Renal hyperparathyroidism- a risk factor in the development of encapsulating peritoneal sclerosis

Background

Encapsulating peritoneal sclerosis (EPS) is a rare complication of prolonged peritoneal dialysis (PD) exposure, characterised by peritoneal thickening, calcification, and fibrosis ultimately presenting with life-threatening bowel obstruction. The presence or role of peritoneal calcification in the pathogenesis of EPS is poorly characterised. We hypothesise that significantly aberrant bone mineral metabolism in patients on PD can cause peritoneal calcification which may trigger the development of EPS. We compared the temporal evolution of bone mineral markers during PD in EPS patients with non-EPS long-term PD controls.

Methods

Linear mixed model and logistic regression analysis were used to compare four-monthly serum levels of calcium, phosphate, parathyroid hormone, and alkaline phosphatase (ALP) over the duration of PD exposure in 46 EPS and 46 controls (PD, non-EPS) patients.

Results

EPS patients had higher mean calcium (2.51 vs. 2.41 mmol/L) and ALP (248.00 vs. 111.13 IU/L) levels compared with controls (p=0.01 and p<0.001 respectively, maximum likelihood estimation). Logistic regression analysis demonstrated that high serum calcium and phosphate levels during PD were associated with a 4.5 and 2.9 fold increase in the risk of developing EPS respectively.

Conclusion

High levels of calcium and phosphate in patients on PD were identified to be risk factors for EPS development. Possible reasons for this may be an imbalance of pro-calcifying factors and calcification inhibitors promoting peritoneal calcification which increases peritoneal stiffness. Mechanical alterations may trigger, unregulated fibrosis and subsequent development of EPS. Improved management of secondary hyperparathyroidism during PD may ultimately diminish the EPS risk.

Donor noradrenaline use is associated with better allograft survival in recipients of pancreas transplantation

INTRODUCTION

Outcomes following pancreas transplantation are suboptimal and better donor selection is required to improve this. Vasoactive drugs (VaD) are commonly used to correct the abnormal haemodynamics of organ donors in intensive care units. VaDs can differentially affect insulin secretion positively (dobutamine) or negatively (noradrenaline). The hypothesis was that some VaDs might induce beta-cell stress or rest and therefore impact pancreas transplant outcomes. The aim of the study was to assess relationships between VaD use and pancreas transplant graft survival.

METHODS

Data from the UK Transplant Registry on all pancreas transplants performed between 2004 and 2016 with complete follow-up data were included. Univariable- and multivariable-adjusted Cox regression analyses determined risks of graft failure associated with VaD use.

RESULTS

In 2,183 pancreas transplants, VaDs were used in the following numbers of donors: dobutamine 76 (3.5%), dopamine 84 (3.8%), adrenaline 161 (7.4%), noradrenaline 1,589 (72.8%) and vasopressin 1,219 (55.8%). In multivariable models, adjusted for covariates and the co-administration of other VaDs, noradrenaline use (vs non-use) was a strong predictor of better graft survival (hazard ratio [95% confidence interval] 0.77 [0.64-0.94], p = 0.01).

CONCLUSIONS

Noradrenaline use was associated with better graft survival in models adjusted for donor and recipient variables - this may be related to inhibition of pancreatic insulin secretion initiating pancreatic beta-cell 'rest'. Further research is required to replicate these findings and establish whether relationships are causal. Identification of alternative methods of inducing beta-cell rest could be valuable in improving graft outcomes.

Beta-cell death and dysfunction drives hyperglycaemia in organ donors

BACKGROUND

Donor hyperglycaemia following brain death has been attributed to reversible insulin resistance. However, our islet and pancreas transplant data suggest that other mechanisms may be predominant. We aimed to determine the relationships between donor insulin use and markers of beta-cell death and beta-cell function in pancreas donors after brain death.

METHODS

In pancreas donors after brain death, we compared clinical and biochemical data in 'insulin-treated' and 'not insulin-treated donors' (IT vs. not-IT). We measured plasma glucose, C-peptide and levels of circulating unmethylated insulin gene promoter cell-free DNA (INS-cfDNA) and microRNA-375 (miR-375), as measures of beta-cell death. Relationships between markers of beta-cell death and islet isolation outcomes and post-transplant function were also evaluated.

