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

Multicenter retrospective analysis of sodium thiosulfate as treatment for non-uremic calciphylaxis

OBJECTIVES

To describe the results obtained in terms of effectiveness and safety of intravenous sodium thiosulfate in patients diagnosed with non-uremic calciphylaxis, to identify and analyse possible etiological factors of the disease, and to determine the associated morbidity and mortality.

METHOD

A multicenter and retrospective study was conducted with patients diagnosed with non-uremic calciphylaxis who received intravenous sodium thiosulfate between 2013 and 2023. Effectiveness was evaluated based on the status of the ulcers at the end of treatment, and safety was assessed according to the main reported adverse effects and the need for dosage adjustment.

RESULTS

A total of 33 patients from three university hospitals were evaluated (93.9% Caucasian, 78.8% women, mean age 80 [SD 8.1] years) with non-uremic calciphylaxis confirmed by skin biopsy. The localization pattern was 90.9% distal. The following complementary therapeutic measures were undertaken: topical wound care, removal of precipitating factors (mainly vitamin D supplements and vitamin K antagonists), medications to reduce calcification (bisphosphonates, cinacalcet), and techniques to promote ulcer healing. The main associated factors for developing calciphylaxis were: non-uremic chronic kidney disease (81.8%), vitamin D supplementation (72.7%), and hypoalbuminemia (66.7%). The most commonly used sodium thiosulfate dosage was 25 g (n = 26) three times per week (n = 28) intravenously, with a median treatment duration of 11.4 (IQR 5.7-18) weeks. A complete resolution or improvement of the ulcers was achieved in 78.8% of the cases. Adverse effects were observed in 96.7% of patients, with the most common being metabolic acidosis (n = 19) and nausea and/or vomiting (n = 18). Dosage adjustments due to toxicity were necessary in 9% of cases. The significant morbidity rate was 69.7% (n = 23). The main complications were: 57.6% ulcer superinfection and 24,3% poor pain control. The overall mortality rate was 66.7%; 42.4% within the first 6 months after diagnosis and 39.4% secondary to non-uremic calciphylaxis.

CONCLUSIONS

Sodium thiosulfate shows a potential benefit in the treatment of ulcers due to non-uremic calciphylaxis, with a similar safety profile to that reported for uremic calciphylaxis, considering the high morbidity and mortality associated with the condition. Further studies are needed to determine its efficacy and assess the specific contribution of the different treatments used.

Sodium Thiosulfate Treatment for Calciphylaxis: Is There an Optimal Duration of Therapy?

Calciphylaxis is a rare and serious disorder characterized by vascular calcification and occlusion of the microvessels in the dermis, subcutaneous adipose tissue, visceral organs, and musculature. Studies have suggested that the major risk factors for developing calciphylaxis are chronic kidney disease and secondary hyperparathyroidism. Its diagnosis is clinical, and the treatment includes a multidisciplinary approach, although there are no clinical protocols based on randomized clinical trials. Therefore, the management and treatment are informed by specialist opinion. Sodium thiosulfate is frequently utilized for its vasodilatory and antioxidant properties, as well as its ability to chelate calcium. However, there are no guidelines regarding the duration of its use. The present report describes a chronic kidney disease patient on hemodialysis with calciphylaxis, who underwent sodium thiosulfate treatment for 2 years associated with debridement and reconstructive plastic surgery with a good response and control of the disease.

Livedoid vasculopathy, calciphylaxis, and Martorell's hypertensive ulcer: update on ischemic ulcers due to impaired microcirculation of the lower limbs

Ischemic ulcers due to compromised microcirculation of the lower limbs cause painful ulcers that represent a challenge for the correct diagnosis and treatment. Livedoid vasculopathy, calciphylaxis, and Martorell's hypertensive ischemic ulcer are part of this group and present some similarities due to microvascular occlusive impairment. They are often misdiagnosed as inflammatory ulcers such as pyoderma gangrenosum and vasculitis. This review discusses the pathophysiology, risk factors, clinical aspects, differential diagnoses, histopathology, and presents a therapeutic update of livedoid vasculopathy, calciphylaxis, and Martorell's ulcer. Although they are less frequent causes of chronic ulcers, a correct diagnosis is essential to reduce the chance of erroneous therapies that may impact morbidity and mortality related to these conditions.

Clinical efficacy and safety of sodium thiosulfate in the treatment of uremic pruritus: a meta-analysis of randomized controlled trials

Uremic pruritus (UP) is a debilitating condition frequently associated with chronic kidney disease, severely impairing patients' quality of life and contributing to increased mortality. Recent studies have suggested that intravenous sodium thiosulfate (STS) may offer therapeutic relief for pruritus in patients undergoing hemodialysis. To assess its effectiveness, we conducted a systematic review and meta-analysis to explore the potential of intravenous STS in managing UP. A comprehensive search of electronic databases was performed up to September 2024 to identify randomized controlled trials evaluating the clinical efficacy of STS in treating UP. Eight studies, encompassing 520 participants, were included in the analysis. The findings indicated that the STS group achieved a significantly higher rate of pruritus suppression compared to control groups. The STS group showed a marked reduction in the Visual Analogue Scale (weighted mean difference = -5.023; 95% CI: -6.137 to -3.909; P < 0.001) and Pittsburgh Sleep Quality Index (weighted mean difference = -4.754; 95% CI: -5.432 to -4.075; P < 0.001). The STS group demonstrated a decrease in CRP levels compared to the non-treatment group in the context of treating UP (WMD = -1.269; 95% CI: -2.014 to -0.523; P = 0.007). No significant differences were observed between the STS and control groups regarding parathyroid hormone, serum calcium, or serum inorganic phosphorus. While this meta-analysis demonstrated a reduction in pruritus symptoms with STS administration, the evidence remains insufficient to conclusively support its therapeutic benefit in managing UP. Further well-designed studies with larger sample sizes are needed to confirm these findings.

Treatment of a patient with inoperable tumoral calcinosis associated with end stage kidney disease: A case report

We describe a case of severe symptomatic tumoral calcinosis in a young man with end stage kidney disease secondary to antineutrophil cytoplasmic antibodies-associated vasculitis with longstanding hyperphosphatemia and secondary hyperparathyroidism while on several years of peritoneal dialysis. The use of intravenous sodium thiosulfate, optimization of clearance with five times weekly hemodialysis, and intradialytic nutrition were used to treat his inoperable tumoral calcinosis. Over 3 months, he had a remarkable reduction in the size of his calcified masses and associated improvement in pain. He subsequently received a living donor kidney transplant.

