Calciphylaxis in Patients With Normal Renal Function: A Case Series and Systematic Review

To define concomitant risk factors, treatment, and outcomes for patients with nonnephrogenic calciphylaxis (NNC).

A retrospective review of Massachusetts General Hospital (MGH) medical records (January 1, 2014, through February 29, 2016) and a systematic literature review of PubMed, Google Scholar, EMBASE, MEDLINE, and CENTRAL (August 1, 1970, through July 31, 2016) were performed. Demographic characteristics and concomitant features were summarized and compared between patients with different lesion characteristics. Outcomes (lesion improvement and mortality) and their predictors were analyzed.

Nine patients (median age, 72 years [interquartile range (IQR), 44-82 years]; 78% women; 89% white race) were identified through MGH records. The literature review identified 107 patients (median age, 60 years [IQR, 49-72 years]; 77% women; 86% white race). Vitamin K antagonism and obesity were the most common concomitant factors. In the literature review, lower age (P<.001) and higher body mass index (P=.03) were associated with the central location of lesions, whereas vitamin K antagonism was associated with the peripheral location (P=.009). In the MGH series, median survival was 24.0 months (95% CI, 7.8-36.0 months), and 33% (95% CI, 14%-60%) had lesion improvement by 6 months. In the literature review, median survival was 4.2 months (95% CI, 1.9-5.9 months), median time to lesion improvement was 5.9 months (95% CI, 3.9-8.9 months), and none of the treatments were associated with lesion improvement or survival.

This description of concomitant traits may augment an earlier recognition of NNC. Future research is needed to investigate NNC pathogenesis and treatments.