NCT03119818

Intracellular Phosphate Concentration Evolution During Hemodialysis by MR Spectroscopy

Intracellular Phosphate and Adenosine Triphosphate (ATP) Concentration Evolution by Magnetic Resonance (MR) Spectroscopy in Patients During Hemodialysis

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 11 (actual)
• Sponsor: Hospices Civils de Lyon · Academic / Other
• Sex: All
• Age: 18 Years – 80 Years
• Healthy volunteers: Not accepted

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)

Interventions

Type	Name	Description
DEVICE	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.
OTHER	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.

Timeline

• Start date: 2017-06-14
• Primary completion: 2017-07-29
• Completion: 2017-07-29
• First posted: 2017-04-19
• Last updated: 2025-12-19

Locations

1 site across 1 country: France