RESULTS

Of 92 pancreas donors, 40 (43%) required insulin. Glycaemic control and beta-cell function were significantly poorer in IT donors versus not-IT donors [median (IQR) peak glucose: 8 (7-11) vs. 6 (6-8) mmol/L, p = .016; C-peptide: 3280 (3159-3386) vs. 3195 (2868-3386) pmol/L, p = .046]. IT donors had significantly higher levels of INS-cfDNA [35 (18-52) vs. 30 (8-51) copies/ml, p = .035] and miR-375 [1.050 (0.19-1.95) vs. 0.73 (0.32-1.10) copies/nl, p = .05]. Circulating donor miR-375 was highly predictive of recipient islet graft failure at 3 months [adjusted receiver operator curve (SE) = 0.813 (0.149)].

CONCLUSIONS

In pancreas donors, hyperglycaemia requiring IT is strongly associated with beta-cell death. This provides an explanation for the relationship of donor IT with post-transplant beta-cell dysfunction in transplant recipients.

Enhanced optical conductivity and many-body effects in strongly-driven photo-excited semi-metallic graphite

The excitation of quasi-particles near the extrema of the electronic band structure is a gateway to electronic phase transitions in condensed matter. In a many-body system, quasi-particle dynamics are strongly influenced by the electronic single-particle structure and have been extensively studied in the weak optical excitation regime. Yet, under strong optical excitation, where light fields coherently drive carriers, the dynamics of many-body interactions that can lead to new quantum phases remain largely unresolved. Here, we induce such a highly non-equilibrium many-body state through strong optical excitation of charge carriers near the van Hove singularity in graphite. We investigate the system's evolution into a strongly-driven photo-excited state with attosecond soft X-ray core-level spectroscopy. We find an enhancement of the optical conductivity of nearly ten times the quantum conductivity and pinpoint it to carrier excitations in flat bands. This interaction regime is robust against carrier-carrier interaction with coherent optical phonons acting as an attractive force reminiscent of superconductivity. The strongly-driven non-equilibrium state is markedly different from the single-particle structure and macroscopic conductivity and is a consequence of the non-adiabatic many-body state.

Using Laser Speckle Contrast Imaging to Quantify Perfusion Quality in Kidney and Pancreas Grafts on Vascular Reperfusion: A Proof-of-Principle Study

The accuracy of intraoperative graft perfusion assessment still remains subjective, with doppler examination being the only objective adjunct. Laser speckle contrast imaging (LSCI) has been used to assess intraoperative blood flow in neurosurgery and in various surgical specialties. Despite its ability to accurately quantify perfusion at the microvascular level, it has not been clinically evaluated in kidney/kidney-pancreas transplantation for perfusion characterization. We aimed to evaluate the utility of LSCI and identify objective parameters that can be quantified at reperfusion.

Methods

This study was registered in ClinicalTrials.gov (NCT04202237). The Moor FLPI-2 blood flow imager was used in 4 patients (1 Simultaneous Pancreas and Kidney, 2 deceased, and 1 living donor kidney transplants) during reperfusion to capture reperfusion data. The following parameters were measured: flux (average speed × concentration of moving red blood cells in the sample volume), doppler centroid, total and valid pixels, valid rate, and total and valid area. Flux data were analyzed with Moor FLPI analysis software.

Results

The perfusion characteristics and flux images correlated with initial graft function.

Conclusions

LSCI is a safe, noncontact imaging modality that provides real-time, accurate, high-resolution, full field blood flow images and a wide range of flux data to objectively quantify organ reperfusion intraoperatively in kidney/kidney-pancreas transplantation. This modality could be used to develop a robust numerical quantification system for the evaluation and reporting of intraoperative organ perfusion, and aid intraoperative decision-making. Perfusion data could be combined with biomarkers and immunological parameters to more accurately predict graft outcomes.

Surgical management of Encapsulating Peritoneal Sclerosis (EPS) in children: international case series and literature review

BACKGROUND

Encapsulating Peritoneal Sclerosis (EPS) is a rare phenomenon in paediatric patients with kidney failure treated with peritoneal dialysis (PD). This study highlights clinical challenges in the management of EPS, with particular emphasis on peri-operative considerations and surgical technique.

