. None of these were considered as treatment-related.

CONCLUSIONS

SNF472 was well-tolerated and improvements from baseline to week 12 in wound healing, pain, and quality of life were observed. A randomized, double-blind, placebo-controlled trial is planned to evaluate SNF472 in patients with calciphylaxis.

Parathyroidectomy as a Cure for Calciphylaxis in a Non-Dialysis Chronic Kidney Disease Patient?

Patient: Male, 61

Final Diagnosis: Calciphylaxis

Symptoms: Finger pain

Medication: —

Clinical Procedure: Subtotal parathyroidectomy

Specialty: Nephrology

Correlation between clinical and pathological features of cutaneous calciphylaxis

Calciphylaxis is a rare and life-threatening disease that classically manifests with painful skin lesions. It occurs mainly in patients with end-stage renal disease (ESRD) treated with dialysis, has poor outcomes, and has no FDA-approved treatment. Our cohort study aims to examine the clinical and pathological features of calciphylaxis and investigates the correlation between cutaneous clinical manifestations and histopathological findings. Data from 70 calciphylaxis patients who were evaluated at the Massachusetts General Hospital between January 2014 and April 2018 were collected from the institutional electronic database. The median age was 58 years (interquartile range [IQR]: 49–69 years), 60% were women, and 73% were of white race. Most (74%) patients reported severe pain at the time of calciphylaxis diagnosis with a median pain intensity score of 8/10 (IQR: 6–10) on a 0–10 pain scale. The median time from symptom onset to clinical diagnosis was 9 weeks (IQR: 6–16 weeks). The majority (87%) of patients presented with open necrotic wounds (advanced stage lesion) at the time of diagnosis. Common cutaneous clinical features included ulceration (79%), induration (57%), and erythema (41%), while common pathological features included cutaneous microvascular calcification (86%) and necrosis (73%). The presence of fibrin thrombi in skin biopsies was associated with pain severity (p = 0.04). The stage of a skin lesion positively correlated with the presence of necrosis on histological analyses (p = 0.02). These findings have implications for improving understanding of calciphylaxis origins and for developing novel treatments.

The Perfect Storm: A Case of Non-Uremic Calciphylaxis

Calciphylaxis is a severe condition associated with chronic kidney disease. We describe a rare case of non-uremic calciphylaxis in a 79-year-old woman with prosthetic aortic and mitral valves, chronic kidney disease and anaemia, who presented with painful skin lesions on her left leg. She was taking warfarin, calcium and iron supplements, and had been recently diagnosed with oligoarthritis and started on prednisolone, all factors associated with calciphylaxis. Despite treatment, the lesions rapidly progressed to large ulceration and sepsis, and pain management was challenging. Calciphylaxis was confirmed following a second skin biopsy but the patient died from septic shock and multi-organ failure. This case highlights the challenges associated with the diagnosis and treatment of calciphylaxis despite a high level of suspicion.

Phenprocoumon based anticoagulation is an underestimated factor in the pathogenesis of calciphylaxis

Background

Calciphylaxis is a life threatening complication in renal patients. Of great importance is the identification of concomitant factors for calciphylaxis. Due to the variability of clinical presentation the evaluation of such factors may be obscured when calciphylaxis diagnosis is based just on clinical features. We aimed to characterize associated factors only in patients with calciphylaxis proven by histomorphological parameters in addition to clinical presentation.

Methods

In a single center retrospective study we analyzed 15 patients in an 8 year period from 2008 to 2016. Only patients with clinical features and histomorphological proof of calciphylaxis were included. Criteria for histological diagnosis of calciphylaxis were intimal hyperplasia, micro thrombi or von Kossa stain positive media calcification.

Results

The mean age of patients was 64.8 years. Nine patients (60%) were female; 12 (80%) were obese with a Body-Mass-Index (BMI) > 30 kg/m²; 3 (20%) had no renal disease; 12 (80%) had CKD 4 or 5 and 10 (66.7%) had end-stage renal disease (ESRD). One-year mortality in the entire cohort was 73.3%.

With respect to medication history, the majority of patients (n = 13 (86.7%)) received vitamin K antagonists (VKA); 10 (66.7%) were treated with vitamin D; 6 (40%) had oral calcium supplementation; 5 (33.3%) had been treated with corticosteroids; 12 (80%) were on proton pump inhibitors (PPI); 13 (86.7%) patients had a clinical proven hyperparathyroidism. Ten (66.7%) patients presented with hypoalbuminemia at diagnosis.

