A case control study of proximal calciphylaxis

Multicenter Evaluation of Certainty and Reliability in Calciphylaxis Diagnosis Using a Digital Imaging Platform

The robustness of histopathologic criteria for diagnosing calciphylaxis depends both on dermatopathologists' confidence in the recognition of individual histologic features and on the interrater reliability (IRR) of these assessments. The aim of this study was to quantify interpretive challenges in calciphylaxis diagnosis through the evaluation of generalized and histopathological feature-specific certainty and IRR and establish which features are most reproducibly recognized. An online diagnostic survey was designed to evaluate accuracy, certainty, and IRR. Case materials comprised a clinical vignette, clinical photograph, and whole slide imaging scans of 1 hematoxylin and eosin and von Kossa-stained section in 20 patients with or without calciphylaxis. Dermatopathologists from multiple institutions independently rendered diagnoses and used a checklist to assess the presence of and certainty in specific histopathologic features. Twenty-three board-certified dermatopathologists (62%) representing 16 institutions responded. Diagnostic accuracy (53% vs 80%) and IRR (Krippendorff alpha [KA]) were lower for calciphylaxis cases compared with mimics (0.171 vs 0.257). Necrosis, finely stippled calcium, and intimal fibroplasia of pannicular arterioles most robustly differentiated calciphylaxis from mimics (P < .05). Among histopathologic features, IRR was the highest for ulceration (KA = 0.66) and necrosis (KA = 0.46) and the lowest for perieccrine calcification (KA = 0.19) and intimal fibroplasia of pannicular arterioles (KA = 0.07). Pathologists' confidence in correctly identifying the presence or absence of each feature correlated linearly with IRR. Digital imaging platforms can facilitate multi-institutional study of diagnostic concordance for uncommon entities. This study identified necrosis, finely stippled calcium, and intimal fibroplasia of pannicular arterioles as the most robust histopathologic features for diagnosing calciphylaxis, although inter-rater concordance for intimal fibroplasia was low. Quantitative trends in pathologists' subjective assessments of histologic features may help guide the development of diagnostic guidelines and inform medical education.

Clinical characteristics and treatment modalities in uremic and non uremic calciphylaxis - a dermatological single-center experience

Calciphylaxis (CP) is a serious, potentially life-threatening disease that presents with medial calcification of small-sized vessels and painful ischemic ulcerations. Although calciphylaxis is frequently seen in patients with end-stage kidney disease on dialysis (calcific uremic arteriolopathy, CUA), there are reported cases of nonuremic calciphylaxis (NUC), which often remain undiagnosed. We conducted a retrospective chart review at our dermatological hospital and evaluated data concerning the epidemiology, comorbidities, medication, laboratory abnormalities, and therapeutic approaches of 60 patients diagnosed with calciphylaxis between 01/2012 and 12/2022. We identified 21 patients diagnosed with NUC and 39 with kidney disease. The predilection sites of skin lesions were the lower legs in 88% (n = 53), followed by the thigh and gluteal regions in 7% (n = 4). Significant differences were identified in comorbidities, such as atrial fibrillation (p < 0.001) and hyperparathyroidism (p < 0.01) accounting for CUA patients. Medication with vitamin K antagonists (p < 0.001), phosphate binders (p < 0.001), and loop diuretics (p < 0.01) was found to be associated with the onset of calciphylaxis. Hyperphosphatemia (p < 0.001), increased parathyroid hormone (p < 0.01) and triglyceride levels (p < 0.01), hypoalbuminemia (p < 0.01) and decreased hemoglobin values (p < 0.001) in the CUA cohort were significantly different from those in the NUC group. All patients with CUA received systemic medication. In contrast, only 38% (n = 8) of patients with NUC received systemic treatment. Striking discrepancies in the treatment of both cohorts were detected. In particular, NUC remains a disease pattern that is still poorly understood and differs from CUA in several important parameters.

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

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

Calciphylaxis - Case Report

Introduction

Calciphylaxis is a rare, but serious, kidney complication. Calciphylaxia is a vasculopathy of small blood vessels characterized by the deposition of calcium deposits in intimal arterioles with the consequent proliferation of intima, fibrosis and thrombosis.

Aim

The aim was to show the significance of recognition of calciphylaxis relies on heightened clinical awareness of the presence of atypical skin nodules or ulcers that occur in patients with hemodialysis dependence and to characterize features of calciphylaxis or components of treatment that may lead to improved outcome.

