Forthcoming Issue Vol 19 No. 4 A RETROSPECTIVE STUDY OF THE BIOCHEMICAL AND RADIOLOGICAL PROFILE OF CHILDREN WITH GENETIC HYPOPHOSPHATEMIC RICKETS AND THEIR RESPONSE TO CONVENTIONAL TREATMENT
Main Article Content
Abstract
ABSTRACT
Background
In South Africa, there is little published data on the management of hypophosphatemic rickets and patients’ response to conventional treatment
Objectives
To assess the biochemical and radiological profile of children with genetic hypophosphatemic rickets and their response to conventional treatment.
Methods
Retrospective descriptive study on children under the age of 18 years with hypophosphatemic rickets. Assessing improvements in calcium, phosphorus, alkaline phosphatase (ALP), and parathyroid hormone (PTH) levels at 3, 6, 9 and 12 months and then every year until follow-up is completed. Assessing changes in the Thacher radiological score from baseline till 12 months after commencing treatment and till the last available radiological assessment.
Results
Seventy patients met the inclusion criteria. Majority of patients were black South African (n=54 (77%)). Positive family history seen in 32 (46%) patients. The patients were short statured with a mean height for age z score (HAZ) of - 3.4 ± 1.79. The mean calcium, phosphate, ALP, PTH levels and median Thacher score was 2.3 ± 0.16 mmol/L, 0.84 ± 0.19 mmol/L, 776.6 ± 531 IU/L, 7.15 ± 4.8 pmol/L and 8 (4-8) respectively. Improvement on the 5-year follow-up with treatment was seen in ALP (776 ±531 vs 525±232; p <0.001) and Thacher scores (8 (4-8) vs 2 (1-3.5); p =0.01), but no changes seen in phosphate or HAZ.
Conclusion
Conventional therapy for treatment of hypophosphatemic rickets is not associated with an improvement in HAZ despite an improvement in radiology and ALP. Adherence is a major challenge for majority of patients.
Article Details
Section
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
The SAJCH is published under an Attribution-Non Commercial International Creative Commons Attribution (CC-BY-NC 4.0) License. Under this license, authors agree to make articles available to users, without permission or fees, for any lawful, non-commercial purpose. Users may read, copy, or re-use published content as long as the author and original place of publication are properly cited.
Exceptions to this license model is allowed for UKRI and research funded by organisations requiring that research be published open-access without embargo, under a CC-BY licence. As per the journals archiving policy, authors are permitted to self-archive the author-accepted manuscript (AAM) in a repository.
How to Cite
References
REFERENCES
1. Lambert AS, Zhukouskaya V, Rothenbuhler A, Linglart A. X-linked hypophosphatemia: Management and treatment prospects. Joint Bone Spine. 2019;86(6):731–738.
2. Fuente R, Gil-Peña H, Claramunt-Taberner D, Hernández O, Fernández-Iglesias A, Alonso-Durán L, et al. X-linked hypophosphatemia and growth. Review Endocrine Metabolic Disorder. 2017 Mar;18(1):107–115.
3. Kinoshita Y, Fukumoto S. X-Linked Hypophosphatemia and FGF23-Related Hypophosphatemic Diseases: Prospect for New Treatment. Endocrine Review. 2018 Jun 1;39(3):274–291.
4. Balani S, Perwad F. Fibroblast growth factor 23 and phosphate homeostasis. Current Opinion in Nephrology Hypertension. 2019 Sep;28(5):465–473.
5. Bitzan M, Goodyer PR. Hypophosphatemic Rickets. Pediatric Clinics of North America. 2019 Feb;66(1):179–207.
6. Rothenbuhler A, Schnabel D, Högler W, Linglart A. Diagnosis, treatment-monitoring and follow-up of children and adolescents with X-linked hypophosphatemia (XLH). Metabolism. 2020 Feb;103S:153892.
7. Thacher TD, Pettifor JM, Tebben PJ, Creo AL, Skrinar A, Mao M, et al. Rickets severity predicts clinical outcomes in children with X-linked hypophosphatemia: Utility of the radiographic Rickets Severity Score. Bone. 2019 May; 122:76–81.
8. Haffner D, Emma F, Eastwood DM, Duplan MB, Bacchetta J, Schnabel D, et al. Clinical practice recommendations for the diagnosis and management of X-linked hypophosphataemia. Nature Review Nephrology. 2019 Jul;15(7):435–455.
9. Lamb YN. Burosumab: First Global Approval. Drugs. 2018 Apr;78(6):707–714.
10. Martín Ramos S, Gil-Calvo M, Roldán V, Castellano Martínez A, Santos F. Positive Response to One-Year Treatment with Burosumab in Pediatric Patients With X-Linked Hypophosphatemia. Front Pediatrics. 2020; 8:48.
11. Cost Comparison. In: Pharmacoeconomic Review Report: Burosumab (Crysvita): Kyowa Kirin Limited: Indication: For the treatment of X-linked hypophosphatemia in adult and pediatric patients one year of age and older. Canadian Agency for Drugs and Technologies in Health; 2020 Jul
12. Thacher TD, Fischer PR, Pettifor JM, Lawson JO, Manaster BJ, Reading JC. Radiographic scoring method for the assessment of the severity of nutritional rickets. Journal of Tropical Pediatrics. 2000 Jun;46(3):132–139.
13. Basu D, Pettifor JM, Kromberg J. X-linked hypophosphataemia in South Africa. 2004;94(6).
14. Linglart A, Biosse-Duplan M, Briot K, Chaussain C, Esterle L, Guillaume-Czitrom S, et al. Therapeutic management of hypophosphatemic rickets from infancy to adulthood. Endocrine Connect. 2014;3(1): R13-30.