Calciphylaxis--a topical overview

Skin necrosis and calcifications after extravasation of vancomycin: a localised form of calciphylaxis?

Vancomycin is a tricyclic glycopeptide antibiotic produced from Streptococcus orientalis. There is much variation in the literature with regard to the recommended dose, dilution rate and type of infusion. Given the vesicant properties of vancomycin at supratherapeutic doses (>10mg/ml), tissue damage including blistering and necrosis have been reported. We report a rare case of bilateral cutaneous necrosis induced by accidental extravasation of vancomycin when being intravenously administered. The skin surrounding the injection site was marked by the appearance of subcutaneous calcifications. The development of iatrogenic skin calcinosis has not yet been described for the extravasation of vancomycin. The mechanism underlying the calcinosis observed in our case remains unclear, but we hypothesised a form of localised calciphylaxis induced by a local triggering factor. The ulcers progressed to re-epithelialisation following necrosis debridement and local conservative treatments. Given the increased prevalence of meticillin-resistant Staphylococcus aureus, which has prompted clinicians to gradually increase vancomycin dosage, clinicians should be aware of the high risk of skin toxicity in cases of vancomycin high-dose extravasation.

Calcific uremic arteriolopathy (calciphylaxis) calls into question the validity of guidelines of diagnosis and treatment

Background: Calciphylaxis is associated with end-stage renal failure or kidney transplant, although, cases of non-uremic calciphylaxis have been reported. It is a rare disorder, with high mortality, characterized by vascular calcification within cutaneous vessels; vascular calcification can occur in other organs, besides skin, like heart, lung, or pancreas, which is named visceral calciphylaxis.Objective: The purpose was to review current knowledge regarding diagnosis and therapeutic approach to cutaneous calciphylaxis.Methods: A literature review has been conducted associated to word "calciphylaxis".Results: The diagnosis is based mainly on clinical features and histologic findings. Therapeutic options are still controversial.Conclusions: Cutaneous calciphylaxis is a puzzling disease, with a challenging diagnosis, and a complex treatment, which requires a multidisciplinary team and expertise.

The Synergistic Interplay between Vitamins D and K for Bone and Cardiovascular Health: A Narrative Review

Vitamins D and K are both fat-soluble vitamins and play a central role in calcium metabolism. Vitamin D promotes the production of vitamin K-dependent proteins, which require vitamin K for carboxylation in order to function properly. The purpose of this review is to summarize available evidence of the synergistic interplay between vitamins D and K on bone and cardiovascular health. Animal and human studies suggest that optimal concentrations of both vitamin D and vitamin K are beneficial for bone and cardiovascular health as supported by genetic, molecular, cellular, and human studies. Most clinical trials studied vitamin D and K supplementation with bone health in postmenopausal women. Few intervention trials studied vitamin D and K supplementation with cardiovascular-related outcomes. These limited studies indicate that joint supplementation might be beneficial for cardiovascular health. Current evidence supports the notion that joint supplementation of vitamins D and K might be more effective than the consumption of either alone for bone and cardiovascular health. As more is discovered about the powerful combination of vitamins D and K, it gives a renewed reason to eat a healthy diet including a variety of foods such as vegetables and fermented dairy for bone and cardiovascular health.

Acute Cutaneous Necrosis: A Guide to Early Diagnosis and Treatment

Acute cutaneous necrosis is characterised by a wide range of aetiologies and is associated with significant morbidity and mortality, warranting complex considerations in management. Early recognition is imperative in diagnosis and management of sudden gangrenous changes in the skin. This review discusses major causes of cutaneous necrosis, examines the need for early assessment, and integrates techniques related to diagnosis and management. The literature, available via PubMed, on acute cutaneous necrotic syndromes was reviewed to summarise causes and synthesise appropriate treatment strategies to create a clinician’s guide in the early diagnosis and management of acute cutaneous necrosis. Highlighted in this article are key features associated with common causes of acute cutaneous necrosis: warfarin-induced skin necrosis, heparin-induced skin necrosis, calciphylaxis, pyoderma gangrenosum, embolic phenomena, purpura fulminans, brown recluse spider bite, necrotising fasciitis, ecthyma gangrenosum, antiphospholipid syndrome, hypergammaglobulinemia, and cryoglobulinemia. This review serves to increase recognition of these serious pathologies and complications, allowing for prompt diagnosis and swift limb- or life-saving management.

