How Does Surgeons' Autonomic Physiology Vary Intraoperatively?: A Real-time Study of Cardiac Reactivity.

OBJECTIVE: To measure the physiological responses of surgical team members under varying levels of intraoperative risk. BACKGROUND: Measurement of intraoperative physiological responses provides insight into how operation complexity, phase of surgery, and surgeon seniority impact stress. METHODS: Autonomic nervous system responses (interbeat intervals, IBIs) were measured continuously during different surgical operations of various complexity. The study investigated whether professional role (eg attending surgeon), operative risk (high vs. low), and type of primary operator (attending surgeon vs. resident) impacted IBI reactivity. Physiological synchrony captured the degree of correspondence between individuals' physiological responses at any given time point. RESULTS: A total of 10,005 observations of IBI reactivity were recorded in 26 participants during 16 high-risk (renal transplant and laparoscopic donor nephrectomy) and low-risk (arteriovenous fistula formation) operations. Attending surgeons showed greater IBI reactivity (faster heart rate) than residents and nurses during high-risk operations and while actively operating (Ps<0.001). Residents showed lower reactivity during high-risk (relative to low-risk) operations (P<0.001) and similar reactivity regardless of whether they or the attending surgeon was operating (P=0.10). Nurses responded similarly during low-risk and high-risk operations (P=0.102) but were more reactive when the resident was operating compared to when the attending surgeon was the primary operator (P<0.001). In high-risk operations, attending surgeons had negative physiological covariation with residents and nurses (P<0.001). In low-risk operations, only attending surgeons and nurses were synchronized (P<0.001). CONCLUSION: Attending surgeons' physiological responses were well-calibrated to operative demands. Residents' and nurses' responses were not callibrated to the same extent. This suggests that risk sensitivity is an adaptive response to stress that surgeons acquire.

European Consensus on the Management of Sensitized Kidney Transplant Recipients: A Delphi Study.

An increasing number of sensitized patients awaiting transplantation face limited options, leading to fatalities during dialysis and higher costs. The absence of established evidence highlights the need for collaborative consensus. Donor-specific antibodies (DSA)-triggered antibody-mediated rejection (AMR) significantly contributes to kidney graft failure, especially in sensitized patients. The European Society for Organ Transplantation (ESOT) launched the ENGAGE initiative, categorizing sensitized candidates by AMR risk to improve patient care. A systematic review assessed induction and maintenance regimens as well as antibody removal strategies, with statements subjected to the Delphi methodology. A Likert-scale survey was distributed to 53 European experts (Nephrologists, Transplant surgeons and Immunologists) with experience in kidney transplant recipient care. A rate ≥75% with the same answer was considered consensus. Consensus was achieved in 95.3% of statements. While most recommendations aligned, two statements related to complement inhibitors for AMR prophylaxis lacked consensus. The ENGAGE consensus presents contemporary recommendations for desensitization and immunomodulation strategies, grounded in predefined risk categories. The adoption of tailored, patient-specific measures is anticipated to streamline the care of sensitized recipients undergoing renal allografts. While this approach holds the promise of enhancing transplant accessibility and fostering long-term success in transplantation outcomes, its efficacy will need to be assessed through dedicated studies.

Donating a Kidney to a Stranger: Are Healthcare Professionals Facilitating the Journey? Results From the BOUnD Study.

Unspecified kidney donors (UKDs) are approached cautiously by some transplant professionals. The aim of this study was to interrogate the views of UK transplant professionals towards UKDs and identify potential barriers. A purposely designed questionnaire was validated, piloted and distributed amongst transplant professionals at each of the 23 UK transplant centres. Data captured included personal experiences, attitudes towards organ donation, and specific concerns about UKD. 153 responses were obtained, with representation from all UK centres and professional groups. The majority reported a positive experience with UKDs (81.7%; p < 0.001) and were comfortable with UKDs undergoing major surgery (85.7%; p < 0.001). 43.8% reported UKDs to be more time consuming and 52% felt that a mental health assessment should take place before any medical tests. 77% indicated the need for a lower age limit. The suggested age range was broad (16-50 years). Adjusted mean acceptance scores did not differ by profession (p = 0.68) but higher volume centres were more accepting (46.2 vs. 52.9; p < 0.001). This is the first quantitative study of acceptance by transplant professionals to a large national UKD programme. Support is broad, however potential barriers to donation have been identified, including lack of training. Unified national guidance is needed to address these.

