Preclinical models versus clinical renal ischemia reperfusion injury: A systematic review based on metabolic signatures.

Despite decennia of research and numerous successful interventions in the preclinical setting, renal ischemia reperfusion (IR) injury remains a major problem in clinical practice, pointing toward a translational gap. Recently, two clinical studies on renal IR injury (manifested either as acute kidney injury or as delayed graft function) identified metabolic derailment as a key driver of renal IR injury. It was reasoned that these unambiguous metabolic findings enable direct alignment of clinical with preclinical data, thereby providing the opportunity to elaborate potential translational hurdles between preclinical research and the clinical context. A systematic review of studies that reported metabolic data in the context of renal IR was performed according to the PRISMA guidelines. The search (December 2020) identified 35 heterogeneous preclinical studies. The applied methodologies were compared, and metabolic outcomes were semi-quantified and aligned with the clinical data. This review identifies profound methodological challenges, such as the definition of IR injury, the follow-up time, and sampling techniques, as well as shortcomings in the reported metabolic information. In light of these findings, recommendations are provided in order to improve the translatability of preclinical models of renal IR injury.

A nationwide evaluation of deceased donor kidney transplantation indicates detrimental consequences of early graft loss.

Early graft loss (EGL) is a feared outcome of kidney transplantation. Consequently, kidneys with an anticipated risk of EGL are declined for transplantation. In the most favorable scenario, with optimal use of available donor kidneys, the donor pool size is balanced by the risk of EGL, with a tradeoff dictated by the consequences of EGL. To gauge the consequence of EGL we systematically evaluated its impact in an observational study that included all 10,307 deceased-donor kidney transplantations performed in The Netherlands between 1990 and 2018. Incidence of EGL, defined as graft loss within 90 days, in primary transplantation was 8.2% (699/8,511). The main causes were graft rejection (30%), primary nonfunction (25%), and thrombosis or infarction (20%). EGL profoundly impacted short- and long-term patient survival (adjusted hazard ratio; 95% confidence interval: 8.2; 5.1-13.2 and 1.7; 1.3-2.1, respectively). Of the EGL recipients who survived 90 days after transplantation (617/699) only 440 of the 617 were relisted for re-transplantation. Of those relisted, only 298 were ultimately re-transplanted leading to an actual re-transplantation rate of 43%. Noticeably, re-transplantation was associated with a doubled incidence of EGL, but similar long-term graft survival (adjusted hazard ratio 1.1; 0.6-1.8). Thus, EGL after kidney transplantation is a medical catastrophe with high mortality rates, low relisting rates, and increased risk of recurrent EGL following re-transplantation. This implies that detrimental outcomes also involve convergence of risk factors in recipients with EGL. The 8.2% incidence of EGL minimally impacted population mortality, indicating this incidence is acceptable.

The Neglectable Impact of Delayed Graft Function on Long-term Graft Survival in Kidneys Donated After Circulatory Death Associates With Superior Organ Resilience.

OBJECTIVE: To explore putative different impacts of delayed graft function (DGF) on long-term graft survival in kidneys donated after brain death (DBD) and circulatory death (DCD). BACKGROUND: Despite a 3-fold higher incidence of DGF in DCD grafts, large studies show equivalent long-term graft survival for DBD and DCD grafts. This observation implies a differential impact of DGF on DBD and DCD graft survival. The contrasting impact is remarkable and yet unexplained. METHODS: The impact of DGF on DBD and DCD graft survival was evaluated in 6635 kidney transplants performed in The Netherlands. DGF severity and functional recovery dynamics were assessed for 599 kidney transplants performed at the Leiden Transplant Center. Immunohistochemical staining, gene expression profiling, and Ingenuity Pathway Analysis were used to identify differentially activated pathways in DBD and DCD grafts. RESULTS: While DGF severely impacted 10-year graft survival in DBD grafts (HR 1.67; P < 0.001), DGF did not impact graft survival in DCD grafts (HR 1.08; P = 0.63). Shorter dialysis periods and superior posttransplant eGFRs in DBD grafts show that the differential impact was not caused by a more severe DGF phenotype in DBD grafts. Immunohistochemical evaluation indicates that pathways associated with tissue resilience are present in kidney grafts. Molecular evaluation showed selective activation of resilience-associated pathways in DCD grafts. CONCLUSIONS: This study shows an absent impact of DGF on long-term graft survival in DCD kidneys. Molecular evaluation suggests that the differential impact of DGF between DBD and DCD grafts relates to donor-type specific activation of resilience pathways in DCD grafts.

