Successful treatment of calciphylaxis with cinacalcet—an alternative to parathyroidectomy?

Calciphylaxis is a rare but serious complication of end-stage renal failure, which has a high mortality due to widespread vascular calcification and refractory infections [1,2]. Parathyroidectomy has been advocated as one of the few treatments that may reverse this condition [3], although this has not been universally accepted and is not always successful [4]. The newly developed calcimimetic, cinacalcet (marketed as Mimpara® in the EU, and as Sensipar® in the USA by Amgen Inc., Thousand Oaks, CA, USA) produces rapid biochemical control of secondary hyperparathyroidism [5,6], and thus may represent an alternative treatment for patients with calciphylaxis. A 45-year-old man with end-stage renal failure due to autosomal dominant polycystic kidney disease started treatment with peritoneal dialysis in 2000. He had hypertension and asthma, but no other comorbidities and was a non-smoker. He transferred to haemodialysis in 2002, after bilateral nephrectomies for infection and haemorrhage. He was assessed for renal transplantation, but it was considered unsuitable for technical reasons related to extensive cystic hepatomegaly. In 2003, his secondary hyperparathyroidism became more difficult to control. Activated vitamin D was relatively contra-indicated by a persistently elevated serum calcium phosphate product (4.79–7.85 mmol2/l2) (Figure 1). Pre-dialysis corrected serum calcium was at or above the upper limit of normal at 2.50–2.72 mmol/l and serum phosphate was elevated between 1.68–2.94 mmol/l, despite therapy with 7.2 g/day of sevelamer and the use of low calcium dialysate (1.25 mmol/l). He was also on calcium carbonate as a phosphate binder, because of poor control of serum phosphate. Serum alkaline phosphatase was progressively and persistently raised to three times the upper limit of normal (reference range 50–179 IU/l). Intact parathyroid hormone levels had reached 244 pmol/l. A 99mTc-sestamibi-pertechnetate subtraction scan showed three areas of increased uptake at the lower poles of both thyroid lobes, and inferior to the left lobe, consistent with the presence of parathyroid adenomata.