POEMS syndrome and calciphylaxis: an unrecognized cause of abnormal small vessel calcification

Background

Calciphylaxis is a syndrome consisting of vascular calcification, thrombosis, and skin necrosis. The syndrome develops often in chronic hemodialysis patients. However, there have been several case reports on calciphylaxis in patients with POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes) syndrome, a systemic disease associated with plasma cell dyscrasia and upregulation of vascular endothelial growth factor (VEGF).

Methods

In 76 POEMS patients and 86 age- and gender-matched disease controls, we studied abnormal small vessel calcification by computed tomography (CT) of the soft tissues. Clinical and laboratory profiles were compared between POEMS patients with and without calciphylaxis. Histological examination was performed in six autopsy cases.

Results

Small vessel calcification on CT was found in 17 % of POEMS patients and in none of the controls (P < 0.001). Autopsy confirmed calciphylaxis in 2 (33 %) patients. Among POEMS patients, higher disease activity, including more severe neuropathy and ascites, higher serum levels of interleukin-6, and lower serum albumin levels, was associated with the development of calciphylaxis. Serum levels of creatinine, calcium, and phosphate were not related to the presence of calciphylaxis.

Conclusions

Calciphylaxis is often present in patients with POEMS syndrome. Upregulation of multiple inflammatory cytokines such as VEGF and interleukin-6 may contribute to the development of calciphylaxis, by entirely different mechanism from that in chronic dialysis. POEMS syndrome should be recognized as a potential cause of calciphylaxis.

Use of Becaplermin for nondiabetic ulcers: pyoderma gangrenosum and calciphylaxis

Large difficult to heal ulcers of various etiologies carry a high morbidity and mortality rate. Becaplermin is a recombinant platelet-derived growth factor approved for treatment of diabetic ulcers. In this two-case series, we report the use of becaplermin in the treatment of ulcers due to (i) calciphylaxis, an often fatal condition resulting from systemic calcification and thrombosis of vessels and (ii) pyoderma gangrenosum (PG), a neutrophilic dermatosis. We also report that topical collagenase worsened PG ulcers, consistent with pathergy. Becaplermin can be used to help treat ulcers resulting from calciphylaxis and PG. These encouraging results lend support for the utilization of becaplermin in the treatment of nondiabetic chronic ulcers of various etiologies.

Calciphylaxis: a case series and the role of radiology in diagnosis

BACKGROUND

Calciphylaxis is a syndrome of vascular calcification most commonly affecting patients with end-stage renal disease (ESRD) on hemodialysis. Because of its high mortality rate, early diagnosis and treatment are necessary. Although diagnosis is usually based on skin biopsy, histopathology is often nonspecific. As the role of imaging in calciphylaxis has not been studied extensively, we examined the utility of radiology in the diagnosis of this disease.

METHODS

A thorough review of electronic medical records for 2005-2013 at Loyola University Medical Center yielded 10 patients with biopsy-proven calciphylaxis. Using the radiological picture archiving and communication system (PACS), all imaging studies of the affected body part obtained within 6 months of diagnosis were analyzed and tabulated.

RESULTS

All 10 patients had undergone imaging (computed tomography, ultrasound, plain radiography, and/or mammography) of the affected anatomy prior to diagnosis by skin biopsy. Nine of these patients were noted to have moderate-to-severe soft tissue vascular calcification in the area of skin biopsy.

CONCLUSIONS

This case series supports the suggestion that findings of superficial vascular calcifications on imaging studies are sensitive for the diagnosis of calciphylaxis. Used in conjunction with histopathological, clinical, and laboratory data, radiology can serve an important role in the diagnosis of calciphylaxis.

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 in the absence of renal failure and hyperparathyroidism in a nonagenarian

Calciphylaxis is a rare, potentially life-threatening syndrome of progressive cutaneous necrosis from calcium deposition. It is well described in uraemic diseases. However, its mechanism is poorly understood and information on non-uraemic causes is lacking. This is the first report of a biopsy-proven non-uraemic calciphylaxis in a nonagenarian.

