Glomerular Filtration Rate (FIT-GFR) Test 

Technical Information

Drug safety has always played a key role in drug development. Unfortunately, drug toxicity studies often omit careful assessment of kidney function as indicated by recent publications.

Accurate measurements of kidney function using a measured glomerular filtration rate (GFR) test provides necessary and reliable information, while biomarker-based estimates are often misleading. On May 2010 (1), the FDA published a draft recommending that the drug development process should include a "measure" GFR.

Based on functional immunoassay technology (FIT™), BioPAL has developed immunoassay kits to measure the renal clearance of ideal filtration markers in order to obtain an accurate GFR measurement. We offer two different kits - Inulin (the gold standard) and Iohexol. Gadolinium-based kits have been discontinued (Gd-DTPA and Gd-DOTA).

(1) A recommendation from the conference is that in drug development, GFR should be measured directly with an inert tracer (e.g. inulin, iohexol, iothalamate, etc.) to determine pharmacokinetic or pharmacodynamic alterations due to kidney dysfunction. FDA KDIGO. Released draft. Guidance for Industry: Pharmacokinetics in Patients with Impaired Renal Function - Study Design, Data Analysis, and Impact on Dosing and Labeling. Docket Number FDA-2010-D-0133 May 16, 2010.

Due to the error associated with estimating GFR (eGFR) using biomarkers and correction equations, the above figure illustrates that researchers may miss important trends using eGFR that would otherwise be obvious using a direct measurement of kidney function (mGFR).

USP Inulin

BioPAL’s Inulin for Injection (USP) is for preclinical applications ONLY. However, BioPAL offers USP Inulin (I-1000) for researchers need to measure inulin clearance for human clinical research. Researchers may purchase USP Inulin (Solid) as a dry powder and then utilize a compounding pharmacy for formulation. BioPAL’s Inulin ELISA kits (FIT-0415) can then be used to measure its concentration is collected samples.

Kidney test to measure kidney function avoiding errors associated with serum creatinine.

Accurate kidney diagnostic that measure

The Product

BioPAL offers FIT-GFR™ (ELISA) kits that support either Inulin or Iohexol, as the filtration marker. Each kit is sold separately. Kidney function test to measure GFR. Iohexol clearance can be used in human research applications.

Iohexol is a clinically available CT contrast agent and is a known GFR marker. BioPAL’s FIT-GFR (Iohexol) kits are suitable for clinical research applications. Kidney function test to measure GFR.

Researchers can order FIT-GFR™ ELISA kits on-line. Two buffers that are required for performing the ELISA are also offered for on-line purchasing. Additional ELISA kit components are available and can be order by contacting BioPAL. A complete ELISA kit price list for each GFR marker is available below. Kidney function test to measure GFR.

FIT-GFR Inulin

BioPAL's inulin immunoassay (ELISA) kits provide a superior analytical method to measure inulin for GFR and nutritional research studies. This inulin test uses immunoassay to overcome all the major limitations associated with current analytical technology to measure inulin. The kit provides a sensitive assay that exceeds other methods to measure inulin and can detect inulin at a concentration of 10 ng/ml.

SINISTRIN (Inutest®): BioPAL's FIT-GFR (Inulin) kit is compatible with Fresenius's sinistrin, which is an inulin-like compound and is highly soluble in water, see comparison curve below. Sinistrin is marketed under the brand-name Inutest®. You should contact your Fresenius representative for availability.

Ultra-Low Dose Method

BioPAL’s ELISA platform provides clinical investigators with the ability to measure GFR using an ultra-low dose of contrast media. FIT-GFR Kits are available for three clinically available reagents: Iohexol, Gd-DTPA and Gd-DOTA.

FOR RESEARCH USE ONLY.

Researchers should validate the required dose and resulting sample dilutions for their unique application. Inulin is ONLY available for pre-clinical investigations!

NOT FOR USE IN DIAGNOSTIC PROCEDURES.