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.

Systematic review of sodium thiosulfate in treating calciphylaxis in chronic kidney disease patients

AIM

Calciphylaxis is a severe complication of advanced chronic kidney disease (CKD). Sodium thiosulphate (STS), an antioxidant and calcium chelating agent, has been used for the treatment of calciphylaxis. However, its efficacy and safety have not been systematically analysed and evaluated.

METHODS

MEDLINE, EMBASE, and the Cochrane Library database were systematically searched for case report or cases series on use of STS for calciphylaxis published between July 1974 and October 2016. We extracted data on clinical characteristics, laboratory tests result and medication use. The effective treatment was defined as improvement in skin lesion cicatrisation or pain relief without death. Non-responding effects were defined as stable skin lesions without remission or exacerbation of the disease in patients who remained alive. All-cause mortality after STS treatment was defined as death due to exacerbations of calciphylaxis or other complications of advanced CKD. We compared the baseline parameters of the patients as well as the efficacy and mortality of the STS therapy between case report and multi-case reports. Statistical analyses were performed using SPSS 19.

RESULTS

A total of 83 papers were screened, 45 of them (n = 358) met the inclusion criteria, including 36 case reports (n = 64) and nine multi-case reports (n = 294). The mean age of the patients with calciphylaxis was 58 ± 14 years (range 26-91 years). They were female predominant, accounting for 74.1%. Among the patients with calciphylaxis, 96.1% patients were on dialysis with median dialysis vintage of 44.5 months (range 24-84 months). STS was effective in 70.1% of patients, 37.6% patients died. The proportion of patients with sepsis was higher among those who received intravenous STS. There was no significant difference in efficacy between the different STS administration methods (P = 0.19).

CONCLUSION

Although the study was unable to assess the efficacy of sodium thiosulphate alone in the treatment of calciphylaxis, it still reveals a promising role of STS as an effective therapy for calciphylaxis. Further prospective studies to define the optimal therapy for calciphylaxis are needed.

Wound Healing in Patients With Impaired Kidney Function

Renal impairment has long been known to affect wound healing. However, information on differences in the spectrum of wound healing depending on the type of renal insufficiency is limited. Acute kidney injury (AKI) may be observed with different wound types. On one hand, it follows acute traumatic conditions such as crush injury, burns, and post-surgical wounds, and on the other hand, it arises as simultaneous targeting of skin and kidneys by autoimmune-mediated vasculitis. Chronic kidney disease (CKD) and end-stage renal disease (ESRD) often occur in older people, who have limited physical mobility and predisposition for developing pressure-related wounds. The common risk factors for poor wound healing, generally observed in patients with CKD and ESRD, include poorly controlled diabetes mellitus, neuropathy, peripheral vascular disease, chronic venous insufficiency, and aging. ESRD patients have a unique spectrum of wounds related to impaired calcium-phosphorus metabolism, including calciphylaxis, in addition to having the risk factors presented by CKD patients. Overall, there is a wide range of uremic toxins: they may affect local mechanisms of wound healing and also adversely affect the functioning of multiple systems. In the present literature review, we discuss the association between different types of renal impairments and their effects on wound healing and examine this association from different aspects related to the management of wounds in renal impairment patients.

Adipocyte induced arterial calcification is prevented with sodium thiosulfate

BACKGROUND

Calcification can occur in fat in multiple clinical conditions including in the dermis, breasts and in the abdomen in calciphylaxis. All of these are more common in patients with advanced kidney disease. Clinically, hyperphosphatemia and obesity are risk factors. Thus we tested the hypothesis that adipocytes can calcify in the presence of elevated phosphorus and/or that adipocytes exposed to phosphorus can induce vascular smooth muscle cell (VSMC) calcification.

METHODS

3T3-L1 preadipocytes were induced into mature adipocytes and then treated with media containing high phosphorus. Calcification was assessed biochemically and PCR performed to determine the expression of genes for osteoblast and adipocyte differentiation. Adipocytes were also co-cultured with bovine VSMC to determine paracrine effects, and the efficacy of sodium thiosulfate was determined.

