Challenges in Measuring Glomerular Filtration Rate: A Clinical Laboratory Perspective

Area of Science:

• Nephrology
• Clinical Chemistry
• Laboratory Medicine

Background:

• Kidney function assessment is crucial for patient management and homeostasis.
• Glomerular filtration rate (GFR) is the standard metric for evaluating kidney function.
• While estimated GFR (eGFR) is common, measured GFR (mGFR) is sometimes necessary for clinical decisions.

Purpose of the Study:

• To review laboratory challenges associated with assessing GFR.
• To outline critical factors for implementing a measured GFR (mGFR) testing protocol.

Main Methods:

• Discussion of marker selection for GFR assessment.
• Evaluation of different clearance methodologies (urinary vs. plasma).
• Consideration of sample collection, number of samples, staff, and analytical technology.

Main Results:

• Implementation of mGFR testing requires careful consideration of specific laboratory and patient factors.
• Site-specific resources and patient population influence the choice of mGFR approach.
• Successful implementation hinges on marker choice, clearance method, and analytical technology.

Conclusions:

• Laboratory challenges in GFR assessment necessitate a tailored approach to mGFR implementation.
• Choosing the right marker, methodology, and technology is key for accurate mGFR.
• Integrating institutional resources with clinical needs ensures optimal mGFR testing protocols.