Sodium thiosulfate in the treatment of calcific uremic arteriolopathy

Abstract

Calcific uremic arteriolopathy (CUA; also known as calciphylaxis) is a life-threatening condition observed mostly in patients on dialysis. The key histopathologic features of CUA include media calcification of small arteries, associated with endovascular fibrosis and thrombosis. Several risk factors for CUA are related to disturbances in bone and mineral metabolism; current treatments largely aim to normalize these disturbances by lowering serum calcium phosphate concentration and thereby preventing, or even reversing, calcium phosphate oversaturation, precipitation and, finally, calcification. Administration of sodium thiosulfate, which sequesters calcium ions to form highly soluble calcium thiosulfate complexes, can prevent calcium phosphate precipitation. As randomized controlled studies on sodium thiosulfate are lacking, this Perspectives article focuses on case reports and case series; in these reports the compound seemed to be effective and was not associated with serious short-term adverse events. Large clinical trials to evaluate the efficacy and long-term safety of sodium thiosulfate are clearly warranted.