Clinical trial NCT04846647: Study of the Inappropriate Secretion of FGF23 in Patients Followed in Hospital in a Context of Hypophosphatemia
Official title: Study of the Inappropriate Secretion of FGF23 in Patients Followed in Hospital in a Context of Hypophosphatemia
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Hypophosphatemia Without Immediate Anteriority
Unexplained Hypophosphatemia
Keywords: FGF-23
Unexplained hypophosphatemia
Phosphate metabolism
Physiopathology of hypophosphatemia
Lead sponsor: University Hospital, Clermont-Ferrand
Sponsor class: OTHER
Collaborators: name: DiaSorin ; Saluggia, Italia
First posted: 2021-04-15
Enrollment: 260
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Major patient, male or female with hypophosphatemia (\< 0.80 mmol/L), without immediate anteriority

Brief summary: The discovery of FGF23, the missing link in the long researched and finally found phosphate metabolism, marked a turning point in the understanding and physiopathology of specific hypophosphatemia. By inhibiting the renal reabsorption of phosphate and the production of calcitriol, FGF23 behaves like a hypophosphatemia hormone.

Hypersecretion of FGF23 can occur in the case of genetic abnormalities (X-linked hypophosphatemic vitamin-resistant rickets, recessive or dominant hypophosphatemic rickets, McCune-Albright syndrome ...) or acquired abnormalities (oncogenic osteomalacia). Oncogenic osteomalacia can be induced by hyperproduction of FGF23 by benign tumours of mesenchymal origin. But more recently, several cases of malignant tumours secreting FGF23 have also been described (prostate, colon, breast, ovarian and lung cancers, pulmonary carcinoma, etc.)

Detailed description: To date, even if the incidence of FGF23-secreting tumours seems rare, no precise bibliographical data is available in the scientific literature. Future studies will have to address this issue in order not to underestimate the frequency of this complication.

In this context, investigators would like to study the incidence of inappropriate FGF23 increase from a collection of biological samples carried out on 500 patients treated at the Clermont-Ferrand University Hospital for hypophosphatemia.

Eligibility criteria: Inclusion Criteria:

* Major patient, male or female
* Taken care of at the Clermont-Ferrand University Hospital or the Jean Perrin Centre
* In a context of hypophosphatemia (\< 0.80 mmol/L), without immediate anteriority and not occurring during hospitalisation
* In capacity to express informed consent to participate in research
* Affiliated to a social security system

Exclusion Criteria:

* Previously diagnosed hypophosphatemia
* Hypophosphatemia during hospitalisation
* Haemodialysis patient
* Refusal to participate

Primary outcomes:
measure: Evaluate the frequency of blood levels of FGF23 unsuitable for hypophosphatemia
timeFrame: day 0
Secondary outcomes:
measure: Investigate the relationship between blood levels of FGF23 and other biochemical parameters in hospital patients with hypophosphatemia..
timeFrame: Day 1
measure: Investigate the relationship between blood levels of FGF23 and other biochemical parameters in hospital patients with hypophosphatemia.
timeFrame: day 1
Other outcomes:
Locations:
city: Clermont-Ferrand
country: France
facility: Chu Clermont Ferrand
city: Clermont-Ferrand
country: France
facility: Centre Jean Perrin
Study officials:
affiliation: University Hospital, Clermont-Ferrand
name: Damien BOUVIER
role: PRINCIPAL_INVESTIGATOR
References:
citation: Suvannasankha A, Tompkins DR, Edwards DF, Petyaykina KV, Crean CD, Fournier PG, Parker JM, Sandusky GE, Ichikawa S, Imel EA, Chirgwin JM. FGF23 is elevated in multiple myeloma and increases heparanase expression by tumor cells. Oncotarget. 2015 Aug 14;6(23):19647-60. doi: 10.18632/oncotarget.3794.
citation: Imel EA, Biggin A, Schindeler A, Munns CF. FGF23, Hypophosphatemia, and Emerging Treatments. JBMR Plus. 2019 May 13;3(8):e10190. doi: 10.1002/jbm4.10190. eCollection 2019 Aug.
citation: Endo I, Fukumoto S, Ozono K, Namba N, Inoue D, Okazaki R, Yamauchi M, Sugimoto T, Minagawa M, Michigami T, Nagai M, Matsumoto T. Nationwide survey of fibroblast growth factor 23 (FGF23)-related hypophosphatemic diseases in Japan: prevalence, biochemical data and treatment. Endocr J. 2015;62(9):811-6. doi: 10.1507/endocrj.EJ15-0275. Epub 2015 Jul 1.