Analysis of OPTN/UNOS registry suggests the number of HLA matches and not mismatches is a stronger independent predictor of kidney transplant survival

Rescue Allocation Modes in Eurotransplant Kidney Transplantation: Recipient Oriented Extended Allocation Versus Competitive Rescue Allocation-A Retrospective Multicenter Outcome Analysis

BACKGROUND

Whenever the kidney standard allocation (SA) algorithms according to the Eurotransplant (ET) Kidney Allocation System or the Eurotransplant Senior Program fail, rescue allocation (RA) is initiated. There are 2 procedurally different modes of RA: recipient oriented extended allocation (REAL) and competitive rescue allocation (CRA). The objective of this study was to evaluate the association of patient survival and graft failure with RA mode and whether or not it varied across the different ET countries.

METHODS

The ET database was retrospectively analyzed for donor and recipient clinical and demographic characteristics in association with graft outcomes of deceased donor renal transplantation (DDRT) across all ET countries and centers from 2014 to 2021 using Cox proportional hazards methods.

RESULTS

Seventeen thousand six hundred seventy-nine renal transplantations were included (SA 15 658 [89%], REAL 860 [4.9%], and CRA 1161 [6.6%]). In CRA, donors were older, cold ischemia times were longer, and HLA matches were worse in comparison with REAL and especially SA. Multivariable analyses showed comparable graft and recipient survival between SA and REAL; however, CRA was associated with shorter graft survival. Germany performed 76% of all DDRTs after REAL and CRA and the latter mode reduced waiting times by up to 2.9 y.

CONCLUSIONS

REAL and CRA are used differently in the ET countries according to national donor rates. Both RA schemes optimize graft utilization, lead to acceptable outcomes, and help to stabilize national DDRT programs, especially in Germany.

Development and characterization of a cell donor registry for virus-specific T cell manufacture in a blood bank

Adoptive cell therapy using virus-specific T cells (VST) is a strategy for treating common opportunistic viral infections after transplantation, particularly when these infections do not resolve through antiviral drug therapy. The availability of third-party healthy donors allows for the immediate use of cells for allogeneic therapy in cases where patients lack an appropriate donor. Here, we present the creation of a cell donor registry of human leukocyte antigen (HLA)-typed blood donors, REDOCEL, a strategic initiative to ensure the availability of compatible cells for donation when needed. Currently, the registry consists of 597 healthy donors with a median age of 29 years, 54% of whom are women. The most represented blood groups were A positive and O positive, with 36.52% and 34.51%, respectively. Also, donors were screened for cytomegalovirus (CMV) and Epstein-Barr virus (EBV). Almost 65% of donors were CMV-seropositive, while less than 5% were EBV-seronegative. Of the CMV-seropositive donors, 98% were also EBV-seropositive. High-resolution HLA-A, -B, -C, -DRB1 and -DQB1 allele and haplotype frequencies were determined in the registry. Prevalent HLA alleles and haplotypes were well represented to ensure donor-recipient HLA-matching, including alleles reported to present viral immunodominant epitopes. Since the functional establishment of REDOCEL, in May 2019, 87 effective donations have been collected, and the effective availability of donors with the first call has been greater than 75%. Thus, almost 89% of patients receiving an effective donation had available at least 5/10 HLA-matched cell donors (HLA-A, -B, -C, -DRB1, and -DQB1). To summarize, based on our experience, a cell donor registry from previously HLA-typed blood donors is a useful tool for facilitating access to VST therapy.

The impact of pretransplant suspected HLA antibody on the long-term outcome of the graft kidney: A retrospective cohort study

INTRODUCTION

The preoperative examination of kidney transplantation includes HLA antibody screening to initially determine the presence of preexisting donor-specific antibody (DSA) that mediates hyperacute rejection. Recipients with positive HLA antibodies require further HLA specificity analysis to type the antigen and determine the antigen mismatches between the donor and recipient. However, recipients with suspected antibodies would have no further HLA specificity analysis. It is unclear whether suspected HLA antibodies would affect renal graft function. This study aimed to explore the impact of pretransplant suspected HLA antibody on the long-term outcome of the graft kidney and thus determine the necessity of routinely performing the HLA specificity analysis in recipients with suspected HLA antibodies preoperatively.

