Multimodal treatment of calcific uraemic arteriolopathy (calciphylaxis): a case series

Calcinosis Cutis and Calciphylaxis in Autoimmune Connective Tissue Diseases

Calcinosis represents a severe complication of several autoimmune disorders. Soft-tissue calcifications have been classified into five major types: dystrophic, metastatic, idiopathic, iatrogenic, and calciphylaxis. Autoimmune diseases are usually associated with dystrophic calcifications, including calcinosis cutis, occurring in damaged or devitalized tissues in the presence of normal serum levels of calcium and phosphate. In particular, calcinosis cutis has been described in dermatomyositis, polymyositis, juvenile dermatomyositis, systemic sclerosis, systemic lupus erythematosus, primary Sjögren's syndrome, overlap syndrome, mixed connective tissue disease, and rheumatoid arthritis. Calciphylaxis, a severe and life-threatening syndrome presenting with vascular calcifications and thrombosis, has also been associated with some autoimmune conditions. Due to the potentially disabling character of calcinosis cutis and calciphylaxis, physicians' awareness about the clinical presentation and management of these diseases should be increased to select the most appropriate treatment option and avoid long-term complications. In this review, we aim to analyze the clinical features of calcinosis cutis and calciphylaxis associated with autoimmune diseases, and the main treatment strategies evaluated up to now for treating this potentially disabling disease.

Sodium Thiosulfate as a Treatment for Calciphylaxis

The use of sodium thiosulfate has emerged as a promising treatment for calciphylaxis, albeit inconclusively in terms of efficacy and variable outcomes. Research in this field has been limited by a paucity of samples due to the rarity of the disease. We herein discuss eight calciphylaxis patients' responses to STS, the potential predictive factors affecting outcomes and compare our results with previously published literature. We are able to show that lesion severity, concomitant drugs, and dialysis duration may be predictive factors of outcomes. Further, improvement of the wound site may be a clinically relevant prognostic determinant.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Calciphylaxis

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Multi-intervention management of calcific uremic arteriolopathy in 24 patients

Background

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

Methods

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

Results

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

Conclusions

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

A 71-Year-Old Female with Myocardial Infarction and Long-Standing Ulcers on the Thigh

Calciphylaxis is most commonly encountered in patients with end-stage renal disease; however, it is increasingly observed in nonuremic patients as well. It is important to consider and diagnose nonuremic calciphylaxis early, as prompt treatment and mitigation of associated risk factors is essential to improve long-term outcomes for these patients. Here, we present the case of a 71-year-old woman with atrial fibrillation on warfarin, but without renal disease, who presented with two long-standing ulcers on her thigh and was diagnosed with the aid of biopsy with calciphylaxis. We review the existing literature on the subject and offer this case as a representative report of a clinicopathologic correlation for this disorder.

Vitamin K-Dependent Carboxylation of Matrix Gla Protein Influences the Risk of Calciphylaxis

Matrix Gla protein (MGP) is a potent inhibitor of vascular calcification. The ability of MGP to inhibit calcification requires the activity of a vitamin K-dependent enzyme, which mediates MGP carboxylation. We investigated how MGP carboxylation influences the risk of calciphylaxis in adult patients receiving dialysis and examined the effects of vitamin K deficiency on MGP carboxylation. Our study included 20 patients receiving hemodialysis with calciphylaxis (cases) and 20 patients receiving hemodialysis without calciphylaxis (controls) matched for age, sex, race, and warfarin use. Cases had higher plasma levels of uncarboxylated MGP (ucMGP) and carboxylated MGP (cMGP) than controls. However, the fraction of total MGP that was carboxylated (relative cMGP concentration = cMGP/[cMGP + uncarboxylated MGP]) was lower in cases than in controls (0.58±0.02 versus 0.69±0.03, respectively; P=0.003). In patients not taking warfarin, cases had a similarly lower relative cMGP concentration. Each 0.1 unit reduction in relative cMGP concentration associated with a more than two-fold increase in calciphylaxis risk. Vitamin K deficiency associated with lower relative cMGP concentration in multivariable adjusted analyses (β=-8.99; P=0.04). In conclusion, vitamin K deficiency-mediated reduction in relative cMGP concentration may have a role in the pathogenesis of calciphylaxis. Whether vitamin K supplementation can prevent and/or treat calciphylaxis requires further study.

A case report of severe calciphylaxis - suggested approach for diagnosis and treatment

BACKGROUND

Calciphylaxis is a serious complication in patients with chronic kidney disease associated mineral and bone disorder. It can occur in conditions with low and high bone turnover. So far, there are no definite diagnostic and therapeutic guidelines which may prevent the devastating outcome in many calciphylaxis patients. We report a case which clearly illustrates that knowledge of the underlying bone disorder is essential for a directed treatment. Based on this experience we discuss a systematic diagnostic and therapeutic approach in patients with calciphylaxis.

CASE PRESENTATION

We report a patient with severe calciphylaxis. Initial evaluation showed an elevated serum parathormone concentration and a bone-specific alkaline phosphatase activity in the upper normal range; however, the bone biopsy clearly showed adynamic bone disease. Extended dialysis with low calcium dialysate concentration and citrate anticoagulation, and administration of teriparatide led to a further increase in bone-specific alkaline phosphatase activity and most importantly, resulted in an activated bone turnover as confirmed by a second bone biopsy 11 weeks later.

CONCLUSIONS

This case illustrates that laboratory tests cannot reliably differentiate between high and low bone turnover in calciphylaxis patients. More importantly, this case highlights the fact that specific therapies that alter bone metabolism cannot be applied without knowledge of the bone status. On this background, we suggest that bone biopsies should be an integral part in the diagnosis and therapeutic decision in these patients and should be evaluated in further studies.