Case report

We present the case of 84-year-old woman with chronic kidney disease and diabetes mellitus as well as severely painful, firm, indurated plaques on the lower extremities. The plaques progressed to involve larger areas with associated local ulceration and necrosis. Laboratory testing revealed hyperparathyroidism and incisional skin biopsy confirmed calciphylaxis. Wound microbiology confirmed Staphylococcus aureus.

Conclusion

The diagnosis can be based on clinical grounds, supported by histological analysis if possible. The laboratory workout must cover all the possible implications of chronic kidney disease with special attention to Ca+ and P+ values and evidence of skin or systemic infection. Calciphylaxis must be known by dermatologist as early diagnosis and proper management can be decisive for better prognosis.

Calcific Uremic Arteriolopathy: A Case Series and Review from an Inner-City Tertiary University Center in End-Stage Renal Disease Patients on Renal Replacement Therapy

Materials and Methods

24 patients with CUA and on RRT were evaluated at Detroit Medical Center from 2007 to 2016. Skin biopsy was used in almost all patients, along with the radiological and clinical findings. The patient's clinical and paraclinical data were retrieved from the electronic medical records. The effect of treatment modalities and the underlying hyperparathyroidism management were compared to the clinical outcomes using appropriate statistical tests.

Results

Twenty-one patients were on hemodialysis, two patients received renal transplants, and one patient was on peritoneal dialysis. Diabetes mellitus was the most prevalent cause of ESRD. The parathyroid hormone level (PTH) was elevated in 22 patients. Fifteen patients were diagnosed 2 weeks or more prior to skin lesion onset. Twenty-two and thirteen patients received sodium thiosulphate and cinacalcet, respectively. Patients with lower PTH and the calcium-phosphate product levels had a relatively better outcome of CUA.

Conclusions

A multifaceted approach may play a role in treating CUA. Referral to a nephrologist may aid in the early diagnosis and prompt management of CUA.

An update on vascular calcification and potential therapeutics

Pathological calcification is a major cause of cardiovascular morbidities primarily in population with chronic kidney disease (CKD), end stage renal diseases (ERSD) and metabolic disorders. Investigators have accepted the fact that vascular calcification is not a passive process but a highly complex, cell mediated, active process in patients with cardiovascular disease (CVD) resulting from, metabolic insults of bone fragility, diabetes, hypertension, dyslipidemia and atherosclerosis. Over the years, studies have revealed various mechanisms of vascular calcification like induction of bone formation, apoptosis, alteration in Ca-P balance and loss of inhibition. Novel clinical studies targeting cellular mechanisms of calcification provide promising and potential avenues for drug development. The interventions include phosphate binders, sodium thiosulphate, vitamin K, calcimimetics, vitamin D, bisphosphonates, Myoinositol hexaphosphate (IP6), Denosumab and TNAP inhibitors. Concurrently investigators are also working towards reversing or curing pathological calcification. This review focuses on the relationship of vascular calcification to clinical diseases, regulators and factors causing calcification including genetics which have been identified. At present, there is lack of any significant preventive measures for calcifications and hence this review explores further possibilities for drug development and treatment modalities.

Vascular Calcification-New Insights Into Its Mechanism

Vascular calcification (VC), which is categorized by intimal and medial calcification, depending on the site(s) involved within the vessel, is closely related to cardiovascular disease. Specifically, medial calcification is prevalent in certain medical situations, including chronic kidney disease and diabetes. The past few decades have seen extensive research into VC, revealing that the mechanism of VC is not merely a consequence of a high-phosphorous and -calcium milieu, but also occurs via delicate and well-organized biologic processes, including an imbalance between osteochondrogenic signaling and anticalcific events. In addition to traditionally established osteogenic signaling, dysfunctional calcium homeostasis is prerequisite in the development of VC. Moreover, loss of defensive mechanisms, by microorganelle dysfunction, including hyper-fragmented mitochondria, mitochondrial oxidative stress, defective autophagy or mitophagy, and endoplasmic reticulum (ER) stress, may all contribute to VC. To facilitate the understanding of vascular calcification, across any number of bioscientific disciplines, we provide this review of a detailed updated molecular mechanism of VC. This encompasses a vascular smooth muscle phenotypic of osteogenic differentiation, and multiple signaling pathways of VC induction, including the roles of inflammation and cellular microorganelle genesis.