METHODS

Retrospective analysis of all paediatric patients with EPS treated at the Manchester Centre for Transplantation.

RESULTS

Four patients were included with a median duration of 78 months on PD. All patients had recurrent peritonitis (> 3 episodes), and all had symptoms within three months of a change of dialysis modality from PD to haemodialysis or transplant. In Manchester, care was delivered by a multi-disciplinary team, including surgeons delivering the adult EPS surgical service with a particular focus on nutritional optimisation, sepsis control, and wound management. The surgery involved laparotomy, lavage, and enterolysis of the small bowel + / - stoma formation, depending on intra-abdominal contamination. Two patients had a formal stoma, which were reversed at three and six months, respectively. Two patients underwent primary closure of the abdomen, whereas two patients had re-look procedures at 48 h with secondary closure. One patient had a post-operative wound infection, which was managed medically. One patient's stoma became detached, leading to an intra-abdominal collection requiring re-laparotomy. The median length of stay was 25 days, and patients were discharged once enteral feeding was established. All patients remained free of recurrence with normal gut function and currently two out of four have functioning transplants.

CONCLUSIONS

This series demonstrates 100% survival and parenteral feed independence following EPS surgery. Post-operative morbidity was common; however, with individualised experience-based decision-making and relevant additional interventions, patients made full recoveries. Health and development post-surgery continued, allowing the potential for transplantation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Donor insulin therapy in intensive care predicts early outcomes after pancreas transplantation

AIMS/HYPOTHESIS

Approximately 50% of organ donors develop hyperglycaemia in intensive care, which is managed with insulin therapy. We aimed to determine the relationships between donor insulin use (DIU) and graft failure in pancreas transplantation.

METHODS

UK Transplant Registry organ donor data were linked with national data from the UK solid pancreas transplant programme. All pancreas transplants performed between 2004 and 2016 with complete follow-up data were included. Logistic regression models determined associations between DIU and causes of graft failure within 3 months. Area under the receiver operating characteristic curve (aROC) and net reclassification improvement (NRI) assessed the added value of DIU as a predictor of graft failure.

RESULTS

In 2168 pancreas transplant recipients, 1112 (51%) donors were insulin-treated. DIU was associated with a higher risk of graft loss from isolated islet failure: OR (95% CI), 1.79 (1.05, 3.07), p = 0.03, and this relationship was duration/dose dependent. DIU was also associated with a higher risk of graft loss from anastomotic leak (2.72 [1.07, 6.92], p = 0.04) and a lower risk of graft loss from thrombosis (0.62 [0.39, 0.96], p = 0.03), although duration/dose-dependent relationships were only identified in pancreas transplant alone/pancreas after kidney transplant recipients with grafts failing due to thrombosis (0.86 [0.74, 0.99], p = 0.03). The relationships between donor insulin characteristics and isolated islet failure remained significant after adjusting for potential confounders: DIU 1.75 (1.02, 2.99), p = 0.04; duration 1.08 (1.01, 1.16), p = 0.03. In multivariable analyses, donor insulin characteristics remained significant predictors of lower risk of graft thrombosis in pancreas transplant alone/pancreas after kidney transplant recipients: DIU, 0.34 (0.13, 0.90), p = 0.03; insulin duration/dose, 0.02 (0.001, 0.85), p = 0.04. When data on insulin were added to models predicting isolated islet failure, a significant improvement in discrimination and risk reclassification was observed in all models: no DIU aROC 0.56; DIU aROC 0.57, p = 0.86; NRI 0.28, p < 0.00001; insulin duration aROC 0.60, p = 0.47; NRI 0.35, p < 0.00001.

CONCLUSIONS/INTERPRETATION

DIU predicts graft survival in pancreas transplant recipients. This assessment could help improve donor selection and thereby improve patient and graft outcomes.