Living Donor Kidney Transplantation in Older Individuals: An Ethical Legal and Psychological Aspects of Transplantation (ELPAT) View.

Living donor transplantation is the optimal treatment for suitable patients with end-stage kidney disease. There are particular advantages for older individuals in terms of elective surgery, timely transplantation, and early graft function. Yet, despite the superiority of living donor transplantation especially for this cohort, older patients are significantly less likely to access this treatment modality than younger age groups. However, given the changing population demographic in recent decades, there are increasing numbers of older but otherwise healthy individuals with kidney disease who could benefit from living donor transplantation. The complex reasons for this inequity of access are explored, including conscious and unconscious age-related bias by healthcare professionals, concerns relating to older living donors, ethical anxieties related to younger adults donating to aging patients, unwillingness of potential older recipients to consider living donation, and the relevant legislation. There is a legal and moral duty to consider the inequity of access to living donor transplantation, recognising both the potential disparity between chronological and physiological age in older patients, and benefits of this treatment for individuals as well as society.

Exploring Staff Attitudes Towards Unspecified Kidney Donors in the United Kingdom: Results From the BOUnD Study.

Unspecified kidney donation (UKD) has made substantial contributions to the UK living donor programme. Nevertheless, some transplant professionals are uncomfortable with these individuals undergoing surgery. This study aimed to qualitatively explore the attitudes of UK healthcare professionals towards UKD. An opportunistic sample was recruited through the Barriers and Outcomes in Unspecified Donation (BOUnD) study covering six UK transplant centres: three high volume and three low volume centres. Interview transcripts were analysed using inductive thematic analysis. The study provided comprehensive coverage of the UK transplant community, involving 59 transplant professionals. We identified five themes: staff's conception of the ethics of UKD; presence of the known recipient in the donor-recipient dyad; need for better management of patient expectations; managing visceral reactions about the "typical" unspecified kidney donor; complex attitudes toward a promising new practice. This is the first in-depth qualitative study of attitudes of transplant professionals towards UKD. The data uncovered findings with strong clinical implications for the UKD programme, including the need for a uniform approach towards younger candidates that is adhered to by all transplant centres, the need to equally extend the rigorous assessment to both specified and unspecified donors, and a new approach to managing donor expectations.

The phenotype of HLA-binding B cells from sensitized kidney transplant recipients correlates with clinically prognostic patterns of interferon-γ production against purified HLA proteins.

B cells play crucial roles in cell-mediated alloimmune responses. In vitro, B cells can support or regulate indirect T-cell alloreactivity in response to donor antigens on ELISpot and these patterns associate with clinical outcome. Previous reports of associations between B-cell phenotype and function have examined global phenotypes and responses to polyclonal stimuli. We hypothesized that studying antigen-specific B cells, using samples from sensitized patients, would inform further study to identify novel targets for intervention. Using biotinylated HLA proteins, which bind HLA-specific B cells via the B-cell receptor in a dose-dependent fashion, we report the specific phenotype of HLA-binding B cells and define how they associated with patterns of anti-HLA response in interferon-γ ELISpot. HLA-binding class-switched and IgM+CD27+ memory cells associated strongly with B-dependent interferon-γ production and appeared not suppressible by endogenous Tregs. When the predominant HLA-binding phenotype was naïve B cells, the associated functional ELISpot phenotype was determined by other cells present. High numbers of non-HLA-binding transitional cells associated with B-suppressed interferon-γ production, especially if Tregs were present. However, high frequencies of HLA-binding marginal-zone precursors associated with B-dependent interferon-γ production that appeared suppressible by Tregs. Finally, non-HLA-binding marginal zone precursors may also suppress interferon-γ production, though this association only emerged when Tregs were absent from the ELISpot. Thus, our novel data provide a foundation on which to further define the complexities of interactions between HLA-specific T and B cells and identify new targets for intervention in new therapies for chronic rejection.