Tumour calcification and calciphylaxis in end-stage renal disease

Although soft tissue and vascular calcifications are common in CKD and progress as an independent risk factor of all-cause mortality, tumour calcification and calciphylaxis are uncommon in patients with end-stage renal disease (ESRD). Here, we discuss a rare case of a patient with tumour calcification complicated with calciphylaxis developed septic shock from infection. Our patient is a 57-year-old man in his late stage of renal disease who presented with a huge mass at the right hip and necrotic cutaneous ulcers on the lower legs followed by local and systemic infection and death due to septic shock.

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.

Fibroblast involvement in soft connective tissue calcification

Soft connective tissue calcification is not a passive process, but the consequence of metabolic changes of local mesenchymal cells that, depending on both genetic and environmental factors, alter the balance between pro- and anti-calcifying pathways. While the role of smooth muscle cells and pericytes in ectopic calcifications has been widely investigated, the involvement of fibroblasts is still elusive. Fibroblasts isolated from the dermis of pseudoxanthoma elasticum (PXE) patients and of patients exhibiting PXE-like clinical and histopathological findings offer an attractive model to investigate the mechanisms leading to the precipitation of mineral deposits within elastic fibers and to explore the influence of the genetic background and of the extracellular environment on fibroblast-associated calcifications, thus improving the knowledge on the role of mesenchymal cells on pathologic mineralization.

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.

Calciphylaxis in chronic renal failure: An approach to risk factors

We present a case of calcifying panniculitis due to calciphylaxis in a nontherapy compliance 65-year-old man suffering from chronic renal failure. Calciphylaxis, a life threatening condition, is characterized by high calcium x phosphate product, presence of calcium crystals in the skin and secondary hyperparathyroidism. The clinical presentation includes painful firm plaques, which could progress to nonhealing ulcers. A review of literature is given with emphasis on identification of risk factors and early diagnosis.

An approach to the patient with retiform purpura

Retiform purpura consists of branching purpuric lesions caused by a complete blockage of blood flow in the dermal and subcutaneous vasculature. The differential diagnosis for retiform purpura is broad, including vasculitides of the small and medium vessels as well as microvascular occlusion due to thrombotic, infectious, and embolic phenomena. Determining the etiology of this important dermatologic sign can be a diagnostic challenge; however, an organized approach can improve the speed and accuracy of diagnosis and identify an effective treatment. This review focuses on early recognition, evaluation, and treatment of hospitalized patients with retiform purpura. Specifically, vasculitis, protein C and S deficiencies, heparin necrosis, warfarin necrosis, antiphospholipid antibody syndrome, disseminated intravascular coagulation, cryoglobulinemia, calciphylaxis, and cholesterol embolization syndrome will be discussed in detail. These conditions are commonly seen in consultative dermatology and can have multiorgan involvement, complicated laboratory evaluation, and long-term therapeutic implications.

Calciphylaxis: no longer rare; no longer calciphylaxis? A paradigm shift for wound, ostomy and continence nursing

This article challenges conventional wisdom that calciphylaxis is a rare condition. Rather, emerging evidence suggests that calciphylaxis is neither rare nor uncommon. In addition, the term calciphylaxis is questioned because misrepresents the underlying etiology of the condition. Multiple researchers and clinicians advocate abandoning the use of the term, but nursing literature has not yet followed suit. This article reviews the epidemiology, clinical manifestations, diagnosis, prevention, and treatment of this condition and associated wounds, and suggests areas for future research. The WOC nurse's role as an educator, leader, researcher, clinical expert, and patient advocate is summarized.

[Cutaneous calciphylaxis]

Calciphylaxis represents a dermatological emergency with a mortality of up to 80%. The disease is characterized by a triad of arteriolar medial calcification, thrombotic cutaneous ischemia and necrotic ulcerations. Recently several mechanisms of vascular calcification have been identified. This may led to preventive measures in the future. Early diagnosis is important to avoid complications such as sepsis. The dermatologist plays an important role in early diagnosis based on the recognition of clinical presentation and histopathology. Patients with end-stage renal disease are most commonly affected by calciphylaxis. The most frequent non-uremic predisposing conditions are primary hyperparathyroidism, malignancies, alcohol-induced liver disease, and autoimmune connective tissue diseases. Medical treatment aims to normalize mineral metabolism to reduce the serum concentration of sodium phosphate and thus to prevent precipitation and calcification. Newer compounds are bisphosphonates, non-sodium/non-aluminium phosphate binders, cinacalcet, paricalcitrol, and sodium thiosulfate. Among the surgical procedures parathyroidectomy did not result in a significant survival benefit. An aggressive surgical debridement of necrotic ulcerations, on the other hand, improved survival. Early diagnosis and a multidisciplinary treatment approach including re-vascularization by the vascular surgeon, repeated surgical debridement and split skin transplantation support wound healing and insure limb conservation.

