Division of Nephrology, Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Division of Nephrology, Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
PLoS One. 2022 Jul 7;17(7):e0270827. doi: 10.1371/journal.pone.0270827. eCollection 2022.
Most transplant centers in the Netherlands use estimated glomerular filtration rate (eGFR) for evaluation of potential living kidney donors. Whereas eGFR often underestimates GFR, especially in healthy donors, measured GFR (mGFR) allows more precise kidney function assessment, and therefore holds potential to increase the living donor pool. We hypothesized that mGFR-based donor screening leads to acceptance of donors with lower pre-donation eGFR than eGFR-based screening.
In this longitudinal cohort study, we compared eGFR (CKD-EPI) before donation in one center using mGFR-based screening (mGFR-cohort, n = 250) with two centers using eGFR-based screening (eGFR-cohort1, n = 466 and eGFR-cohort2, n = 160). We also compared differences in eGFR at five years after donation.
Donor age was similar among the cohorts (mean±standard deviation (SD) mGFR-cohort 53±10 years, eGFR-cohort1 52±13 years, P = 0.16 vs. mGFR-cohort, and eGFR-cohort2 53±9 years, P = 0.61 vs. mGFR-cohort). Estimated GFR underestimated mGFR by 10±12 mL/min/1.73m2 (mean±SD), with more underestimation in younger donors. In the overall cohorts, mean±SD pre-donation eGFR was lower in the mGFR-cohort (91±13 mL/min/1.73m2) than in eGFR-cohort1 (93±15 mL/min/1.73m2, P<0.05) and eGFR-cohort2 (94±12 mL/min/1.73m2, P<0.05). However, these differences disappeared when focusing on more recent years, which can be explained by acceptance of more older donors with lower pre-donation eGFR over time in both eGFR-cohorts. Five years post-donation, mean±SD eGFR was similar among the centers (mGFR-cohort 62±12 mL/min/1.73m2, eGFR-cohort1 61±14 mL/min/1.73m2, eGFR-cohort2 62±11 mL/min/1.73m2, P = 0.76 and 0.95 vs. mGFR-cohort respectively). In the mGFR-cohort, 38 (22%) donors were excluded from donation due to insufficient mGFR with mean±SD mGFR of 71±9 mL/min/1.73m2.
Despite the known underestimation of mGFR by eGFR, we did not show that the routine use of mGFR in donor screening leads to inclusion of donors with a lower pre-donation eGFR. Therefore eGFR-based screening will be sufficient for the majority of the donors. Future studies should investigate whether there is a group (e.g. young donors with insufficient eGFR) that might benefit from confirmatory mGFR testing.
荷兰大多数移植中心使用估算肾小球滤过率（eGFR）来评估潜在的活体供肾者。尽管 eGFR 常常低估 GFR，尤其是在健康供者中，但测量的 GFR（mGFR）可更精确地评估肾功能，因此有可能增加活体供者库。我们假设基于 mGFR 的供者筛选会导致接受比基于 eGFR 的筛选更低的预捐 eGFR 的供者。
在这项纵向队列研究中，我们比较了一个中心使用 mGFR 进行基于 mGFR 的筛选的 eGFR（CKD-EPI）（mGFR 队列，n=250）与两个中心使用基于 eGFR 的筛选的 eGFR（eGFR 队列 1，n=466 和 eGFR 队列 2，n=160）的情况。我们还比较了捐赠后五年的 eGFR 差异。
各队列之间的供者年龄相似（mGFR 队列的平均年龄±标准差为 53±10 岁，eGFR 队列 1 为 52±13 岁，P=0.16 与 mGFR 队列，eGFR 队列 2 为 53±9 岁，P=0.61 与 mGFR 队列）。估计的 GFR 低估了 mGFR，差值为 10±12 mL/min/1.73m2（平均值±标准差），年轻供者的低估更明显。在整个队列中，mGFR 队列的预捐 eGFR（91±13 mL/min/1.73m2）低于 eGFR 队列 1（93±15 mL/min/1.73m2，P<0.05）和 eGFR 队列 2（94±12 mL/min/1.73m2，P<0.05）。然而，当关注最近几年时，这些差异就消失了，这可以解释为在 eGFR 队列中，随着时间的推移，接受更多较年长、预捐 eGFR 较低的供者。捐赠后 5 年，各中心的平均 eGFR 相似（mGFR 队列为 62±12 mL/min/1.73m2，eGFR 队列 1 为 61±14 mL/min/1.73m2，eGFR 队列 2 为 62±11 mL/min/1.73m2，P=0.76 和 0.95 与 mGFR 队列）。在 mGFR 队列中，有 38（22%）名供者因 mGFR 不足而被排除在捐赠之外，其平均 mGFR 为 71±9 mL/min/1.73m2。
尽管 mGFR 常低估 eGFR，但我们并未发现基于 mGFR 的供者筛选会导致接受预捐 eGFR 较低的供者。因此，基于 eGFR 的筛选将足以满足大多数供者的需求。未来的研究应该调查是否有一个群体（例如，eGFR 不足的年轻供者）可能受益于确认性 mGFR 测试。
