Outcomes in Living Donor Kidney Transplantation: The Role of Donor's Kidney Function

Renal transplants increase in size and function in keeping with compensatory renal hypertrophy

AIM

To evaluate changes in allograft kidney length in renal transplant recipients and the relationship with estimated glomerular filtration rate (eGFR).

METHODS

This single-centre retrospective study of renal transplant recipients was conducted at Flinders Medical Centre (FMC) from January 2007 to June 2020. Donor and recipient details, renal allograft length from transplant ultrasounds at 0, 1, 3, 6 and 12 months were collected. The association between compensatory renal hypertrophy (CRH) and eGFR and its magnitude was analysed using multivariate multilevel mixed-effects linear regression models.

RESULTS

A total of 183 renal transplant recipients were studied. 100 of 175 recipients (62.9%) demonstrated an increase in renal length defined as any increase in maximal longitudinal diameter on serial ultrasounds. Twenty-three recipients (13.1%) had no change in transplant length and 42 recipients (24%) had a decrease in length. The mean increase in kidney length over the first 12 months was 0.57 cm. Ninety of 156 (57.7%) recipients with a renal ultrasound within a month post-transplant demonstrated a mean increase kidney length of 0.3 cm. Multivariate analysis demonstrated that eGFR increased by 2.5 mL/min/1.73 m2 (95% CI 0.72- 4.4; p = .006) with every 1 cm increase in kidney length. Absolute changes in kidney length did not demonstrate any statistically significant correlation with eGFR in both complete case and multiple imputation analysis.

CONCLUSION

An increase in transplant kidney length is common in renal transplant recipients and is associated with enhanced eGFR. However, further studies need to be performed to study the association of absolute change in kidney length and eGFR.

A Single-Center Study on the Clinical Profiles and Ultrasonographic Assessments of Living Kidney Donors in the Marathwada Region of Maharashtra

Living donor kidney transplantation plays a vital role in renal replacement therapy, particularly in India, where a substantial increase in kidney transplants has been observed. Thorough assessments of living kidney donors are crucial, focusing on parameters such as kidney size and glomerular filtration rate (GFR). Despite the importance of GFR in donor assessments, there is a noticeable lack of data on normal GFR ranges in the Indian population. This study aims to address the gap in knowledge by establishing a reference range for GFR in healthy kidney donors from the Marathwada region of Maharashtra. The research also explores the clinical profiles and ultrasonographic features of living kidney donors. A retrospective analysis was conducted at the Mahatma Gandhi Mission (MGM) Medical College and Hospital in Aurangabad, involving 134 living kidney donors. Inclusion criteria encompassed healthy donors with a BMI of less than 30 kg/m², while donors with uncontrolled hypertension, diabetes, microalbuminuria, or a measured GFR below 70 mL/min/1.73 m² were excluded. Comprehensive medical histories, demographic parameters, and ultrasonographic assessments were conducted, with GFR measured using 99M technetium diethylenetriamine pentaacetate scans. The study reveals that the majority of donors were females (80.6%), and the highest number fell within the 41-50 age group. Parents constituted the primary donor category (68.7%), reflecting a familial inclination toward organ donation. Ultrasonographic assessments indicated larger kidney sizes compared to other studies, suggesting regional or population-specific differences. The mean GFR for the right and left kidneys, as well as the total GFR, was within the expected range. The negative correlation between age and GFR emphasizes the need to consider age in donor assessments. The findings emphasize the unique features of this population, including a higher average age, female preponderance, and larger kidney sizes. The study contributes to the understanding of living kidney donors' profiles in the region and highlights the importance of individualized assessments in the donor selection process.

Predictive Value of Camera-based Donor Glomerular Filtration Rate Estimation on the Immediate Renal Allograft Outcome Following Live-related Renal Transplant: A Single-center Retrospective Study

Purpose of the Study

The purpose of this study was to assess the association of measured glomerular filtration rate (mGFR) using camera-based method with early transplant outcomes.

Methodology

Diethylenetriamine pentaacetate renograms of all voluntary kidney donors between January 2016 and December 2022 at Kasturba Hospital, Manipal, India, were retrieved for the study. Recipients' posttransplant biochemical parameters were collected and compared against donors with scaled mGFR >80 ml/min/1.73 m2 (Group 1) and with mGFR between 60 and 80 ml/min/1.73 m2 (Group 2). Donor-recipient pair age, anthropometric parameters, and their differences were also assessed against the immediate transplant outcome. Posttransplant immediate graft function was assessed by posttransplant nadir serum creatinine, day to achieve nadir serum creatinine, the incidence of slow graft or delayed graft function, and serum creatinine at 1-month posttransplantation. Recipients with serum creatinine of >2.5 mg/dl on posttransplant day 7 were taken as slow graft function.