RESULTS

The results demonstrated that high phosphorus induced the calcification of differentiated adipocytes with increased expression of osteopontin, the osteoblast transcription factor Runx2 and decreased expression of adipocyte transcription factors peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT-enhancer-binding protein α (CEBPα), indicating that high phosphorus led to a phenotypic switch of adipocytes to an osteoblast like phenotype. Sodium thiosulfate, dose dependently decreased adipocyte calcification and inhibited adipocyte induced increase of VSMC calcification. Co-culture studies demonstrated that adipocytes facilitated VSMC calcification partially mediated by changes of secretion of leptin and vascular endothelial growth factor (VEGF) from adipocytes.

CONCLUSION

High phosphorus induced calcification of mature adipocytes, and adipocytes exposed to elevated phosphorus can induce calcification of VSMC in a paracrine manner. Sodium thiosulfate inhibited this calcification and decreased the secretin of leptin and VEGF from adipocytes. These results suggest that adipocyte exposure to elevated phosphorus may be a pathogenic factor in calcification observed in the skin in calciphylaxis and other diseases.

The Successful Use of Apixaban in Dialysis Patients with Calciphylaxis Who Require Anticoagulation: A Retrospective Analysis

Calciphylaxis is a disease of dermal arteriolar calcification that results in necrosis. It commonly occurs in individuals with end-stage renal disease (ESRD) on hemodialysis and is associated with a high morbidity and mortality. Warfarin use is an identified risk factor. Twenty patients with ESRD on dialysis with calciphylaxis who were treated with apixaban for indications of deep vein thrombosis or atrial fibrillation were identified. There were no reports of thrombosis. Three individuals experienced bleeding requiring a transfusion, and anticoagulation was resumed without further event. Findings suggest that apixaban may be a safe and effective alternative to warfarin in patients with ESRD on dialysis with calciphylaxis.

Calciphylaxis and its diagnosis: A review

Calciphylaxis also known as Calcific uremic arteriolopathy (CUA), is a rare fatal complication usually associated with end-stage renal disease (ESRD). It is characterized by skin ulceration and necrosis leading to significant pain. The disease calciphylaxis is pathological state resulting in accumulation of calcium content in medial wall of small blood vessels along with the fibrotic changes in intima. The aetiopathogenesis of this disease, small vessel vasculopathy, remains complicated, and unclear. It is believed that development of calciphylaxis depends on medial calcification, intimal fibrosis of arterioles and thrombotic occlusion. The disease is rare, life-threatening medical condition that occurs mostly in population with kidney disease or in patients on dialysis. Skin biopsy and radiographic features are helpful in the diagnosis of calciphylaxis, but negative results do not necessarily exclude the diagnosis. This article highlights steps undertaking in the diagnosis of calciphylaxis.

Calciphylaxis and Kidney Disease: A Review

Calciphylaxis is a life-threatening complication most often associated with chronic kidney disease that occurs as a result of the deposition of calcium in dermal and adipose microvasculature. However, this condition may also be seen in patients with acute kidney injury. The high morbidity and mortality rates associated with calciphylaxis highlight the importance to correctly diagnose and treat this condition. However, calciphylaxis remains a diagnosis that may be clinically challenging to make. Here, we review the literature on uremic calciphylaxis with a focus on its pathophysiology, clinical presentation, advances in diagnostic tools, and treatment strategies. We also discuss the unique histopathological features of calciphylaxis and contrast it with those of other forms of general vessel calcification. This review emphasizes the need for multidisciplinary collaboration including nephrology, dermatology, and palliative care to ultimately provide the best possible care to patients with calciphylaxis.

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.

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.

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.