Calciphylaxis: An Analysis of Concomitant Factors, Treatment Effectiveness and Prognosis in 30 Patients

Background

Calciphylaxis is a rare but severe complication mostly affecting patients with end-stage renal disease (ESRD) and is associated with high morbidity and mortality. The natural history, concomitant factors, pathogenesis, and treatment for calciphylaxis remain equivocal.

Methods

We conducted a retrospective study on patients diagnosed with calciphylaxis in a tertiary care center between January 1, 2012, and December 31, 2017. We describe demographics, co-morbidities, laboratory parameters, effectiveness of sodium thiosulfate treatment and outcomes.

Results

Of the 30 patients (age 65.6 ± 12.79 years, male:female = 8:22), 23 (76.67%) had ESRD and were either on hemodialysis (15 [65.22%], median duration 22.5 months [range 0.2–96 months]) or peritoneal dialysis (8 [34.78%], duration 29±10 months). Predisposing home medications: 8 (28%) had calcium supplements, 10 (36%) had warfarin, 16 (57%) had vitamin D and 5 (18%) had iron supplements. The median parathyroid hormone (PTH) level was 239.8 pg/mL (range 4.7–2922). Calciphylaxis was found on extremities in 21 (70%) and on torso in 6 (20%) patients. Sodium thiosulfate (STS) was given for treatment in 20 (67%) patients and 3 were cured in <2.25 months. One-year survival for all patients with calciphylaxis was 26% (29% for STS group and 20% for those that did not receive STS) and following any surgical treatment regardless of STS use was 14%.

Limitations

Retrospective design, absence of a control group and low power.

Conclusion

Calciphylaxis was more common among females with a predilection for extremities over the torso. Elevations in PTH and inflammatory markers were common. Treatment with STS did not show a statistically significant improvement in survival. Those who were cured, were treated with STS up to three months.

Calciphylaxis in a Patient on Home Hemodialysis

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The use of cinacalcet for the treatment of calciphylaxis in patients with chronic kidney disease: A comprehensive review

Calciphylaxis is a rare but life-threatening condition, most commonly affecting patients with stage 4 or 5 chronic kidney disease. No universally accepted therapy exists so far. In an attempt to avoid surgical intervention with parathyroidectomy, which is of questionable efficacy and carries several risks, a number of noninvasive treatments have been trialled with variable success. These treatments are aimed at modifying risk factors for calciphylaxis, in particular hypercalcaemia, hyperphosphataemia and hyperparathyroidism. The aim of this review was to summarise the available evidence to determine the potential role of cinacalcet in the treatment of calciphylaxis in patients with chronic kidney disease. Demographic, clinical and laboratory data were retrospectively collected from the available English and non-English literature. Overall, there was a very high response rate (partial or complete) of calciphylaxis lesions to both cinacalcet monotherapy and cinacalcet as part of a combination therapy (83.4% and 82.8%, respectively). When examining complete response to treatment specifically, combination therapy with cinacalcet proved more efficacious than monotherapy (62.1% versus 41.7%). There was also an associated rapid reduction of intact parathyroid hormone over a period of 2-33 months in both groups. While there are limitations as to how our data can be interpreted due to the heterogeneity of the methods and follow-up of the included case reports and case series, prompt and consistent therapy including cinacalcet may help improve the disease outcome. Additional research needs to be performed in this area, to further define the optimal use of cinacalcet for the treatment of calciphylaxis.

Vitamin D in Vascular Calcification: A Double-Edged Sword?

Vascular calcification (VC) as a manifestation of perturbed mineral balance, is associated with aging, diabetes and kidney dysfunction, as well as poorer patient outcomes. Due to the current limited understanding of the pathophysiology of vascular calcification, the development of effective preventative and therapeutic strategies remains a significant clinical challenge. Recent evidence suggests that traditional risk factors for cardiovascular disease, such as left ventricular hypertrophy and dyslipidaemia, fail to account for clinical observations of vascular calcification. Therefore, more complex underlying processes involving physiochemical changes to mineral balance, vascular remodelling and perturbed hormonal responses such as parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF-23) are likely to contribute to VC. In particular, VC resulting from modifications to calcium, phosphate and vitamin D homeostasis has been recently elucidated. Notably, deregulation of vitamin D metabolism, dietary calcium intake and renal mineral handling are associated with imbalances in systemic calcium and phosphate levels and endothelial cell dysfunction, which can modulate both bone and soft tissue calcification. This review addresses the current understanding of VC pathophysiology, with a focus on the pathogenic role of vitamin D that has provided new insights into the mechanisms of VC.

