Measured Glomerular Filtration Rate in Live Related Kidney Donors Three Months Post-Kidney Donation: A Single-Center Experience From Western India

Abstract

Background Glomerular filtration rate (GFR) estimation is pivotal in the evaluation of kidney donors. There are various methods available for assessing GFR, but there has been a lack of consensus on the measurement of GFR and the frequency of renal evaluation after kidney donation. Our study aims to analyze the measured GFR (m-GFR) before and three months after kidney donation and note the compensatory abilities of the remnant kidney in live related kidney donors. Methods This prospective observational study was conducted at the Department of Nephrology, Dr. D. Y. Patil Medical College, Hospital & Research Centre, Pune, from April 2021 to December 2022. The study included 30 donors from both genders aged between 23 and 73 years. The measured GFR was calculated using a technetium-99m diethylene triamine pentaacetic acid (Tc-99m DTPA) scan. We analyzed donor characteristics and various parameters that included demography, anthropometry, blood pressure, and serum creatinine and measured GFR (m-GFR) using a Tc-99m DTPA scan, which was compared before and three months after donor nephrectomy. Results Of the 30 donors, 25 (83.3%) were females and five (16.7%) were males. The mean age of donors was 49.23 ± 12.29 years. The mean body mass index (BMI) was noted to be 24.73 ± 5.58 kg/m², whereas the mean body surface area (BSA) was 1.59 ± 0.12 m². In terms of the measured GFR by DTPA scan, pre-donation and post-donation, the average GFR for our population was 103.83 ± 10.07 mL/minute/1.73 m² and 60.47±6.57 mL/minute/1.73 m², respectively. The mean measured GFR of remnant kidney increased by 9.21 ± 4.39 mL/minute/1.73 m² in 28 donors, while two donors had a fall in the mean measured GFR by 6.8 ± 1.69 mL/minute/1.73 m². Conclusions To safeguard donor health, accurate measurement of GFR at various timelines after kidney donation should be considered as there are various limitations associated with the use of serum creatinine-based GFR estimating equations for solitary kidneys. However, long-term studies are required to analyze the changes in GFR after nephrectomy and determine the adequacy of compensatory changes in the remnant kidney post-kidney donation.

Keywords: diethylene triamine pentaacetic acid (dtpa) renal scan; donor evaluation; glomerular filtration rate (gfr); kidney donors; living donor nephrectomy.

Figure 1. m-GFR pre- and post-nephrectomy

x-axis: study participants (N = 30), y-axis: m-GFR pre- and post-nephrectomy m-GFR: measured glomerular filtration rate

Figure 2. Rise in m-GFR in relation to age

x-axis: study participants (N = 30), y-axis: m-GFR rise in relation to age m-GFR: measured glomerular filtration rate