METHODS

This is a single-center retrospective cohort study. 179 kidney transplant recipients (KTRs) were included and further divided into HLA antibody-negative group (Group 1) and HLA antibody-suspected groups (Group 2) based on the result of the pretransplant HLA antibody screen test. And the antibody-suspected group was further divided into a low-mismatched group (Group A) and a high-mismatched group (Group B) according to the HLA specificity analysis. We tracked the renal function indexes, biochemical indexes, and posttransplant adverse events within 5 years after transplantation and explored the necessity of further HLA specificity analysis in recipients with pretransplant suspected HLA antibodies.

RESULTS

There was no statistically significant difference in demographics between HLA antibody-negative group and HLA antibody-suspected groups. At 5 years of follow-up, the KTRs in HLA antibody-negative group had significantly higher eGFR levels, lower serum creatinine levels, and less urinary protein compared to those in antibody-suspected group. Meanwhile, the KTRs in low-mismatched group also had significantly higher eGFR levels, lower serum creatinine levels, and less proteinuria compared to those in high-mismatched group. Correlation analysis showed that the age of KTRs, urinary protein levels and the load capacity of HLA mismatches were associated with eGFR levels of KTRs at 5 year posttransplant.

CONCLUSION

KTRs with suspected HLA antibodies before kidney transplantation have worse graft function than the preoperative HLA antibody-negative recipients in the long-term posttransplant follow-up. The specific load capacity of HLA mismatches, the age of the recipient and the urinary protein was found to be negatively correlated with long-term posttransplant renal outcomes. It is necessary to undergo further HLA specificity analysis for recipients with suspected HLA antibodies in HLA antibody screen test to explicit HLA mismatches and improve long-term posttransplant outcomes.

Immunosuppression of HLA identical living-donor kidney transplant recipients: A systematic review

BACKGROUND

Kidney transplant (KT) recipients of HLA identical siblings (HLAid) have lower immunological risk, but there are no specific recommendations for immunosuppression. Our aim was to analyze evidence about results from HLAid living-donor recipients under different immunosuppression in the current era of immunological risk assessment.

METHODS

Systematic review of studies describing associations between outcomes of HLAid living-donor KT recipients according to their immunological risk and applied immunosuppression.

RESULTS

From 1351 studies, 16 (5636 KT recipients) were included in the analysis. All studies were retrospective, ten comparing immunosuppression strategies, and six immunological risk strata. Of those ten, six studies were published in 1990 or earlier and only three included tacrolimus. The evidence is poor, and the inclusion of calcineurin inhibitors does not demonstrate better results. Furthermore, only few studies describe different immunosuppression regimens according to the patient immunological risk and, in general, they do not include the assessment with new solid phase assays.

CONCLUSIONS

There are no studies analyzing the association of outcomes of HLAid KT recipients with current immunological risk tools. In the absence of evidence, no decision or proposal of immunosuppression adapted to modern immunological risk assessment can be made currently by the Descartes Working Group.

Complement Binding Anti-HLA Antibodies and the Survival of Kidney Transplantation

Background: Antibody-mediated rejection (AMR) is one of the most important challenges in the context of renal transplantation, because the binding of de novo donor-specific antibodies (dnDSA) to the kidney graft triggers the activation of the complement, which in turn leads to loss of transplant. In this context, the objective of this study was to evaluate the association between complement-fixing dnDSA antibodies and graft loss as well as the possible association between non-complement-fixing antibodies and transplanted organ survival in kidney transplant recipients. Methods: Our study included a cohort of 245 transplant patients over a 5-year period at Virgen de las Nieves University Hospital (HUVN) in Granada, Spain. Results: dnDSA was observed in 26 patients. Of these patients, 17 had non-complement-fixing dnDSA and 9 had complement-fixing dnDSA. Conclusions: Our study demonstrated a significant association between the frequency of rejection and renal graft loss and the presence of C1q-binding dnDSA. Our results show the importance of the individualization of dnDSA, classifying them according to their ability to activate the complement, and suggest that the detection of complement-binding capacity by dnDSA could be used as a prognostic marker to predict AMR outcome and graft survival in kidney transplant patients who develop dnDSA.

Simpson's paradox and the impact of donor-recipient race-matching on outcomes post living or deceased donor kidney transplantation in the United States

Background

Race is a prognostic indicator in kidney transplant (KT). However, the effect of donor-recipient race-matching on survival after KT remains unclear.