Synthesising conceptual frameworks for patient and public involvement in research - a critical appraisal of a meta-narrative review.

BACKGROUND: A number of conceptual frameworks for patient and public involvement (PPI) in research have been published in recent years. Although some are based on empirical research and/or existing theory, in many cases the basis of the conceptual frameworks is not evident. In 2015 a systematic review was published by a collaborative review group reporting a meta-narrative approach to synthesise a conceptual framework for PPI in research (hereafter 'the synthesis'). As the first such synthesis it is important to critically scrutinise this meta-narrative review. The 'RAMESES publication standards for meta-narrative reviews' provide a framework for critically appraising published meta-narrative reviews such as this synthesis, although we recognise that these were published concurrently. Thus the primary objective of this research was to appraise this synthesis of conceptual frameworks for PPI in research in order to inform future conceptualisation. METHODS: Four researchers critically appraised the synthesis using the RAMESES publication standards as a framework for assessment. Data were extracted independently using a data extraction form closely based on the RAMESES publication standards. Each item from the standards was assessed on a four point scale (0 = unmet, 1 = minimally met, 2 = partly met, 3 = fully met). The four critical appraisals were then compared and any differences resolved through discussion. RESULTS: A good degree of inter-rater reliability was found. A consensus assessment of the synthesis as a meta-narrative review of PPI conceptual frameworks was achieved with an average of '1' (minimally met) across all 20 items. Two key items ('evidence of adherence to guiding principles of meta-narrative review' and 'analysis and synthesis processes') were both wholly unmet. Therefore the paper did not meet our minimum requirements for a meta-narrative review. We found the RAMESES publication standards were a useful tool for carrying out a critical appraisal although some minor improvements are suggested. CONCLUSIONS: Although the aims of the authors' synthesis were commendable, and the conceptual framework presented was coherent and attractive, the paper did not demonstrate a transparent and replicable meta-narrative review approach. There is a continuing need for a more rigorous synthesis of conceptual frameworks for PPI.

Donor characteristics and their impact on kidney transplantation outcomes: Results from two nationwide instrumental variable analyses based on outcomes of donor kidney pairs accepted for transplantation.

Background: Donor-characteristics and donor characteristics-based decision algorithms are being progressively used in the decision process whether or not to accept an available donor kidney graft for transplantation. While this may improve outcomes, the performance characteristics of the algorithms remains moderate. To estimate the impact of donor factors of grafts accepted for transplantation on transplant outcomes, and to test whether implementation of donor-characteristics-based algorithms in clinical decision-making is justified, we applied an instrumental variable analysis to outcomes for kidney donor pairs transplanted in different individuals. Methods: This analysis used (dis)congruent outcomes of kidney donor pairs as an instrument and was based on national transplantation registry data for all donor kidney pairs transplanted in separate individuals in the Netherlands (1990-2018, 2,845 donor pairs), and the United Kingdom (UK, 2000-2018, 11,450 pairs). Incident early graft loss (EGL) was used as the primary discriminatory factor. It was reasoned that a scenario with a dominant impact of donor variables on transplantation outcomes would result in high concordance of EGL in both recipients, whilst dominance of asymmetrical outcomes could indicate a more complex scenario, involving an interaction of donor, procedural and recipient factors. Findings: Incidences of congruent EGL (Netherlands: 1·2%, UK: 0·7%) were slightly lower than the arithmetical (stochastic) incidences, suggesting that once a graft has been accepted for transplantation, donor factors minimally contribute to incident EGL. A long-term impact of donor factors was explored by comparing outcomes for functional grafts from donor pairs with asymmetrical vs. symmetrical outcomes. Recipient survival was similar for both groups, but a slightly compromised graft survival was observed for grafts with asymmetrical outcomes in the UK cohort: (10-years Hazard Ratio for graft loss: 1·18 [1·03-1·35] p<0·018); and 5 years eGFR (48·6 [48·3-49·0] vs. 46·0 [44·5-47·6] ml/min in the symmetrical outcome group, p<0·001). Interpretation: Our results suggest that donor factors for kidney grafts deemed acceptable for transplantation impact minimally on transplantation outcomes. A strong reliance on donor factors and/or donor-characteristics-based decision algorithms could result in unjustified rejection of grafts. Future efforts to optimize transplant outcomes should focus on a better understanding of the recipient factors underlying transplant outcomes. Funding: None.