The use of health information technology in renal transplantation: A systematic review

Renal transplantation is a complex, multi-disciplinary and cross-center service. Clinical pathways naturally traverse specialty and organizational boundaries as patients transition from chronic kidney disease to renal failure and ultimately transplantation. Health information technology (IT) has the potential to support transplant care by improving access to data, information sharing and communication. This novel review aimed to identify and characterize health IT solutions in renal transplantation, and where possible evaluate any intended benefits. A systematic literature review was conducted of studies covering any part of the clinical pathway, with end-users being clinical staff or patients. Interventions were characterized and evaluated for achieved benefits using the World Health Organization (WHO) Classification of Digital Health Interventions and the mixed methods assessment tool (MMAT) was used to determine the quality of experimental studies. Of 4498 articles, 12 descriptive and 6 experimental studies met the inclusion criteria. Median MMAT percentage score of experimental studies was 64 (i.q.r. 57 to 74.8). The most frequent functionality of technology involved overcoming communication roadblocks and improving access to data. Intended benefits included improving information management and supporting workflow, however only one study reported evaluated results. Six patient-facing applications that primarily addressed adherence-to-treatment were identified, five of which were evaluated for intended benefits, showing overall positive results. Overall, despite transplantation being well suited to health IT interventions, this review demonstrates a scarcity of literature in this field. A small number of clinician- and patient-facing IT solutions have been reported, albeit mostly in non-experimental studies. Due to this lack of formal evaluation, the effectiveness of solutions remains unclear. High-quality evaluative studies are required to develop effective IT solutions that improve clinical care.

A Successful Treatment of Encapsulating Peritoneal Sclerosis in an Adolescent Boy on Long-term Peritoneal Dialysis: A Case Report

Encapsulating peritoneal sclerosis (EPS) is a rare life-threatening complication associated with peritoneal dialysis (PD). EPS is characterized by progressive fibrosis and sclerosis of the peritoneum, with the formation of a membrane and tethering of loops of the small intestine resulting in intestinal obstruction. It is very rare in children. We present a case of a 16-year-old adolescent boy who developed EPS seven years after being placed on continuous ambulatory peritoneal dialysis (CAPD) complicated by several episodes of bacterial peritonitis. The diagnosis was based on clinical, radiological, intraoperative and histopathological findings. The patient was successfully treated with surgical enterolysis. During a 7-year follow-up, there have been no further episodes of small bowel obstruction documented. He still continues to be on regular hemodialysis and is awaiting a deceased donor kidney transplant. EPS is a long-term complication of peritoneal dialysis and is typically seen in adults. Rare cases may be seen in the pediatric population and require an appropriate surgical approach that is effective and lifesaving for these patients.

Peri-transplant glycaemic control as a predictor of pancreas transplant survival

AIMS

The relationship between peri-transplant glycaemic control and outcomes following pancreas transplantation is unknown. We aimed to relate peri-transplant glycaemic control to pancreas graft survival and to develop a framework for defining early graft dysfunction.

METHODS

Peri-transplant glycaemic control profiles over the first 5 days postoperatively were determined by an area under the curve [AUC; average daily glucose level (mmol/L) × time (days)] and the coefficient of variation of mean daily glucose levels. Peri-transplant hyperglycaemia was defined as an AUC ≥35 mmol/day/L (daily mean blood glucose ≥7 mmol/L). Risks of graft failure associated with glycaemic control and variability and peri-transplant hyperglycaemia were determined using covariate-adjusted Cox regression.

RESULTS

We collected 7606 glucose readings over 5 days postoperatively from 123 pancreas transplant recipients. Glucose AUC was a significant predictor of graft failure during 3.6 years of follow-up (unadjusted HR [95% confidence interval] 1.17 [1.06-1.30], P = .002). Death censored non-technical graft failure occurred in eight (10%) recipients with peri-transplant normoglycaemia, and eight (25%) recipients with peri-transplant hyperglycaemia such that hyperglycaemia predicted a 3-fold higher risk of graft failure [HR (95% confidence interval): 3.0 (1.1-8.0); P = .028].

CONCLUSION

Peri-transplant hyperglycaemia is strongly associated with graft loss and could be a valuable tool guiding individualized graft monitoring and treatment. The 5-day peri-transplant glucose AUC provides a robust and responsive framework for comparing graft function.