Sodium Thiosulfate: An Innovative Multi-Target Repurposed Treatment Strategy for Late-Onset Alzheimer's Disease

Late-onset Alzheimer's disease (LOAD) is a chronic, multifactorial, and progressive neurodegenerative disease that associates with aging and is highly prevalent in our older population (≥65 years of age). This hypothesis generating this narrative review will examine the important role for the use of sodium thiosulfate (STS) as a possible multi-targeting treatment option for LOAD. Sulfur is widely available in our environment and is responsible for forming organosulfur compounds that are known to be associated with a wide range of biological activities in the brain. STS is known to have (i) antioxidant and (ii) anti-inflammatory properties; (iii) chelation properties for calcium and the pro-oxidative cation metals such as iron and copper; (iv) donor properties for hydrogen sulfide production; (v) possible restorative properties for brain endothelial-cell-derived bioavailable nitric oxide. Thus, it becomes apparent that STS has the potential for neuroprotection and neuromodulation and may allow for an attenuation of the progressive nature of neurodegeneration and impaired cognition in LOAD. STS has been successfully used to prevent cisplatin oxidative-stress-induced ototoxicity in the treatment of head and neck and solid cancers, cyanide and arsenic poisoning, and fungal skin diseases. Most recently, intravenous STS has become part of the treatment plan for calciphylaxis globally due to vascular calcification and ischemia-induced skin necrosis and ulceration. Side effects have been minimal with reports of metabolic acidosis and increased anion gap; as with any drug treatment, there is also the possibility of allergic reactions, possible long-term osteoporosis from animal studies to date, and minor side-effects of nausea, headache, and rhinorrhea if infused too rapidly. While STS poorly penetrates the intact blood-brain barrier(s) (BBBs), it could readily penetrate BBBs that are dysfunctional and disrupted to deliver its neuroprotective and neuromodulating effects in addition to its ability to penetrate the blood-cerebrospinal fluid barrier of the choroid plexus. Novel strategies such as the future use of nano-technology may be helpful in allowing an increased entry of STS into the brain.

Calciphylaxis: A Case Report and Review of the Role of Sodium Thiosulphate and Other Treatment Modalities

Calciphylaxis is a rare and serious disorder almost exclusively seen in patients on dialysis or those with advanced chronic kidney disease (CKD) not on dialysis and is associated with very high mortality. We present the case of a 50-year-old male with a background of end-stage renal disease (ESRD) compliant with dialysis, parathyroid adenoma, secondary hyperparathyroidism, and high body mass index (BMI). Whilst receiving 31 doses of intravenous sodium thiosulphate (STS) over an 11-week period, the patient underwent surgical debridement of multiple painful ulcerative lesions in his lower abdomen and left thigh and then subsequently a subtotal parathyroidectomy at 70 days from admission. Afterwards, he recovered from the surgery but became septic secondary to infection of calciphylaxis ulcers, later developed hospital-acquired pneumonia, and died with palliative care input. Despite intravenous STS being the most commonly used drug in the treatment of calciphylaxis, it did not provide symptomatic relief or clinical improvement to the patient in this case. As there is no consensus on treatment duration for optimal response, this prompts future studies on the use of STS in addition to alternative treatment modalities of calciphylaxis.

Vascular Calcification: Where is the Cure?

With the progress of aging, the incidence of vascular calcification (VC) gradually increases, which is correlated with cardiovascular events and all-cause death, aggravating global clinical burden. Over the past several decades, accumulating approaches targeting the underlying pathogenesis of VC have provided some possibilities for the treatment of VC. Unfortunately, none of the current interventions have achieved clinical effectiveness on reversing or curing VC. The purpose of this review is to make a summary of novel perspectives on the interventions of VC and provide reference for clinical decision-making.

Hydrogen Sulfide: A Versatile Molecule and Therapeutic Target in Health and Diseases

In recent years, research has unveiled the significant role of hydrogen sulfide (H2S) in many physiological and pathological processes. The role of endogenous H2S, H2S donors, and inhibitors has been the subject of studies that have aimed to investigate this intriguing molecule. The mechanisms by which H2S contributes to different diseases, including inflammatory conditions, cardiovascular disease, viral infections, and neurological disorders, are complex. Despite noteworthy progress, several questions remain unanswered. H2S donors and inhibitors have shown significant therapeutic potential for various diseases. This review summarizes our current understanding of H2S-based therapeutics in inflammatory conditions, cardiovascular diseases, viral infections, and neurological disorders.

Intravenous treatment of calcinosis cutis with sodium thiosulfate - A case series

Calcinosis cutis is defined as the deposition of calcium salts in the skin. The dystrophic form is the most common and usually occurs in chronic inflammatory processes associated with collagenoses. Therapeutic options include surgical excision as well as a few pharmacological treatments. Overall, the evidence for the known therapeutic interventions is very limited and there is a lack of valid recommendations. Intravenous sodium thiosulfate has been used successfully in the treatment of calciphylaxis. In our case series, five patients with dystrophic calcinosis cutis received intravenous sodium thiosulfate for at least six cycles on five consecutive days per month, with single doses of 12.5 g and 25.0 g, respectively. A reduction in the calcified lesions could not be proven with certainty, but stable disease conditions were achieved. Intravenous sodium thiosulfate may counteract the progression of calcinosis cutis. The successful use of epicutaneously applied sodium thiosulfate, as described in the literature, suggests that a higher cutaneous bioavailability can be achieved to exert a lytic effect on calcinosis cutis. This is further supported by the reported efficacy of high-dose sodium thiosulfate in the treatment of calciphylaxis.

Role of hydrogen sulfide in health and disease

In the past, hydrogen sulfide (H2S) was recognized as a toxic and dangerous gas; in recent years, with increased research, we have discovered that H2S can act as an endogenous regulatory transmitter. In mammals, H2S-catalyzing enzymes, such as cystathionine-β-synthase, cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase, are differentially expressed in a variety of tissues and affect a variety of biological functions, such as transcriptional and posttranslational modification of genes, activation of signaling pathways in the cell, and metabolic processes in tissues, by producing H2S. Various preclinical studies have shown that H2S affects physiological and pathological processes in the body. However, a detailed systematic summary of these roles in health and disease is lacking. Therefore, this review provides a thorough overview of the physiological roles of H2S in different systems and the diseases associated with disorders of H2S metabolism, such as ischemia-reperfusion injury, hypertension, neurodegenerative diseases, inflammatory bowel disease, and cancer. Meanwhile, this paper also introduces H2S donors and novel release modes, as well as the latest preclinical experimental results, aiming to provide researchers with new ideas to discover new diagnostic targets and therapeutic options.

Hexasodium fytate for the treatment of calciphylaxis: a randomised, double-blind, phase 3, placebo-controlled trial with an open-label extension

Background

In the CALCIPHYX trial, we investigated hexasodium fytate, an inhibitor of vascular calcification, for the treatment of calcific uraemic arteriolopathy (calciphylaxis), a rare condition characterised by painful, non-healing skin lesions.

Methods

In this international, phase 3, randomised, double-blind, placebo-controlled trial, adults with an ulcerated calciphylaxis lesion and pain visual analogue scale (VAS) score ≥50/100 were randomised 1:1 to hexasodium fytate 7 mg/kg or placebo intravenously during maintenance haemodialysis. Primary efficacy outcomes were an 8-item modification of the Bates-Jensen Wound Assessment Tool (BWAT-CUA) and Pain VAS in the intention-to-treat population. ClinicalTrials.gov number: NCT04195906.