Role of Phosphate in Biomineralization

Inorganic phosphate is a vital constituent of cells and cell membranes, body fluids, and hard tissues. It is a major intracellular divalent anion, participates in many genetic, energy and intermediary metabolic pathways, and is important for bone health. Although we usually think of phosphate mostly in terms of its level in the serum, it is needed for many biological and structural functions of the body. Availability of adequate calcium and inorganic phosphate in the right proportions at the right place is essential for proper acquisition, biomineralization, and maintenance of mass and strength of the skeleton. The three specialized mineralized tissues, bones, teeth, and ossicles, differ from all other tissues in the human body because of their unique ability to mineralize, and the degree and process of mineralization in these tissues also differ to suit the specific functions: locomotion, chewing, and hearing, respectively. Biomineralization is a dynamic, complex, and lifelong process by which precipitations of inorganic calcium and inorganic phosphate divalent ions form biological hard tissues. Understanding the biomineralization process is important for the management of diseases caused by both defective and abnormal mineralization. Hypophosphatemia results in mineralization defects and osteomalacia, and hyperphosphatemia is implicated in abnormal excess calcification and/or ossification, but the exact mechanisms underlying these processes are not fully understood. In this review, we summarize available evidence on the role of phosphate in biomineralization. Other manuscripts in this issue of the journal deal with other relevant aspects of phosphate homeostasis, phosphate signaling and sensing, and disorders resulting from hypo- and hyperphosphatemic states.

Early stages of calciphylaxis: are skin biopsies the answer?

Calciphylaxis, nowadays called calcific uremic arteriolopathy (CUA), is a rare but life-threatening syndrome characterized by systemic medial calcification and arterial occlusion of the arterioles, leading to skin necrosis. Actually, the pathogenesis of CUA is complex and poorly understood. The vast majority of published cases presented with ulcers. We present a 71-year-old male who was referred to the Nephrology Department for evaluation and therapy for refractory edema of both legs. There were no subcutaneous plaques, ulcers or other focal lesions. We performed a deep skin biopsy of the thigh. After the biopsy, the patient developed necrosis around the sampling location. Diagnosing CUA in the early stages of the disease, however, is challenging. Should a skin biopsy be performed in the early stages of CUA in patients without ulcerations, knowing the risk of inducing ulcerations, or should an intensive treatment – after considering clinical manifestations, other noninvasive diagnostic tools (bone scan, X-ray mammography technique) and laboratory tests – be started? Although there are no specific diagnostic laboratory tests for CUA and the clinical manifestations of CUA are similar to those of other disorders, a skin biopsy is not routinely recommended to confirm the diagnosis of early-stage calciphylaxis.

Plant phosphates, phytate and pathological calcifications in chronic kidney disease

Phytate, or myo-inositol 1,2,3,4,5,6-hexakis dihydrogen phosphate (InsP6), is a naturally occurring phosphorus compound that is present in many foods, mainly legumes, whole grains and nuts. Patients with chronic kidney disease (CKD) have cardiovascular disease mortality up to 30times higher than the general population. Vascular calcifications (VCs) directly contribute to overall morbidity and mortality, especially in CKD. In part, this high mortality is due to elevated levels of phosphorus in the blood. Therefore, control of dietary phosphorus is essential. Dietary phosphorus can be classified according to its structure in organic phosphorus (plant and animal) and inorganic (preservatives and additives). Plant-phosphorus (legumes and nuts), mainly associated with InsP6, is less absorbable by the human gastrointestinal tract as the bioavailability of phosphorous from plant-derived foods is very low. Recent data indicate that restriction of foods containing plant phosphates may compromise the adequate supply of nutrients that have a beneficial effect in preventing cardiovascular events, such as InsP6 or fibre found in legumes and nuts. Experimental studies in animals and observational studies in humans suggest that InsP6 can prevent lithiasis and VCs and protect from osteoporosis. In conclusion, we need prospective studies to elucidate the potential benefits and risks of phytate (InsP6) through the diet and as an intravenous drug in patients on haemodialysis.