Intersectionality and Cognitive Impairment Risk in Older Persons With HIV: Age, Ethnicity, and LGBT Status

The Latinx population is disproportionately affected by HIV-infection and older Latinx persons living with HIV (PLWH) are at greater risk for neurocognitive impairment (NCI). However, no studies have examined whether intersectionality (including Lesbian Gay Bisexual Transgender [LGBT] status) increases NCI risk. This study investigated whether LGBT status increases NCI risk in 126 PLWH (Ages 19-73 years; 74% Male; 66% Latinx, 34% NHW) who completed a comprehensive NC battery. Domain average T-scores were based on demographically-corrected norms. Multiple regressions revealed that after accounting for covariates (cocaine use, premorbid IQ) and other dimensions of intersectionality (age, ethnicity), LGBT status significantly contributed to NCI risk in attention/working memory (B=-4.50, p=.01) and executive functioning (trend-level; B=-3.67, p=.06). LGBT status, a key dimension of intersectionality, should be considered in NC assessment of PLWH. Future research is needed to identify factors (e.g., discrimination) that may confer increased NCI risk in this population.

Donor insulin use predicts beta-cell function after islet transplantation

Insulin is routinely used to manage hyperglycaemia in organ donors and during the peri-transplant period in islet transplant recipients. However, it is unknown whether donor insulin use (DIU) predicts beta-cell dysfunction after islet transplantation. We reviewed data from the UK Transplant Registry and the UK Islet Transplant Consortium; all first-time transplants during 2008-2016 were included. Linear regression models determined associations between DIU, median and coefficient of variation (CV) peri-transplant glucose levels and 3-month islet graft function. In 91 islet cell transplant recipients, DIU was associated with lower islet function assessed by BETA-2 scores (β [SE] -3.5 [1.5], P = .02), higher 3-month post-transplant HbA1c levels (5.4 [2.6] mmol/mol, P = .04) and lower fasting C-peptide levels (-107.9 [46.1] pmol/l, P = .02). Glucose at 10 512 time points was recorded during the first 5 days peri-transplant: the median (IQR) daily glucose level was 7.9 (7.0-8.9) mmol/L and glucose CV was 28% (21%-35%). Neither median glucose levels nor glucose CV predicted outcomes post-transplantation. Data on DIU predicts beta-cell dysfunction 3 months after islet transplantation and could help improve donor selection and transplant outcomes.

A-06 Current Norms May Overestimate Rates of Neurocognitive Impairment among American Indian and Alaskan Native Adults

Objective

Currently available normative data subsume American Indian and Alaskan Native (AI/AN) populations within the non-Latinx white (NLW) ethnoracial group. The classification accuracy of such norms among AI/AN remains unknown. This cross-sectional study aims to identify whether disparities exist in the rates of neurocognitive impairment (NCI) between AI/AN and NLW adults. &lt; br&gt;&lt;br &gt; 

Method

Two hundred community-dwelling adults (50&#37; NLW; 50&#37; Male; M Age = 42 ± 14 years; M Education = 13 ± 3 years) completed comprehensive neurocognitive, quality of education (Wide Range Achievement Test- 4 [WRAT-4]), neuromedical, urine toxicology, and psychiatric/substance use evaluations. Average T-scores were calculated using widely used demographically corrected (age, gender, education) NLW norms to identify NCI (&gt; 1 SD; e.g., Heaton et al., 2004; Heaton & Marcotte, 2000). A comorbid condition propensity score (CCPS) identified the probability to which comorbid conditions (e.g., Heaton et al., 2010) informed ethnoracial identity. &lt;br&gt;&lt;br &gt; 

Results

After adjusting for WRAT-4 and CCPS, the results of a logistic regression analysis demonstrated a significant ethnoracial disparity in risk for NCI (X2(3) = 13.88, p&lt;.01, R2 = .07), such that the AI/AN group was at 2.52 times higher odds (32.3&#37; vs. 16.0, CI: 1.15–5.46, p = .01, Cohen’s d = .51) for NCI in comparison to the NLW group. &lt;br&gt;&lt;br &gt; 

Conclusions

Published norms for NLW adults may overestimate impairment in AI/AN adults. Thus, population-specific normative data are needed to clarify the classification accuracy of neurocognitive impairment and possible disparities in neurocognitive disorders (e.g., HIV-associated neurocognitive disorders) among AI/AN adults. Future work should replicate these findings among other diverse populations (e.g., Caribbean, Middle Eastern) lacking population-specific normative data.876199.