Critically important outcomes for infection in trials in kidney transplantation: An international survey of patients, caregivers, and health professionals.

BACKGROUND: Infections are a common complication following kidney transplantation, but are reported inconsistently in clinical trials. This study aimed to identify the infection outcomes of highest priority for patients/caregivers and health professionals to inform a core outcome set to be reported in all kidney transplant clinical trials. METHODS: In an international online survey, participants rated the absolute importance of 16 infections and eight severity dimensions on 9-point Likert Scales, with 7-9 being critically important. Relative importance was determined using a best-worst scale. Means and proportions of the Likert-scale ratings and best-worst preference scores were calculated. RESULTS: 353 healthcare professionals (19 who identified as both patients/caregiver and healthcare professionals) and 220 patients/caregivers (190 patients, 22 caregivers, eight who identified as both) from 55 countries completed the survey. Both healthcare professionals and patients/caregivers rated bloodstream (mean 8.4 and 8.5, respectively; aggregate 8.5), kidney/bladder (mean 7.9 and 8.4; aggregate 8.1), and BK virus (mean 8.1 and 8.6; aggregate 8.3) as the top three most critically important infection outcomes, whilst infectious death (mean 8.8 and 8.6; aggregate 8.7), impaired graft function (mean 8.4 and 8.7; aggregate 8.5) and admission to the intensive care unit (mean 8.2 and 8.3; aggregate 8.2) were the top three severity dimensions. Relative importance (best-worst) scores were consistent. CONCLUSIONS: Healthcare professionals and patients/caregivers consistently identified bloodstream infection, kidney/bladder infections, and BK virus as the three most important infection outcomes, and infectious death, admission to intensive care unit and infection impairing graft function as the three most important infection severity outcomes.

European Guideline for the Management of Kidney Transplant Patients With HLA Antibodies: By the European Society for Organ Transplantation Working Group.

This guideline, from a European Society of Organ Transplantation (ESOT) working group, concerns the management of kidney transplant patients with HLA antibodies. Sensitization should be defined using a virtual parameter such as calculated Reaction Frequency (cRF), which assesses HLA antibodies derived from the actual organ donor population. Highly sensitized patients should be prioritized in kidney allocation schemes and linking allocation schemes may increase opportunities. The use of the ENGAGE 5 ((Bestard et al., Transpl Int, 2021, 34: 1005-1018) system and online calculators for assessing risk is recommended. The Eurotransplant Acceptable Mismatch program should be extended. If strategies for finding a compatible kidney are very unlikely to yield a transplant, desensitization may be considered and should be performed with plasma exchange or immunoadsorption, supplemented with IViG and/or anti-CD20 antibody. Newer therapies, such as imlifidase, may offer alternatives. Few studies compare HLA incompatible transplantation with remaining on the waiting list, and comparisons of morbidity or quality of life do not exist. Kidney paired exchange programs (KEP) should be more widely used and should include unspecified and deceased donors, as well as compatible living donor pairs. The use of a KEP is preferred to desensitization, but highly sensitized patients should not be left on a KEP list indefinitely if the option of a direct incompatible transplant exists.

Alloimmune Risk Stratification for Kidney Transplant Rejection.

