Development of calciphylaxis in kidney transplant recipients with a functioning graft

Background: Calciphylaxis is not uniquely observed in uraemic patients, as some cases have also been reported in patients with normal renal function or moderate chronic kidney disease (CKD), in association with severe vasculopathy or systemic inflammation. A particular subset worthy of studying is represented by those patients who develop calciphylaxis after kidney transplantation (KT).

Methods: Analysis of the local series of calciphylaxis after KT (n = 14) along with all the other cases reported in the literature from 1969 to 2019 (n = 31), for a total population of 45 patients, is presented. Demographic data, CKD history, risk factors, immunosuppression, clinical presentation and management have been analysed both as a whole and according to the time period (before or after the year 2000).

Results: Calciphylaxis developed during the first year after KT in 43.2% of patients and median (interquartile range) creatinine at diagnosis was 2.4 (1.25-4.64) mg/dL. The most frequent presentation included distal purpura or ulcers in one-third of cases and 39.1% of patients were receiving vitamin K antagonists. PTH values were above 500 pg/mL and below 100 pg/mL in 50.0% and 25.0% of cases, respectively. Whole population mortality was 55.6%. As expected, clinical presentation, immunosuppression and management varied depending on the time period. Patients diagnosed after 2000 were older, with longer dialysis vintage, and treatment was usually multimodal; on the contrary, in patients diagnosed before 2000, parathyroidectomy was the treatment of choice in 61.9% of cases.

Conclusions: Calciphylaxis can still occur after KT, in many cases during the first year and in patients with a good renal function. Risk factors and management varied according to the time period studied.