Conclusions

The evaluation of biopsy proven calciphylaxis demonstrates that especially treatment with vitamin K antagonists and liver dysfunction are most important concomitant factors in development of calciphylaxis. As progression and development of calciphylaxis are chronic rather than acute processes, early use of DOACs instead of VKA might be beneficial and reduce the incidence of calciphylaxis.

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.

Impact of biobanks on research outcomes in rare diseases: a systematic review

Background

Alleviating the burden of rare diseases requires research into new diagnostic and therapeutic strategies. We undertook a systematic review to identify and compare the impact of stand-alone registries, registries with biobanks, and rare disease biobanks on research outcomes in rare diseases.

Methods

A systematic review and meta-aggregation was conducted using the preferred reporting items for systematic reviews and meta-analyses (the PRISMA statement). English language publications were sourced from PubMed, Medline, Scopus, and Web of Science. Original research papers that reported clinical, epidemiological, basic or translational research findings derived from data contained in stand-alone registries, registries with biobanks, and rare disease biobanks were considered. Articles selected for inclusion were assessed using the critical appraisal instruments by JBI-QARI. Each article was read in its entirety and findings were extracted using the online data extraction software from JBI-QARI.

Results

Thirty studies including 28 rare disease resources were included in the review. Of those, 14 registries were not associated to biobank infrastructure, 9 registries were associated with biobank infrastructure, and 6 were rare disease biobank resources. Stand-alone registries had the capacity to uncover the natural history of disease and contributed to evidence-based practice. When annexed to biobank infrastructure, registries could also identify and validate biomarkers, uncover novel genes, elucidate pathogenesis at the Omics level, and develop new therapeutic strategies. Rare disease biobanks in this review had similar capacity for biological investigations, but in addition, had far greater sample numbers and higher quality laboratory techniques for quality assurance processes.

Discussion

We examined the research outcomes of three specific populations: stand-alone registries, registries with biobanks, and stand-alone rare disease biobanks and demonstrated that there are key differences among these resources. These differences are a function of the resources’ design, aims, and objectives, with each resource having a distinctive and important role in contributing to the body of knowledge for rare disease research. Whilst stand-alone registries had the capacity to uncover the natural history of disease, develop best practice, replace clinical trials, and improve patient outcomes, they were limited in their capacity to conduct basic research. The role of basic research in rare disease research is vital; scientists must first understand the pathways of disease before they can develop appropriate interventions. Rare disease biobanks, on the other hand (particularly larger biobanks), had the key infrastructure required to conduct basic research, making novel Omics discoveries, identify and validate biomarkers, uncover novel genes, and develop new therapeutic strategies. However, these stand-alone rare disease biobanks did not collect comprehensive data or impact on clinical observations like a rare disease registry.

Rare disease research is important not only for rare diseases, but also for also common diseases. For example, research of low-density lipoprotein (LDL)-receptors in the rare disease known as familial hypercholesterolemia led to the discovery of statins, a drug therapy that is now used routinely to prevent heart disease.

Conclusions

Rare diseases are still under-researched worldwide. This review made the important observation that registries with biobanks had the function of both stand-alone registries (the capacity to collect comprehensive clinical and epidemiological data) and stand-alone rare disease biobanks (the ability to contribute to Omics research). We found registries with biobanks offer a unique, practical, cost-effective, and impactful solution for rare disease research. Linkage of stand-alone registries to rare disease biobanks will provide the appropriate resources required for the effective translation of basic research into clinical practice. Furthermore, facilitators such as collaboration, engagement, blended recruitment, pro-active marketing, broad consent, and “virtual biobank” online catalogues will, if utilised, add to the success of these resources. These important observations can serve to direct future rare diseases research efforts, ultimately improve patient outcomes and alleviate the significant burden associated with rare disease for clinicians, hospitals, society, and most importantly, the patients and their families.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0942-z) contains supplementary material, which is available to authorized users.