Calciphylaxis: a review

Human calciphylaxis reflects a form of severe tissue compromise attributable to a unique microangiopathy that combines features of vascular thrombotic occlusion with endoluminal calcification. While most frequently described in patients with renal failure, it is seen in other settings, such as multiple myeloma; polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome; cirrhosis; and rheumatoid arthritis. Although most commonly involving the skin, calciphylaxis can affect other organs including the heart and gastrointestinal tract, in which cases it falls under the appellation of systemic calciphylaxis. There are cases in which the main pathology is one of endovascular thrombosis of the vessels of the fat without discernible calcification or one manifesting a pseudoangiosarcomatous pattern, hence adding to the histomorphologic spectrum of calciphylaxis. A variety of factors contribute to this severe occlusive microangiopathy, including an underlying procoagulant state and ectopic neo-osteogenesis of the microvasculature through varied mechanisms, including increased osteopontin production by vascular smooth muscle or reduced synthesis of fetuin and GLA matrix protein, important inhibitors of ectopic neo-osteogenesis. Certain factors adversely affect outcome, including truncal and genital involvement and systemic forms of calciphylaxis. With a better understanding of its pathophysiology, more-effective therapies, such as sodium thiosulfate and biphosphanates to reduce reactive oxygen species and receptor activator of nuclear factor κβ-mediated nuclear factor κβ activity, respectively, are being developed.

Benefits of intralesional injections of sodium thiosulfate in the treatment of calciphylaxis

Calciphylaxis (CPX) is a rare calcifying thrombotic vasculopathy responsible for painful necrotic ulcers, with a high mortality rate, and its management is often difficult. Recently, intravenous infusions of sodium thiosulfate (STS) have shown efficacy. The aim of this study was to assess the efficacy of intralesional STS (IL STS) in four patients. Our aim was to assess the efficacy of IL STS in a prospective mono-centric open study that included four patients with a biopsy-proven cutaneous CPX. Four women (55-84 years old, mean age: 71·2 years) with a uremic (n = 1) or non-uremic CPX (n = 3) and primary hyperparathyroidism induced by teriparatide or after the initiation of oral anti-vitamin K were treated by IL STS (250 mg/ml). The injections were performed around the ulcers, on the active borders, once or twice a week and then at 1-2 weeks intervals. The injected quantity varied from 1·5 to 15 ml. Pain usually improved after two series of injections. Clinical response was visible after 2 weeks. Three patients (75%) healed completely or almost completely. A failure was observed in the last patient who also had lower limb arteriopathy. The main side effect was the pain during injections. IL STS is an interesting alternative therapeutic option in the management of CPX necrotic ulcers with limited side effects. Larger studies are warranted to precisely define its place, its administration procedure and the patients who could benefit from it.

Cardiovascular calcifications in chronic kidney disease: Potential therapeutic implications

Cardiovascular (CV) calcification is a highly prevalent condition at all stages of chronic kidney disease (CKD) and is directly associated with increased CV and global morbidity and mortality. In the first part of this review, we have shown that CV calcifications represent an important part of the CKD-MBD complex and are a superior predictor of clinical outcomes in our patients. However, it is also necessary to demonstrate that CV calcification is a modifiable risk factor including the possibility of decreasing (or at least not aggravating) its progression with iatrogenic manoeuvres. Although, strictly speaking, only circumstantial evidence is available, it is known that certain drugs may modify the progression of CV calcifications, even though a direct causal link with improved survival has not been demonstrated. For example, non-calcium-based phosphate binders demonstrated the ability to attenuate the progression of CV calcification compared with the liberal use of calcium-based phosphate binders in several randomised clinical trials. Moreover, although only in experimental conditions, selective activators of the vitamin D receptor seem to have a wider therapeutic margin against CV calcification. Finally, calcimimetics seem to attenuate the progression of CV calcification in dialysis patients. While new therapeutic strategies are being developed (i.e. vitamin K, SNF472, etc.), we suggest that the evaluation of CV calcifications could be a diagnostic tool used by nephrologists to personalise their therapeutic decisions.

