Evaluation of Protein Loading on Measurement of Renal Reserve

Study Summary

The goal of this clinical trial is to evaluate the effect of protein loading on the measurement of renal reserve using the MediBeacon Transdermal glomerular filtration rate (tGFR) system. Adults with estimated glomerular filtration rate (eGFR) \>30 ml/min/1.73 m\^2 will be recruited to join the study. This is a potential new use for the tGFR for the assessment of renal reserve. Renal reserve is the increase in GFR that occurs in response to various stimuli, such as when one kidney is removed. The remaining kidney will often show an increase in GFR to compensate. Renal reserve is typically measured after a high protein meal and requires a reproducible stimulus and a repeated measurement of GFR. The main questions it aims to answer are: * To characterize the effect of protein loading on GFR (dose response curve) as assessed by the MediBeacon Transdermal GFR System * To determine Renal Reserve in participants with chronic kidney disease (CKD) using the MediBeacon Transdermal GFR System * To demonstrate whether any change in GFR following the protein stimulus is associated with a change in cardiac output using non-invasive bioimpedance (NICaS) Participants will participate in a Screening visit that will take place within 28 days of the scheduled administration of Lumitrace. On dosing day, participants will have the tGFR reusable sensor with disposable adhesive ring placed on their chest, and the MediBeacon Transdermal GFR System initiated to collect background fluorescence. Following an injection of Lumitrace and the initiation of GFR assessments, participants will ingest a high protein meal over 15-20 minutes. They will be followed at the study center for up to 6-8 hours following administration of Lumitrace. All participants will participate in a follow-up phone call approximately 7 days after the last exposure to Lumitrace. Researchers will analyze the results to see if there is a detectable difference in fluorescence clearance rate following the high protein meal

Primary Outcome

Renal reserve (%) will be calculated as Peak glomerular filtration rate (GFR) during the assessment period minus the average baseline GFR/average baseline GFR.

Interventions

• DEVICE MediBeacon Transdermal Glomerular Filtration Rate Measurement System (TGFR)
• DEVICE Lumitrace