Findings

Overall, 34/37 patients randomised to hexasodium fytate and 26/34 patients randomised to placebo completed the 12-week randomised treatment period. At Week 12, both groups (hexasodium fytate versus placebo) showed similar improvements in BWAT-CUA (mean [standard deviation (SD)], -5.3 [5.2] versus -6.0 [6.2]; least squares mean difference, 0.3 [96% confidence interval (CI): -2.5, 3.0]; p = 0.88) and Pain VAS (mean [SD], -19.5 [26.9] versus -32.2 [38.5]; least squares mean difference, 11.5 [96% CI: -4.8, 27.8]; p = 0.15). One patient randomised to placebo briefly received hexasodium fytate in error. Serious adverse events through Week 12 included: calciphylaxis-related events leading to hospitalisation (2/38 [5%] versus 11/33 [33%]) and death (1/38 [3%] versus 5/33 [15%]). During the subsequent 12 weeks of open-label hexasodium fytate and 4 weeks of follow-up, there were no additional calciphylaxis-related events leading to hospitalisation. Over the course of the entire trial, deaths were 2/38 [5%] for the hexasodium fytate group and 7/33 [21%] for the placebo group.

Interpretation

In patients with calciphylaxis, BWAT-CUA and Pain VAS improved similarly in hexasodium fytate- and placebo-treated patients; over the course of the entire trial, there were fewer deaths and calciphylaxis-related events leading to hospitalisation in the hexasodium fytate group.

Funding

Funded by Sanifit, a CSL Vifor company.

Inflammatory and Immune-Mediated Myopathies, What Do We Know?

Inflammatory myopathies or myositis encompass diseases characterized by the presence of inflammatory cellular infiltrates, mainly polymorphonuclear cells and/or lymphocytes, in muscle. This is in contrast to most forms of muscle disease characterized by myodegeneration that results in macrophage infiltration. Inflammatory myopathies could have infectious or noninfectious causes. Noninfectious causes consist of primary (genetic, autoimmune) or acquired immune-mediated disease. Focal, multifocal or diffuse, acute or recurrent forms of disease can occur. This article will mainly review immune-mediated myopathies in horses. Myositis directly caused by infection such as Clostridium spp and others will not be discussed here.

Sodium thiosulfate: A donor or carrier signaling molecule for hydrogen sulfide?

Sodium thiosulfate has been used for decades in the treatment of calciphylaxis and cyanide detoxification, and has recently shown initial therapeutic promise in critical diseases such as neuronal ischemia, diabetes mellitus, heart failure and acute lung injury. However, the precise mechanism of sodium thiosulfate remains incompletely defined and sometimes contradictory. Although sodium thiosulfate has been widely accepted as a donor of hydrogen sulfide (H2S), emerging findings suggest that it is the executive signaling molecule for H2S and that its effects may not be dependent on H2S. This article presents an overview of the current understanding of sodium thiosulfate, including its synthesis, biological characteristics, and clinical applications of sodium thiosulfate, as well as the underlying mechanisms in vivo. We also discussed the interplay of sodium thiosulfate and H2S. Our review highlights sodium thiosulfate as a key player in sulfide signaling with the broad clinical potential for the future.

Occlusive cutaneous vasculopathies as cause of chronic ulcers

The term occluding vasculopathies covers a large number of different conditions. These often manifest as skin ulcers. Occluding vasculopathies should be considered in the differential diagnosis of leg ulcers. The term "occlusive vasculopathies" encompasses pathophysiologically related entities that share structural or thrombotic obliteration of small cutaneous vessels. In this article, we will focus on livedoid vasculopathy with and without antiphospholipid syndrome and calciphylaxis with differentiation from hypertonic leg ulcer as the most relevant differential diagnoses of leg ulcer. The term also includes vascular occlusion, for example due to oxalate or cholesterol embolism, and septic vasculopathy. This often leads to acral ulceration and is therefore not a differential diagnosis with classic leg ulcers. It will not be discussed in this article. Occlusive vasculopathy may be suspected in the presence of the typical livedo racemosa or (non-inflammatory) retiform purpura as a sign of reduced cutaneous perfusion in the wound area. Inflammatory dermatoses, especially vasculitides, must be differentiated. This is achieved by histopathological evaluation of a tissue sample of sufficient size and depth taken at the appropriate time. In addition, specific laboratory parameters, particularly coagulation parameters, can support the diagnosis.

Okkludierende kutane Vaskulopathien als Ursachen chronischer Unterschenkelulzerationen

Unter den Begriff der okkludierenden Vaskulopathien fällt eine Reihe unterschiedlicher Krankheitsbilder. Diese manifestieren sich an der Haut häufig mit Ulzerationen. Gerade bei Ulzerationen der Unterschenkel sollten okkludierende Vaskulopathien in die differenzialdiagnostischen Überlegungen einbezogen werden. Der Begriff „okkludierende Vaskulopathien“ umfasst pathophysiologisch verwandte Entitäten, die eine strukturelle oder thrombotische Obliteration von kleinsten Hautgefäßen gemein haben. In diesem Artikel wird vor allem auf die Livedovaskulopathie mit und ohne Antiphospholipidsyndrom sowie die Calciphylaxie mit Abgrenzung zum Ulcus cruris hypertonicum als die relevantesten Differenzialdiagnosen von Unterschenkelulzerationen eingegangen. Der Begriff umfasst auch Gefäßverschlüsse, beispielsweise durch Oxalat oder Cholesterinembolie, sowie die septische Vaskulopathie. Diese führt häufig zu akralen Ulzerationen und stellt somit keine Differenzialdiagnose zum klassischen Ulcus cruris dar. Sie wird daher in diesem Artikel nicht behandelt.

Der Verdacht einer okkludierenden Vaskulopathie kann über die typische Livedo racemosa beziehungsweise die (nichtinflammatorische) retiforme Purpura als Zeichen der kutanen Minderdurchblutung in der Wundumgebung gestellt werden. Entzündliche Dermatosen, insbesondere Vaskulitiden, müssen differenzialdiagnostisch abgegrenzt werden. Dies geschieht zum Teil klinisch und durch die histopathologische Beurteilung einer Gewebeprobe, die in ausreichender Größe und Tiefe sowie zum richtigen Zeitpunkt entnommen werden muss. Ergänzend können spezifische Laborparameter, insbesondere die Gerinnungsdiagnostik, die Diagnosestellung unterstützen.

Alveolar Microlithiasis with Mild Clinical Symptoms But Severe Imaging Findings: A Case Report

Pulmonary alveolar microlithiasis (PAM) is a rare genetic disorder that causes calcium phosphate microliths to form in the alveoli. Symptoms usually appear in a person's third or fourth decade of life. A definitive diagnosis does not always demand a lung biopsy but can be achieved in families with more than one member with PAM and compatible chest imaging. We present the case of a 47-year-old woman referred to us for shortness of breath. Chest imaging revealed bilateral diffuse ground-glass opacities, interlobar fissure calcification, and subpleural linear calcifications, leading to a diagnosis of PAM. Although there is no specific treatment for this condition, early diagnosis can help prevent it from progressing rapidly by avoiding exposure to risk factors.