Methods

Using the United Network for Organ Sharing (UNOS) database, a retrospective study was conducted on 244,037 adults who received first-time, kidney-alone transplantation between 2000 and 2019. All patients were categorized into two groups according to donor-recipient race-matching, and the living and deceased donor KT (LDKT and DDKT) were analyzed in subgroups.

Results

Of the 244,037 patients, 149,600 (61%) were race-matched, including 107,351 (87%) Caucasian, 20,741 (31%) African Americans, 17,927 (47%) Hispanics, and 3,581 (25%) Asians. Compared with race-unmatching, race-matching showed a reduced risk of overall mortality and graft loss (unadjusted hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.84-0.87; and unadjusted HR 0.79, 95% CI: 0.78-0.80, respectively). After propensity score-matching, donor-recipient race-matching was associated with a decreased risk of overall graft loss (P < 0.001) but not mortality. In subgroup analysis, race-matching was associated with higher crude mortality (HR 1.12, 95% CI: 1.06-1.20 in LDKT and HR 1.11, 95% CI: 1.09-1.14 in DDKT). However, race-matching was associated with a decreased risk of graft loss in DDKT (unadjusted HR 0.97, 95% CI: 0.96-0.99), but not in LDKT. After propensity score-matching, race-matching had better outcomes for LDKT (patient survival, P = 0.047; graft survival, P < 0.001; and death-censored graft survival, P < 0.001) and DDKT (death-censored graft survival, P = 0.018). Nonetheless, race-matching was associated with an increased adjusted mortality rate in the DDKT group (P < 0.001).

Conclusion

Race-matching provided modest survival advantages after KT but was not enough to influence organ offers. Cofounding factors at baseline led to a contorted crude conclusion in subgroups, which was reversed again to normal trends in the combined analysis due to Simpson's paradox caused by the LDKT/DDKT ratio.

Kidney Transplantation After Rescue Allocation-the Eurotransplant Experience: A Retrospective Multicenter Outcome Analysis

BACKGROUND

At Eurotransplant (ET), kidneys are transferred to "rescue allocation" (RA), whenever the standard allocation (SA) algorithms Eurotransplant Kidney Allocation System (ETKAS) and Eurotransplant Senior Program (ESP) fail. We analyzed the outcome of RA.

METHODS

Retrospective patient clinical and demographic characteristics association analyses were performed with graft outcomes for 2422 recipients of a deceased donor renal transplantation (DDRT) after RA versus 25 481 after SA from 71 centers across all ET countries from 2006 to 2018.

RESULTS

Numbers of DDRTs after RA increased over the time, especially in Germany. RA played a minor role in ESP versus ETKAS (2.7% versus 10.4%). RA recipients and donors were older compared with SA recipients and donors, cold ischemia times were longer, waiting times were shorter, and the incidence of primary nonfunction was comparable. Among ETKAS recipients, HLA matching was more favorable in SA (mean 3.7 versus 2.5). In multivariate modeling, the incidence of graft loss in ETKAS recipients was reduced in RA compared with SA (subdistribution hazard ratio, 0.80; 95% confidence interval [0.70-0.91], P < 0.001), whereas other outcomes (mortality, death with functioning graft (DwFG)) were not significantly different. None of the 3 outcomes were significantly different when comparing RA with SA within the ESP program.

CONCLUSIONS

Facing increased waiting times and mortality on dialysis due to donor shortage, this study reveals encouragingly positive DDRT outcomes following RA. This supports the extension of RA to more patients and as an alternative tool to enable transplantation in patients in countries with prohibitively long waiting times or at risk of deterioration.