Calciphylaxis: a rare but fatal delayed complication of Roux-en-Y gastric bypass surgery

Gastric bypass is a commonly used surgical procedure that has shown impressive health benefits for patients with morbid obesity. However, mineral bone abnormalities (hypocalcemia, hypovitaminosis D, and secondary hyperparathyroidism) and micronutrient (e.g., iron) deficiencies are common complications after gastric bypass surgery due to alterations in the digestive anatomy. These abnormalities, their treatments, and a number of other factors associated with obesity can set up a perfect storm to induce calciphylaxis, a rare but highly fatal condition with severe comorbid conditions. We present a fatal case of nonuremic calciphylaxis coincident with symptomatic hypocalcemia in a morbidly obese man with a history of Roux-en-Y gastric bypass surgery.

Calciphylaxis: from the disease to the diseased

Calciphylaxis, or calcific uremic arteriolopathy, is a vascular ossification-calcification disease involving cutaneous or visceral arterioles, with ischemic damage of the surrounding tissues, usually in the setting of chronic kidney disease. Pathogenesis is still unclear and probably comprises the participation of vascular smooth muscle cells, endothelial cells and macrophages surrounded by a uremic and/or pro-calcifying environment. According to the original concept of calcific uremic arteriolopathy coined by Hans Selye, risk factors may be divided into sensitizers and challengers and their knowledge is useful in clinical practice to pre-emptively identify both uremic and non-uremic 'at risk' patients and guide treatment. Systemic calcific uremic arteriolopathy is a rarity. Cutaneous calcific uremic arteriolopathy is more frequent and clinically presents as a first phase of cutaneous hardening and erythema, followed by a second phase of ulcerations and scars; these two phases are probably associated with the initial development of arteriolar lesion and tissue ischemic damage, respectively. Clinical history, physical examination, laboratory analysis, histology and imaging are the main tools to exclude important differential diagnoses and obtain a definitive diagnosis. Treatment is generally unrewarding and consists of rigorous control of comorbid conditions, anti-oxidant, anti-inflammatory and antithrombotic strategies, avoidance of iatrogeny and wound and pain management. Prognosis remains poor in terms of morbidity and mortality. Efforts should be made towards a greater awareness of calcific uremic arteriolopathy, development of better therapies and improvement of clinical outcomes.

Penile gangrene in diabetes mellitus with renal failure: A poor prognostic sign of systemic vascular calciphylaxis

Penile gangrene associated with chronic renal failure is very uncommon. A 52-year-old man with diabetes mellitus, diffuse atherosclerosis, ischemic cardiomyopathy and end-stage renal disease presented with blackening of distal penis for 10 days. His general condition was poor and gangrene of prepuce and glans was noted. Doppler and magnetic-resonance angiography revealed bilateral internal iliac artery obstruction. He underwent trocar suprapubic cystostomy and was planned for partial penectomy. But he died of severe diabetic complications in the interim period. Penile gangrene is a manifestation of widespread vascular calcifications associated with end-stage renal disease and is a marker of poor prognosis.

Calciphylaxis in patients with chronic kidney disease: A disease which is still bewildering and potentially fatal

Calciphylaxis, also known as calcific uraemic arteriolopathy, is a rare syndrome that typically causes skin necrosis and usually affects dialysis patients. Its pathogenesis is multifactorial and is the consequence of many factors causing ectopic calcifications in patients with chronic kidney disease, such as calcium-phosphate metabolism disorders, hyper- or hypo-parathyroidism, diabetes, obesity, systemic inflammation and the use of vitamin K antagonists, among others. From a clinical point of view, calciphylaxis may progress from painful purpura to extensive areas of skin necrosis that can potentially lead to superinfection and the death of the patient due to sepsis. Treatment is primarily based on managing the wounds, eliminating all the possible precipitating factors of ectopic calcification and administering agents which are capable of inhibiting the process of calcification.