Penile calciphylaxis in a patient on combined peritoneal dialysis and hemodialysis

Calciphylaxis presents with painful purpura and intractable skin ulcers on the trunk and particularly the distal extremities, and it mainly occurs in patients on chronic dialysis. A 66-year-old man with renal failure due to diabetic nephropathy was on peritoneal dialysis alone for 1 year, followed by peritoneal dialysis combined with hemodialysis for 3 years. He developed calciphylaxis of the penis, which was diagnosed from the skin biopsy findings and clinical observation. To treat this condition, PD was stopped and HD was performed three times a week. In addition, warfarin therapy was discontinued and infusion of sodium thiosulfate was performed. The penile ulcers decreased in size and pain was markedly improved, so the patient was discharged from hospital. Following discharge, PD was resumed after changing the peritoneal dialysis fluid to bicarbonate-buffered dialysate. The penile ulcers eventually resolved completely. There have been very few reports about calciphylaxis in patients on combined dialysis modalities. In our patient, penile calciphylaxis progressed when lactate-buffered peritoneal dialysis fluid was used and resolved after switching to bicarbonate-buffered fluid together with cessation of warfarin therapy and infusion of sodium thiosulfate.

A Nationally Representative Study of Calcific Uremic Arteriolopathy Risk Factors

Accurate identification of risk factors for calcific uremic arteriolopathy (CUA) is necessary to develop preventive strategies for this morbid disease. We investigated whether baseline factors recorded at hemodialysis initiation would identify patients at risk for future CUA in a matched case-control study using data from a large dialysis organization. Hemodialysis patients with newly diagnosed CUA (n=1030) between January 1, 2010, and December 31, 2014, were matched by age, sex, and race in a 1:2 ratio to hemodialysis patients without CUA (n=2060). Mean ages for patients and controls were 54 and 55 years, respectively; 67% of participants were women and 49% were white. Median duration between hemodialysis initiation and subsequent CUA development was 925 days (interquartile range, 273-2185 days). In multivariable conditional logistic regression analyses, diabetes mellitus; higher body mass index; higher levels of serum calcium, phosphorous, and parathyroid hormone; and nutritional vitamin D, cinacalcet, and warfarin treatments were associated with increased odds of subsequent CUA development. Compared with patients with diabetes receiving no insulin injections, those receiving insulin injections had a dose-response increase in the odds of CUA involving lower abdomen and/or upper thigh areas (odds ratio, 1.49; 95% confidence interval, 1.03 to 2.51 for one or two injections per day; odds ratio, 1.88; 95% confidence interval, 1.30 to 3.43 for 3 injections per day; odds ratio, 3.74; 95% confidence interval, 2.28 to 6.25 for more than three injections per day), suggesting a dose-effect relationship between recurrent skin trauma and CUA risk. The presence of risk factors months to years before CUA development observed in this study will direct the design of preventive strategies and inform CUA pathobiology.

Calciphylaxis and the persistence of medical misinformation in the era of Google

OBJECTIVES

We illustrate the important and troubling issue of persistent misinformation and false claims in the medical literature using a frequently cited case inaccurately believed by many to be the first case of calciphylaxis.

METHODS

We identified a recurring error in the medical literature in the form of numerous citations of a study from the 1890s of a 6-month-old child with idiopathic infantile arterial calcification that is purported to be the first description of a case of calciphylaxis. We performed searches to determine the frequency of this error. Google Scholar and PubMed were searched for references citing the Bryant and White article. Accuracy of the citations was determined.

RESULTS

A Google Scholar search identified 33 references that incorrectly cite the Bryant and White article as the first description of a case of calciphylaxis. Of the 100 most recent PubMed publications on calciphylaxis, we identified five studies that incorrectly attribute the Bryant and White article as the first description of calciphylaxis, which accounts for approximately 5% of the contemporary literature on this topic.

CONCLUSIONS

Medical misinformation such as this is frequently perpetuated. We propose that computational resources could be better used to flag erroneous and contradicted claims to update and correct the literature.