Risk Due to ABO Incompatibility and Donor-Recipient Weight Mismatch in Living Donor Kidney Transplantation: A National Cohort Study

The effect of donor-recipient weight mismatch is not well established in ABO-incompatible living donor kidney transplantation (LDKT). A total of 2584 LDKT patients in the Korean Organ Transplantation Registry were classified into four groups according to the presence or absence of ABO incompatibility and donor-recipient weight mismatch (donor-to-recipient weight ratio (DRWR) < 0.8). In a multivariable Cox analysis, the combination of ABO incompatibility and DRWR incompatibility (n = 124) was an independent risk factor for graft survival (HR = 2.73, 95% CI = 1.11-6.70) and patient survival (HR = 3.55, 95% CI = 1.39-9.04), whereas neither factor alone was a significant risk factor for either outcome. The combination of ABO incompatibility and DRWR incompatibility was not an independent risk factor for biopsy-proven graft rejection (HR = 1.27, 95% CI = 0.88-1.82); however, it was an independent risk factor for pneumonia (HR = 2.94, 95% CI = 1.64-5.57). The mortality rate due to infection was higher among patients with both ABO incompatibility and DRWR incompatibility than among patients with neither factor or with either factor alone. The combination of ABO incompatibility and DRWR incompatibility was an independent risk factor for graft and patient survival after LDKT, whereas neither factor alone significantly affected graft or patient survival. Thus, donor-recipient weight matching should be cautiously considered in LDKT with ABO incompatibility.

Association of Bw4/Bw6 mismatch across class I HLA loci with renal graft outcomes in first time transplants

Bw4 and Bw6 are strongly immunogenic epitopes routinely assigned based on HLA-B typing results per Organ Procurement and Transplantation Network (OPTN) policies. These public epitopes and their variants are shared by some cross-reactive HLA-A and -C antigens. Although epitope mismatch has been associated with poor transplant outcomes, previous studies did not find such associations for Bw4/6 mismatch as defined by HLA-B antigens only. We hypothesized that a broader definition for Bw4/Bw6 mismatch that includes cross-reactive HLA-A and -C antigens may reveal the risk associated with these epitopes. In this retrospective cohort study, we examined kidney transplantations between 2000 and 2016 in the OPTN database and determined the association of Bw4/6 mismatch across all class I HLA antigens and renal graft outcomes. Even by this broader definition, Bw4/6 mismatch was not independently associated with 1-year graft rejection (adjusted OR: 0.99, 95%CI 0.93-1.06) or death-censored graft survival (adjusted HR: 1.02, 95%CI 1.00-1.05). There was no significant association among recipients who were already sensitized at transplant either. Our findings suggest that Bw4/6 mismatch alone is not associated with poor renal graft outcomes despite their strong immunogenicity, and the load of epitope mismatches over a certain threshold is likely required to cause adverse clinical consequences.

Repeated kidney re-transplantation in times of organ shortage - a critical review

PURPOSE OF REVIEW

Organ shortage forces those responsible to streamline allocation rules to provide a maximum of candidates with a graft and to optimize transplant outcome. Recently, repeated kidney re-transplantation was investigated in several studies with different analytic settings concerning the control group, the donors, parameters influencing outcome, and demographic characteristics. This review gives an overview on the candidates awaiting a repeated re-transplantation, summarizes the outcome, and comments on the relevance of these findings in the context of sustained organ shortage.

RECENT FINDINGS

Repeated kidney re-transplantation is technically and immunologically feasible and the recipients' survival is better compared to candidates remaining on dialysis or on the waiting-list. However, the outcome is mainly reported to be worse as compared to first or second kidney transplantation. Kidneys from living donors seem to have a favorable impact on outcome in this setting.

SUMMARY

The survival benefit of repeated re-transplantation recipients over patients on dialysis demands for continuation of this procedure. Comprehensive registries are essential to continuously optimize allocation. Governmental authorities are obliged to set the course to increase organ donation rather than forcing transplant decision makers to withhold a third or fourth graft from any candidate.

Kidney transplantation after rescue allocation-meticulous selection yields the chance for excellent outcome

BACKGROUND

The small number of organ donors forces transplant centres to consider potentially suboptimal kidneys for transplantation. Eurotransplant established an algorithm for rescue allocation (RA) of kidneys repeatedly declined or not allocated within 5 h after procurement. Data on the outcomes and benefits of RA are scarce to date.

METHODS

We conducted a retrospective 8-year analysis of transplant outcomes of RA offers based on our in-house criteria catalogue for acceptance and decline of organs and potential recipients.

RESULTS

RA donors and recipients were both older compared with standard allocation (SA). RA donors more frequently had a history of hypertension, diabetes or fulfilled expanded criteria donor key parameters. RA recipients had poorer human leucocyte antigen (HLA) matches and longer cold ischaemia times (CITs). However, waiting time was shorter and delayed graft function, primary non-function and biopsy-proven rejections were comparable to SA. Five-year graft and patient survival after RA were similar to SA. In multivariate models accounting for confounding factors, graft survival and mortality after RA and SA were comparable as well.

