Diagnosing Calciphylaxis: A Review With Emphasis on Histopathology

Elastic fiber alterations and calcifications in calcific uremic arteriolopathy

Calcific uremic arteriolopathy (CUA) is a severely morbid disease, affecting mostly dialyzed end-stage renal disease (ESRD) patients, associated with calcium deposits in the skin. Calcifications have been identified in ESRD patients without CUA, indicating that their presence is not specific to the disease. The objective of this retrospective multicenter study was to compare elastic fiber structure and skin calcifications in ESRD patients with CUA to those without CUA using innovative structural techniques. Fourteen ESRD patients with CUA were compared to 12 ESRD patients without CUA. Analyses of elastic fiber structure and skin calcifications using multiphoton microscopy followed by machine-learning analysis and field-emission scanning electron microscopy coupled with energy dispersive X-ray were performed. Elastic fibers specifically appeared fragmented in CUA. Quantitative analyses of multiphoton images showed that they were significantly straighter in ESRD patients with CUA than without CUA. Interstitial and vascular calcifications were observed in both groups of ESRD patients, but vascular calcifications specifically appeared massive and circumferential in CUA. Unlike interstitial calcifications, massive circumferential vascular calcifications and elastic fibers straightening appeared specific to CUA. The origins of such specific elastic fiber's alteration are still to be explored and may involve relationships with ischemic vascular or inflammatory processes.

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.

Calciphylaxis and Kidney Disease: A Review

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

Successful Treatment Using Apixaban in a Patient on Hemodialysis with Uremic Calciphylaxis

Calciphylaxis is a rare but serious condition in which microvessel occlusion occurs within the subcutaneous adipose tissue and dermis, leading to painful lesions. End-stage renal disease requiring hemodialysis and warfarin therapy can increase the risk of calciphylaxis. In this report, we describe the evaluation and treatment of a 75-year-old female patient with warfarin-induced calciphylaxis who presented unique symptoms. The patient required intensive care unit admission due to hemodynamic instability, which was treated with inotropes and broad-spectrum intravenous antibiotics. This description of the patient's unusual symptoms has the potential to provide insights needed to improve the diagnosis of future patients. Due to the unavailability of FDA-approved treatment for calciphylaxis, its management is based on data from observational studies and clinical experience.

Prevalence and Clinical Characteristics of Calciphylaxis in Chinese Hemodialysis Patients

Background

Calciphylaxis is a grievous life-threatening vascular disease that commonly affects dialysis population. This is the first epidemiological survey of calciphylaxis initiated in China.

Methods

In the cross-sectional survey, a stratified sampling method was used to select 24 dialysis centers in Jiangsu Province. The participants were all adult patients in each center who had been on hemodialysis for more than 6 months. Calciphylaxis patients were uniformly diagnosed based on characteristic skin lesions and histopathological features.

Results

A total of 3,867 hemodialysis patients (average age of 55.33 ± 13.89 years; 61.81% of males) were included. Forty eight cases were diagnosed with calciphylaxis, and prevalence was 1.24%. Among calciphylaxis patients, 33 cases were male, and the average age and median dialysis duration were 53.85 ± 15.17 years and 84.00 (48.00, 138.75) months, respectively. Skin biopsy was performed in 70.83% of calciphylaxis patients, and positive rate was 64.71%. Meanwhile, the positive rate of bone scintigraphy in the diagnosis of calciphylaxis was 62.5%. The prevalence of hyperparathyroidism in case group was as high as 72.92% with longer duration, and 42.86% had undergone parathyroidectomy. Multivariate analysis indicated that increased BMI, prolonged dialysis duration, warfarin therapy, hyperparathyroidism, diabetes, tumors, low serum albumin and high serum alkaline phosphatase levels were high-risk factors for calciphylaxis.

Conclusions

The prevalence of calciphylaxis in Chinese hemodialysis patients was 1.24% according to regional epidemiological survey, but its actual prevalence would be presumably far beyond present data. It's urgent to improve clinical understanding of calciphylaxis, and multifaceted diagnostic methods should be applied for early screening.

Case Report: Idiopathic Subcutaneous Thrombotic Vasculopathy

Lower extremity ulcers have significant morbidity, with treatment determined by the underlying disorder. Reported is a 32-year-old female presenting with small skin nodules and bruises across her legs 4 weeks following her second COVID vaccination. These lesions progressed into large, necrotic ulcers over several months. Initial work-up showed widespread pannicular thrombotic vasculopathy with ischemic skin necrosis. The tissue was negative for calcification on Von Kossa histochemistry, and a working diagnosis of subcutaneous thrombotic vasculopathy was suggested. The ulcers progressed despite treatments with corticosteroids, therapeutic anticoagulation, intravenous immunoglobulin, plasmapheresis, sodium thiosulfate, wound care, and repeat debridement. Later debridement specimens demonstrated rare vascular and pannicular calcifications. This finding supports the hypothesis that subcutaneous thrombotic vasculopathy is a precursor to calciphylaxis, the patient’s current working diagnosis. However, based on the patient’s entire clinical picture, a definitive diagnosis has yet to be found. This report highlights the challenges of working with rare diseases and the importance of multidisciplinary cooperation.

Cutaneous vascular calcification. Peri-eccrine calcification as a diagnostic key for calciphylaxis

BACKGROUND

Attempts have been made to establish discriminative criteria between classic calciphylaxis (CPX) and those cases in which cutaneous vascular calcification (CVC) represents an incidental finding (epiphenomenon).

METHODS

Retrospective, observational cohort study of patients with CVC with the aim of distinguishing clinicopathological features between CVC as classic CPX (CVC in cutaneous lesions with erythemato-violaceous plaques with or without ulceration) or as epiphenomenon (CVC in cutaneous lesions with known diagnosis). Different clinicopathological parameters and presence of perieccrine calcification and pseudoxanthoma-elasticum (PXE)-like changes were evaluated.

RESULTS

Sixty-six patients were studied. The CPX group showed a significantly higher percentage of renal failure, hypertension, altered laboratory parameters, painful lesions and mortality rate. Histopathologically, the CPX group was associated with more than one vessel per field involved with subintimal concentric calcification and perieccrine calcification (observed exclusively in CPX group), while PXE changes, although more frequent in the CPX group, were also observed in the epiphenomenon group.

CONCLUSIONS

Perieccrine calcification and the presence of more than one vessel per field involved by concentric pattern calcification could be used as a diagnostic marker of CPX. Although PXE-like changes are not an exclusive marker, they could suggest CPX diagnosis. This article is protected by copyright. All rights reserved.

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.

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

Introduction

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

Methods

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

Results

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

Conclusion

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

Clinical and Histopathologic Characteristics of the Main Causes of Vascular Occusion - Part II: Coagulation Disorders, Emboli, and Other

Vascular occlusion has multiple, diverse clinical manifestations, some of which can have grave consequences for patients. It also has a wide variety of causes, including thrombi, which we recently addressed in partI of this review. In this second part, we look at additional causes of vascular occlusion.