Crucial Role of Extended Criteria Donors in Deceased Donor Single Kidney Transplantation to Face Chronic Shortage in the Heart of the Mediterranean Basin: A Single-Center Experience

Impact of T Lymphocytes Isolated from Liver Perfusate of Deceased Brain Donors on Kidney Transplantation: Preliminary Evidence and Future Directions

BACKGROUND

Ischemia/reperfusion injury (IRI), acute rejection (AR), and delayed graft function (DGF) might occur as major complications following kidney transplantation. Thus, the identification of biomarkers for the IRI, AR, and/or DGF development becomes crucial as it may help to guide post-transplant management. Natural killer (NK) cells, hepatic interstitial T-lymphocytes (T-Li), and NK-T cells are crucial in both innate and adaptive immunity after abdominal solid organ transplantation. Hence, the aim of this study was to evaluate the impact of the immune system after graft reperfusion during KT in adults in order to identify predictive biomarkers.

METHODS

The NK, T-Li, and NK-T phenotypes and concentrations were retrospectively analyzed in a consecutive series of liver perfusates obtained after organ procurement flushing the abdominal cavity recovered from deceased brain donors (DBDs). Their percentage was compared with the renal transplant recipients' characteristics with kidneys taken from the same DCDs. The hepatic perfusate cells were purified by density gradient centrifugation. Flow cytometric investigation was used to determine their phenotype with the following immunological markers in order to determine the relative percentage of T-Li, NK-T, and NK cells: CD3, CD4, CD8, and CD56.

RESULTS

42 DBDs' liver perfusates were analyzed. The related clinical outcomes of kidney transplant recipients from 2010 to 2020 performed at our Institute were evaluated. Time in days of delayed functional recovery of transplanted kidneys (DGF) (p = 0.02) and the onset of secondary infection from a cytomegalovirus (p = 0.03) were significantly associated with the T-Li percentage. An increased relative risk (HR) of organ survival was significantly associated with the percent cell concentration of T-Li and time to DGF, on COX analysis, were (HR = 1.038, p = 0.04; and HR = 1.029, p = 0.01, respectively). None relevant clinical outcomes in kidney transplant patients were associated with the specificity of the NK and NK-T cell proportions.

CONCLUSIONS

A new potential role of T-Li cells was detected in the context of hepatic perfusate from DBDs. It could detect potential impacts in organ allocation, surgical procuring techniques, and in the analysis of IRI pathophysiological events.

Proteomic analysis of machine perfusion solution from brain dead donor kidneys reveals that elevated complement, cytoskeleton and lipid metabolism proteins are associated with 1-year outcome

Assessment of donor kidney quality is based on clinical scores or requires biopsies for histological assessment. Noninvasive strategies to identify and predict graft outcome at an early stage are, therefore, needed. We evaluated the perfusate of donation after brain death (DBD) kidneys during nonoxygenated hypothermic machine perfusion (HMP). In particular, we compared perfusate protein profiles of good outcome (GO) and suboptimal outcome (SO) 1‐year post‐transplantation. Samples taken 15 min after the start HMP (T1) and before the termination of HMP (T2) were analysed using quantitative liquid chromatography–tandem mass spectrometry (LC‐MS/MS). Hierarchical clustering of the 100 most abundant proteins showed discrimination between grafts with a GO and SO at T1. Elevated levels of proteins involved in classical complement cascades at both T1 and T2 and a reduced abundance of lipid metabolism at T1 and of cytoskeletal proteins at T2 in GO versus SO was observed. ATP‐citrate synthase and fatty acid‐binding protein 5 (T1) and immunoglobulin heavy variable 2‐26 and desmoplakin (T2) showed 91% and 86% predictive values, respectively, for transplant outcome. Taken together, DBD kidney HMP perfusate profiles can distinguish between outcome 1‐year post‐transplantation. Furthermore, it provides insights into mechanisms that could play a role in post‐transplant outcomes.

Impact of center donor acceptance patterns on utilization of extended-criteria donors and outcomes

BACKGROUND

This study investigated the impact of transplanting center donor acceptance patterns on usage of extended-criteria donors (ECDs) and posttransplant outcomes following orthotopic heart transplantation (OHT).

METHODS

The Scientific Registry of Transplant Recipients was queried to identify heart donor offers and adult, isolated OHT recipients in the United States from January 1, 2013 to October 17, 2018. Centers were stratified into three equal-size terciles based on donor heart acceptance rates (<13.7%, 13.7%-20.2%, >20.2%). Overall survival was compared between recipients of ECDs (≥40 years, left ventricular ejection fraction [LVEF] <60%, distance ≥500 miles, hepatitis B virus [HBV], hepatitis C virus [HCV], or human immunodeficiency virus [HIV], or ≥50 refusals) and recipients of traditional-criteria donors, and among transplanting terciles.

RESULTS

A total of 85,505 donor heart offers were made to 133 centers with 15,264 (17.9%) accepted for OHT. High-acceptance programs (>20.2%) more frequently accepted donors with LVEF <60%, HIV, HCV, and/or HBV, ≥50 offers, or distance >500 miles from the transplanting center (each p < .001). Posttransplant survival was comparable across all three terciles (p = .11). One- and five-year survival were also similar across terciles when examining recipients of all five ECD factors. Acceptance tier and increasing acceptance rate were not found to have any impact on mortality in multivariable modeling. Of ECD factors, only age ≥40 years was found to have increased hazards for mortality (hazard ratio, 1.33; 95% confidence interval [CI], 1.22-1.46; p < .001).

CONCLUSIONS

Of recipients of ECD hearts, outcomes are similar across center-acceptance terciles. Educating less aggressive programs to increase donor acceptance and ECD utilization may yield higher national rates of OHT without major impact on outcomes.

Quality Assessment of Donor Kidneys and the Tendency of Kidney Acceptance: A Single-Center Experience

PURPOSE

The increasing age of donors and the increasing tendency of comorbidities requires an extension in acceptance criteria. In this review, the tendency for acceptance and refusal was analyzed by examining reasons for declining donor kidneys at the kidney transplantation center in Debrecen. This analysis aimed to assess the quality of donor kidneys and indicate why two-thirds of donated organs were refused.

METHOD

Our center in Debrecen received 535 kidney offers (based on exclusion criteria) between November 2016 and August 2019, which were retrospectively analyzed. Donor kidneys were evaluated using expanded criteria donor, kidney donor profile index (KDPI), and kidney donor risk index criteria systems.

RESULTS

Thirty-five percent (n = 189) of the kidneys offered to the center in Debrecen had been approved in advance, and later 63% (n = 119) were transplanted. Using the KDPI system, 41% of donors had a KDPI above 85, of which 23% were accepted, while acceptance of kidneys with a KDPI of 0 to 35 was around 70%. When examining causes of donor kidney refusal, 90% of the organs had donor quality problems, 13% had logistical cause (long cold ischemic time, large age difference between donor and recipient), and 10.5% had immunologic cause. In 13% of cases, the refusal of donor organs was due to the coexistence of several problems.

CONCLUSION

Our data showed that high-risk donor organs were being refused in our center; however, they are being transplanted at a higher rate in other Eurotransplant centers. The decision to refuse or accept donor organs depends on several factors, including expected waiting time, patient's clinical characteristics, and quality of life.