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.

Warfarin in haemodialysis patients with atrial fibrillation: what benefit?

Warfarin is commonly used to prevent stroke in patients with atrial fibrillation; however, patients on haemodialysis may not derive the same benefit from warfarin as the general population. There are no randomized controlled studies in dialysis patients which demonstrate the efficacy of warfarin in preventing stroke. In fact, warfarin places the dialysis patient at increased risk for haemorrhagic stroke and possibly ischaemic stroke. Additionally, warfarin increases the risk of major bleeding and has been associated with vascular calcification. Routine use of warfarin in dialysis for stroke prevention should be discouraged, and therapy should only be reserved for dialysis patients at high risk for thrombo-embolic stroke and carefully monitored if implemented.

Calciphylaxis as a Catastrophic Complication in a Patient with POEMS Syndrome

Calciphylaxis is a vascular calcification-cutaneous necrosis syndrome, usually seen in patients with end-stage renal disease and secondary hyperparathyroidism. We report a 57-year-old polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome patient complicated with extensive skin ulcers due to calciphylaxis. He first noted a painful cutaneous ulcer on his left thigh, and then skin lesions rapidly worsened, resulting in multiple intractable ulcers with gangrene on his legs and trunk in a few months. Serum vascular endothelial growth factor (VEGF) was markedly elevated. Biopsy samples from his skin ulcers showed the deposition of calcium in the medial layer of cutaneous vessels, this finding being compatible with calciphylaxis. This is the second reported case with POEMS syndrome complicated with calciphylaxis. Both patients had no evidence of renal failure, hyperparathyroidism, or clotting disorders. The pathogenic link between POEMS syndrome and calciphylaxis is still unclear, but VEGF is known to regulate vascular calcification, in cooperation with bone morphogenetic proteins. Further, corticosteroid and several proinflammatory cytokines activate nuclear factor-κB pathway, known as the final common pathway leading to vascular calcification. Taken together, we consider that POEMS syndrome can be an independent risk condition for calciphylaxis.

Calciphylaxis

Calciphylaxis is defined by the presence of calcium deposits within the wall of small and medium-sized vessels. It is classically considered a life-threatening disease in patients with end-stage renal disease under dialysis. Clinically, it is characterized by the presence of painful plaques surrounded by a reticulate purpura that progresses to nonhealing ulcers, predominately in the lower limbs. It is associated with elevated parathyroid hormone levels and a dysregulation of the calcium/phosphate metabolism. In the absence of renal disease, normal parathyroid hormone levels, and calcium/phosphorus product, a good prognosis and the observation of similar calcium deposits associated with different conditions or even an epiphenomenon in diseases with well-known diagnosis leads one to consider the term calciphylaxis controversial.

Deep ulcer shaving combined with split-skin transplantation in distal calciphylaxis

Calciphylaxis is a cause of painful deep ulcers. There is controversy about best wound management in this disease. A retrospective study of inpatients during the 3 years was made. Seven calciphylaxis patients were identified. All patients suffered from various associated pathologies including diabetes mellitus type II and chronic renal insufficiency. Ulcers were treated by aggressive and deep shaving combined with autologous split-skin grafting in the same session. A 30% to 90% take rate of the grafts eventually with a complete ulcer healing in 6 of 7 patients was achieved. No patient developed a deep cutaneous infection or sepsis. All patients are still alive except one. The single death was related to cardiovascular complications. In distal calciphylaxis, aggressive ulcer surgery with defect closure offers a marked improvement in quality of life and prevents early deep skin infections and sepsis as major causes of mortality.

