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The following is a summary of “Short and long-term effects of kidney donation on mineral and bone metabolism,” published in the October 2024 issue of Nephrology by Duque et al. 

Living kidney donors (LKD) experience a sudden decrease in glomerular filtration rate (GFR), leading to abnormalities in mineral and bone metabolism (MBD) that may impact skeletal health. 

Researchers conducted a prospective study on the acute and long-term adaptations of MBD in LKD from 2 transplant centers in São Paulo, Brazil, and Miami, USA. 

They assessed renal function and MBD parameters at baseline (D0) and on days 1, 14, 180, and 360 after surgery in 74 patients (40 years old, 73% female, 54% Brazilian). Additionally, a subset of 20 donors from Brazil was evaluated 10 years following nephrectomy. 

The results showed that at baseline, Brazilian donors had lower intact FGF23 (20.8 vs. 80.1 pg/mL, P < 0.01) and higher PTH (47.4 vs. 40.1, P = 0.04) compared to US donors. GFR decreased to 63% of baseline immediately after donation but improved by 10% in the first year. PTH levels increased on D1, returning to baseline by D14, while FGF23 remained elevated. LKD experienced a significant reduction in serum phosphate on D1, returning to baseline by D180, with a higher fractional excretion of phosphate (FEP) starting on D14. After 10 years, 20 LKD showed a sustained reduction in GFR (74.8 ± 14 mL/min), with serum FGF23 returning to baseline [21.8 (18–30) pg/mL] and FEP, along with increased serum calcium. PTH remained elevated (57.9 ± 18 pg/mL), while serum calcitriol and Klotho decreased compared to pre-donation levels. 

The study concluded that the sudden decrease in kidney mass leads to increased PTH and FGF23, alongside a sustained reduction in GFR and decreased serum calcitriol and Klotho, warranting further investigation into these effects. 

Source: bmcnephrol.biomedcentral.com/articles/10.1186/s12882-024-03827-0