Cargando…
Yield of diagnostic tests in unexplained renal hypophosphatemia: a case series
BACKGROUND: Isolated renal hypophosphatemia may be inherited or acquired. An increasing number of patients with unexplained renal hypophosphatemia is being referred to our clinics, but the optimal diagnostic work-up is not known. Therefore, the aim of this study was to assess the diagnostic yield in...
Autores principales: | , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2018
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6123988/ https://www.ncbi.nlm.nih.gov/pubmed/30180816 http://dx.doi.org/10.1186/s12882-018-1017-z |
_version_ | 1783352945811652608 |
---|---|
author | Bech, A. P. Hoorn, E. J. Zietse, R. Wetzels, J. F. M. Nijenhuis, T. |
author_facet | Bech, A. P. Hoorn, E. J. Zietse, R. Wetzels, J. F. M. Nijenhuis, T. |
author_sort | Bech, A. P. |
collection | PubMed |
description | BACKGROUND: Isolated renal hypophosphatemia may be inherited or acquired. An increasing number of patients with unexplained renal hypophosphatemia is being referred to our clinics, but the optimal diagnostic work-up is not known. Therefore, the aim of this study was to assess the diagnostic yield in these patients. METHODS: We retrospectively evaluated all patients who were referred because of unexplained isolated renal hypophosphatemia to two academic tertiary referral centers in The Netherlands in the period of 2013–2017. RESULTS: We evaluated 17 patients. In five female patients renal hypophosphatemia could be attributed to the use of oral contraceptives. The other 12 patients had a median age of 48 years (10 males). There were no other signs of tubulopathy and none of the patients used drugs known to be associated with hypophosphatemia. FGF23 levels were above normal (> 125 RU/ml) in 2/12 patients. Genetic testing, performed in all patients, did not identify a mutation in genes known to be associated with renal phosphate wasting. A scan with a radiolabeled somatostatin analogue was performed in 8 patients. In one patient, with an FGF23 level of 110 RU/ml, an increased uptake of the somatostatin analog was observed due to tumor induced osteomalacia (TIO). CONCLUSIONS: Oral contraceptive use is an important but under-recognized cause of renal hypophosphatemia. The cause of isolated renal hypophosphatemia remained unexplained in the majority of other patients despite extensive and expensive additional investigations. The pre-test probability for tumor-induced osteomalacia or inherited renal hypophosphatemia in a patient with aspecific complaints and a normal FGF23 level is low. Further research is needed to investigate which patients should be screened for TIO. At present we suggest to perform somatostatin scans only in patients with severe complaints, elevated FGF23 levels, or progressive disease. |
format | Online Article Text |
id | pubmed-6123988 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-61239882018-09-10 Yield of diagnostic tests in unexplained renal hypophosphatemia: a case series Bech, A. P. Hoorn, E. J. Zietse, R. Wetzels, J. F. M. Nijenhuis, T. BMC Nephrol Research Article BACKGROUND: Isolated renal hypophosphatemia may be inherited or acquired. An increasing number of patients with unexplained renal hypophosphatemia is being referred to our clinics, but the optimal diagnostic work-up is not known. Therefore, the aim of this study was to assess the diagnostic yield in these patients. METHODS: We retrospectively evaluated all patients who were referred because of unexplained isolated renal hypophosphatemia to two academic tertiary referral centers in The Netherlands in the period of 2013–2017. RESULTS: We evaluated 17 patients. In five female patients renal hypophosphatemia could be attributed to the use of oral contraceptives. The other 12 patients had a median age of 48 years (10 males). There were no other signs of tubulopathy and none of the patients used drugs known to be associated with hypophosphatemia. FGF23 levels were above normal (> 125 RU/ml) in 2/12 patients. Genetic testing, performed in all patients, did not identify a mutation in genes known to be associated with renal phosphate wasting. A scan with a radiolabeled somatostatin analogue was performed in 8 patients. In one patient, with an FGF23 level of 110 RU/ml, an increased uptake of the somatostatin analog was observed due to tumor induced osteomalacia (TIO). CONCLUSIONS: Oral contraceptive use is an important but under-recognized cause of renal hypophosphatemia. The cause of isolated renal hypophosphatemia remained unexplained in the majority of other patients despite extensive and expensive additional investigations. The pre-test probability for tumor-induced osteomalacia or inherited renal hypophosphatemia in a patient with aspecific complaints and a normal FGF23 level is low. Further research is needed to investigate which patients should be screened for TIO. At present we suggest to perform somatostatin scans only in patients with severe complaints, elevated FGF23 levels, or progressive disease. BioMed Central 2018-09-04 /pmc/articles/PMC6123988/ /pubmed/30180816 http://dx.doi.org/10.1186/s12882-018-1017-z Text en © The Author(s). 2018 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Research Article Bech, A. P. Hoorn, E. J. Zietse, R. Wetzels, J. F. M. Nijenhuis, T. Yield of diagnostic tests in unexplained renal hypophosphatemia: a case series |
title | Yield of diagnostic tests in unexplained renal hypophosphatemia: a case series |
title_full | Yield of diagnostic tests in unexplained renal hypophosphatemia: a case series |
title_fullStr | Yield of diagnostic tests in unexplained renal hypophosphatemia: a case series |
title_full_unstemmed | Yield of diagnostic tests in unexplained renal hypophosphatemia: a case series |
title_short | Yield of diagnostic tests in unexplained renal hypophosphatemia: a case series |
title_sort | yield of diagnostic tests in unexplained renal hypophosphatemia: a case series |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6123988/ https://www.ncbi.nlm.nih.gov/pubmed/30180816 http://dx.doi.org/10.1186/s12882-018-1017-z |
work_keys_str_mv | AT bechap yieldofdiagnostictestsinunexplainedrenalhypophosphatemiaacaseseries AT hoornej yieldofdiagnostictestsinunexplainedrenalhypophosphatemiaacaseseries AT zietser yieldofdiagnostictestsinunexplainedrenalhypophosphatemiaacaseseries AT wetzelsjfm yieldofdiagnostictestsinunexplainedrenalhypophosphatemiaacaseseries AT nijenhuist yieldofdiagnostictestsinunexplainedrenalhypophosphatemiaacaseseries |