The Bone-Vascular Axis in Chronic Kidney Disease: From Pathophysiology to Treatment

PURPOSE OF REVIEW

This review aims to describe the pathogenic factors involved in bone-vessel anomalies in CKD which are the object of numerous experimental and clinical research.

RECENT FINDINGS

Knowledge on the pathophysiological mechanisms involved in the regulation of vascular calcification and mineral-bone disorders is evolving. Specific bone turnover anomalies influence the vascular health while recent studies demonstrate that factors released by the calcified vessels also contribute to bone deterioration in CKD. Current therapies used to control mineral dysregulations will impact both the vessels and bone metabolism. Available anti-osteoporotic treatments used in non-CKD population may negatively or positively affect vascular health in the context of CKD. It is essential to study the bone effects of the new therapeutic options that are currently under investigation to reduce vascular calcification. Our paper highlights the complexity of the bone-vascular axis and discusses how current therapies may affect both organs in CKD.

Clinical experience with intraperitoneal sodium thiosulphate for calciphylaxis in peritoneal dialysis: A case series

Calciphylaxis is an uncommon but life-threatening syndrome in end-stage kidney disease, characterised by painful medial and intimal calcification of the arterioles in the deep dermis and subcutaneous tissues. Intravenous sodium thiosulfate serves as an off-label but effective treatment in haemodialysis patients. However, this approach confers considerable logistical challenges for affected peritoneal dialysis patients. In this case series, we demonstrate that intraperitoneal administration can be a safe, convenient and long-term alternative.

Effectiveness of topical sodium thiosulfate for ectopic calcifications and ossifications. Results of the CATSS-O study

INTRODUCTION

Ectopic calcifications (ECs) and heterotopic ossifications (HOs) form in non-mineralized tissues, most often in subcutaneous and muscular areas. Local and systemic complications can cause severe disability. Systemic administration of sodium thiosulfate (STS) gives promising results but is difficult to use in clinical practice.

OBJECTIVE

Evaluation of the efficacy and safety of topical STS in ECs and HOs.

METHODS

Retrospective analysis of the CATSS-O registry that included patients receiving topical STS 25 % prepared by the pharmacy of Limoges hospital during 2014-2020. The efficacy of STS was assessed by imaging (radiography or CT) after at least 6 months' treatment.

RESULTS

Among 126 patients who received STS 25 %, 35 had complete clinical and radiographic data for analysis (28 with ECs and 7 with HOs; 18 children [mean age 8.9 years, range 1.5-16], 17 adults [mean age 52.4 years, range 24-90]). Calcifications or ossifications were due to dermatomyositis (8 children, 6 adults), systemic scleroderma (6 adults) or pseudo-hypoparathyroidism 1A (7 children). They were single (37.1 %) or multiple (62.9 %). Treated regions were in the lower limbs (31.4 %), upper limbs (37.1 %) or both (28.6 %) and the axial region (2.9 %). Topical STS was clinically effective in 9/28 (32.1 %) patients with ECs and 2/7 (28.6 %) children with HOs. Three patients experienced complete disappearance of their calcifications. Response for ECs was better in children than adults (54.5% vs 17.6 %, p = 0.035). Topical STS was well tolerated.

CONCLUSION

Local STS seems effective for ossifications, particularly pediatric calcifications or ossifications. Randomized and experimental studies are needed to confirm this observation and to identify the underlying mechanisms.

Hydrogen sulfide and sulfaceutic or sulfanutraceutic agents: Classification, differences and relevance in preclinical and clinical studies

Hydrogen sulfide (H2S) has been extensively studied as a signal molecule in the body for the past 30 years. Researchers have conducted studies using both natural and synthetic sources of H2S, known as H2S donors, which have different characteristics in terms of how they release H2S. These donors can be inorganic salts or have various organic structures. In recent years, certain types of sulfur compounds found naturally in foods have been characterized as H2S donors and explored for their potential health benefits. These compounds are referred to as "sulfanutraceuticals," a term that combines "nutrition" and "pharmaceutical". It is used to describe products derived from food sources that offer additional health advantages. By introducing the terms "sulfaceuticals" and "sulfanutraceuticals," we categorize sulfur-containing substances based on their origin and their use in both preclinical and clinical research, as well as in dietary supplements.

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.

Sulfur-Element containing metabolic pathways in human health and crosstalk with the microbiome

In humans, methionine derived from dietary proteins is necessary for cellular homeostasis and regeneration of sulfur containing pathways, which produce inorganic sulfur species (ISS) along with essential organic sulfur compounds (OSC). In recent years, inorganic sulfur species have gained attention as key players in the crosstalk of human health and the gut microbiome. Endogenously, ISS includes hydrogen sulfide (H2S), sulfite (SO32-), thiosulfate (S2O32-), and sulfate (SO42-), which are produced by enzymes in the transsulfuration and sulfur oxidation pathways. Additionally, sulfate-reducing bacteria (SRB) in the gut lumen are notable H2S producers which can contribute to the ISS pools of the human host. In this review, we will focus on the systemic effects of sulfur in biological pathways, describe the contrasting mechanisms of sulfurylation versus phosphorylation on the hydroxyl of serine/threonine and tyrosine residues of proteins in post-translational modifications, and the role of the gut microbiome in human sulfur metabolism.

Clinical Potential of Hydrogen Sulfide in Peripheral Arterial Disease

Peripheral artery disease (PAD) affects more than 230 million people worldwide. PAD patients suffer from reduced quality of life and are at increased risk of vascular complications and all-cause mortality. Despite its prevalence, impact on quality of life and poor long-term clinical outcomes, PAD remains underdiagnosed and undertreated compared to myocardial infarction and stroke. PAD is due to a combination of macrovascular atherosclerosis and calcification, combined with microvascular rarefaction, leading to chronic peripheral ischemia. Novel therapies are needed to address the increasing incidence of PAD and its difficult long-term pharmacological and surgical management. The cysteine-derived gasotransmitter hydrogen sulfide (H₂S) has interesting vasorelaxant, cytoprotective, antioxidant and anti-inflammatory properties. In this review, we describe the current understanding of PAD pathophysiology and the remarkable benefits of H₂S against atherosclerosis, inflammation, vascular calcification, and other vasculo-protective effects.

Calciphylaxis and its co-occurrence with connective tissue diseases

Calciphylaxis, also known as calcific uremic arteriopathy, is a rare calcification syndrome that presents as ischemic skin necrosis and severe pain. It has a high mortality rate and is characterised by calcification of the small and medium arteries and micro-thrombosis. Calciphylaxis mainly occurs in patients with end-stage renal disease. In recent years, there have been an increasing number of cases of calciphylaxis associated with connective tissue diseases. Given the absence of clear diagnostic criteria for calciphylaxis thus far, an early diagnosis is crucial for designing an effective multidisciplinary treatment plan. In this article, we review the research progress on calciphylaxis and describe its characteristics in the context of connective tissue diseases.

Refractory wounds induced by normal-renal calciphylaxis: An under-recognised calcific arteriolopathy

BACKGROUND

Normal-renal calciphylaxis (NRC) is a devastating calcific vasculopathy characterised by refractory wounds. It is more likely to be misdiagnosed because of the absence of renal insufficiency. Failure to effectively control may lead to rapid deterioration and ultimately death. However, current knowledge of it is still inadequate.