Circumventing the Crabtree effect in cell culture: A systematic review.

Metabolic reprogramming and mitochondrial dysfunction are central elements in a broad variety of physiological and pathological processes. While cell culture established itself as a versatile technique for the elaboration of physiology and disease, studying metabolism using standard cell culture protocols is profoundly interfered by the Crabtree effect. This phenomenon refers to the adaptation of cultured cells to a glycolytic phenotype, away from oxidative phosphorylation in glucose-containing medium, and questions the applicability of cell culture in certain fields of research. In this systematic review we aim to provide a comprehensive overview and critical appraisal of strategies reported to circumvent the Crabtree effect.

Improving outcomes for donation after circulatory death kidney transplantation: Science of the times.

The use of kidneys donated after circulatory death (DCD) remains controversial due to concerns with regard to high incidences of early graft loss, delayed graft function (DGF), and impaired graft survival. As these concerns are mainly based on data from historical cohorts, they are prone to time-related effects and may therefore not apply to the current timeframe. To assess the impact of time on outcomes, we performed a time-dependent comparative analysis of outcomes of DCD and donation after brain death (DBD) kidney transplantations. Data of all 11,415 deceased-donor kidney transplantations performed in The Netherlands between 1990-2018 were collected. Based on the incidences of early graft loss, two eras were defined (1998-2008 [n = 3,499] and 2008-2018 [n = 3,781]), and potential time-related effects on outcomes evaluated. Multivariate analyses were applied to examine associations between donor type and outcomes. Interaction tests were used to explore presence of effect modification. Results show clear time-related effects on posttransplant outcomes. The 1998-2008 interval showed compromised outcomes for DCD procedures (higher incidences of DGF and early graft loss, impaired 1-year renal function, and inferior graft survival), whereas DBD and DCD outcome equivalence was observed for the 2008-2018 interval. This occurred despite persistently high incidences of DGF in DCD grafts, and more adverse recipient and donor risk profiles (recipients were 6 years older and the KDRI increased from 1.23 to 1.39 and from 1.35 to 1.49 for DBD and DCD donors). In contrast, the median cold ischaemic period decreased from 20 to 15 hours. This national study shows major improvements in outcomes of transplanted DCD kidneys over time. The time-dependent shift underpins that kidney transplantation has come of age and DCD results are nowadays comparable to DBD transplants. It also calls for careful interpretation of conclusions based on historical cohorts, and emphasises that retrospective studies should correct for time-related effects.

Challenges and opportunities for involving patients and the public in acute antimicrobial medicine development research: an interview study.

OBJECTIVES: To explore what approaches to patient and public involvement (PPI) in antimicrobial medicines development are currently being used, what the impacts of PPI are on antimicrobial medicines development and what the barriers are to its implementation. DESIGN: Interview study. SETTING: Antimicrobial medicines development research. PARTICIPANTS: Principal investigators known to have led studies involving PPI or expressed an interest in PPI. RESULTS: There is very little published work on PPI in antimicrobial research. Individual interviewees expressed scepticism about the contribution that PPI could make to different stages of the medicines development life cycle but collectively identified a range of potential benefits of PPI covering most stages of the medicines development process. CONCLUSIONS: A major issue in developing PPI in antimicrobial medicines development research will be in overcoming the view that, at best, PPI has only a marginal contribution to make in this area of research. The findings from this study, although mixed, suggest that well-designed PPI has an untapped potential to enhance antimicrobial research.