Calciphylaxis: risk factors, diagnosis, and treatment

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

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.

Calciphylaxis and subtotal parathyroidectomy: a double-edged sword

Calciphylaxis, also called calcific uremic arteriolopathy is a dreadful, life-threatening ischemic vasculopathy, primarily involving skin and subcutaneous tissue, mostly on patients with end-stage kidney disease. Calciphylaxis is a well-described, but still a poorly understood disorder of mineral metabolism. Its occurrence is rare, but increasingly reported. We describe a 62-year-old obese lady on hemodialysis for end-stage kidney disease due to type 2 diabetes, who developed two episodes of calciphylactic skin lesions during the 3 years observation. The healing of lesions in the first episode was prompted by a subtotal parathyroidectomy for severe secondary hyperparathyroidism. However, the resumption of oral calcium and vitamin D analog for the parathyroidectomy-related hypocalcemia induced another occurrence of widespread calciphylactic skin lesions in areas of great adiposity. The typical regimen of IV sodium thiosulfate brought a successful outcome to the second episode. Now, growing numbers of successful treatment for calciphylaxis are reported with more specific therapies and a clear understanding of the pathogenetic mechanism is in sight.

Calcific uremic arteriolopathy ameliorated by hyperbaric oxygen therapy in high-altitude area

BACKGROUND

Calcific uremic arteriolopathy (CUA), previously called calciphylaxis, is a devastating complication of end-stage kidney disease (ESKD) with an annual incidence of 1-4% in dialysis patients and the mortality is as high as 80%. The rarity of the disease and the multifactorial nature of its causes have compromised good evidences that could determine the best therapy for the condition. For inhabitants in high-altitude area, the content of oxygen in the air is significantly lower than that in sea level area, which leads to the differences in the clinical manifestations and treatments to CUA.

CASE PRESENTATION

We presented a patient with CUA on Tibetan Plateau successfully treated by hyperbaric oxygen (HBO). This 46-year-old uremic Tibetan peasant received hemodialysis for 10 years, and over the last six months, skin necrosis occurred progressively on the distal joint of the middle finger of his right hand and the distal knuckles became paled, hardened, and severely painful. Extensive calcification of the arteries of both hands was revealed and his serum phosphorus elevated and serum calcium decreased. After diagnosis of CUA, patient was treated with HBO therapy for successive three weeks with a session per day, on the basis of secondary infection prevention. Pain of the affected finger was quickly alleviated in one week and the lesions of the affected finger healed in two months.

CONCLUSION

As the dialysis population in high-altitude area increasing rapidly in recent years, this management strategy of improving focal oxygen supply by HBO might act as a reference for the treatment of CUA patients in similar conditions.

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.

Painful skin ulcers in a hemodialysis patient

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

Calciphylaxis: a report of six cases and review of literature

Calciphylaxis is usually a fatal condition that develops in a few chronic renal failure patients, and it is characterized by calcifications in subcutaneous arteries, infarcts in skin, and the neighboring subcutis. Calciphylaxis, once considered as a rare condition, has been reported to have an annual incidence of 1% and a prevalence of 4% in dialysis patients. We describe our clinical experience in six end-stage renal disease patients on dialysis that presented with calciphylaxis and died due to sepsis, and review the pathogenesis, epidemiology, clinical and histopathologic features, and treatment of calciphylaxis. Physicians should initially consider the possibility of calciphylaxis in case of development of skin lesions in chronic renal failure patients with impaired calcium, phosphorus, and parathyroid hormone levels. The most important cause of mortality in this condition is infection. Therefore, differential diagnosis of these lesions from systemic vasculitis in their early stages and withdrawal of immunosuppressive therapy that increases the tendency to infections are essential.

Calciphylaxis with normal renal function: treated with intravenous sodium thiosulfate

Calciphylaxis is a rare and potentially life-threatening condition. It is thought to result from arterial calcification causing complete vascular occlusion and subsequent cutaneous infarction. Most often, it is a complication of end-stage renal failure or hyperparathyroidism; without either of these associated conditions, it is extremely rare. We report a case of calciphylaxis in a 58-year-old white British man, who had received long-term oral prednisolone for asthma control, with prophylactic calcium supplementation. There was no history of renal failure, and the patient's parathyroid function was normal. He was found to be heterozygous for the Factor V Leiden mutation. The acute presentation was seemingly precipitated by an episode of trauma and subsequent compression bandaging. The patient responded promptly to intravenous sodium thiosulfate. To our knowledge, this is the first case with no history of renal failure and normal parathyroid function, precipitated by compression bandaging and with an associated Factor V Leiden mutation.