Different types of kidney transplantations are performed worldwide, including biologically diverse donor/recipient combinations, which entail distinct patient/graft outcomes. Thus, proper immunological and non-immunological risk stratification should be considered, especially for patients included in interventional randomized clinical trials. This paper was prepared by a working group within the European Society for Organ Transplantation, which submitted a Broad Scientific Advice request to the European Medicines Agency (EMA) relating to clinical trial endpoints in kidney transplantation. After collaborative interactions, the EMA sent its final response in December 2020, highlighting the following: 1) transplantations performed between human leukocyte antigen (HLA)-identical donors and recipients carry significantly lower immunological risk than those from HLA-mismatched donors; 2) for the same allogeneic molecular HLA mismatch load, kidney grafts from living donors carry significantly lower immunological risk because they are better preserved and therefore less immunogenic than grafts from deceased donors; 3) single-antigen bead testing is the gold standard to establish the repertoire of serological sensitization and is used to define the presence of a recipient's circulating donor-specific antibodies (HLA-DSA); 4) molecular HLA mismatch analysis should help to further improve organ allocation compatibility and stratify immunological risk for primary alloimmune activation, but without consensus regarding which algorithm and cut-off to use it is difficult to integrate information into clinical practice/study design; 5) further clinical validation of other immune assays, such as those measuring anti-donor cellular memory (T/B cell ELISpot assays) and non-HLA-DSA, is needed; 6) routine clinical tests that reliably measure innate immune alloreactivity are lacking.

Donor Autonomy and Self-Sacrifice in Living Organ Donation: An Ethical Legal and Psychological Aspects of Transplantation (ELPAT) View.

Clinical teams understandably wish to minimise risks to living kidney donors undergoing surgery, but are often faced with uncertainty about the extent of risk, or donors who wish to proceed despite those risks. Here we explore how these difficult decisions may be approached and consider the conflicts between autonomy and paternalism, the place of self-sacrifice and consideration of risks and benefits. Donor autonomy should be considered as in the context of the depth and strength of feeling, understanding risk and competing influences. Discussion of risks could be improved by using absolute risk, supra-regional MDMs and including the risks to the clinical team as well as the donor. The psychological effects on the donor of poor outcomes for the untransplanted recipient should also be taken into account. There is a lack of detailed data on the risks to the donor who has significant co-morbidities.

Changing patterns of clinical decision making: are falling numbers of antibody incompatible transplants related to the increasing success of the UK Living Kidney Sharing Scheme? A national cohort study.

Antibody incompatibility is a barrier to living kidney transplantation; antibody incompatible transplantation (AIT) is an accepted treatment modality, albeit higher risk. This study aims to determine changes to clinical decision making and access to AIT in the UK. An electronic survey was sent to all UK renal transplant centres (n = 24), in 2014, and again in 2018. Questions focused on entry & duration in the UKLKSS for HLA and ABO-incompatible pairs, Can and provision of direct AIT transplantation within those centres. Between 2014 & 2018, the duration recommended for patients in the UKLKSS increased. In 2014, 34.8% of centres reported leaving HLA-i pairs in the UKLKSS indefinitely, or reviewing on a case by case basis, by 2018 this increased to 61%. Centres offering direct HLA-i transplantation reduced from 58% to 37%. For low titre (1:8) ABO-i recipients, 66% of centres recommended at least 9 months (3 matching runs) in the UKLKSS scheme in 2018, compared to 47% in 2014, 50% fewer units consider direct ABO-i transplantation for unsuccessful pairs with high ABO titres (>1:512). Over time, clinicians appear to be facilitating more conservative management of AIT patients, potentially limiting access to living donor transplantation.

Early relapse of atypical hemolytic uremic syndrome following ABO-incompatible living-related pediatric kidney re-transplant successfully treated with eculizumab.

BACKGROUND: A 3-year-old girl with clinical features of atypical HUS (complement Factor I mutation inherited from an asymptomatic mother and Factor H autoantibodies) was treated with plasma exchange, progressed to kidney failure (KF) aged 4 years, and received an en bloc kidney DCD transplant aged 8 years with primary graft non-function necessitating transplant nephrectomy at the time of transplantation. She subsequently underwent re-transplantation from her father. This is a retrospective study of electronic patient records and medical notes. CASE-DIAGNOSIS/TREATMENT: A 9-year-old girl received an ABO-incompatible (ABOi) living-related kidney transplant from her father with recipient and donor blood groups of O and A, respectively, with baseline recipient anti-A titers 1:128 reducing to 1:4 at the time of transplant with B lymphocyte depletion with rituximab and four sessions of immunoadsorption. Six hours post-transplant, she had recurrence of aHUS and received the first dose of eculizumab. She continues on monthly home eculizumab infusions with stable kidney allograft function and negative anti-A titers 7 years post-kidney transplantation. CONCLUSIONS: This is the first report of a pediatric high-risk ABOi living-related kidney transplantation in whom early relapse of aHUS was successfully treated with eculizumab with good long-term patient and allograft outcome.