OBJECTIVES

To provide a relatively comprehensive review of NRC.

METHODS

Nine electronic medical databases including PubMed, Web of Science, Embase, the Cochrane Library and so on were searched from inception to April 1, 2022. Articles in which calciphylaxis was diagnosed in patients with normal renal function were included.

RESULTS

Totally 140 articles were retrieved with 187 patients (median age, 62 years [IQR, 49.63 ~ 75.70 years]; 83.42% female; 84.5% Caucasian). Vitamin K antagonism (43.32%) and diabetes (39.57%) accounted for most of the concomitant factors. Cutaneous presentations were the most common. Pathological confirmation was made in 97.86% of patients with an accuracy of 99.45%. Multidisciplinary therapeutic strategies were usually implemented while the final prognosis was not ideal, with a 6-month mortality rate of 21.10% and a 1-year mortality rate of 27.52%.

CONCLUSION

NRC is an under-recognised disease caused by a variety of factors; meanwhile, multidisciplinary efforts are required to inform diagnostic and therapeutic decisions.

Clinical features and outcomes of calciphylaxis in Chinese patients with chronic kidney disease

AIM

Calciphylaxis is a rare disease, predominantly in chronic kidney disease (CKD), characterized by high morbidity and mortality. Data from the Chinese population have been an invaluable resource for a better understanding of natural history, optimal treatments and outcomes of calciphylaxis.

METHODS

A retrospective study was conducted in 51 Chinese patients diagnosed with calciphylaxis at Zhong Da Hospital affiliated to Southeast University from December 2015 to September 2020.

RESULTS

Between 2015 and 2020, 51 cases of calciphylaxis were registered in The China Calciphylaxis Registry (http://www.calciphylaxis.com.cn), which was developed by Zhong Da Hospital. The mean age of the cohort was 52.02 ± 14.09 years, and 37.3% were female. Forty-three patients (84.3%) were on haemodialysis, with a median dialysis vintage of 88 months. Eighteen patients (35.3%) had a resolution of calciphylaxis and 20 patients (39.2%) died. Patients in later stages had higher overall mortality than those in earlier stages. Delay from skin lesions onset to diagnosis and calciphylaxis-related infections were risk factors in both early and overall mortality. Additionally, dialysis vintage and infections were significant risk factors in calciphylaxis-specific mortality. Among therapeutic strategies, only the use of sodium thiosulfate (STS) ≥3 courses (14 injections) was significantly associated with decreased hazard of death in both early and overall mortality.

CONCLUSION

For Chinese patients with calciphylaxis, delay from skin lesions onset to diagnosis and infections secondary to wounds are risk factors for the prognosis of patients with calciphylaxis. Additionally, patients in earlier stages have better survival and early continuous use of STS is highly suggested.

Sodium thiosulfate through preserving mitochondrial dynamics ameliorates oxidative stress induced renal apoptosis and ferroptosis in 5/6 nephrectomized rats with chronic kidney diseases

Chronic kidney disease (CKD) progression may be evoked through dysregulated mitochondrial dynamics enhanced oxidative stress and inflammation contributing to high cardiovascular morbidity and mortality. Previous study has demonstrated sodium thiosulfate (STS, Na2S2O3) could effectively attenuate renal oxidative injury in the animal model of renovascular hypertension. We explored whether the potentially therapeutic effect of STS is available on the attenuating CKD injury in thirty-six male Wistar rats with 5/6 nephrectomy. We determined the STS effect on reactive oxygen species (ROS) amount in vitro and in vivo by an ultrasensitive chemiluminescence-amplification method, ED-1 mediated inflammation, Masson's trichrome stained fibrosis, mitochondrial dynamics (fission and fusion) and two types of programmed cell death, apoptosis and ferroptosis by western blot and immunohistochemistry. Our in vitro data showed STS displayed the strongest scavenging ROS activity at the dosage of 0.1 g. We applied STS at 0.1 g/kg intraperitoneally 5 times/week for 4 weeks to these CKD rats. CKD significantly enhanced the degree in arterial blood pressure, urinary protein, BUN, creatinine, blood and kidney ROS amount, leukocytes infiltration, renal 4-HNE expression, fibrosis, dynamin-related protein 1 (Drp1) mediated mitochondrial fission, Bax/c-caspase 9/c-caspase 3/poly (ADP-ribose) polymerase (PARP) mediated apoptosis, iron overload/ferroptosis and the decreased xCT/GPX4 expression and OPA-1 mediated mitochondrial fusion. STS treatment significantly ameliorated oxidative stress, leukocyte infiltration, fibrosis, apoptosis and ferroptosis and improved mitochondrial dynamics and renal dysfunction in CKD rats. Our results suggest that STS as drug repurposing strategy could attenuate CKD injury through the action of anti-mitochondrial fission, anti-inflammation, anti-fibrosis, anti-apoptotic, and anti-ferroptotic mechanisms.

Pre-Treatment of Transplant Donors with Hydrogen Sulfide to Protect against Warm and Cold Ischemia-Reperfusion Injury in Kidney and Other Transplantable Solid Organs

Ischemia-reperfusion injury (IRI), a pathological condition resulting from prolonged cessation and subsequent restoration of blood flow to a tissue, is an inevitable consequence of solid organ transplantation. Current organ preservation strategies, such as static cold storage (SCS), are aimed at reducing IRI. However, prolonged SCS exacerbates IRI. Recent research has examined pre-treatment approaches to more effectively attenuate IRI. Hydrogen sulfide (H₂S), the third established member of a family of gaseous signaling molecules, has been shown to target the pathophysiology of IRI and thus appears to be a viable candidate that can overcome the transplant surgeon's enemy. This review discusses pre-treatment of renal grafts and other transplantable organs with H₂S to mitigate transplantation-induced IRI in animal models of transplantation. In addition, ethical principles of pre-treatment and potential applications of H₂S pre-treatment in the prevention of other IRI-associated conditions are discussed.

Patient-Reported and Clinical Outcomes Among Patients With Calciphylaxis

Objective

To describe the pain intensity among hospitalized patients with calciphylaxis, elucidate the factors associated with pain improvement, and examine the link between pain improvement and clinical outcomes.

Patients and Methods

Patients were identified from the Partners Research Patient Data Registry and the Partners Calciphylaxis Registry and Biorepository (Clinicaltrials.gov ID: NCT03032835). Those with calciphylaxis requiring hospitalization for at least 14 consecutive days during the study period from May 2016 through December 2021 were included. Pain intensity was assessed using patient-reported pain scores on numerical rating scales from 0 to 10. Associations between pain improvement and clinical outcomes, including lesion improvement, amputation, and mortality, were examined using univariate and multivariate regression models.