Non-uraemic calciphylaxis (NUC) postliver transplantation

Calciphylaxis is a rare and life-threatening disease characterized by cutaneous arteriolar stenosis and vascular thrombosis leading to skin ischaemia and necrosis. While calciphylaxis occurs mostly in patients with end-stage renal disease, the disorder has been described in patients with normal renal function, namely non-uraemic calciphylaxis (NUC). A 41-year-old African-American woman presented with a painful ulcerative rash on her thighs and right buttock 2 months after undergoing an orthotopic liver transplantation. She underwent debridement of the lesions and an excisional biopsy of one of the lesions, which revealed calciphylaxis. She was treated with sodium thiosulfate, cinacalcet and hyperbaric oxygen with complete resolution of the lesions 4-5 months after presentation. While she was treated with a course of high-dose glucocorticoids after the transplant, she did not have other risk factors for calciphylaxis. NUC should be considered in the differential diagnosis of necrotic skin lesions in postliver transplant patients.

Parathyroidectomy in the Management of Secondary Hyperparathyroidism

Secondary hyperparathyroidism develops in CKD due to a combination of vitamin D deficiency, hypocalcemia, and hyperphosphatemia, and it exists in nearly all patients at the time of dialysis initiation. There is insufficient data on whether to prefer vitamin D analogs compared with calcimimetics, but the available evidence suggests advantages with combination therapy. Calcium derangements, patient adherence, side effects, and cost limit the use of these agents. When parathyroid hormone level persists >800 pg/ml for >6 months, despite exhaustive medical interventions, monoclonal proliferation with nodular hyperplasia is likely present along with decreased expression of vitamin D and calcium-sensing receptors. Hence, surgical parathyroidectomy should be considered, especially if concomitant disorders exist, such as persistent hypercalcemia or hyperphosphatemia, tissue or vascular calcification including calciphylaxis, and/or worsening osteodystrophy. Parathyroidectomy is associated with 15%-57% greater survival in patients on dialysis, and it also improves hypercalcemia, hyperphosphatemia, tissue calcification, bone mineral density, and health-related quality of life. The parathyroidectomy rate in the United States declined to approximately seven per 1000 dialysis patient-years between 2002 and 2011 despite an increase in average parathyroid hormone levels, reflecting calcimimetics introduction and uncertainty regarding optimal parathyroid hormone targets. Hospitalization rates are 39% higher in the first postoperative year. Hungry bone syndrome occurs in approximately 25% of patients on dialysis, and profound hypocalcemia requires high doses of oral and intravenous calcium along with calcitriol supplementation. Total parathyroidectomy with autotransplantation carries a higher risk of permanent hypocalcemia, whereas risk of hyperparathyroidism recurrence is higher with subtotal parathyroidectomy. Given favorable long-term outcomes from observational parathyroidectomy cohorts, despite surgical risk and postoperative challenges, it is reasonable to consider parathyroidectomy in more patients with medically refractory secondary hyperparathyroidism.

Oral Anticoagulation in Chronic Kidney Disease and Atrial Fibrillation

BACKGROUND

Cardiological societies recommend, in their guidelines, that patients with atrial fibrillation and an intermediate (or higher) risk of stroke and systemic embolization should be treated with oral anticoagulant drugs. For patients who do not have mitral valve stenosis or a mechanical valve prosthesis, non-vitamin-K dependent oral anticoagulants (NOAC) are preferred over vitamin K antagonists (VKA) for this purpose. It is unclear, however, whether patients with chronic kidney disease and atrial fibrillation benefit from oral anticoagulation to the same extent as those with normal kidney function. It is also unclear which of the two types of anti - coagulant drug is preferable for patients with chronic kidney disease; NOAC are, in part, renally eliminated.

METHODS

This review is based on pertinent publications retrieved by a selective literature search, and on international guidelines.

RESULTS

Current evidence suggests that patients with atrial fibrillation who have chronic kidney disease with a glomerular filtration rate (GFR) above 15 mL/ min/1.73 m² should be treated with an oral anticoagulant drug if they have an at least intermediate risk of embolization, as assessed with the CHA2DS2-VASc score. For patients with advanced chronic kidney disease (GFR from 15 to 29 mL/ min/1.73 m²), however, this recommendation is based only on registry studies. For dialysis patients with atrial fibrillation, decisions whether to give oral anticoagulant drugs should be taken on an individual basis, in view of the elevated risk of hemorrhage and the unclear efficacy of such drugs in these patients. The subgroup analyses of the NOAC approval studies show that, for patients with atrial fibrillation and chronic kidney disease with a creatinine clearance of >25-30 mL/min, NOAC should be given in preference to VKA, as long as the patient does not have mitral valve stenosis or a mechanical valve prosthesis. For those whose creatinine clearance is less than 25 mL/min, the relative merits of NOAC versus VKA are still debated.

