19
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Hungry bone syndrome and normalisation of renal phosphorus threshold after total parathyroidectomy for tertiary hyperparathyroidism in X-linked hypophosphataemia: a case report

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Introduction

          This is the first report of which the authors are aware to describe this c.2166delinsGG mutation in X-linked hypophosphataemia and to describe normalisation of renal threshold for phosphate excretion after parathyroidectomy for tertiary hyperparathyroidism in X-linked hypophosphataemia.

          Case presentation

          We present the case of a 34-year-old Caucasian woman with X-linked hypophosphataemia. She developed tertiary hyperparathyroidism with markedly high bone turnover requiring total parathyroidectomy and had prolonged requirement for intravenous calcium infusion after surgery. She had a novel mutation in her phosphate-regulating gene with homologies to endopeptidases on the X-chromosome and had an unusual degree of dependence on phosphate supplementation. Prior to operative intervention she had a trial of cinacalcet that improved bone turnover markers when used in isolation but which led to a paradoxical rise in parathyroid hormone levels when given with phosphate supplementation. After correction of hungry bone syndrome, the renal phosphorus threshold normalised as a manifestation of hypoparathyroid state despite marked elevation in level of fibroblast growth factor 23.

          Conclusions

          This case illustrates the risk of tertiary hyperparathyroidism as a complication of treatment for hypophosphataemia; it highlights the morbidity associated with hungry bone syndrome and provides novel insight into renal handling of phosphorus.

          Related collections

          Most cited references 11

          • Record: found
          • Abstract: found
          • Article: not found

          Approach to the hypophosphatemic patient.

          Hypophosphatemia is commonly missed due to nonspecific signs and symptoms, but it causes considerable morbidity and in some cases contributes to mortality. Three primary mechanisms of hypophosphatemia exist: increased renal excretion, decreased intestinal absorption, and shifts from the extracellular to intracellular compartments. Renal hypophosphatemia can be further divided into fibroblast growth factor 23-mediated or non-fibroblast growth factor 23-mediated causes. Proper diagnosis requires a thorough medication history, family history, physical examination, and assessment of renal tubular phosphate handling to identify the cause. During the past decade, our understanding of phosphate metabolism has grown greatly through the study of rare disorders of phosphate homeostasis. Treatment of hypophosphatemia depends on the underlying disorder and requires close biochemical monitoring. This article illustrates an approach to the hypophosphatemic patient and discusses normal phosphate metabolism.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Effects of therapy in X-linked hypophosphatemic rickets.

            Patients with X-linked hypophosphatemic rickets, which is clinically manifested by growth failure and bowing of the legs, are usually treated with phosphate and a vitamin D preparation. However, the efficacy of this treatment has been disputed, and nephrocalcinosis is a recognized complication of therapy. We studied 24 patients with X-linked hypophosphatemic rickets (9 boys and 15 girls) ranging in age from 1 to 16 years (median, 5.3). The duration of combination therapy ranged from 0.3 to 11.8 years (median, 3.0). We measured height as a standard-deviation (SD) score (the number of SDs from the mean height for chronologic age). Measurements made before the age of two years or after the onset of puberty were excluded. We compared the results with those reported in 1971 for 16 untreated prepubertal Australian patients. We also determined the severity of nephrocalcinosis (on a scale of 0 to 4, with 0 indicating no abnormalities and 4 stone formation) with renal ultrasonography and whether it could be related to the dosage of phosphate or vitamin D or to other factors. Patients treated for at least two years before the onset of puberty (n = 19) had a mean height SD score of -1.08, as compared with -2.05 in the untreated historical controls. The 13 patients who had been treated with calcitriol and phosphate for at least two years had an increase in the mean height SD score of 0.33, from -1.58 to -1.25 (95 percent confidence interval, 0 to 0.67; P = 0.05). Nineteen of the 24 patients (79 percent) had nephrocalcinosis detected on renal ultrasonography. The grade of nephrocalcinosis was significantly correlated with the mean phosphate dose (r = 0.60, P = 0.002), but not with the dose of vitamin D or the duration of therapy. All patients had normal serum creatinine concentrations. Therapy with calcitriol and phosphate may increase the growth of children with X-linked hypophosphatemic rickets. Nephrocalcinosis in these children represents a complication of therapy and is associated with the dose of phosphate received.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Calcimimetics as an adjuvant treatment for familial hypophosphatemic rickets.

              The treatment for X-linked hypophosphatemia (XLH) with phosphate and calcitriol can be complicated by secondary hyperparathyroidism and nephrocalcinosis. Furthermore, vitamin D and phosphate stimulate FGF23 production, the pathogenic factor causing XLH. We investigated in XLH patients: 1) whether treatment with the calcimimetic agent, cinacalcet, will block the rise in parathyroid hormone (PTH) caused by phosphate administration; and 2) whether treatment with oral phosphate and calcitriol increases FGF23 levels. Eight subjects with XLH were given a single oral dose of phosphate, followed the next day by combined treatment with phosphate and cinacalcet. Serum measurements of ionized calcium (Ca), phosphate, creatinine, intact PTH, 1,25(OH)(2)D, FGF23, and tubular threshold for phosphate/glomerular filtration rate (TP/GFR) were assessed in response to short-term treatment with phosphate and cinacalcet and compared with long-term administration of phosphate and calcitriol. Oral phosphate load increased serum phosphate, decreased ionized calcium, and increased PTH. Twenty-four hours later, FGF23 significantly increased and 1,25(OH)(2)D decreased. The concomitant administration of phosphate and cinacalcet resulted in further decrease in serum Ca(2+) but suppression of PTH and greater increase in serum phosphate and TP/GFR. Chronic treatment with phosphate and calcitriol resulted in a smaller increment in serum phosphate and high serum FGF23. Traditional therapy of XLH with phosphate and calcitriol elevates FGF23 and has the potential to stimulate PTH. Short-term treatment with cinacalcet suppresses PTH, leading to increase in TP/GFR and serum phosphate. Thus, long-term clinical studies are needed to investigate whether cinacalcet may be a useful adjuvant in the treatment of XLH, allowing the use of lower doses of phosphate and calcitriol.
                Bookmark

                Author and article information

                Contributors
                Journal
                J Med Case Rep
                J Med Case Rep
                Journal of Medical Case Reports
                BioMed Central
                1752-1947
                2014
                4 March 2014
                : 8
                : 84
                Affiliations
                [1 ]Department of Endocrinology, St. Vincent’s University Hospital, Dublin, Ireland
                [2 ]Metabolism Laboratory, St. Vincent’s University Hospital, Dublin, Ireland
                [3 ]DXA Unit, St. Vincent’s University Hospital, Dublin, Ireland
                [4 ]School of Medicine and Medical Sciences, University College Dublin, Dublin, Ireland
                Article
                1752-1947-8-84
                10.1186/1752-1947-8-84
                3946034
                24594262
                Copyright © 2014 Crowley et al.; licensee BioMed Central Ltd.

                This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.

                Categories
                Case Report

                Comments

                Comment on this article