Systemic calciphylaxis

An 11-year-old male developed systemic calciphylaxis during induction therapy for acute lymphoblastic leukemia. His predisposing conditions were hypercalcemia, supplements for pamidronate-induced hypocalcemia and hypophosphatemia and renal insufficiency. He died of cardiorespiratory arrest on the 20th day of induction treatment. Autopsy revealed extensive calcium deposits in the heart, lungs and kidneys. He had diffused alveolar damage, acute tubular necrosis, chronic pancreatitis and marked hepatic steatosis. Systemic calcium deposition may progress rapidly in children with hypercalcemia of malignancy. Since pamidronate reduces mineral resorption from tissues, calcium and phosphate replacements increase systemic mineral deposits. Thus, mineral supplements should be considered only to combat symptoms.

Unusual case of calciphylaxis associated with primary hyperparathyroidism without coexistent renal failure

OBJECTIVE

To report a case of calciphylaxis in a patient with primary hyperparathyroidism without coexistent renal failure.

METHODS

The clinical, laboratory, and radiographic details of this case are reviewed, and the pathogenesis of calciphylaxis and the associated prognosis are discussed.

RESULTS

A 52-year-old woman had progressive fatigue, cachexia, severe osteoporosis, and necrotizing skin lesions. Her serum calcium level was 16 mg/dL, serum phosphorus level was 2.13 mg/dL, and parathyroid hormone level was 2,257 pg/mL (reference range, 15 to 65). On physical examination, gangrenous skin lesions with black crusts were noted on her legs, abdomen, and gluteal region. A mass lesion was detected in the parathyroid region by both ultrasonography and a parathyroid scan. The patient underwent a bilateral neck exploration, and a parathyroid adenoma measuring 3.5 by 1.5 by 1.2 cm was found on pathologic examination. After the operation, biochemical findings normalized, and the skin lesions progressively improved.

CONCLUSION

Severe primary hyperparathyroidism may be a factor leading to calciphylaxis, even in the absence of renal failure and a high calcium-phosphate product. This potentially life-threatening condition should not be left untreated if the levels of serum calcium and parathyroid hormone are severely elevated.

Recognizing calcific uremic arteriolopathy in autoimmune disease: an emerging mimicker of vasculitis

Calcinosis has long been associated with autoimmune disease and has a distinctive profile in scleroderma, dermatomyositis, systemic lupus erythematosus, and overlap syndromes. However, there have also been a number of case studies of calcific uremic arteriolopathy, or calciphylaxis, described within vessels, including patients with chronic renal insufficiency and several forms of vasculitis. Interestingly, the calciphylaxis associated with vasculitis appears to be unique, although relatively uncommon and is likely secondary to a disruption in the calcium-phosphate-parathyroid hormone axis. However, there appears to be an additional trigger, given that calciphylaxis is seen both in the absence of chronic kidney disease, and in the absence of a deranged calcium-phosphate-parathyroid hormone axis. These additional triggers include a high female predominance, obesity, diabetes and, possibly, warfarin use. In this review, we describe the clinical features of calciphylaxis, particularly in the context of autoimmune disease.

Intractable wounds caused by calcific uremic arteriolopathy treated with bisphosphonates

BACKGROUND

Calcific uremic arteriolopathy (calciphylaxis) is a calcification syndrome that predominantly affects relatively small vessels and is a life-threatening entity usually seen in patients with end-stage renal disease. Intractable skin necrosis sometimes causes lethal sepsis because it progresses rapidly as a result of mechanical stress.

OBJECTIVE

We sought to investigate the efficacy of etidronate disodium (bisphosphonates) in treating intractable ulcers occurred in a patient on hemodialysis accompanied with calcific uremic arteriolopathy.

METHODS AND RESULTS

A 53-year-old patient receiving hemodialysis with chronic renal failure accompanied with calciphylaxis had bilateral leg ulcers caused by minor trauma. The aggressive debridement worsened his skin condition as is usually seen in pyoderma gangrenosum. It eventually healed by lowering calcium-phosphorus levels with the administration of bisphosphonates and with the continuous use of sevelamer hydrochloride.

LIMITATIONS

This study reporting a single case limits the interpretation of results.

CONCLUSION

Bisphosphonates may be effective in treating calciphylaxis and arteriosclerosis obliterans by reducing the formation of ectopic calcification around blood vessels.