Results

A total of 161 donor-recipient pairs were analyzed in the study. In recipients who showed persistently high serum creatinine posttransplant, older donor age(p < 0.001), higher difference in body mass index among the donor-recipient pair (p= 0.03), and mGFR <80ml/min (p < 0.001) were significantly associated. Slow graft function was significantly more in Group II recipients, with donors having mGFR <80ml/min as compared to Group I with mGFR >80 ml/min (37.3% vs. 10.6%) (P < 0.001).

Conclusions

Camera-based mGFR using Gates' formula is a reliable tool to predict inferior graft outcomes in the immediate posttransplant period. Kidneys from donors with mGFR of 60-80 mL/min/1.73 m2 are likely to experience slow graft function in the immediate posttransplant period.

Caring for Patients With Advanced Chronic Kidney Disease: Dietary Options and Conservative Care Instead of Maintenance Dialysis

An expert advisory board discussed the prevention and treatment of chronic kidney disease (CKD), with a focus on dietary options. This is timely, given the uptake of value based models for kidney care in the United States. Timing of dialysis start is influenced by patients' clinical status and complex patient-clinician interactions. Patients value personal freedom and quality of life and may want to delay dialysis, whilst physicians are sometimes more concerned with clinical outcomes. Kidney-preserving therapy can prolong the dialysis-free period and preserve residual kidney function, thus patients are asked to adjust their lifestyle and diet, to follow a low- or very low-protein diet, with or without ketoacid analogues. Multi-modal approaches include pharmacotherapies, management of symptoms, and a gradual, individualized dialysis transition. Patient empowerment is vital, including CKD education and involvement in decision making. These ideas may help patients, their families, and clinical teams to improve the management of CKD.

Predictors of Short-Term Outcomes in Living Donor Renal Allograft Recipients: A Prospective Study From a Tertiary Care Center in North India

Background Renal transplantation is the optimal treatment for patients of all ages with end-stage kidney disease. The long-term outcomes of renal transplantation are assessed by graft and patient survival rates. These outcomes are, in turn, influenced by post-transplant events such as delayed graft function, rejections, post-transplant infections, and post-transplant diabetes mellitus (PTDM). Each of these short-term outcomes is, in turn, determined by the interplay of various factors in the pre-, peri-, and post-transplant period. This prospective study was designed to understand the factors affecting short-term outcomes in living donor transplantation and their effect on graft and patient survival. Methodology A total of 86 patients underwent live donor renal transplantation between January 1, 2015, and March 31, 2016, at a tertiary care hospital in north India. Of these, five were lost to follow-up, and the remaining 81 patients were prospectively followed up to December 31, 2017. Results The majority of the recipients were males (91%) and the donors were females (74%). Spousal and related donors comprised 49% and 51% of donations, respectively. The mean estimated glomerular filtration rate (eGFR) of donors was 98 ± 9.2 mL/minute/1.73m². Induction therapy with basiliximab was given to 21/81 (26%) recipients. The majority of recipients (68/81, 84%) received triple-drug immunosuppression with prednisolone, tacrolimus, and mycophenolate mofetil. Delayed graft function (DGF) occurred in 4/81 (4.9%) cases. Biopsy-proven acute rejections (BPARs) occurred in 15/81 (18.5%) cases, two-thirds of which were acute antibody-mediated rejections (ABMRs). During the follow-up period, 50 episodes of infections occurred in 35/81 (43.2%) recipients, with the most common being urinary tract infection (23/81, 28.5%). PTDM was diagnosed in 22/81 (27.2%) patients beyond six weeks of transplant. On multivariate logistic regression analysis, the most significant predictor of DGF was acute rejections and vice versa. Acute rejections also predicted the occurrence of post-transplant infections. Pre-transplant hepatitis C virus (HCV) infection and cyclosporine-based therapy were significant predictors of PTDM. At the six-month follow-up, 10/81 (12.3%) patients developed graft dysfunction. The predictors of graft dysfunction at six months were recipients of related donors and rural patients. One-year graft survival, death-censored graft survival, and patient survival rates were 85.2%, 92.6%, and 91.3%, respectively. The most common cause of death was post-transplant infections (5/7, 71.4%) of which the majority (4/5, 80%) were fungal infections. On multivariate logistic regression analysis, the most significant predictor of graft loss and patient loss was low pre-transplant donor eGFR and PTDM, respectively. Conclusions Graft and patient survival in living donor kidney transplantation are influenced by a multitude of interdependent factors during the pre-transplant (donor eGFR, type of donor, socioeconomic status, HCV infection in recipient, type of immunosuppression) and the post-transplant (DGF, rejections, infections, and PTDM) period.