Integrating Local Knowledge into a National Programme: Evidence from a Community-Based Diabetes Prevention Education Programme.

Type 2 diabetes prevention is a major priority for healthcare services and public health. This study aimed to evaluate how a local authority in England piloted a diabetes prevention programme. The South Gloucestershire Diabetes Prevention (Pilot) Programme (SGDPP) comprised a group health education course over six weeks with subsequent support provision up to six months post-enrolment. Of the 300 patients invited onto the programme, 32% enrolled and 29% completed the full six-month programme. There was an attendance rate of 84% throughout group sessions and at a six-month follow-up. There were significant improvements across most measures at six months, including a 4 kg mean weight loss and a 3.45 mmol/mol mean HbA1c reduction. Clear goals, high quality organization and personal qualities of educators were identified as central for the programme's success. The unit costs were similar to pilots of other healthy lifestyle programmes. The evaluation found evidence of reduced type 2 diabetes risk markers, positive impacts for dietary and physical activity, and potential cost-effectiveness for this format of group-based diabetes prevention intervention. Feedback from multiple stakeholders provided insight on how to successfully embed and scale-up delivery of diabetes prevention work. This evidence enables the integration of learning in local service delivery and provides a basis to support development of the national diabetes prevention programme.

Finding and engaging patients and the public to work collaboratively on an acute infection microbiology research public panel.

PLAIN ENGLISH SUMMARY: In 2015 a microbiology team in Bristol joined a European research project that aims to develop new antibiotics to fight drug resistant infections. The microbiology team were convinced of the benefits of patient and public involvement, but had found it difficult to find former patients to work with on earlier microbiology research. This paper describes how the team overcame this challenge to successfully recruit a PPI panel to develop PPI within the European project.The advice from people with experience in public involvement was to decide what criteria were desirable for panel membership, think about what the work of the panel might involve and how long the project will go on. The team decided that experience of suffering a serious acute infection would qualify people to comment on this project. Next, the team needed to identify ways of finding people to join the PPI panel.The microbiology research team tried different ways to approach potential panel members. These included distributing flyers at public research events, sending emails to potentially interested people, posting a message on the hospital Facebook page and approaching eligible people known to the team. A direct approach was the most successful method - either by email, mail or in person. Ultimately 16 people were selected to form the panel. Key factors for success were planning what the work of the panel might be, perseverance despite early lack of success, and one person having overall responsibility for setting up the panel, with the support of the whole team. ABSTRACT: Background In 2015 the microbiology research team became involved in a large European programme of research aiming to bring new antimicrobial drugs onto the market to combat the increasing problem of multi-drug resistant infection. With the purpose of developing patient and public involvement (PPI) in this project, the team decided to recruit a PPI panel to work with. The microbiology team had previously worked with a PPI panel on other research, but had found it difficult to recruit members. Methods Steps taken to recruit the panel were as follows:Advice was sought from people experienced in co-ordinating public involvement in research.One person in the team had overall responsibility but the whole research team was committed and met regularly.Two of the team undertook training in group facilitation and connecting with the public.Decisions were made about the criteria for inclusion into the panel, what tasks we envisaged for the panel, the length of and frequency of meetings.Advertising the involvement opportunity through flyers, social media, emails and direct contact with possible panel recruits known to the research team.Relevant documents such as a Role Profile and expression of interest form were drafted.An initial public meeting was planned for all who had shown interest in the panel.The expression of interest form was used for us to select as broad a group as possible.. Results Two out of three people who were approached directly and known by team members expressed interest in joining the panel (66%). Three out of seven members of a former panel were next (43%), then 10 out of 25 spinal infection clinic patients (40%), and finally 12 people responded to an email sent to 1261 foundation trust members (1%). No-one who was approached by indirect methods e.g. flyers or advertising on Facebook, expressed interest in the panel. Sixteen people were eventually selected for the panel. Conclusions It is possible to recruit a patient and public involvement panel for research in a discipline as challenging as microbiology. Good planning and the commitment of the research team were key to success.