Outcomes of paediatric kidney transplant recipients using the updated 2013/2017 Banff histopathological classification for antibody-mediated rejection.

BACKGROUND: After the major changes with regard to acute and chronic ABMR in the Banff classification initiated in 2013, there has been an improvement in diagnosing antibody-mediated rejection (ABMR) in adult studies but no data have been published in the paediatric population. METHODS: We assessed 56 paediatric kidney transplant biopsies due to kidney dysfunction in patients with donor-specific antibodies (DSA) in a retrospective single-centre study between January 2006 and March 2012. The results were compared with 2003/2007 Banff classification noting the subsequent 2017 and 2019 modifications do not change the 2013 Banff classification with regard to acute antibody-mediated rejection (apart from the addition of gene transcripts/classifiers that do not affect our analysis). RESULTS: Following the 2013 Banff classification, there were seven cases (12.5%) diagnosed with ABMR that would have been misclassified when applying the 2003/2007 classification. Evaluating the histological features of all ABMR-related cases, we report the importance of v- (intimal arteritis) and t- (tubulitis) lesions: absence of v- and t- lesions in the biopsy is related to significantly higher kidney allograft survival (OR 7.3, 95%CI 1.1-48.8, p = 0.03 and OR 5.3, 95%CI 1.2-25.5, p = 0.04 respectively). Moreover, absence of t- lesions was associated with significantly fewer rejection episodes the year after the initial biopsy (OR 5.1, 95%CI 1.4-19.8, p = 0.01). CONCLUSIONS: Our study supports that the updated 2013 Banff classification shows superior clinicopathological correlation in identifying ABMR in paediatric kidney transplant recipients. Our results can be extrapolated to the recently updated 2019 Banff classification.

Donating a Kidney to a Stranger: A Review of the Benefits and Controversies of Unspecified Kidney Donation.

OF BACKGROUND DATA: Unspecified kidney donation (UKD) describes living donation of a kidney to a stranger. The practice is playing an increasingly important role within the transplant programme in the United Kingdom, where these donors are commonly used to trigger a chain of transplants; thereby amplifying the benefit derived from their donation. The initial reluctance to accept UKD was in part due to uncertainty about donor motivations and whether the practice was morally and ethically acceptable. OBJECTIVES: This article provides an overview of UKD and answers common questions regarding the ethical considerations, clinical assessment, and how UKD kidneys are used to maximize utility. Existing literature on outcomes after UKD is also discussed, along with current controversies. CONCLUSIONS: We believe UKD is an ethically acceptable practice which should continue to grow, despite its controversies. In our experience, these donors are primarily motivated by a desire to help others and utilization of their kidney as part of a sharing scheme means that many more people seek to benefit from their very generous donation.

Prophylaxis of Wound Infections-antibiotics in Renal Donation (POWAR): A UK Multicentre Double Blind Placebo Controlled Randomised Trial.