The impact of the COVID-19 pandemic on renal transplantation in the UK

COVID-19 is impacting provision of renal transplantation in the UK with a reduction in clinical activity. Publicly available Renal Registry and NHS Blood and Transplant reports were analysed to model the number of missed transplant opportunities, waiting list size and change in dialysis population over a six-month period starting 5 March 2020. An estimated 1,670 kidney transplant opportunities may be lost, which will lead to 6,317 active patients on the kidney-alone waiting list, compared to 4,649 based on usual activity estimates. This will result in 1,324 additional patients on dialysis who would otherwise have been transplanted. COVID-19 will lead to a marked loss of transplant opportunities and a significantly larger national waiting list. The existing strain on dialysis capacity will be exacerbated as patients remain on dialysis as the only available form of renal replacement therapy. These findings will help inform policy and service specific strategies.

Living donor kidney transplantation: Let's talk about it

Transplantation is the preferred treatment option for end-stage renal disease as it offers superior results and patient reported outcomes in comparison to dialysis. Patients treated with a transplant live longer, healthier and more independent lives. Transplantation is also more cost-effective, reducing the overall burden of renal disease. Despite the rising incidence of renal failure, the uptake of living donor kidney transplantation has been static across the UK for several years. Among transplantation, living donation offers a number of advantages compared with deceased donor transplantation. The procedure is more likely to be performed pre-dialysis and the elective nature allows for better perioperative planning. Awareness for living donation processes among healthcare professionals, patients and the public appears to be poor. Sharing information regarding the process will help educate colleagues, dispel myths and, crucially, allow patients the opportunity to talk about this treatment option with their hospital doctor.

HIV-Negative Cryptococcal Meningoencephalitis Results in a Persistent Frontal-Subcortical Syndrome

Twenty-seven previously healthy (of 36 consecutive eligible patients), HIV-negative cryptococcal meningoencephalitis (CM) patients underwent comprehensive neuropsychological evaluation during the late post-treatment period (1.3-4 years post diagnosis), assessing attention, language, learning, memory, visuospatial, executive function, information processing, psychomotor functioning, as well as mood symptoms. Seven of eight domains (all except attention) showed increased percentages of CM patients scoring in the less than 16^th percentile range compared to standardized normative test averages, adjusted for education level and age. Comparison with a matched archival dataset of mild cognitive impairment/Alzheimer's disease patients showed that CM patients exhibited relative deficits in psychomotor and executive function with fewer deficits in memory and learning, consistent with a frontal-subcortical syndrome. MRI evaluation at the time of testing demonstrated an association of lower neuropsychological functioning with ventriculomegaly. These studies suggest that CM should be included in the list of treatable causes of dementia in neurological work ups. Future studies are needed to identify diagnostic and treatment regimens that may enhance neurological function after therapy.

The Transplant Surgeon: An Unlikely, Yet Suitably Qualified, Member of The Complex Neuro Endocrine Multi-Disciplinary Team

Curative surgery for retro-peritoneal tumours involving vascular structures is challenging and multi-visceral resection is often required to obtain clear resection margins. Abdominal transplant surgeons have considerable experience in all aspects of visceral, vascular and retro-peritoneal surgery. Application of these skills to resect tumours involving vascular structures, and re-implant organs to preserve function is unique. We present the case of a 15- year old girl with a complex retro-peritoneal tumour which was resected en-bloc with the kidneys and vena-cava followed by auto-transplantation of the left kidney. Seven years later, the patient represented with a recurrent tumour which was successfully excised in its entirety. We discuss how innovative surgical strategies can be performed safely on an individualized basis. We highlight the importance of balancing the benefits of the ‘technically possible procedure’ with its risks, along with consideration of the outcomes of treatment and non-treatment alike.