Pearls and Pitfalls in Pediatric Kidney Transplantation After 5 Decades

Worldwide, over 1,300 pediatric kidney transplantations are performed every year. Since the first transplantation in 1959, healthcare has evolved dramatically. Pre-emptive transplantations with grafts from living donors have become more common. Despite a subsequent improvement in graft survival, there are still challenges to face. This study attempts to summarize how our understanding of pediatric kidney transplantation has developed and improved since its beginnings, whilst also highlighting those areas where future research should concentrate in order to help resolve as yet unanswered questions. Existing literature was compared to our own data of 411 single-center pediatric kidney transplantations between 1968 and 2020, in order to find discrepancies and allow identification of future challenges. Important issues for future care are innovations in immunosuppressive medication, improving medication adherence, careful donor selection with regard to characteristics of both donor and recipient, improvement of surgical techniques and increased attention for lower urinary tract dysfunction and voiding behavior in all patients.

Glomerular Filtration Rate Estimation With Commonly Used Methods Among Healthy Live Kidney Donors of South Punjab, Pakistan

Background

Accurate estimation of the donor’s glomerular filtration rate (GFR) is crucial for not only ensuring the medical appropriateness of the donor but also for the prediction of future allograft performance. The aim of this study was to compare the GFR estimation formulas and 24-hour urine creatinine clearance with diethylene triamine pentaacetic acid (DTPA) renal scan GFR.

Methods

This cross-sectional study was done at the Department of Nephro Urology Dialysis & Renal Transplantation, Bahawal Victoria Hospital, Quaid e Azam Medical College, Bahawalpur, Pakistan from September 2018 to September 2021. A total of 92 potential healthy live-related kidney donors of both genders, aged 18 to 60 years having body mass index below 35 kg/m² were included. GFR was calculated with modification of diet in renal disease (MDRD), Cockcroft-Gault (CG), chronic kidney disease epidemiology (CKD-EPI) equations as well as by 24-hour urine creatinine clearance. DTPA renal scan was done to record GFR findings. GFR was compared using analysis of variance (ANOVA) among different methods.

Results

Out of a total of 92 individuals, 49 (53.3%) were male and 43 (46.7%) female. Mean age and BMI were noted to be 34.62±10.57 years and 24.40±2.71 kg/m², respectively. Statistically significant differences existed between various methods of GFR estimation (p<0.001). Mean GFR as per DTPA renal scan findings was noted to be 97.32±9.39 ml/min/1.73 m². Difference of 31.48±20.81, 27.37±21.1, 23.38±6.38, 15.52±37.52 was noted in estimated GFR (ml/min/1.73 m²) with CG formula, MDRD formula, EPI-CKD formula and 24-hour urine creatinine clearance respectively when compared with DTPA renal scan findings. The highest proportion of patients was seen with normal GFR with DTPA renal scan findings as 83 (90.2%) individuals while 24-hour urine creatinine clearance observed these to be 59 (64.1%), CG EPI-CKD formula 44 (47.8%), MDRD formula 39 (42.4%) and 40 (43.5%) with CG formula.

Conclusion

None of the GFR estimation methods resulted in similar findings. With reference to the DTPA renal scan, 24-hour urine creatinine clearance was the closest GFR estimation followed by CKD-EPI and MDRD equations.

The Evaluation of Kidney Function in Living Kidney Donor Candidates

Living kidney donors incur a small increased risk of ESKD, of which predonation GFR is an important determinant. As a result, kidney function assessment is central to the donor candidate evaluation and selection process. This article reviews the different methods of GFR assessment, including eGFR, creatinine clearance, and measured GFR, and the current guidelines on GFR thresholds for donor acceptance. eGFR obtained using the 2009 CKD Epidemiology Collaboration equation that, although the best of estimating estimations, tends to underestimate levels and has limited accuracy, especially near-normal GFR values. In the United States, the Organ Procurement and Transplantation Network policy on living donation mandates either measured GFR or creatinine clearance as part of the evaluation. Measured GFR is considered the gold standard, although there is some variation in performance characteristics, depending on the marker and technique used. Major limitations of creatinine clearance are dependency on accuracy of timed collection, and overestimation as a result of distal tubular creatinine secretion. GFR declines with healthy aging, and most international guidelines recommend use of age-adapted selection criteria. The 2017 Kidney Disease: Improving Global Outcomes Guideline for the Evaluation and Care of Living Kidney Donors diverges from other guidelines and recommends using absolute cutoff of <60 ml/min per 1.73m2 for exclusion and ≥90 ml/min per 1.73m2 for acceptance, and determination of candidacy with intermediate GFR on the basis of long-term ESKD risk. However, several concerns exist for this strategy, including inappropriate acceptance of younger candidates due to underestimation of risk, and exclusion of older candidates whose kidney function is in fact appropriate for age. The role of cystatin C and other newer biomarkers, and data on the effect of predonation GFR on not just ESKD risk, but also advanced CKD risk and cardiovascular outcomes are needed.