BACKGROUND: Postoperative infection after hand-assisted laparoscopic donor nephrectomy (HALDN) confers significant morbidity to a healthy patient group. Current UK guidelines cite a lack of evidence for routine antibiotic prophylaxis. This trial assessed if a single preoperative antibiotic dose could reduce post HALDN infections. METHODS: Eligible donors were randomly and blindly allocated to preoperative single-dose intravenous co-amoxiclav or saline. The primary composite endpoint was clinical evidence of any postoperative infection at 30 days, including surgical site infection (SSI), urinary tract infection (UTI), and lower respiratory tract infection (LRTI). FINDINGS: In all, 293 participants underwent HALDN (148 antibiotic arm and 145 placebo arm). Among them, 99% (291/293) completed follow-up. The total infection rate was 40.7% (59/145) in the placebo group and 23% (34 of 148) in the antibiotic group (P = 0.001). Superficial SSIs were 20.7% (30/145 patients) in the placebo group versus 10.1% (15/148 patients) in the antibiotic group (P = 0.012). LRTIs were 9% (13/145) in the placebo group and 3.4% (5/148) in the antibiotic group (P = 0.046). UTIs were 4.1% (6/145) in the placebo group and 3.4% (5/148) in the antibiotic group (P = 0.72).Antibiotic prophylaxis conferred a 17.7% (95% confidence interval 7.2%-28.1%), absolute risk reduction in developing postoperative infection, with 6 donors requiring treatment to prevent 1 infection. INTERPRETATION: Single-dose preoperative antibiotic prophylaxis dramatically reduces post-HALDN infection rates, mainly impacting SSIs and LRTIs.

Safety and efficacy of eculizumab in the prevention of antibody-mediated rejection in living-donor kidney transplant recipients requiring desensitization therapy: A randomized trial.

We report results of a phase 2, randomized, multicenter, open-label, two-arm study evaluating the safety and efficacy of eculizumab in preventing acute antibody-mediated rejection (AMR) in sensitized recipients of living-donor kidney transplants requiring pretransplant desensitization (NCT01399593). In total, 102 patients underwent desensitization. Posttransplant, 51 patients received standard of care (SOC) and 51 received eculizumab. The primary end point was week 9 posttransplant treatment failure rate, a composite of: biopsy-proven acute AMR (Banff 2007 grade II or III; assessed by blinded central pathology); graft loss; death; or loss to follow-up. Eculizumab was well tolerated with no new safety concerns. No significant difference in treatment failure rate was observed between eculizumab (9.8%) and SOC (13.7%; P = .760). To determine whether data assessment assumptions affected study outcome, biopsies were reanalyzed by central pathologists using clinical information. The resulting treatment failure rates were 11.8% and 21.6% for the eculizumab and SOC groups, respectively (nominal P = .288). When reassessment included grade I AMR, the treatment failure rates were 11.8% (eculizumab) and 29.4% (SOC; nominal P = .048). This finding suggests a potential benefit for eculizumab compared with SOC in preventing acute AMR in recipients sensitized to their living-donor kidney transplants (EudraCT 2010-019630-28).

Safety and efficacy of eculizumab for the prevention of antibody-mediated rejection after deceased-donor kidney transplantation in patients with preformed donor-specific antibodies.

The presence of preformed donor-specific antibodies in transplant recipients increases the risk of acute antibody-mediated rejection (AMR). Results of an open-label single-arm trial to evaluate the safety and efficacy of eculizumab in preventing acute AMR in recipients of deceased-donor kidney transplants with preformed donor-specific antibodies are reported. Participants received eculizumab as follows: 1200 mg immediately before reperfusion; 900 mg on posttransplant days 1, 7, 14, 21, and 28; and 1200 mg at weeks 5, 7, and 9. All patients received thymoglobulin induction therapy and standard maintenance immunosuppression including steroids. The primary end point was treatment failure rate, a composite of biopsy-proved grade II/III AMR (Banff 2007 criteria), graft loss, death, or loss to follow-up, within 9 weeks posttransplant. Eighty patients received transplants (48 women); the median age was 52 years (range 24-70 years). Observed treatment failure rate (8.8%) was significantly lower than expected for standard care (40%; P < .001). By 9 weeks, 3 of 80 patients had experienced AMR, and 4 of 80 had experienced graft loss. At 36 months, graft and patient survival rates were 83.4% and 91.5%, respectively. Eculizumab was well tolerated and no new safety concerns were identified. Eculizumab has the potential to provide prophylaxis against injury caused by acute AMR in such patients (EudraCT 2010-019631-35).