Results

Our analysis included 111 patients (age, 58±14 years; men, 40%; on maintenance dialysis, 79%). No significant improvement of pain intensity was observed over the 14 days of hospitalization (mean difference, -0.71; P=.08). However, among 49 (44.1%) patients who showed at least 1-point improvement in the pain score, there was an association with surgical debridement during hospitalization (odds ratio, 3.37; 95% CI, 1.17-9.67; P=.02). Hyperbaric oxygen therapy was associated with pain improvement (odds ratio, 5.38; 95% CI, 1.14-25.50; P=.03) in patients on maintenance dialysis. Pain improvement was associated with lower rates of subsequent amputation at 6 months of follow up (6% vs 13%; P<.05) but did not predict lesion improvement or survival.

Conclusion

Pain control remains a challenge among hospitalized patients with calciphylaxis. Surgical debridement and hyperbaric oxygen therapy may improve pain intensity. Pain improvement predicted a lower risk of future amputation.

Vascular smooth muscle cells in intimal hyperplasia, an update

Arterial occlusive disease is the leading cause of death in Western countries. Core contemporary therapies for this disease include angioplasties, stents, endarterectomies and bypass surgery. However, these treatments suffer from high failure rates due to re-occlusive vascular wall adaptations and restenosis. Restenosis following vascular surgery is largely due to intimal hyperplasia. Intimal hyperplasia develops in response to vessel injury, leading to inflammation, vascular smooth muscle cells dedifferentiation, migration, proliferation and secretion of extra-cellular matrix into the vessel's innermost layer or intima. In this review, we describe the current state of knowledge on the origin and mechanisms underlying the dysregulated proliferation of vascular smooth muscle cells in intimal hyperplasia, and we present the new avenues of research targeting VSMC phenotype and proliferation.

Cartilage calcification in osteoarthritis: mechanisms and clinical relevance

Pathological calcification of cartilage is a hallmark of osteoarthritis (OA). Calcification can be observed both at the cartilage surface and in its deeper layers. The formation of calcium-containing crystals, typically basic calcium phosphate (BCP) and calcium pyrophosphate dihydrate (CPP) crystals, is an active, highly regulated and complex biological process that is initiated by chondrocytes and modified by genetic factors, dysregulated mitophagy or apoptosis, inflammation and the activation of specific cellular-signalling pathways. The links between OA and BCP deposition are stronger than those observed between OA and CPP deposition. Here, we review the molecular processes involved in cartilage calcification in OA and summarize the effects of calcium crystals on chondrocytes, synovial fibroblasts, macrophages and bone cells. Finally, we highlight therapeutic pathways leading to decreased joint calcification and potential new drugs that could treat not only OA but also other diseases associated with pathological calcification.

Mitochondria and vascular calcification in chronic kidney disease: Lessons learned from the past to improve future therapy

Chronic kidney disease-mineral and bone disorders (CKD-MBD) is a common complication of CKD Stages 3-5. Hyperphosphatemia is one of the major metabolic components of CKD-MBD, frequently resulting in vascular calcification (VC) in advanced-stage patients. Also, a long duration of renal replacement therapy can cause the worsening of VC, leading to increased cardiovascular morbidity and mortality. Vascular smooth muscle cells play an important role in the development of VC through osteochondrogenic transformation and the apoptotic process. It has been shown that mitochondrial dysfunction is involved with CKD progression, and excessive oxidative stress can aggravate osteoblastic transformation and VC. Currently, novel interventions targeting mitochondrial function and dynamics, in addition to mitochondrial antioxidants, have been studied with the aim of attenuating VC. This review aims to comprehensively summarize and discuss the experimental and clinical reports concerning mitochondrial studies, along with the purpose of interventions that can improve the outcomes of VC among CKD patients.

The Role of Iron in Calciphylaxis—A Current Review

Calcific uraemic arteriolopathy (CUA), also known as calciphylaxis, is a rare and often fatal condition, frequently diagnosed in end-stage renal disease (ESRD) patients. Although exact pathogenesis remains unclear, iron supplementation is suggested as a potential risk factor. Iron and erythropoietin are the main stay of treatment for anaemia in ESRD patients. Few observational studies support the role of iron in the pathogenesis of calciphylaxis although data from the pivotal trial was not strongly supportive of this argument, i.e., no difference in incidence of calciphylaxis between the low-dose and high-dose iron treatment arms. Elevated levels of vascular cell adhesion molecules in association with iron excess were postulated to the pathogenesis of CUA by causing inflammation and calcification within the microvasculature. In-addition, oxidative stress generated because of iron deposition in cases of systemic inflammation, such as those seen in ESRD, may play a role in vascular calcification. Despite these arguments, a direct correlation between cumulative iron exposure with CUA incidence is not clearly demonstrated in the literature. Consequently, we do not have evidence to recommend iron reduction or cessation in ESRD patients that develop CUA.

Thiosulfate sulfurtransferase prevents hyperglycemic damage to the zebrafish pronephros in an experimental model for diabetes

Thiosulfate sulfurtransferase (TST, EC 2.8.1.1), also known as Rhodanese, was initially discovered as a cyanide detoxification enzyme. However, it was recently also found to be a genetic predictor of resistance to obesity-related type 2 diabetes. Diabetes type 2 is characterized by progressive loss of adequate β-cell insulin secretion and onset of insulin resistance with increased insulin demand, which contributes to the development of hyperglycemia. Diabetic complications have been replicated in adult hyperglycemic zebrafish, including retinopathy, nephropathy, impaired wound healing, metabolic memory, and sensory axonal degeneration. Pancreatic and duodenal homeobox 1 (Pdx1) is a key component in pancreas development and mature beta cell function and survival. Pdx1 knockdown or knockout in zebrafish induces hyperglycemia and is accompanied by organ alterations similar to clinical diabetic retinopathy and diabetic nephropathy. Here we show that pdx1-knockdown zebrafish embryos and larvae survived after incubation with thiosulfate and no obvious morphological alterations were observed. Importantly, incubation with hTST and thiosulfate rescued the hyperglycemic phenotype in pdx1-knockdown zebrafish pronephros. Activation of the mitochondrial TST pathway might be a promising option for therapeutic intervention in diabetes and its organ complications.

[Uremic calciphylaxis]

Uremic calciphylaxis is a rare disease that affects patients with chronic end-stage renal disease. It is a pathology of the microvessels of the dermis and hypodermis which are calcified and whose thrombosis leads to skin necrosis. Calciphylaxis lesions can be distal and axial. They lead to pain, infection and are associated with denutrition and in high mortality rate (40-80% at 1 year). This general review describes the clinical and para-clinical presentations of calciphylaxis. It summarizes the current knowledge on its pathogenesis and the therapeutical options that can be proposed to improve the management and attempt to reduce the mortality of patients with uremic calciphylaxis.

Inflammatory skin diseases and wounds

Inflammatory wounds of the skin can be caused by many different diseases. Of particular importance here are the very heterogeneous groups of vasculitides and vasculopathies. These are usually interdisciplinary relevant diseases that require extensive diagnostics in specialized centres. Clinically, these inflammatory wounds present as very painful ulcers that develop from necrosis and are surrounded by erythematous livid borders. The healing process is often difficult and protracted. Moreover, it considerably impairs the quality of life of the affected patients. In addition to clinical evaluation, histopathological examination of biopsies taken as early as possible is particularly important in diagnosis. Numerous differential diagnoses must be ruled out. Therapeutically, in addition to the often necessary systemic therapies, which include immunosuppressants (immunomodulating drugs and/or rheologics), appropriate topical wound treatment, usually in combination with compression therapy, should always be considered. Whenever possible, the causative factors should be diagnosed early and avoided or treated.

