Iohexol GFR
- Description
- This test is part of the transfer of services from the WellChild laboratory at the Evelina Children's Hospital. Glomerular filtration rate (GFR) is determined by measurement of plasma clearance of iohexol. Iohexol, a contrast agent or dye, is injected into the bloodstream and blood samples are collected at specified time-points (5, 120, 180 and 240 min). Iohexol, creatinine, SDMA and ADMA are all measured by liquid chromatography mass spectrometry (LC-MS/MS) as part of this test. This test is performed using a defined protocol and dedicated request form. It requires accurately timed sample collection and patient information. This test is not currently included in the laboratory's UKAS scope of accreditation to ISO15189:2022
- Clinical details
Glomerular filtration rate (GFR) has been considered one of the best physiological measures of kidney function. Estimated glomerular filtration rate (eGFR) by equations based on creatinine and/or cystatin C are less accurate than measured GFR. In specific clinical situations the precision of the equations can be relatively poor and a measured GFR may be required.
- Related condition
- Units
ml/min/1.73m2
- Synonyms
Iohexol GFR, mGFR, GFR, Iohexol,
- Testing site
- Synnovis : Reference Services : Blackfriars Hub
- Laboratory
- Inherited Metabolic Disease
- Sample type and volume required
Lithium heparin plasma. Minimum sample volume 100 µL plasma, however smaller sample volumes can be accepted on occasion. If required, please contact the lab to discuss.
- Special sample instructions
This test is performed using a defined protocol and dedicated request form. Accurately timed sample collection and patient information including height and weight are required. Samples that are received without a minimum of three forms of patient identifiable information will be rejected and will not be analysed.
- Storage and transport
Samples should be sent immediately to central specimen reception (CSR) where they should be separated and the plasma immediately frozen ideally at or below -70 °C.
- Patient instructions
Patients should have been sent information about the procedure beforehand.
- Contacts
Inherited Metabolic Diseases Unit at Blackfriars Hub
Phone: 020 4591 0070
IMD Duty Biochemist: 07592 502653
Email: ClinicalScientistIMD@synnovis.co.uk
Reference Chemistry
Floor 1, Synnovis hub
Friars Bridge Court
41-43 Blackfriars Road
London
SE1 8NZ