Time-zero renal biopsy in living kidney transplantation: a valuable opportunity to correlate predonation clinical data with histological abnormalities.

ABSTRACT

BACKGROUND: Living kidney donation is increasing as a partial solution for wait-listed patients. Despite properly followed guideline criteria for donor selection, current reports identify unsuspected renal pathology at preimplantation or time-zero biopsy (T0-RBx). METHODS: T0-RBx was evaluated for following interstitial fibrosis (IF), tubular atrophy (TA), arteriolar hyalinosis (AH), mesangial increase (MI), and glomerulosclerosis (GS). Predonation data were demography, body weight, body mass index (BMI), systolic/diastolic blood pressure (BP), serum creatinine (SCr), estimated glomerular filtration rate (eGFR), and proteinuria. RESULTS: Two hundred nineteen T0-RBx were analyzed. Of these 54.4% had abnormal findings, namely, IF in 29%, TA in 13%, MI in 12%, AH in 10%, and GS in 10%. Mean clinical data were as follows age 35.4+/-10 years, weight 66.27+/-10.14 kg, BMI 25.53+/-2.99, systolic BP 115+/-9 mm Hg, diastolic BP 74+/-7 mm Hg, SCr 0.91+/-0.25 mg/dL, eGFR 96+/-16.65 mL/min, and proteinuria 70.25+/-62.8 mg/24 hr. A total of 56.7% were women. IF correlated to age (r=0.22, P=0.001) and SCr (r=0.19, P=0.005); TA to diastolic BP (r=0.15, P=0.03) and proteinuria (r=0.20, P=0.009); AH to SCr (r=0.15, P=0.02) and eGFR (r=-0.16, P=0.018); MI to BMI (r=0.13, P=0.047). Multivariate analysis failed to sustain the significant associations found on bivariate analysis, most likely due to a low event/parameter relation and sample size. CONCLUSIONS: A significant correlation was established between T0-RBx findings and clinical predonation parameters. Whether these mild histologic findings at the time of kidney donation represent a higher risk for the remaining kidney ought to be evaluated during follow-up. In an era, when living kidney donation is increasing, we advise closer donor surveillance to modify risk factors that participate in kidney damage progression.