Intracellular Phosphate Concentration Evolution During Hemodialysis by MR Spectroscopy

NCT ID: NCT03119818

Last Updated: 2025-12-19

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 11 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2017-06-14
• Study Completion Date: 2017-07-29

Brief Summary

End-stage renal disease is associated with hyperphosphatemia due to a decrease of renal phosphate excretion. This hyperphosphatemia is associated with an increase of cardiovascular risk and mortality. Thus, three therapeutic options have been developed: dietary restriction, administration of phosphate binders and phosphorus clearance by hemodialysis (HD).

During a standard HD session, around 600 to 700mg phosphate is removed from the plasma, whereas it contains only 90 mg inorganic phosphate (Pi); 85% of phosphate is stored in bones and teeth in hydroxyapatite form, 14% is stored in the intracellular space (90% organic phosphate and 10% Pi), and 1% remains in the extracellular space.

Currently, the source of Pi cleared during HD remains to be determined. Phosphorus (31P) magnetic resonance spectroscopy allows reliable, dynamic and non-invasive measurements of phosphate intracellular concentration. The investigator's team recently published data obtained in anephric pigs, suggesting that phosphate intracellular concentration increases during a HD session. In parallel, we showed that ATP intracellular concentration decreased. These results suggest that the source of Pi cleared during HD could be located inside the cell.

In this study, investigators will measure intracellular phosphate and ATP concentrations and intracellular potential of hydrogen (pH) evolution during hemodialysis in 12 patients suffering from end-stage renal disease by MR spectroscopy.

If these results were confirmed in humans, it could explain, at least in part, HD intolerance in some patients and would lead to modify therapeutic approaches of hyperphosphatemia, for example, by modifying HD sessions time.

Conditions

End-Stage Renal Disease (ESRD)

Keywords

ESRD; hemodialysis; phosphate; ATP; magnetic resonance spectroscopy

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Patients suffering from ESRD treated by chronic hemodialysis

Patients aged from 18 to 80 years old, suffering from ESRD, treated by chronic hemodialysis since at least 6 months and whose phosphatemia at the beginning of HD sessions ranged from 1.5 to 3 mmol/L. Phosphorus (31P) magnetic resonance spectroscopy will be performed in these patients during hemodialysis in order to measure intracellular phosphate and ATP concentrations and intracellular pH evolution during hemodialysis.

Group Type: EXPERIMENTAL

Phosphorus (31P) magnetic resonance spectroscopy

Intervention Type: DEVICE

Phosphorus MR spectroscopy realized using a 3-Tesla MR imaging system. A twenty-cm circular surface coil will be set to the 31P resonance frequency and placed over the leg muscle region to obtain spectroscopy acquisitions. 31P MR spectra will be acquired before, during (every 160 seconds), and 30 minutes after dialysis. 31P MR system data will be analyzed using jMRUI Software. Five different peaks will be analyzed: inorganic phosphate, phosphocreatine, α-, β-, and γ-ATP.

Hemodialysis

Intervention Type: OTHER

Hemodialysis realized using a 5008 generator, a portable plant, a FX80 Dialyzer, a dialyzing solution with a standard electrolytes composition. The dialysis generator will be placed outside of the MRI examination room. The dialysis lines will pass through a wave guide to connect patients positioned on the bed of the MRI. A suitably trained nurse will proceed to the cannulation of the fistula, the connection of the catheter, and the monitoring of the clinical tolerance of the session.

Interventions

Phosphorus (31P) magnetic resonance spectroscopy

Phosphorus MR spectroscopy realized using a 3-Tesla MR imaging system. A twenty-cm circular surface coil will be set to the 31P resonance frequency and placed over the leg muscle region to obtain spectroscopy acquisitions. 31P MR spectra will be acquired before, during (every 160 seconds), and 30 minutes after dialysis. 31P MR system data will be analyzed using jMRUI Software. Five different peaks will be analyzed: inorganic phosphate, phosphocreatine, α-, β-, and γ-ATP.

Intervention Type: DEVICE

Hemodialysis

Hemodialysis realized using a 5008 generator, a portable plant, a FX80 Dialyzer, a dialyzing solution with a standard electrolytes composition. The dialysis generator will be placed outside of the MRI examination room. The dialysis lines will pass through a wave guide to connect patients positioned on the bed of the MRI. A suitably trained nurse will proceed to the cannulation of the fistula, the connection of the catheter, and the monitoring of the clinical tolerance of the session.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Patient suffering from end-stage renal disease, treated by chronic hemodialysis since at less 6 months
• Phosphatemia (at the start of the session) ≥ 1,5 mmol/L and ≤ 3 mmol/L
• written consent signed

Exclusion Criteria

• Major subject protected by law
• Prisoners or subjects who are involuntarily incarcerated
• Denutrition (weight loss ≥ 5 kg in one months/10 kg in 6 months, Body Mass Index (BMI) ≤ 21 kg/m2, albuminemia ≤ 35 g/L)
• Obesity (BMI ≥ 30 kg/m2)
• Phosphatemia at the start of the dialysis < 1,5 mmol/L or > 3 mmol/L
• Secondary hyperparathyroidism with parathormone (PTH) ≥ 1000 pg/mL
• Adynamic osteopathy (PTH ≤ 50 pg/mL)
• Hypoparathyroidism with a history of parathyroidectomy
• Hemoglobin ≤ 100 g/L
• Contraindication to heparin
• Temporary vascular access
• Contraindication to resonance magnetic spectroscopy (pacemaker or insulin pump, metallic valvular prosthesis, valvular prosthesis not compatible with resonance magnetic spectroscopy, dental appliance, intracerebral clip, claustrophobic subject).
• Simultaneous participation to another research protocol
• Patient not affiliated to a social security system

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Hospices Civils de Lyon

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Laurent JUILLARD, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Hospices Civils de Lyon

Locations

Service de Néphrologie Pavillon P, Hôpital E. Herriot

Lyon, , France

Countries

France

References

Chazot G, Lemoine S, Kocevar G, Kalbacher E, Sappey-Marinier D, Rouviere O, Juillard L. Intracellular Phosphate and ATP Depletion Measured by Magnetic Resonance Spectroscopy in Patients Receiving Maintenance Hemodialysis. J Am Soc Nephrol. 2021 Jan;32(1):229-237. doi: 10.1681/ASN.2020050716. Epub 2020 Oct 22.

Reference Type: RESULT

PMID: 33093193 (View on PubMed)

Other Identifiers

69HCL17_0047

Identifier Type: -

Identifier Source: org_study_id