A case-control study of calciphylaxis in Japanese end-stage renal disease patients

BACKGROUND

Calciphylaxis, also called calcific uremic arteriolopathy, is a rare and often fatal complication of end-stage renal disease and is characterized by painful skin ulceration, necrosis, medial calcification and intimal proliferation of small arteries. Studies in western countries have reported incidences ranging from 1 to 4% in chronic hemodialysis patients. Since no systematic studies of calciphylaxis have ever been performed in Japan, we conducted a nationwide survey and a case-control study to identify the characteristics of calciphylaxis in the Japanese dialysis population.

METHODS

Firstly, we sent a questionnaire to 3760 hemodialysis centers in Japan, asking whether calciphylaxis cases had been encountered in the past, and detailed clinical data regarding each case were then collected from the centers. In addition, two control dialysis patients matched for age and duration of hemodialysis to each calciphylaxis case were identified at the participating centers, and their data were analyzed to identify risk factors for calciphylaxis.

RESULTS

Responses to the questionnaire were obtained from 1838 centers (48.3%), and 151 centers reported that a total of 249 cases had been encountered. Sixty-four centers agreed to participate in the case-control study, and detailed clinical data in regard to 67 cases were obtained. In 28 of the 67 cases, a definite diagnosis of calciphylaxis was made by our study group based on the clinical characteristics and skin biopsy findings. A univariate logistic regression model comparing them with 56-matched controls identified warfarin therapy [odds ratio (OR) 11.4, 95% confidence interval (CI)] 2.7-48.1, P=0.0009], each 1 g/dL decline in serum albumin level (OR 19.8, 95% CI 4.4-89.5, P=0.0001), each 100 mg/dL increment in plasma glucose level (OR 3.74, 95% CI 1.08-12.9, P=0.037) and each 1 mg/dL increment in adjusted serum calcium level (OR 3.2, 95% CI 1.63-6.30, P=0.0008) at the time of diagnosis as significantly associated with calciphylaxis, but no significant associations were found with female gender, vitamin D analog therapy, serum phosphate level, adjusted calcium-phosphate products or serum alkaline-phosphatase level. Warfarin therapy and lower serum albumin levels were still significant risk factors after a multivariate logistic regression model analysis.

CONCLUSION

The results of this study showed that warfarin therapy and lower serum albumin levels are significant and strong risk factors for the development of calciphylaxis in chronic hemodialysis patients in Japan.

Calciphylaxis: a systematic review of existing and emerging therapies

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

[Skin diseases in hemodialysis and kidney transplant patients]

Recently, the world is facing an escalate in the incidence of chronic kidney disease (CKD). Databases containing information about patients in end stage renal disease (ESRD), especially in the United States, were the sources of initial information about it. Brazil has the third largest population on dialysis in the world, and there are about 680 dialysis centers, spread across all units of the federation in the present, providing treatment to an estimated population of almost 90,000 patients. Cutaneous involvement in the chronic renal failure is characterized by a number of manifestations, which may be related to three processes: the primary renal disease, the uremic state, or the therapeutic measures used in their handling. The skin changes in these two classes of patients, dialysis and transplant recipients, have been the subject of several studies. n recent years, however, great progress has been achieved in these two therapeutic modalities, which may have changed not only the type of the dermatologic disorders associated with these two conditions, but also their intensity or frequency. This article aims to yield an update as to the topic skin diseases in hemodialysis and kidney transplant patients.

Calcific uremic arteriolopathy in peritoneal dialysis populations

Calciphylaxis or calcific uremic arteriolopathy is an infrequent complication of end stage kidney disease. It is characterized by arteriolar medial calcification, thrombotic cutaneous ischemia, tissue necrosis often leading to ulceration, secondary infection and increased mortality rates. Current, multimodality treatment involves local wound care, well-controlled calcium, phosphate and parathyroid hormone levels and combination therapy with sodium thiosulfate and hyperbaric oxygen therapy. This combination therapy may be changing the historically poor prognosis of calcific uremic arteriolopathy reported in the literature. Peritoneal dialysis is considered a risk factor based on limited publications, however this remains to be proven. Clinical presentation, diagnosis, pathogenesis and treatment of calcific uremic arteriolopathy in these patients are no different from other patients manifesting with this condition.

