July - September 2015, Volume 11, Issue 3

Crista C, Muresan A, Cadariu F, Petrica L, Zosin I

Secondary Hyperparathyroidism in a Patient Diagnosed with Pseudoxanthoma Elasticum and Associated Nephrocalcinosis

Acta Endo (Buc) 2015, 11 (3): 371-376
doi: 10.4183/aeb.2015.371

Introduction. Pseudoxanthoma elasticum (PXE) is a generalized progressive connective tissue disorder which affects elastic fibers and has multiple systemic manifestations. Case presentation. The patient, female, 39 years old, who was diagnosed in the teenage years with PXE, was hospitalized presenting asymptomatic nephrocalcinosis and increased plasma parathyroid hormone (PTH) levels. The laboratory data revealed: normal levels of calcium and phosphorus in serum, very low serum level of 25-hydroxycholecalciferol [25(OH)D] and low serum level of 1,25-dihydroxycholecalciferol [1,25(OH)2D3]. It was considered that our patient presented secondary hyperparathyroidism. The patient received therapy with alphacalcidol 0.5 μg/day and after 6 months of therapy, the evaluation of the plasma PTH level showed a normal value associated with an improvement of the serum level of the 25(OH)D (27.5 μg/L). Conclusions. Our case is original in terms of association of pseudoxanthoma elasticum with nephrocalcinosis and elevated plasma levels of PTH, which requires a differential diagnosis between normocalcemic primary hyperparathyroidism and secondary hyperparathyroidism. The very low level of 25(OH)D in serum associated with low levels of 1,25 (OH)2 D3 and a normal level of phosphorus led the diagnosis towards secondary hyperparathyroidism.

Keywords: pseudoxanthoma elasticum, nephrocalcinosis, parathyroid hormone, 25-hydroxycholecalciferol.

Correspondence: Corina Crista MD, “Victor Babes” University of Medicine and Pharmacy, Clinic of Endocrinology, 10th I. Bulbuca Blvd., Timisoara, Timis, 1900, Romania, E-mail: corina_crista@yahoo.com