Kidney transplantation of living unrelated donor-recipient combinations

Association of Primary Kidney Disease Type and Donor Relatedness With Live Donor Kidney Transplant Outcomes: An Analysis of ANZDATA

RATIONALE & OBJECTIVE

There is limited information about the association between primary kidney disease and donor relatedness with transplant outcomes. This study addresses this gap by evaluating clinical outcomes after kidney transplantation in recipients of living donor kidneys as a function of primary kidney disease type and donor relatedness in Australia and New Zealand.

STUDY DESIGN

Retrospective observational study.

SETTING & PARTICIPANTS

Kidney transplant recipients who received allografts from living donors between January 1, 1998, and December 31, 2018, as recorded in the Australian and New Zealand Dialysis and Transplant Registry (ANZDATA).

EXPOSURES

Primary kidney disease type categorized as majority monogenic, minority monogenic, or other primary kidney disease based on disease heritability as well as donor relatedness.

OUTCOME

Primary kidney disease recurrence, graft failure.

ANALYTICAL APPROACH

Kaplan-Meier analysis and Cox proportion hazards regression to generate hazard ratios for primary kidney disease recurrence, allograft failure, and mortality. Partial likelihood ratio test was used to examine possible interactions between primary kidney disease type and donor relatedness for both study outcomes.

RESULTS

Among 5,500 live donor kidney transplant recipients, majority monogenic (adjusted HR, 0.58, P<0.001) and minority monogenic primary kidney diseases (adjusted HR, 0.64, P<0.001) were associated with reduced primary kidney disease recurrence compared with other primary kidney diseases. Majority monogenic primary kidney disease was also associated with reduced allograft failure (adjusted HR, 0.86, P=0.04) compared with other primary kidney diseases. Donor relatedness was not associated with primary kidney disease recurrence nor graft failure. No interaction was detected between primary kidney disease type and donor relatedness for either study outcome.

LIMITATIONS

Potential misclassification of primary kidney disease type, incomplete ascertainment of primary kidney disease recurrence, unmeasured confounding.

CONCLUSIONS

Monogenic primary kidney disease is associated with lower rates of primary kidney disease recurrence and allograft failure. Donor relatedness was not associated with allograft outcomes. These results may inform pretransplant counseling and live donor selection.

PLAIN-LANGUAGE SUMMARY

There are theoretical concerns that live-donor kidney transplants may be associated with increased risks of kidney disease recurrence and transplant failure due to unmeasurable shared genetic factors between the donor and the recipient. This study analyzed data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) registry and showed that, although disease type was associated with the risk of disease recurrence and transplant failure, donor relatedness did not impact transplant outcomes. These findings may inform pretransplant counseling and live donor selection.

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.

Single antigen testing to reduce early antibody-mediated rejection risk in female recipients of a spousal donor kidney

Female recipients of a spousal donor kidney transplant are at greater risk of donor-specific pre-immunization, which may increase the risk of acute antibody-mediated rejection (ABMR). We assessed the incidence of early ABMR (within two weeks after transplantation), risk factors for ABMR and graft function in 352 complement-dependent cytotoxicity test-negative LURD transplant recipients, transplanted between 1997 and 2014 at the Leiden University Medical Center in The Netherlands. Risk factors for immunization were retrieved from the health records. As methods to screen for preformed donor-specific antibodies (pDSA) have developed through time, we retrospectively screened those with ABMR for pDSA using pooled-antigen bead (PAB) and single-antigen bead (SAB) assays. The cumulative incidence of rejection in the first six months after transplantation was 18% (TCMR 15%; early ABMR 3%). Early ABMR resulted in inferior graft survival and was more common in women who received a kidney from their spouse (10%) than in other women (2%) and men (<1%). The SAB assay retrospectively identified pDSA in seven of nine cases of early ABMR (78%), while the PAB detected pDSA in only three cases (33%). Seeing that early ABMR occurred in 10% of women who received a kidney from their spouse, a SAB assay should be included in the pre-transplant assessment of this group of women, regardless of the result of the PAB assay.

