Post-kidney donation glomerular filtration rate measurement and estimation

Area of Science:

• Nephrology
• Transplant Surgery
• Clinical Chemistry

Background:

• Long-term consequences of kidney donation are debated, with glomerular filtration rate (GFR) crucial for risk assessment.
• Limited data exists in Latin America on kidney function evaluation in donors using GFR.
• Standard GFR estimation equations include MDRD and CKD-EPI.

Purpose of the Study:

• To evaluate the performance of MDRD and CKD-EPI equations in assessing post-nephrectomy GFR dynamics in kidney donors.
• To compare estimated GFR (eGFR) with measured GFR (mGFR) in kidney donors over time.

Main Methods:

• Prospective cohort study of 189 kidney donors in Argentina (2007-2016).
• GFR evaluated pre- and post-nephrectomy using iothalamate clearance (HPLC) for mGFR and MDRD/CKD-EPI for eGFR.
• Donors divided into two groups based on evaluation time: up to 5 years (Group 1) and 5-10 years (Group 2) post-donation.

Main Results:

• MDRD and CKD-EPI equations underestimated GFR compared to mGFR, particularly at lower GFR levels.
• CKD-EPI demonstrated better diagnostic performance (AUC=0.79) than MDRD (AUC=0.66) for identifying mGFR < 60 ml/min/1.73 m².
• Estimated GFR showed poor performance for post-nephrectomy follow-up in donors over 50 years old.

Conclusions:

• GFR estimation equations exhibit inadequate performance for long-term monitoring of kidney function in post-nephrectomy donors.
• Measured GFR is recommended for screening and follow-up of kidney donors based on current selection criteria.