Factors associated with the compensation of renal function after nephrectomy of a kidney donor

Abstract

Introduction: Kidney transplant donors lose 50% of their renal mass after nephrectomy. The remaining kidney compensates for this loss and it is estimated that 70% of the baseline renal function prior to donation is recovered. Factors associated with post-donation renal compensation are not well understood. Methods: Retrospective study of 66 consecutive kidney donors (mean age 48.8 years, 74.2% women). We analyzed the potential factors associated with the compensatory mechanisms of the remaining kidney by comparing donors according to their renal compensation rate (RCR) (Group A, infra-compensation [70%]). Results: We compared Group A (n = 38) and group B (n = 28). Predictors for RCR > 70% were higher baseline creatinine (A vs. B: 0.73 ± 0.14 vs. 0.82 ± 0.11; p = 0.03) and a lower baseline glomerular filtration rate (GFR), estimated both by MDRD-4 (A vs. B: 97.7 ± 18.8 vs. 78.6 ± 9.6 ml/min; p 70% compensation (MDRD-4, OR = 0.94 [95% CI 0.8–0.9], p = 0.01). The compensation rate decreased by 0.4% (p 70%]). Resultados: Comparamos los grupos A (n = 38) y B (n = 28). Los factores predictores de una TCR > 70% fueron una mayor creatinina basal (A vs. B 0,73 ± 0,14 vs. 0,82 ± 0,11; p = 0,03) y menor filtrado glomerular (FG), tanto estimado mediante MDRD-4 (A vs. B 97,7 ± 18,8 vs. 78,6 ± 9,6 ml/min; p 70% (MDRD-4, odds ratio [OR] = 0,94 [IC 95%: 0,8-0,9], p = 0,01). La tasa de compensación era 0,4% (p < 0,001) y 0,3% (p = 0,006), menor por cada ml/min de FG basal más, por MDRD-4 y CKD-EPI respectivamente. Conclusiones: Un año después de la donación renal el riñón remanente compensa parcialmente la función renal basal. En nuestra experiencia el FGe basal se asocia de forma inversamente proporcional a la tasa de compensación renal al año. Keywords: Living kidney donor, Nephrectomy, Renal compensation rate, Renal function, Palabras clave: Donante renal vivo, Nefrectomía, Tasa compensación renal, Función renal