Management of Calciphylaxis in End-Stage Renal Disease

Diagnosis and Assessment

Calciphylaxis is a rare but life-threatening complication of CKD-MBD characterized by vascular calcification leading to ischemic skin ulceration 3
Serum calcium and phosphate levels are not predictive of outcomes in calciphylaxis and cannot be reliably used for guiding therapy 1, 3
C-reactive protein is the most helpful laboratory test in diagnosing calciphylaxis, reflecting the inflammatory component of the condition 3
Skin biopsy has significant limitations with variable sensitivity (20-80%) and risk of traumatizing vulnerable tissue, potentially triggering additional non-healing ulcers 1, 3

The National Kidney Foundation recommends sodium thiosulfate as first-line therapy at dosages of 12.5–25 g/session, 2–3 times/week, for 3–6 months 1
Discontinue medications that may contribute to calciphylaxis development, including warfarin and other vitamin K antagonists (associated with up to 11-fold increased risk) 1, 4
Limit exposure to excess calcium and phosphate 1
Consider magnesium supplementation (magnesium oxide or hydroxide) as it may prevent phosphate-induced vascular calcification, though clinical trial results have been contradictory 1

SNF472 (Hexaphosphate Phytate) is an emerging therapy showing promise in clinical trials with improvements in wound healing and reduced hospitalizations 1, 3
Parathyroidectomy should be considered in patients with calciphylaxis and elevated PTH levels (>500 pg/mL [55.0 pmol/L]) 2

Regular monitoring of wound healing and inflammatory markers (C-reactive protein) 3
Ongoing vascular surveillance to assess for progression of calcification 5

Avoid aggressive phosphate-lowering therapy in patients without overt hyperphosphatemia, as there are safety concerns and limited evidence of benefit 6, 7
Be aware that hypocalcemia may require individualized treatment rather than routine correction in all patients 6
Recognize that calciphylaxis can occur even with normal calcium and phosphate levels 1, 3
Patients on dialysis with calciphylaxis should avoid vitamin K antagonists for anticoagulation due to significantly increased risk 1, 4