Patient-specific 3D Printing: A Novel Technique for Complex Pediatric Renal Transplantation.

OBJECTIVE: The authors investigated a novel application of patient-specific three-dimensional (3D) printing, to enhance preoperative, multidisciplinary planning in complex, living-donor pediatric renal transplantation. SUMMARY BACKGROUND DATA: For children with end-stage kidney disease, the transplantation of adult-sized, living-donor kidneys into small recipients (<20 kg) with increasingly complex structural anomalies can be difficult. Establishing the operative feasibility in such cases demands a surgical understanding of anatomy to be derived from medical imaging. However, this is hampered by the representation of complex structures in 2D, the inherent interpretive expertise this demands, and the challenge of conveying this appreciation to others. METHODS: We report the novel use of patient-specific 3D printed models to achieve personalized management for 3 children who underwent living-donor renal transplantation. Each presented a unique surgical challenge that would otherwise prevent preoperative determination of transplantation feasibility. Patient-specific geometries were segmented from imaging data and fabricated using polyjet, 3D printing technology. Models were verified by an expert radiologist and presented during multidisciplinary discussion and surgical simulation. RESULTS: 3D printed models enhanced preoperative deliberation and surgical simulation and allowed on-table exploration of a small child to be avoided. We have critically determined specific clinical indications, technical insights, limitations, and outcomes of this approach. At latest follow-up (>16 mo) all patients remain well with functioning renal allografts. CONCLUSIONS: We report the new and safe integration of patient-specific 3D printing into complex pediatric renal transplantation. This technique enhances surgical planning and can inform operative feasibility in those cases which would otherwise be uncertain.

For the many: permitting deceased donor kidney transplantation across low-titre blood group antibodies can reduce wait times for blood group B recipients, and improve the overall number of 000MM transplants - a multicentre observational cohort study.

Blood group O or B recipients wait longer for a kidney transplant. We studied the distribution of anti-ABO blood group antibody titres in patients awaiting a kidney transplant, and modelled the effect of altering the UK National Kidney Allocation Scheme to allow for patients with 'LOW' titres (≤1:8, ≤3 dilutions) to receive a deceased donor ABOi (ddABOi) transplant. In a prospective study of 239 adult patients on the waiting list for a transplant in 2 UK centres, ABO-antibody titres (anti-A and anti-B) were measured. Based on the proportions of 'LOW' anti-A or anti-B antibodies, four simulations were performed to model the current allocation rules compared with variations allowing ddABOi allocation under various conditions of blood group, HLA matching, and waiting time. The simulations permitting ddABOi resulted in more blood group B recipients being transplanted, with median waiting time reduced for this group of recipients, and more equitable waiting times across blood groups. Additionally, permitting ddABOi resulted in greater numbers of 000MM allocations overall in compatible transplants under modelled conditions. Changing allocation in the UK to permit ddABOi in patients with 'LOW' titres would not change the total number of transplants, but redistributes allocation more equitably amongst blood groups, altering waiting times accordingly.

Utilisation of small paediatric donor kidneys for transplantation.

With the increasing need for kidney transplantation in the paediatric population and changing donor demographics, children without a living donor option will potentially be offered an adult deceased donor transplant of marginal quality. Given the importance of long-term graft survival for paediatric recipients, consideration is now being given to kidneys from small paediatric donors (SPDs). There exist a lack of consensus and a reluctance amongst some centres in transplanting SPDs due to high surgical complication rates, graft loss and concerns regarding low nephron mass and long-term function. The aim of this review is to examine and present the evidence base regarding the transplantation of these organs. The literature in both the paediatric and adult renal transplant fields, as well as recent relevant conference proceedings, is reviewed. We discuss the surgical techniques, long-term graft function and rates of complications following transplantation of SPDs. We compare graft survival of SPDs to adult deceased donors and consider the use of small paediatric donors after circulatory death (DCD) organs. In conclusion, evidence is presented that may refute historically held paradigms regarding the transplantation of SPDs in paediatric recipients, thereby potentially allowing significant expansion of the donor pool.