Sodium thiosulfate as a treatment for calciphylaxis: A case series

BACKGROUND

Calciphylaxis is a rare disorder predominantly seen in patients with chronic kidney disease. Calcification of cutaneous vessels leads to extremely painful plaques and ulcerations. Mortality is high, sepsis being the leading cause of death. There is no standardized treatment. In the last years, administration of sodium thiosulfate (STS) has yielded some promising results.

METHODS

We retrospectively collected data of eight calciphylaxis patients treated with STS at the University Hospital of Leuven between June 2009 and June 2014.

RESULTS

Eight patients, of whom two without related renal risk factors, received STS treatment in different dosing schemes. Four patients (50%) achieved complete healing of skin lesions; two patients had only stabilization of the disease while experiencing pain relief. In the two remaining patients who had further progression of the disease, STS treatment led to analgesia in one patient. Overall, seven patients (87.5%) had some benefit from STS treatment. However, four patients (50%) eventually died due to causes related to calciphylaxis. STS was generally well tolerated, although almost all patients (87.5%) had metabolic acidosis.

CONCLUSIONS

Treatment of calciphylaxis remains challenging. Although STS therapy, together with other treatment modalities, seems to improve disease outcome, more studies focusing on optimal dosing schemes and duration of treatment are necessary.

Calciphylaxis: Approach to Diagnosis and Management

Calciphylaxis is a rare disorder of poor prognosis that can lead to intense, painful lesions involving the skin and subcutaneous tissue. Although mostly described in dialysis patients, it can affect patients with normal kidney function. The diagnosis of calciphylaxis is complicated by the absence of a gold standard marker of disease such as a clear histopathological finding. Late diagnosis and advanced lesions can significantly shorten life expectancy. Calciphylaxis wounds can have a major influence on the quality of life of patients, usually due to the immense unbearable pain these patients suffer from. The management of calciphylaxis mainly comprises aggressive wound care and symptomatic management. Therapeutic options are few and far between and are limited to off-label uses. Recent understanding of the pathogenesis of lesions has enabled development of novel therapeutic options, some of which are being studied in clinical trials (sodium thiosulfate, vitamin K). Vascular calcification and thrombosis underlie development of these lesions and research has been aimed at studying drugs that counteract such processes. Future research is required to establish clear causal pathways and improve on the treatment options currently available to patients.

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.

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.

Sodium thiosulfate is effective in calcific uremic arteriolopathy complicating chronic hemodialysis

BACKGROUND

Calcific uremic arteriolopathy (CUA) or calciphylaxis is a severe complication of advanced chronic kidney disease (CKD) and dialysis. Few effective treatments are available and the mortality rate is high. We report 4 cases in which sodium thiosulfate therapy was rapidly effective.

CASES

Sodium thiosulfate therapy was given to 4 Caucasian patients (3 females and 1 male aged 49 to 91 years) with CUA. The causes of end-stage CKD were nephroangiosclerosis (n=2) and diabetic nephropathy (n=2). The lesions developed 1 to 6.5 years after the initiation of hemodialysis and involved the lower limbs in 2 patients, the fingers in 1 patient, and a breast in the remaining patient. They were responsible for pain and skin necrosis in all 4 patients. Local superinfection occurred in 3 patients. Intravenous sodium thiosulfate was given in a dosage of 12.5 to 25g after each hemodialysis session, for 12 to 24 weeks. The pain and trophic disorders resolved fully in all 4 patients. The side effects consisted of nausea and vomiting (n=2) and a moderate blood pressure decrease (n=1). No recurrences were noted during the follow-up of 5 to 17 months after treatment discontinuation.

CONCLUSION

The findings from this small case-series suggest that sodium thiosulfate may hold promise for the treatment of CUA.