LAUSR

small, the condition affected a high percentage of women receiving anticoagulation therapy, adding further support to the body of evidence that sex and anticoagulant use are 2 important risk factors for NUC. Warfarin, in particular, has been hypothesized topromoteNUCbyinhibitingvitaminK–dependentcarboxylation of matrix Gla protein, decreasing inhibition of local calcification.4 The estimated 1-year survival rate for all patients with calciphylaxis has previously been reported as 45.8%5; and patients with ulceration fare worse, with an estimated 80% mortality.6 Patients in the present study had a high survival rate (75%) despite the fact that all patients had ulceration. One possible reason for this improved survival rate is the frequent use of sodium thiosulfate, with 63% of patients (n = 10) in our analysis receiving this form of therapy. This finding contrasts with the 48% survivalratepreviouslyreportedamongNUCpatients2;notably,none of these patients received sodium thiosulfate, suggesting a possible benefit associated with sodium thiosulfate therapy for NUC. A limitation of the study is that only patients who had a skin biopsywereincluded.Thediagnosisofcalciphylaxisisoftenmade on clinical grounds, particularly in the setting of end-stage renal disease, and a skin biopsy is not always performed.