Clinical Use of Hydrogen Sulfide to Protect Against Intimal Hyperplasia

Arterial occlusive disease is the narrowing of the arteries via atherosclerotic plaque buildup. The major risk factors for arterial occlusive disease are age, high levels of cholesterol and triglycerides, diabetes, high blood pressure, and smoking. Arterial occlusive disease is the leading cause of death in Western countries. Patients who suffer from arterial occlusive disease develop peripheral arterial disease (PAD) when the narrowing affects limbs, stroke when the narrowing affects carotid arteries, and heart disease when the narrowing affects coronary arteries. When lifestyle interventions (exercise, diet…) fail, the only solution remains surgical endovascular and open revascularization. Unfortunately, these surgeries still suffer from high failure rates due to re-occlusive vascular wall adaptations, which is largely due to intimal hyperplasia (IH). IH develops in response to vessel injury, leading to inflammation, vascular smooth muscle cells dedifferentiation, migration, proliferation and secretion of extra-cellular matrix into the vessel’s innermost layer or intima. Re-occlusive IH lesions result in costly and complex recurrent end-organ ischemia, and often lead to loss of limb, brain function, or life. Despite decades of IH research, limited therapies are currently available. Hydrogen sulfide (H₂S) is an endogenous gasotransmitter derived from cysteine metabolism. Although environmental exposure to exogenous high H₂S is toxic, endogenous H₂S has important vasorelaxant, cytoprotective and anti-inflammatory properties. Its vasculo-protective properties have attracted a remarkable amount of attention, especially its ability to inhibit IH. This review summarizes IH pathophysiology and treatment, and provides an overview of the potential clinical role of H₂S to prevent IH and restenosis.

Calciphylaxis after kidney transplantation: a rare but life-threatening disorder

Calciphylaxis is a rare disorder characterized by vascular calcification and thrombosis of the subcutaneous microcirculation, leading to painful necrotic skin lesions and bearing a dreadfully high mortality rate. This syndrome is frequently also termed uraemic calcific arteriolopathy, since most cases are observed in patients with kidney failure. However, it is increasingly clear that calciphylaxis may also affect patients with normal or only slightly impaired renal function, including kidney transplant recipients. A precise definition of the characteristics and risk factors of calciphylaxis developing after kidney transplantation has been hindered by the extreme rarity of this condition, which also hampered the development of effective therapeutic strategies. In the present issue of CKJ, Guillén and colleagues report the largest case series of calciphylaxis in kidney transplant recipients to date, outlining several features that are apparently specific to this population. In this editorial, we briefly present the epidemiology and pathogenesis of calciphylaxis in different patient populations and discuss recent findings for its therapeutic management.

Cardiac Calcifications: Phenotypes, Mechanisms, Clinical and Prognostic Implications

There is a growing interest in arterial and heart valve calcifications, as these contribute to cardiovascular outcome, and are leading predictors of cardiovascular and kidney diseases. Cardiovascular calcifications are often considered as one disease, but, in effect, they represent multifaced disorders, occurring in different milieus and biological phenotypes, following different pathways. Herein, we explore each different molecular process, its relative link with the specific clinical condition, and the current therapeutic approaches to counteract calcifications. Thus, first, we explore the peculiarities between vascular and valvular calcium deposition, as this occurs in different tissues, responds differently to shear stress, has specific etiology and time courses to calcification. Then, we differentiate the mechanisms and pathways leading to hyperphosphatemic calcification, typical of the media layer of the vessel and mainly related to chronic kidney diseases, to those of inflammation, typical of the intima vascular calcification, which predominantly occur in atherosclerotic vascular diseases. Finally, we examine calcifications secondary to rheumatic valve disease or other bacterial lesions and those occurring in autoimmune diseases. The underlying clinical conditions of each of the biological calcification phenotypes and the specific opportunities of therapeutic intervention are also considered and discussed.

The Abcc6a Knockout Zebrafish Model as a Novel Tool for Drug Screening for Pseudoxanthoma Elasticum

Pseudoxanthoma elasticum (PXE) is a multisystem ectopic mineralization disorder caused by pathogenic variants in the ABCC6 gene. Though complications of the disease can be treated, PXE itself remains currently intractable. A strategy for rapid and cost-effective discovery of therapeutic drugs would be to perform chemical compound screening using zebrafish, but this approach remains to be validated for PXE. In this paper, we validate a stable CRISPR/Cas9 abcc6a knockout zebrafish model–which has spinal column hypermineralization as its primary phenotypic feature–as a model system for compound screening in ectopic mineralization. We evaluated the anti-mineralization potential of five compounds, which had (anecdotal) positive effects reported in Abcc6 knockout mice and/or PXE patients. Abcc6a knockout zebrafish larvae were treated from 3 to 10 days post-fertilization with vitamin K1, sodium thiosulfate, etidronate, alendronate or magnesium citrate and compared to matching controls. Following alizarin red S staining, alterations in notochord sheath mineralization were semiquantified and found to largely congrue with the originally reported outcomes. Our results demonstrate that the use of this abcc6a knockout zebrafish model is a validated and promising strategy for drug discovery against ectopic mineralization.

A novel long-term intravenous combined with local treatment with human amnion-derived mesenchymal stem cells for a multidisciplinary rescued uremic calciphylaxis patient and the underlying mechanism

Calciphylaxis is a rare disease characterized histologically by microvessel calcification and microthrombosis, with high mortality and no proven therapy. Here, we reported a severe uremic calciphylaxis patient with progressive skin ischemia, large areas of painful malodorous ulcers, and mummified legs. Because of the worsening symptoms and signs refractory to conventional therapies, treatment with human amnion-derived mesenchymal stem cells (hAMSCs) was approved. Pre-clinical release inspections of hAMSCs, efficacy, and safety assessment including cytokine secretory ability, immunocompetence, tumorigenicity, and genetics analysis in vitro were introduced. We further performed acute and long-term hAMSC toxicity evaluations in C57BL/6 mice and rats, abnormal immune response tests in C57BL/6 mice, and tumorigenicity tests in neonatal Balbc-nu nude mice. After the pre-clinical research, the patient was treated with hAMSCs by intravenous and local intramuscular injection and external supernatant application to the ulcers. When followed up to 15 months, the blood-based markers of bone and mineral metabolism improved, with skin soft tissue regeneration and a more favorable profile of peripheral blood mononuclear cells. Skin biopsy after 1-month treatment showed vascular regeneration with mature non-calcified vessels within the dermis, and 20 months later, the re-epithelialization restored the integrity of the damaged site. No infusion or local treatment-related adverse events occurred. Thus, this novel long-term intravenous combined with local treatment with hAMSCs warrants further investigation as a potential regenerative treatment for uremic calciphylaxis with effects of inhibiting vascular calcification, stimulating angiogenesis and myogenesis, anti-inflammatory and immune modulation, multi-differentiation, re-epithelialization, and restoration of integrity.