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.

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

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

Association of cumulatively low or high serum calcium levels with mortality in long-term hemodialysis patients

BACKGROUND

The outcome-predictability of baseline and instantaneously changing serum calcium in hemodialysis patients has been examined. We investigated the mortality-predictability of time-averaged calcium values to reflect the 'cumulative' effect of calcium burden over time.

METHODS

We employed a Cox model using up-to-5-year (7/2001-6/2006) time-averaged values to examine the mortality-predictability of cumulative serum calcium levels in 107,200 hemodialysis patients prior to the use of calcimimetics, but during the time where other calcium-lowering interventions, including lower dialysate calcium, were employed.

RESULTS

Both low (<9.0 mg/dl) and high (>10.0 mg/dl) calcium levels were associated with increased mortality (reference: 9.0 to <9.5 mg/dl). Whereas mortality of hypercalcemia was consistent, hypocalcemia mortality was most prominent with higher serum phosphorus (>3.5 mg/dl) and PTH levels (>150 pg/ml). Higher paricalcitol doses shifted the calcium range associated with the greatest survival to the right, i.e. from 9.0 to <9.5 to 9.5 to <10.0 mg/dl. African-Americans exhibited the highest death hazard ratio of hypocalcemia <8.5 mg/dl, being 1.35 (95% CI: 1.22-1.49). Both a rise and drop in serum calcium over 6 months were associated with increased mortality compared to the stable group.

CONCLUSIONS

Whereas in hemodialysis patients cumulatively high or low calcium levels are associated with higher death risk, subtle but meaningful interactions with phosphorus, PTH, paricalcitol dose and race exist.

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

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

Surgical management of calciphylaxis associated with primary hyperparathyroidism: a case report and review of the literature

Calciphylaxis, or calcific uremic arteriolopathy, commonly affects people with end-stage renal disease and carries with it a high rate of morbidity and mortality. Here, we present the unusual case of a 56-year-old woman, with extensive medical problems, who developed calciphylaxis in the presence of primary hyperparathyroidism. Our patient initially presented with bilateral, exquisitely tender thigh lesions. The diagnosis of calciphylaxis was rendered histologically by extensive calcification of the subcutaneous blood vessels. Subsequent parathyroidectomy identified the presence of a hyperactive mediastinal parathyroid adenoma, weighing 0.62 grams. Postoperatively, the patient had normalization of hypercalcemia and parathyroid hormone levels, with subsequent healing of her thigh wounds. Currently, there have been sixteen cases described in the English literature, with only nine being offered a potentially therapeutic parathyroidectomy. It is contingent upon the vigilant physician to diagnose and properly manage this difficult yet treatable condition.

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

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

Metal deposition in calcific uremic arteriolopathy

BACKGROUND

Calcific uremic arteriolopathy (CUA) is an often fatal disease that affects patients with end-stage renal disease. Although animal studies support a role for metals in the pathogenesis of CUA, metal accumulation in human tissue has not been previously evaluated.

OBJECTIVE

We sought to evaluate metal deposition in CUA.

METHODS

Twelve histologically proven cases of CUA were identified from our dermatopathology database. Five skin biopsy specimens from patients with chronic kidney disease exposed to gadolinium contrast but without CUA were used as controls. Quantification of metals including iron, aluminum, and gadolinium in the lesional skin was performed using inductively coupled mass spectrometry.

RESULTS

Seven patients had documented exposure to gadolinium-based contrast in the 2 years before CUA. Three of them had concurrent nephrogenic systemic fibrosis. Highly significant quantities of iron (P = .03) and aluminum (P = .0002) were detected in CUA specimens compared with controls. Significant amounts of gadolinium were present in several CUA biopsy specimens.

LIMITATIONS

Observational, retrospective study design and small sample size are limitations.

CONCLUSION

Tissue iron and aluminum content is increased in CUA. A significant amount of gadolinium is also present in some CUA specimens. Based on animal studies that strongly implicate metals in the pathogenesis of CUA, our data suggest that metal deposition should be considered in the pathogenesis of human CUA.