Single-Center Long-Term Follow-Up of Kidney Donors in Argentina (Hospital Italiano de Buenos Aires).

INTRODUCTION: Living kidney donor (LKD) transplantation is increasing due to organ shortage. Clinical studies have shown that the risk of developing end-stage renal disease (ESRD) in donors is similar to that in the general population. Our goal was to evaluate postdonation renal outcomes assessed by glomerular filtration rate (GFR), proteinuria, and blood pressure. METHODS: A total of 210 LKD transplants were performed at Hospital Italiano de Buenos Aires between 2000 and 2014. Postdonation outcomes were analyzed in 109 donors. GFR was assessed by 24-hour creatinine clearance (as 24-hour ClCr) and estimated using the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. Additionally, we correlated the predonation renal functional reserve (RFR) with postdonation GFR. Donor results were compared to the expected GFR (adjusted to age and single kidney). Other renal outcome indicators measured were albuminuria and blood pressure, and they were compared (predonation and postdonation) using univariate analysis. RESULTS: A total of 109 patients were followed up for 47 ± 34 months (range, 12-168): 70% were female, age at donation was 48.58 years (range, 25-70), and predonation serum creatinine was 0.85 ± 0.17 mg/dL. Postnephrectomy GFR (24-hour ClCr) was significantly lower compared to predonation GFR (105.38 ± 21.78 mL/min/1.73 m2 vs 90.14 ± 17.78 mL/min/1.73 m2). However, postdonation GFR was not significantly different compared to the expected GFR. No differences were found for blood pressure or albuminuria. Age >50 and an RFR (<20%) was associated with a lower GFR. CONCLUSIONS: In this population of LKD, renal outcome (24-hour CrCl, albuminuria, and blood pressure) was within the expected outcome for healthy individuals after uninephrectomy.

Comparison Between CKD-EPI Creatinine and MDRD Equations to Estimate Glomerular Filtration Rate in Kidney Transplant Patients.

BACKGROUND: The Modification of Diet in Renal Disease (MDRD) equation is widely used to estimate glomerular filtration rate (eGFR) in kidney transplant (KT) patients. The novel Chronic Kidney Disease-Epidemiology Collaboration equation (CKD-EPI) could improve accuracy of GFR estimation. Our aim was to compare both equations for staging of CKD in KT patients. METHODS: In a cohort of KT patients, correlation of eGFR according to MDRD and CKD-EPI with 24-hour creatinine clearance (24h-CrCl) was evaluated. Concordance between both equations for CKD staging was performed. MDRD was used for initial CKD staging. The mean difference of GFR between 24h-CrCl and each equation was calculated and Bland-Altman analysis applied. RESULTS: A cohort of 463 KT patients were studied: 67% female, overall average age 46 ± 14 years, 41% living donor, mean time of transplantation 71 months (3-95), and mean serum creatinine 1.68 ± 1.03 mg/dL. For the whole cohort (all CKD stages), eGFR by CKD-EPI was 5.33 mL/min/1.73 m(2) higher than by MDRD (P < .01). For CKD stages 1, 2, and 3A, the mean eGFR differences (CKD-EPI - MDRD) were 13.98 ± 3.27, 8.2 ± 1.98, and 5.34 ± 1.32 mL/min/1,73 m(2), respectively. The percentage of patients with eGFR <60 mL/min/1.73 m(2) decreased from 63.8% according to MDRD to 53.9% with the use of CKD-EPI. In women and patients ≤65 years old, eGFR by CKD-EPI was 5.98 and 5.81 mL/min/1.73 m(2) higher, respectively, than by MDRD (P < .01). CONCLUSIONS: The novel CKD-EPI reduces the number of patients with eGFR <60 mL/min/1.73 m(2) and consequently assigns lower CKD stages to our KT population.

Proteinuria/creatininuria index and its correlation with the 24-hour proteinuria in renal transplanted patients.

BACKGROUND: Proteinuria (P) is a early sign of inflammation and renal damage. It has an important role in the detection, diagnosis, and monitoring of renal disease in transplanted patients. The aim of this study was to examine the correlation between random urinary proteinuria/creatininuria index (P/CI) and 24-hour total protein excretion among stable renal transplant patients. MATERIALS AND METHODS: We obtained 1511 samples of 24-hour protein excretion (24-hr P) with corresponding P/CI were obtained from 197 adult patients beyond 6 months post-transplantation between 2009 and 2011. The population was divided into 2 groups: One to obtain a population of justification (755) and another, of validation (755). A scatter graft yielded was obtained by Pearson's coefficient of correlation. A "receiver operater characteristic curve" analysis was carried out to evaluate the sensitivity and specifity of PCI and 24hr-P, showing a cutoff of 0.15 for PCI. RESULTS: The PCI and 24 hr P Pearson's correlation was significant (r = 0.89; P = .0001). The sensitivities of the P/CI for the justification and the validation samples were 97% and 94%, respectively; the a cutoff was 0.15. Their negative predictive values for P/CI were 92% and 84% respectively (cutoff, 0.15). The specificity was below 50% in both groups. CONCLUSIONS: We observed a significant correlation between P/CI and 24 hr P. The sensitivity was slightly higher than the specificity (50%) but the negative predictive value was >92%. The use of P/CI seemed to be adequate for screening of protein excretion during renal transplant recipient follow-up.