Donor considerations in pediatric kidney transplantation

This article reviews kidney transplant donor options for children with end-stage kidney disease (ESKD). Global access to kidney transplantation is variable. Well-established national policies, organizations for organ procurement and allocation, and donor management policies may account for higher deceased donor (DD transplants) in some countries. Living donor kidney transplantation (LD) predominates in countries where organ donation has limited national priority. In addition, social, cultural, religious and medical factors play a major role in both LD and DD kidney transplant donation. Most children with ESKD receive adult-sized kidneys. The transplanted kidney has a finite survival and the expectation is that children who require renal replacement therapy from early childhood will probably have 2 or 3 kidney transplants in their lifetime. LD transplant provides better long-term graft survival and is a better option for children. When a living related donor is incompatible with the intended recipient, paired kidney exchange with a compatible unrelated donor may be considered. When the choice is a DD kidney, the decision-making process in accepting a donor offer requires careful consideration of donor history, kidney donor profile index, HLA matching, cold ischemia time, and recipient's time on the waiting list. Accepting or declining a DD offer in a timely manner can be challenging when there are undesirable facts in the donor's history which need to be balanced against prolonging dialysis in a child. An ongoing global challenge is the significant gap between organ supply and demand, which has increased the need to improve organ preservation techniques and awareness for organ donation.

Gender Bias in Kidney Donation in India: Has It Changed Over the Past 2 Decades?

OBJECTIVE

To study the trend among Indian women living kidney donation over the past 18 years and see if a gender bias still exists as described in literature before.

METHODS

This is a retrospective, single-center, observational cohort study with data collected from the medical records department of all living donor kidney transplants between January 2001 to December 2018, which were categorized into 2 groups of 9 years each for comparison using categorical variables in form of number, percentage, χ² test, and Pearson correlation coefficient.

RESULTS

A total of 557 kidney transplants were analyzed, with women having 78.5% higher incidence of donation (P < .001). Among them, parents (72.20% mothers), spouses (87.20% wives), siblings (47.50% sisters), and children (44.44% daughters) were the major participants. Further analysis revealed wife donation reduced from 92.3% to 85.6% (P = .41) and mother donation reduced from 72.5% to 71.7% (P = .91), whereas sister donation increased from 28.5% to 51.5% (P = .14) and daughter donation increased from 0% to 44.4% during the 18-year period. Also, female to male donation decreased from 63.8% to 51.6% (P = .02) during the same period. Thus, the overall percentage of female donation is decreasing (73.9% to 61.4%, P = .01), and a significant negative correlation with time was observed in this study (correlation coefficient, r = -0.55, P = .017).

CONCLUSIONS

A lot has changed over the past 18 years, with more male kidney donors now coming forward. Larger prospective studies are required to understand the diverse reason for this sex discrepancy.

Results of Pediatric Kidney Transplants in an 8-Year Period: A Retrospective Study

BACKGROUND

Patient survival and quality of life is better after a kidney transplant compared with dialysis. In this retrospective study, we analyzed the results of pediatric kidney transplants in an 8-year period in our center.

METHODS

We reviewed the files of 166 children and adolescents who had undergone kidney transplants between 2008 and 2015 in our center. All the patients were younger than 18 years old and had been followed up for at least 2 years.

RESULTS

The transplanted kidneys were taken from live donors in 146 (88%) of the cases and from cadavers in 20 (12%) of the cases. They were procured from unrelated and related donors in 129 (90%) and 17 (10%) of the cases, respectively. Laparoscopic nephrectomy was done on 141 donors. The kidney vessels were anastomosed to the aorta, the common iliac, and the internal iliac in 3.6%, 56%, and 40.4% of cases, respectively. Preemptive kidney transplants were performed on 62 patients. The mean of patient survival was 124 ± 1.37 months. One- and five-year patient survival rates were 99% and 97%, respectively. The mean of graft survival was 118.29 ± 2.47 months. One- and five-year graft survival rates were 94% and 93%, respectively. Preemptive kidney transplants had a higher graft survival rate (P < .02).

CONCLUSION

Kidney transplant is a safe and feasible procedure in children and adolescents based on patient and graft survival outcomes. In our center, surgery complications led to kidney loss in very few cases.

Comparison of clinical outcomes between ABO-compatible and ABO-incompatible spousal donor kidney transplantation

Background

Kidney transplantation (KT) is the treatment of choice for end-stage renal disease patients. The spouse is a major donor in living KT. Clinical outcomes of spousal donor KT are not inferior to those of living related donor KT. In this study, we compared clinical outcomes between ABO-compatible (ABOc) and ABO-incompatible (ABOi) spousal donor KTs.