CONCLUSION

The cardiological societies' recommendation that patients with atrial fibrillation should be given oral anticoagulant drugs applies to the majority of such patients who also have chronic kidney disease.

Calciphylaxis

PURPOSE OF REVIEW

Calciphylaxis remains a poorly understood vascular calcification disorder with predilection for patients with end-stage renal disease (ESRD). Recent data from large patient registries and databases have begun to provide information regarding incidence, risk factors, and outcomes in patients with calciphylaxis.

RECENT FINDINGS

The most recent estimate places the incidence of calciphylaxis at 3.5 new cases/1000 patient-years among the patients with ESRD on chronic hemodialysis. It is possible that misdiagnosis or subclinical disease may attribute to lower than the true incidence. There is a suggestion that the incidence is higher in peritoneal dialysis patients compared with patients with hemodialysis. Recent studies have identified a number of risk factors and point to the effects of vitamin K deficiency mediated impairment in Matrix Gla Protein carboxylation as one of the likely pathogenic mechanisms. The outcomes in calciphylaxis patients remain poor with mortality approaching 30% at 6 months and 50% at 12 months.

SUMMARY

The present review describes recent literature in the field of calciphylaxis. Calciphylaxis registries and specimen biorepositories promise to provide insights into the pathogenesis of calciphylaxis and will pave the way for much needed clinical trials.

Multi-intervention management of calcific uremic arteriolopathy in 24 patients

Background

Calcific uremic arteriolopathy (CUA), also known as calciphylaxis, is a rare but life-threatening condition predominately occurring in patients with end-stage renal disease on dialysis. In the absence of randomized clinical trials to guide management, clinicians must rely on observational data. We have previously reported the outcomes of our multi-intervention management in seven patients and now present a larger series of patients with extended follow-up.

Methods

We performed a retrospective analysis of all patients diagnosed with CUA at a single academic center between 2008 and 2017. We identified 24 patients including 13 hemodialysis, 8 peritoneal dialysis and 3 predialysis Stage 5 chronic kidney disease patients.

Results

Mean age at diagnosis was 60.5 years (range 35–83) and mean follow-up 30.5 months (range <1–99). Patients were predominately female (71%) and Caucasian (83%) with diabetes mellitus diagnosed in 16 of 24 patients. Fifteen of 24 patients had ulcerating lesions suggestive of advanced disease and 20 of 24 had extensive involvement (bilateral disease or lesion size >5 cm). Treatment consisted of intensive hemodialysis (>20 h per week), sodium thiosulfate, wound care, analgesics and discontinuation of trigger medications including warfarin. Hyperbaric oxygen, cinacalcet, bisphosphonates and vitamin K were used in some cases. Overall 1 year mortality was 41% (9/22) and overall mortality at the end of follow-up was 64% (14/24). Cause of death was felt to be attributable to CUA in only four cases (16.7%). Complete or partial resolution of lesions occurred in 17 of 24 patients. One patient had recurrence of CUA 20 months after initial diagnosis.

Conclusions

Although mortality remains high in this group, direct CUA-attributable mortality is lower than historic reports. We conclude that a multi-intervention approach can be successful in treating a group of patients with severe CUA lesions.

Calciphylaxis in a dialysis patient successfully treated with high-dose vitamin K supplementation

Calciphylaxis has high mortality. Vitamin K deficiency is common in haemodialysis patients and may be a trigger for calciphylaxis due to its role in activating matrix Gla protein (a tissue inhibitor of calcification). We report the case of a 43-year-old female haemodialysis patient who developed calciphylaxis. Two months prior to the diagnosis she was found to have an undetectable plasma vitamin K concentration. The calciphylaxis completely resolved with vitamin K supplementation and an increase in haemodialysis frequency. She did not receive sodium thiosulphate or bisphosphonates. Supplementation of vitamin K in deficient patients may improve the outcome of this condition.