CONCLUSIONS

Facing relevant comorbidities and rapid deterioration with the risk of being removed from the waiting list, kidney transplantation after RA was identified to allow for earlier transplantation with excellent outcome. Data from this survey propose not to reject categorically organs from multimorbid donors with older age and a history of hypertension or diabetes to aim for the best possible HLA matching and to carefully calculate overall expected CIT.

Acute rejection in pediatric renal transplantation: Retrospective study of epidemiology, risk factors, and impact on renal function

AR is a major relevant and challenging topic in pediatric kidney transplantation. Our objective was to evaluate cumulative incidence of AR in pediatric kidney transplant patient, risk factors for this outcome, and impact on allograft function and survival. A retrospective cohort including pediatric patients that underwent kidney transplantation between 2011 and 2015 was designed. Risk factors for AR were tested by competing risk analysis. To estimate its impact, graft survival and difference in GFR were evaluated. Two hundred thirty patients were included. As a whole, the incidence of AR episodes was 0.16 (95% CI = 0.12-0.20) per person-year of follow-up. And cumulative incidence of AR was 23% in 1 year and 39% in 5 years. Risk factors for AR were number of MM (SHR 1.36 CI 1.14-1.63 P = .001); ISS with CSA, PRED, and AZA (SHR 2.22 CI 1.14-4.33 P = .018); DGF (SHR 2.49 CI 1.57-3.93 P < .001); CMV infection (SHR 5.52 CI 2.27-11.0 P < .001); and poor adherence (SHR 2.28 CI 1.70-4.66 P < .001). Death-censored graft survival in 1 and 5 years was 92.5% and 72.1%. Risk factors for graft loss were number of MM (HR 1.51 CI 1.07-2.13 P = .01), >12 years (HR 2.66 CI 1.07-6.59 P = .03), and PRA 1%-50% (HR 2.67 CI 1.24-5.73 P = .01). Although occurrence of AR did not influence 5-year graft survival, it negatively impacted GFR. AR was frequent in patients assessed and associated with number of MM, ISS regimen, DGF, CMV infection, and poor adherence, and had deleterious effect on GFR.

Chronic Histologic Changes Are Present Regardless of HLA Mismatches: Evidence from HLA Identical Living Donor Kidney Transplants

BACKGROUND

At 5 and 10 years after kidney transplantation, chronic histologic changes such as arteriolar hyalinosis and mesangial expansion are common, however, determining etiology is difficult. We compared surveillance biopsies in living donor kidney transplants (LDKTx) from HLA matched siblings (termed HLA-identical (HLA-ID)) to HLA non-ID to investigate which histologic changes were likely due to alloimmune injury and which were due to non-alloimmune injury.

METHODS

We performed a retrospective, cohort study comparing HLA-ID sibling LDKTx (n=175) to HLA non-ID LDKTx (n=175; matched for age, sex and year of transplant +/- 2 years) performed at a single institution from 03/1999 to 11/2018.

RESULTS

Baseline characteristics and maintenance immunosuppression were similar. Mortality rates were similar, but in the HLA-ID group, 10-year death-censored graft survival was higher (93.8% vs 80.9% HLA non-ID LDKTx, p<0.001), rejection rates were lower (after 1 year 9.6% vs 27.1%; p<0.001) and Banff inflammation scores including glomerulitis and peritubular capillaritis were lower on surveillance biopsies at 1, 5 and 10 years. In contrast, chronic Banff scores (interstitial fibrosis, arteriolar hyalinosis, mesangial expansion, etc.) were similar in prevalence and severity on surveillance biopsies at 1, 5 and 10 years.

CONCLUSIONS

HLA-ID LDKTx have less inflammation and less transplant glomerulopathy, but most chronic histologic changes were similar to less-well matched LDKTx. We conclude that these types of chronic changes are not associated with HLA mismatches and may be due to non-immunologic causes (hypertension, obesity, etc.) suggesting that new management approaches to prevent these lesions may be needed.