Methods

Thirty-two cases of spousal donor KT performed from January 2011 to August 2013 were analyzed retrospectively. Twenty-one ABOc KTs and 11 ABOi KTs were performed. We investigated patient survival, graft survival, acute rejection, graft function, and complications.

Results

During follow-up, patient and graft survival rates were 100% in both groups. There were no significant differences in the incidence of delayed graft function, acute rejection, and the change in graft function between the 2 groups. Medical and surgical complications were not significantly different between the groups.

Conclusion

The clinical outcomes of ABOc and ABOi spousal donor KTs were equivalent. In ABOi KT, an emotionally motivated spousal donor KT may be a good alternative to the problem of the absolute shortage of kidney donations.

Outcomes of spousal versus related donor kidney transplants: A comparative study

This study was designed to compare the outcomes of spousal donor (SD) with related donor (RD) kidney transplants performed at our center between January 2010 and October 2012. A total of 323 adult, ABO-compatible kidney transplants (SD 150 [46.4%], RD 173 [53.6%]) were included. Data on outcomes at 6 months post-transplant was collected retrospectively (2010-2011) and prospectively (January-October 2012). Majority of the donors (SD 88%, RD 72.2%) were females. In the SD group, donors were younger (SD 35.6 ± 8.2 years, RD 45.2 ± 11.5 years; P < 0.0001), whereas recipients were older (SD 42.2 ± 8.3 years, RD 30.0 ± 9.5 years; P < 0.0001). A significantly higher proportion of patients in the SD group were given induction therapy (43% vs 12%; P < 0.001). Biopsy proven acute rejections were more common in the RD group (16% vs 28.3%; P = 0.01). Majority (80.8%) of the acute rejections occurred in the first 2 weeks post-transplant in both groups. Isolated acute cellular rejections (ACRs) and isolated antibody mediated rejections constituted 50% and 25% of rejection episodes in both groups, whereas the remainder had histological evidence of both. The proportion of steroid responsive ACRs was similar in both groups (SD 83.3%, RD 65.4%; P = 0.2). The number of patients with abnormal graft function at the end of the study was higher in the RD group (2.3% vs. 12.3%; P = 0.001). Patient survival and infection rates were similar in the two groups. We conclude that short-term outcomes of SD transplants are not inferior to RD transplants. Lesser use of induction therapy in the RD group may explain the poorer outcomes as compared to the SD group.

The impact of nephrectomy and renal transplantation on serum levels of soluble Klotho protein

BACKGROUND

Klotho, a single-pass transmembrane protein primarily expressed in the kidneys, parathyroid glands, and choroid plexus of the brain, has a short cytoplasmic tail and a long extracellular domain, which can be cleaved and released as a soluble form. However, information regarding the origins and kinetics of soluble serum Klotho remains poorly understood. We evaluated serial changes in serum Klotho levels among living donors before and after retroperitoneoscopic nephrectomy as well as in their renal transplant recipients.

METHODS

The levels of soluble Klotho in serum obtained from 10 living donors and their renal transplant recipients were determined using a sandwich enzyme-linked immunosorbent assay system.

RESULTS

Serum soluble Klotho was detectable in all subjects. The baseline serum Klotho concentrations in the living donors ranged from 726.4 to 1417.1 pg/mL (median, 909.8 pg/mL; interquartile ranges [IR], 754.8-1132.4), whereas that in the concomitant renal transplant recipients ranged from 397.5 to 1047.2 pg/mL (median, 613.0 pg/mL; IR, 445.9-750.8; P = .003). The levels of soluble serum Klotho measured 5 days after retroperitoneoscopic nephrectomy (median, 619.0 pg/mL; IR, 544.6-688.5; P = .001) were significantly lower than the baseline values. Among the renal transplant recipients, no significant changes in serum Klotho levels were observed during the observation period.

CONCLUSION

Our data regarding soluble serum Klotho levels obtained from living donors support the idea that the kidneys are a major source of soluble serum Klotho in human subjects without a deterioration of renal function. In recipients, concomitant acute kidney injuries and immunosuppressive protocols might modulate the release of soluble Klotho from the grafts into the circulation.