Creatinine-Based Estimations of Kidney Function Are Unreliable in Obese Kidney Donors

Accurate assessment of kidney function by measurement of glomerular filtration rate (GFR) is essential to the risk assessment of prospective living kidney donors. We evaluated the performance of various estimating equations for creatinine clearance (Cockcroft-Gault), GFR (Modification of Diet in Renal Disease, Chronic Kidney Disease Epidemiology Collaboration), and 24-hour urine collections for creatinine clearance in obese potential kidney donors. We evaluated 164 potential kidney donors including 49 with a BMI of 30–35 and 32 with a BMI >35 that have completed a routine living donor evaluation with a measured GFR. All the estimating equations performed poorly in obese donors. While 24-hour urine collections performed better, only 15% had an adequate 24-hour urine collection. Since obese kidney donors may be at higher than average risk for kidney failure, accurate assessment of kidney function in these donors is crucial to ensure their long-term health postdonation

Novel Urinary Biomarkers of Interstitial Fibrosis/Tubular Atrophy Progression in Kidney Transplantation

Interstitial Fibrosis/Tubular Atrophy (IF/TA) is a common problem in kidney transplantation that ultimately leads to allograft failure. There are no early non-invasive biomarkers of IF/TA available that can be used to identify early IF/TA where interventions can be implemented to prevent irreversible injury. The object of this work is to identify novel biomarkers of IF/TA in the urine of kidney transplant recipients using proteomic methods. Mass spectrometry with isobaric tagging with iTRAQ labeling was used to quantify protein abundance in urine samples. We used individuals from two separate cohorts to identify these biomarkers. The discovery phase of the study used a cross-sectional cohort to identify candidate biomarkers of IF/TA. The validation phase used the prospective cohort to see which of the candidate biomarkers could predict progression of IF/TA. From a sample size of 24 in the cross-sectional cohort, we identified 55 candidate biomarkers that were upregulated in at least of the 1 of the fibrosis comparisons (none-mild, none-moderate/severe, mild-moderate/severe). In the validation cohort, 4 of these biomarkers were able to differentiate progressors versus non-progressors of IF/TA. These biomarkers include alpha-1-acid glycoprotein, alpha-2-macroglobulin, apolipoprotein A-IV, apolipoprotein C-III, immunoglobulin J chain, pigment epithelium-derived factor, profilin-1, and retinol binding protein 4. Using proteomic methods, we identified 4 novel urinary biomarkers of IF/TA in kidney transplant recipients. Further studies are needed to confirm these findings and assess the clinical utility of these biomarkers in transplantation

Three year outcomes following positive cross match renal transplantation despite failure to convert to Negative Flow Cross Match after Desensitization

Desensitization allows successful transplantation of patients with a positive crossmatch (PXM) against their live donor. We evaluated outcomes following PXM renal transplant despite failure to convert to negative flow cytometric crossmatch (FCXM) after desensitization. Patients that underwent desensitization before PXM transplant between 1/1/00 and 11/1/11 were identified for analysis. Patients who received a transplant despite failure to convert to negative FCXM were identified as the not converted group. Patients who converted to negative FCXM after desensitization comprised the converted group control arm. 108 patients were desensitized before PXM transplant, (not converted group=42; converted group=66). Mean eGFR was comparable between groups at all time points, and 3-year eGFR was 57.8 mL/min vs. 57.1 mL/min, p=0.91. Patients with eGFR < 30mL/min at 3 years did not differ significantly (28% vs. 14%, p=0.15). Biopsy-proven rejection rates were numerically higher within the not converted group for each type of rejection and time point, but the values did not differ significantly. Opportunistic infections rates were comparable. Patient survival (95% vs. 91%) and death-censored allograft survival (84% vs. 95%, p=0.07) were similar between arms at 3 years post-transplant

Donor exchange programs in kidney transplantation: rationale and operational details from the north central donor exchange cooperative

The increasing need for kidney transplants has led to innovations such as donor exchange programs. These programs offer transplant recipients with incompatible donors an opportunity to receive a compatible kidney. They also provide an alternative to costly desensitization protocols that have unproven long-term outcomes. Donor exchange programs have multiple options including simple two-pair exchanges to the more complicated domino exchanges or chain donations. The United States is currently limited by regional programs that provide for kidney donor exchanges. However, with the increasing public interest and need for kidney transplants, general nephrologists will be approached with questions about these donor exchange programs. The goal of this review is to discuss donor exchange programs including their role in expanding the donor pool, the various types of exchanges, regional centers that provide these programs, and the process involved in patient enrollment. A general knowledge of donor exchange programs will help providers in discussing options with patients approaching end-stage kidney disease and transplantation

Efficacy and Safety of Once-Daily LCP-Tacrolimus Versus Twice-Daily Immediate-Release Tacrolimus in Adult Hispanic Stable Kidney Transplant Recipients: Sub-Group Analysis from a Phase 3 Trial

BACKGROUND The pharmacokinetics and metabolism of tacrolimus, an immunosuppressant commonly used to prevent transplant rejection, can differ in specific subpopulations. This analysis examined treatment outcomes and safety of immediate-release tacrolimus (IR-Tac) and LCP-tacrolimus (LCPT) in stable Hispanic kidney transplant recipients. MATERIAL AND METHODS This was a post hoc analysis of clinical trial data from Hispanic adult stable kidney transplant recipients randomized to remain on IR-Tac or convert from IR-Tac to a reduced dose of LCPT (NCT00817206). Composite treatment failure was evaluated at 12 months. Estimated glomerular filtration rate and tacrolimus trough concentrations were evaluated over 12 months. RESULTS Fifty-five stable (LCPT n=26, IR-Tac n=29) kidney transplant recipients who self-identified as Hispanic or Latino were included in this analysis. Composite treatment failure occurred in 1 patient (4%) who converted to LCPT and 1 (3%) who remained on IR-Tac. The estimated glomerular filtration rate was stable over time and similar in the 2 treatment groups (P=0.08). Tacrolimus trough levels for both groups were similar over time in the 2 treatment groups (P=0.98). Treatment-emergent adverse events were similar in patients who converted to LCPT and in those who remained on IR-Tac. CONCLUSIONS Efficacy and safety were similar in Hispanic kidney transplant recipients who converted from IR-Tac to LCPT and in those remaining on IR-Tac