Donor-specific cell-free DNA as a biomarker in liver transplantation: A review

Due to advances in modern medicine, liver transplantation has revolutionised the prognosis of many previously incurable liver diseases. This progress has largely been due to advances in immunosuppressant therapy. However, despite the judicious use of immunosuppression, many liver transplant recipients still experience complications such as rejection, which necessitates diagnosis via invasive liver biopsy. There is a clear need for novel, minimally-invasive tests to optimise immunosuppression and improve patient outcomes. An emerging biomarker in this ''precision medicine'' liver transplantation field is that of donor-specific cell free DNA. In this review, we detail the background and methods of detecting this biomarker, examine its utility in liver transplantation and discuss future research directions that may be most impactful.

Continuous function of 80 primary renal allografts for 30-47 years with maintenance prednisone and azathioprine/mycophenolate mofetil therapy: A clinical mosaic of long-term successes

Eighty primary renal allograft recipients, 61 living-related and 19 deceased donor, transplanted from 1963 through 1984 had continuous graft function for 30-47 years. They were treated with three different early immunosuppression programs (1963-1970: thymectomy, splenectomy, high oral prednisone; 1971-1979: divided-dose intravenous methylprednisolone; and 1980-1984: antilymphocyte globulin) each with maintenance prednisone and azathioprine, and no calcineurin inhibitor. Long-term treatment often included the anti-platelet medication, dipyridamole. Although both recipient and donor ages were young (27.2 ± 9.5 and 33.1 ± 12.0 years, respectively), six recipients with a parent donor had >40-year success. At 35 years, death-censored graft survival was 85.3% and death with a functioning graft 84.2%; overall graft survival was 69.5% (Kaplan-Meier estimate). Biopsy-documented early acute cellular and highly probable antibody-mediated rejections were reversed with divided-dose intravenous methylprednisolone. Complications are detailed in an integrated timeline. Hypogammaglobulinemia identified after 20 years doubled the infection rate. An association between a monoclonal gammopathy of undetermined significance and non-plasma-cell malignancies was identified. Twenty-seven azathioprine-treated patients tested after 37 years had extremely low levels of T1/T2 B lymphocytes representing a "low immunosuppression state of allograft acceptance (LISAA)". The lifetime achievements of these patients following a single renal allograft and low-dose maintenance immunosuppression are remarkable. Their success evolved as a clinical mosaic.

Kidney transplantation for primary glomerulonephritis: Recurrence risk and graft outcomes with related versus unrelated donors

Primary glomerulonephritis can recur after kidney transplantation and may jeopardize the survival of the renal allograft. The risks of living-related kidney transplantation remain controversial in this group of patients. Living related transplantation offers potentially better HLA matching, therefore improve the long-term graft survival. However, the concern for increased rates of recurrence of the primary glomerulonephritis in the transplanted kidney from living related donors complicates the selection of donors. With the recent dramatic rise in the use of paired kidney exchange, there is now often the option of having a living related donor donate through a paired exchange. This raises the question of whether patients with primary glomerulonephritis should receive living donor kidneys through paired kidney exchange programs to obtain the benefits of a living donor kidney transplant while also reducing the risk of recurrent glomerulonephritis. Our review of the literature suggests that although the recurrence of primary glomerulonephritis occurs more often when donation occurs from a living related donor as compared to an unrelated donor, the graft survival advantage of living related donation is generally maintained despite the recurrence. We suggest that despite the increased risk of recurrence, living related donation should not be avoided in patients with primary glomerulonephritis as the cause of their end-stage renal disease.

Non-HLA donor-recipient mismatches in kidney transplantation-A stone left unturned

In kidney transplantation, short-term allograft survival has improved due to improvements in acute rejection episodes without corresponding improvements in long-term survival. Although current organ allocation algorithms take into account human leukocyte antigen (HLA) matching to reduce antidonor alloimmune responses, it is likely that genomic variation at non-HLA loci (ie, non-HLA donor-recipient [D-R] pair mismatches) play a role in the "non-self" responses and ultimately affect long-term allograft survival. Existing data from both animal models and human studies suggest an association between non-HLA D-R mismatches and kidney allograft outcomes. In this minireview, we examine existing and emerging data and discuss putative mechanisms on the role of non-HLA D-R mismatches on long-term allograft outcomes in kidney transplantation.

A Half-Century 3000 Cases of Kidney Transplant Experiences in a Single Hospital: the Longest Registry in Korea

BACKGROUND

This study aims to analyze the entire registry of kidney transplant over the past 50 years and understand the clinical significance.