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.

Sodium Thiosulfate Improves Hypertension in Rats with Adenine-Induced Chronic Kidney Disease

Hypertension is highly prevalent in chronic kidney disease (CKD). Hydrogen sulfide (H₂S) is an endogenously produced gasotransmitter with vasodilator properties. We, hence, investigated whether oral administration of sodium thiosulfate (STS), a clinically applicable H₂S-based therapy, can exert a protective effect against hypertension in an adenine-induced CKD rat model. Eight-week-old male Sprague–Dawley rats were fed with 0.5% adenine chow for 3 weeks to induce CKD. After 1 week, the rats were divided into two groups: one without and one with STS (2 g/kg body weight/day) in drinking water for 2 weeks. Treatment with STS lowered systolic and diastolic blood pressure by 7 and 9 mm Hg, respectively. Renal H₂S-generating enzyme expression was inhibited by CKD, while STS therapy increased plasma levels of H₂S and thiosulfate. Additionally, restoration of nitric oxide bioavailability and rebalance of the renin–angiotensin system may contribute to the protective effects of STS. Our data suggest that the oral administration of STS improves hypertension in an adenine-induced CKD model, which brings us closer to the clinical translation of H₂S-targeting therapy in CKD-induced hypertension.

Success of small-dose fractionated sodium thiosulfate in the treatment of calciphylaxis in a peritoneal dialysis patient

BACKGROUND

Calciphylaxis, or calcific uremic arteriolopathy (CUA), is a rare, fatal disorder of microvascular calcification and thrombosis that typically affects patients with end-stage renal disease (ESRD) receiving long-term dialysis. Fewer reports describe calciphylaxis in peritoneal dialysis patients than hemodialysis patients as per a literature review. To date, there are no clear guidelines for CUA diagnosis and treatment. While sodium thiosulfate (STS) has been increasingly used for treatment in recent years, there have also been reports of severe side effects. There is no uniform standard for its usage and dosage, especially for peritoneal dialysis patients.

CASE PRESENTATION

We present a case of a 40-year-old Chinese male patient with ESRD on peritoneal dialysis who developed calciphylaxis with severe painful cutaneous ulcers on the fingers and toes that were managed successfully for 6 months with comprehensive treatment composed mainly of small-dose fractionated sodium thiosulfate.

CONCLUSIONS

Our experience suggests that the treatment of calciphylaxis requires timely and multi-angle intervention. Treatment with small-dose fractionated sodium thiosulfate has proven effective and tolerated in this patient.

Clinical Efficacy and Safety of Sodium Thiosulfate in the Treatment of Uremic Pruritus: A Meta-Analysis of Randomized Controlled Trials

Uremic pruritus is a distressful complication of chronic kidney disease and results in impaired quality of life and higher mortality rates. Intravenous sodium thiosulfate has been reported to alleviate pruritus in hemodialysis patients. We performed a systematic review and meta-analysis to estimate the efficacy of intravenous sodium thiosulfate in patients with uremic pruritus. A systematic search of electronic databases up to June 2021 was conducted for randomized controlled trials that evaluated the clinical effects of sodium thiosulfate in the management of patients with uremic pruritus. Two reviewers selected eligible articles and evaluated the risk of bias; the results of pruritus assessment and uremic pruritus-related laboratory parameters in selected studies were analyzed. There are four trials published between 2018 and 2021, which include 222 participants. The sodium thiosulfate group displayed significant decrease in the pruritus score (standardized mean difference = -3.52, 95% confidence interval = -5.63 to -1.41, p = 0.001), without a significant increase in the adverse effects (risk ratio = 2.44, 95% confidence interval = 0.37 to 15.99, p = 0.35) compared to the control group. Administration of sodium thiosulfate is found to be a safe and efficacious complementary therapy in improving uremic pruritus in patients with chronic kidney disease.

Local, non-systemic, and minimally invasive therapies for calcinosis cutis: a systematic review

Calcinosis cutis is a deposition of calcium in the skin and subcutaneous tissue, often accompanied by pain, reduced mobility, and chronic infections. Limited evidence is available about the feasibility and efficacy of therapies alternative to systemic treatment and surgical excision, both of which often lead to unsatisfactory results or complications. We conducted a systematic review to evaluate the efficacy and safety of topical and intralesional sodium thiosulfate, extracorporeal shock-wave lithotripsy (ESWL), and laser for calcinosis cutis. PubMed, Embase, and Web of Science were searched. Reports of calciphylaxis and treatment combined with systemic medications were excluded. A total of 40 studies including 136 patients were analysed. Partial or complete remission after monotherapy was observed in 64% to 81% of cases. Self-applied topical sodium thiosulfate required patient’s adherence (mean treatment duration, 4.9 months; range 2–24). Laser therapy enabled complete remission of microcalcifications after a single procedure (57%; 12/21). ESWL and intralesional sodium thiosulfate injections decreased calcinosis-associated pain (median reduction in VAS score, 3; range 0–9 and 1; range 0–5, respectively). The most common adverse event was scarring and hyperkeratosis, observed after CO₂ laser (56%; 10/18). Intralesional sodium thiosulfate injections caused transient pain in over 11% of patients. Recurrences within the follow-up were rare (2%; 3/136). This study provides an overview of minimally invasive and local therapies that in selected cases might transcend conventional treatment. The limitation of this study is the poor level of evidence, which emerges mainly from non-randomized studies at high risk of bias.

Therapeutic effect of intravenous sodium thiosulfate for uremic pruritus in hemodialysis patients

Objectives

This study aimed to compare the efficacy of intravenous sodium thiosulfate (IV STS) with that of loratadine in the treatment of uremic pruritus in hemodialysis (HD) patients.

Methods

This retrospective study included 44 HD patients with pruritus aged over 18 years between June 2018 and January 2020 at the Aerospace Center Hospital of China. Twenty-four HD patients received 3.2 g IV STS treatment three times per week at the end of each HD session for 8 weeks. Twenty HD patients received loratadine (10 mg/day) for 8 weeks. Pruritus intensity was measured using a visual analog scale (VAS) and the detailed pruritus score (DPS) at three time points. The safety of STS was evaluated according to adverse event symptoms and biological variable changes.

Results

There was no significant difference between the STS and loratadine groups in age, sex, characteristics of pruritus, or other clinical variables before treatment. After 8 weeks of treatment, the VAS score (7.07 ± 2.56 and 2.67 ± 2.01) and DPS (30.72 ± 4.81 and 8.04 ± 2.86) decreased significantly in the STS group (p < 0.05). The mean decrease in VAS score (6.89 ± 1.98 and 6.34 ± 2.35) and DPS (28.90 ± 3.24 and 26.92 ± 2.41) in the loratadine group was not statistically significant (p > 0.05). There were no morbidities or mortalities associated with the use of either drug. All biological variables remained stable after therapy.

Conclusions

STS can improve uremic pruritus in HD patients. However, literature on the subject remains lacking. Close monitoring for adverse effects is advised.