[Calcific uraemic arteriolopathy (calciphylaxis): incidence, clinical features and long term outcomes]

Calcific uraemic arteriolopathy, also named calciphylaxis, is a rare but serious disorder characterized by medial mural calcification of small vessel leading to tissue ischaemia. It most commonly occurs in end stage renal disease patients on dialysis or recently received renal transplant with chronic nephropathy allograft. The pathogenesis of calciphylaxis is poorly understood. Abnormalities in mineral metabolism are clearly involved, but the specific factors that induces this disorder are not completely known.

Describe the main clinical features, outcomes and follow up of all calciphylaxis cases recorded in our dialysis unit in order to analyse the incidence, the main biologic parameters and the therapeutic background in which calciphylaxis appeared.

We performed a descriptive study about all the calciphylaxis cases diagnosed at our dialysis unit between the years 1991 and 2005.

8 cases, 6 women. Mean age: 65.3 years. All the patients were on haemodialysis treatment (one previous renal transplant). Mean time on dialysis was 76.6 months. Cumulative incidence was 1.17%. The principal end stage renal disease aethiology was neprhoangioeslerosis in four patients. Secondary hiperparatyrhoidism was present in 4 patients and 2 of them had been paratyrhoidectomized previously. A second cutaneous biopsy was needed for correct diagnosis in 3 patients. Calciphylaxis distal lesions were present in 7 patients. Two cases required urgent paratyrhoidectomy in order to control calciphylaxis. Only in 2 cases a Ca x P product > 60 mg/dL was present and 3 cases had PTHi values higher than 300 pg/mL. Calcium phosphate binders and vitamin D were present in 2 and 4 cases, respectively. One patient with proximal calciphylaxis died due to skin injury infection.

Calciphylaxis is a rare disorder but not exceptional, related to end stage renal disease patients. The diagnosis requires a high clinical suspicion, being sometimes difficult to distinguish from other entities in spite of pathological study. Proximal distribution of calciphylaxis had worst prognostic. Metabolic disorders and therapeutics background were not different from other patients included in dialysis treatment.