METHODS

From the data on 3012 kidney transplants performed at our center between March 1969 and September 2018, we analyzed retrospectively clinical variables.

RESULTS

Until September 2018, there have been 3012 kidney transplants performed. The number of primary transplant cases was 2755 (91.8%), which included 16 cases of simultaneous liver-kidney transplant, and the number of repeated transplants was 245 (225 second transplants [7.5%] and 20 third transplants [0.7%]). There were 3 simultaneous pancreas kidney transplants, and 3 small bowel-kidney transplants, one of them being transplanted at the same time. There was a single simultaneous heart-kidney transplant. The viability rates of a transplanted kidney for 1, 5, 10, 20, and 30 years were 97%, 92%, 90%, 51%, and 36%, respectively, and the patient survival rates were 96%, 89%, 82%, 64%, and 52%, respectively. Five-year graft survival rate of the first 1000 cases was 64.6%; those of the 1001st to 2000th cases and 2001^st to 3012th cases were 87.6% and 88.8%, respectively. There are statistically significant differences among the groups.

CONCLUSION

This study has identified the appropriate selection or control of immunotherapy, based on the risk level of kidney transplant recipient, is needed to minimize chronic rejection, which is the key cause of transplanted kidney failure.

The impact of donor/recipient age difference and HLA mismatch on graft outcome in pediatric kidney transplantation

BACKGROUND

Understanding the relationship between the factors that influence long-term kidney transplant survival remains a key priority for pediatric nephrologists. We assessed the relative impact of donor/recipient age difference and HLA matching on long-term graft outcomes.

METHODS

We conducted a retrospective cohort study of pediatric and adolescent recipients who received a primary kidney transplant in Australia and New Zealand between January 1, 1990, and December 31, 2015. The primary outcome was graft survival analyzed by Kaplan-Meier method.

RESULTS

During the 26-year period, 1134 primary (395 DD and 739 LD) kidney transplants were performed in recipients less than 20 years of age. The median follow-up time was 10.2 years. Overall, 405 patients (35.7%) lost their transplant with graft survival 93.8% at 1 year, 82.5% at 5 years, 65.8% at 10 years, and 49.9% at 15 years post-transplant. There was consistently higher graft loss of DD kidneys as compared to LD kidneys at each time point. Both increasing donor/recipient age difference (aHR 1.11 per 10 years; 95% CI, 1.02-1.20; P = 0.009) and increasing HLA mismatch (aHR 1.20 per mismatch; 95% CI, 1.10-1.30; P < 0.001) were associated with decreased graft survival.

CONCLUSIONS

Donor/recipient age difference and HLA matching are important factors influencing long-term graft outcomes in pediatric kidney transplantation. HLA mismatch remains a strong predictor of graft loss. For patients without the option of a LD, we suggest that the degree of HLA mismatch should not be discounted as part of the decision-making process of organ allocation.

Evaluation of predictive models for delayed graft function of deceased kidney transplantation

Background

This study aimed to evaluate the predictive power of five available delayed graft function (DGF)-prediction models for kidney transplants in the Chinese population.

Results

Among the five models, the Irish 2010 model scored the best in performance for the Chinese population. Irish 2010 model had an area under the receiver operating characteristic (ROC) curve of 0.737. Hosmer-Lemeshow goodness-of-fit test showed that the Irish 2010 model had a strong correlation between the calculated DGF risk and the observed DGF incidence (p = 0.887). When Irish 2010 model was used in the clinic, the optimal upper cut-off was set to 0.5 with the best positive likelihood ratio, while the lower cut-off was set to 0.1 with the best negative likelihood ratio. In the subgroup of donor aged ≤ 5, the observed DGF incidence was significantly higher than the calculated DGF risk by Irish 2010 model (27% vs. 9%).

Materials and Methods

A total of 711 renal transplant cases using deceased donors from China Donation after Citizen's Death Program at our center between February 2007 and August 2016 were included in the analysis using the five predictive models (Irish 2010, Irish 2003, Chaphal 2014, Zaza 2015, Jeldres 2009).

Conclusions

Irish 2010 model has the best predictive power for DGF risk in Chinese population among the five models. However, it may not be suitable for allograft recipients whose donor aged ≤ 5-year-old.