BMC Nephrology (Jul 2019)

Prediction model of compensation for contralateral kidney after living-donor donation

  • Kenji Okumura,
  • Shigeyoshi Yamanaga,
  • Kosuke Tanaka,
  • Kohei Kinoshita,
  • Akari Kaba,
  • Mika Fujii,
  • Masatomo Ogata,
  • Yuji Hidaka,
  • Mariko Toyoda,
  • Soichi Uekihara,
  • Akira Miyata,
  • Akito Inadome,
  • Hiroshi Yokomizo

DOI
https://doi.org/10.1186/s12882-019-1464-1
Journal volume & issue
Vol. 20, no. 1
pp. 1 – 5

Abstract

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Abstract Background Compensation of contralateral kidney function after living-donor kidney donation is well known, and many predictive factors have been proposed. However, no prediction model has been proposed. This study was performed to establish a tool with which to estimate the degree of compensation of the contralateral kidney after living-donor kidney donation. Methods We retrospectively analyzed 133 living donors for renal transplantation in our institution. We defined a favorable compensation as a post-donation estimated glomerular filtration rate (eGFR) at 1 year (calculated by the Chronic Kidney Disease Epidemiology Collaboration equation) of > 60% of the pre-donation eGFR. We analyzed the living donors’ clinical characteristics and outcomes. Results The median (range) donor age was 59 (24–79) years, median (range) body mass index was 22.9 (16.8–32.7) kg/m2, and median (range) body surface area was 1.6 (1.3–2.0) m2. All donors were Japanese, and 73% of the donors were biologically related. The median (range) donor pre-donation eGFR was 108.7 (82–144) ml/min/1.73 m2, and the median (range) post-donation eGFR at 1 year was 86.9 (43–143) ml/min/1.73 m2. Eighty-six percent of donors had compensatory hypertrophy. In the univariate analysis, age, female sex, history of hypertension, body surface area, and pre-donation eGFR were significantly associated with hypertrophy (p < 0.05). In the multivariate analysis, age, female sex, history of hypertension, and ratio of the remnant kidney volume to body weight were significantly associated with hypertrophy (p < 0.05). Based on these results, we created a compensation prediction score (CPS). The median (range) CPS was 8.7 (1.1–17.4). Receiver operating characteristic analysis showed strong diagnostic accuracy for predicting favorable compensation (area under the curve, 0.958; 95% confidence interval, 0.925–0.991, p < 0.001). The optimal cut-off value of the CPS was 5.0 (sensitivity, 92.0%; specificity, 89.5%). The CPS had a strong positive correlation with the post-donation eGFR (R = 0.797, p < 0.001). Conclusion The CPS might be useful tool with which to predict a favorable compensation of the contralateral kidney and remnant kidney function. If the CPS is low, careful management and follow-up might be necessary. Further investigations are needed to validate these findings in larger populations.

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