Application of the single blood sample method to estimate feline glomerular filtration rate in a clinically relevant...

Area of Science:

• Veterinary Medicine
• Nephrology
• Pharmacokinetics

Background:

• Accurate estimation of glomerular filtration rate (GFR) is crucial for diagnosing and managing feline kidney diseases.
• Traditional GFR measurement methods can be complex and time-consuming in clinical practice.
• Non-ionic contrast media offer potential as alternative GFR tracers.

Purpose of the Study:

• To compare GFR estimated by a single-blood-sample method using iodixanol with the standard inulin clearance method in cats.
• To evaluate the feasibility and safety of the iodixanol method for long-term GFR monitoring in feline kidney transplantation.

Main Methods:

• Co-administration of iodixanol and inulin via intravenous bolus injection to 12 cats.
• Blood sample collection at 60 and 90 minutes post-injection.
• Quantification of serum iodixanol and inulin concentrations using high-performance liquid chromatography and colorimetric assay, respectively.

Main Results:

• A strong positive correlation (r = 0.90, P < 0.01) was observed between GFR values estimated by iodixanol and inulin.
• The simplified iodixanol method demonstrated no adverse reactions during a 750-day monitoring period in a feline kidney transplantation study.
• The method, incorporating volume of distribution, proved effective for GFR estimation.

Conclusions:

• The single-blood-sample method using iodixanol is a reliable and accurate alternative for estimating feline GFR.
• This simplified approach offers a practical and expedient tool for clinical application in veterinary medicine.
• The iodixanol method is suitable for long-term GFR monitoring, even in challenging clinical scenarios like kidney transplantation.