Abstract: FR-PO1067

Rapid Bedside Plasma Volume (PV) and Measured GFR (mGFR) in Normal and CKD Subjects

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 302 CKD: Estimating Equations, Incidence, Prevalence, Special Populations

Authors

  • Rizk, Dana, University of Alabama, Birmingham, Alabama, United States
  • Molitoris, Bruce A., Indiana University School of Medicine, Indianapolis, Indiana, United States
  • Meier, Daniel, FAST BioMedical, Carmel, Indiana, United States
  • Sandoval, Ruben M., Indiana University School of Medicine, Indianapolis, Indiana, United States
  • Chacana, Teresa, University of Alabama at Birmingham, Birmingham, Alabama, United States
  • Reilly, Erinn S., FAST BioMedical, Carmel, Indiana, United States
  • Seegmiller, Jesse C, University of Minnesota, Minneapolis, Minnesota, United States
  • Denoia, Emanuel, Icon, San Antonio, Texas, United States
  • Strickland, James S., FAST BioMedical, Carmel, Indiana, United States
  • Muldoon, Joseph, FAST BioMedical, Carmel, Indiana, United States
Background

Quantitative measurement of plasma volume (PV) and glomerular filtration rate (mGFR) remain arduous clinical tasks having wide ranges for individual subjects. Estimated GFRs (eGFRs), derived from endogenous markers such as creatinine, are commonly employed in both clinical AKI and CKD studies to evaluate severity of injury and disease progression. However, at the present time the eGFR results typically suffer in the healthy and end stage renal disease populations.

Methods

FAST BioMedical has developed a rapid PV and mGFR technique based on the plasma disappearance following a single IV injection containing a large 150kDa (12 mg) rhodamine derivative monitored as a signature of PV and small 5kDa fluorescein carboxy methylated dextrans (35mg) for mGFR determination, respectively. PV is quantified after only 15 minutes following injection by dilution of the large dextran which is stable for over 6 hours allowing repeat determinations without redosing.

Results

In a recently finished phase 2b study, involving 16 normal subjects and 8 CKD III and 8 CKD IV patients, injections were well tolerated and no SAEs were reported. A 24 hour repeat dose measurement in 8 healthy subjects showed PV reproducibility of better than +/- 5% and mGFR within 5% . In response to intravenous infusion of a 350 ml 5% albumin over 30 minutes the increase in PV, measured using dilution principles of the 150kd carboxy methylated dextran, was on average plus 290ml at 30 minutes post infusion. mGFR determination required three 0.5 ml blood draws over 2.5 hours and values compared well, +/- 5%, with standard Iohexol plasma disappearance studies using samples taken over 6 hours for all patients.

Conclusion

Use of this FAST BioMedical approach allows for the rapid bedside determination of PV, changes in PV with clinical maneuvers, accurate measurement of GFR and renal reserve (stimulated maximal GFR) while maintaining patient safety, measurement accuracy and reproducibility.

Funding

  • NIDDK Support