Calciphylaxis: emerging concept in vascular patients

Successful treatment of calciphylaxis by a multidisciplinary approach

A 48-year-old woman performing peritoneal dialysis for end-stage renal disease presented with a painful leg ulcer. The investigation revealed an elevated parathyroid hormone level and the histological examination of the biopsy tissue from the ulcer revealed medial calcification of the arterioles, consistent with calciphylaxis. The patient developed additional ulcers in the lower limbs and treatment with antibiotics, cinacalcet, sevelamer, sodium thiosulfate, low calcium dialysate and hyperbaric oxygen therapy was instituted. The patient had a favourable outcome and after 9 months the ulcers had healed and the parathyroid hormone level reached the normal range. Calciphylaxis is a rare and life-threatening disorder associated with a mortality of 60-80%. Its pathogenesis is not fully understood hence there is no consensus in the treatment of this pathology.

Mechanisms and clinical consequences of vascular calcification

Vascular calcification has severe clinical consequences and is considered an accurate predictor of future adverse cardiovascular events, including myocardial infarction and stroke. Previously vascular calcification was thought to be a passive process which involved the deposition of calcium and phosphate in arteries and cardiac valves. However, recent studies have shown that vascular calcification is a highly regulated, cell-mediated process similar to bone formation. In this article, we outline the current understanding of key mechanisms governing vascular calcification and highlight the clinical consequences. By understanding better the molecular pathways and genetic circuitry responsible for the pathological mineralization process novel drug targets may be identified and exploited to combat and reduce the detrimental effects of vascular calcification on human health.

Calciphylaxis from nonuremic causes: a systematic review

BACKGROUND AND OBJECTIVES

Calciphylaxis, or calcific uremic arteriolopathy, is a well-described entity in end-stage kidney disease and renal transplant patients; however, little systematic information is available on calciphylaxis from nonuremic causes. This systematic review was designed to characterize etiologies, clinical features, laboratory abnormalities, and prognosis of nonuremic calciphylaxis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A systematic review of literature for case reports and case series of nonuremic calciphylaxis was performed. Cases included met the operational definition of nonuremic calciphylaxis-histopathologic diagnosis of calciphylaxis in the absence of end-stage kidney disease, renal transplantation, or acute kidney injury requiring renal replacement therapy.

RESULTS

We found 36 cases (75% women, 63% Caucasian, aged 15 to 82 yr) of nonuremic calciphylaxis. Primary hyperparathyroidism, malignancy, alcoholic liver disease, and connective tissue disease were the most common reported causes. Preceding corticosteroid use was reported for 61% patients. Protein C and S deficiencies were seen in 11% of patients. Skin lesions were morphologically similar to calcific uremic arteriolopathy. Mortality rate was 52%, with sepsis being the leading cause of death.

CONCLUSION

Calciphylaxis should be considered while evaluating skin lesions in patients with predisposing conditions even in the absence of end-stage kidney disease and renal transplantation. Nonuremic calciphylaxis is reported most often in white women. Mineral abnormalities that are invoked as potential causes in calcific uremic arteriolopathy are often absent, suggesting that heterogeneous mechanisms may contribute to its pathogenesis. Nonuremic calciphylaxis is associated with high mortality, and there is no known effective treatment.