Insulin therapy in organ donation and transplantation

Hyperglycaemia is common in hospitalized individuals, and is often caused by physiological stress associated with critical illness or major surgery. Insulin therapy is an established treatment for hyperglycaemia and acute hyperkalaemia, and has also been used for myocardial dysfunction resistant to inotropic support. Insulin is commonly used in both organ donors and transplant recipients for hyperglycaemia, but the underlying knowledge base supporting its use remains limited. Insulin therapy plays an important yet poorly understood role in both organ donation and transplantation. Tight glycaemic control has been extensively studied in critical care over the past 15 years; however, this has not yet translated into the field of transplantation, where patients are more unwell and where improved outcomes remain an ongoing challenge. Insulin therapy and optimization of glycaemic control represent important areas for future hypothesis-driven research into organ donation and transplantation, such as amelioration of ischaemia-reperfusion injury, rejection and infection.

Major Adverse Cardiovascular Events Following Simultaneous Pancreas and Kidney Transplantation in the United Kingdom

OBJECTIVE

People with type 1 diabetes and kidney failure have an increased risk for major adverse cardiovascular events (MACE). Simultaneous pancreas and kidney transplantation (SPKT) improves survival, but the long-term risk for MACE is uncertain.

RESEARCH DESIGN AND METHODS

We assessed the frequency and risk factors for MACE (defined as fatal cardiovascular disease and nonfatal myocardial infarction or stroke) and related nonfatal MACE to allograft failure in SPKT recipients with type 1 diabetes who underwent transplantation between 2001 and 2015 in the U.K. In a subgroup, we related a pretransplant cardiovascular risk score to MACE.

RESULTS

During 5 years of follow-up, 133 of 1,699 SPKT recipients (7.8%) experienced a MACE. In covariate-adjusted models, age (hazard ratio 1.04 per year [95% CI 1.01-1.07]), prior myocardial infarction (2.6 [1.3-5.0]), stroke (2.3 [1.2-4.7]), amputation (2.0 [1.02-3.7]), donor history of hypertension (1.8 [1.05-3.2]), and waiting time (1.02 per month [1.0-1.04]) were significant predictors. Nonfatal MACE predicted subsequent allograft failure (renal 1.6 [1.06-2.6]; pancreas 1.7 [1.09-2.6]). In the subgroup, the pretransplant cardiovascular risk score predicted MACE (1.04 per 1% increment [1.02-1.06]).

CONCLUSIONS

We report a high rate of MACE in SPKT recipients. There are a number of variables that predict MACE, while nonfatal MACE increase the risk of subsequent allograft failure. It may be beneficial that organs from hypertensive donors are matched to recipients with lower cardiovascular risk. Pretransplant cardiovascular risk scoring may help to identify patients who would benefit from risk factor optimization or alternative transplant therapies and warrants validation nationally.

Simultaneous en-bloc pancreas and kidney transplantation from a small pediatric donor after circulatory death

Simultaneous pancreas and kidney transplantation (SPKT) is an effective treatment option for patients with type 1 diabetes and end stage renal disease. Increasing demands for organs for transplantation coupled with a rise in age and size of adult donors has led to greater utilization of pediatric donors, and with good outcomes. Nonetheless, there remains reticence among transplant surgeons to transplant pancreases from small pediatric donors despite the optimal characteristics and macroscopic features of the younger pancreas. We report a successful case of SPKT from a small pediatric donor and explore the aspects of potential concern that might have led some clinicians to decline these organs. We also discuss the measures taken to overcome potential obstacles to successful transplantation from this donor source, and the rationale behind them.

Systematic review to assess the possibility of return of cerebral and cardiac activity after normothermic regional perfusion for donors after circulatory death

BACKGROUND

Normothermic regional perfusion (NRP) is a novel technique that aids organ recovery from donors after circulatory death (DCDs). However, ethical concerns exist regarding the potential return of spontaneous cerebral and cardiac activity (ROSCCA). This study aimed to determine the likelihood of ROSCCA in NRP-DCDs of abdominal organs.

METHODS

Extracorporeal cardiopulmonary resuscitation (ECPR) for refractory out-of-hospital cardiac arrest (OOHCA) was identified as a comparator for NRP-DCDs and as a validation cohort. A systematic search identified all articles relating to NRP-DCDs and ECPR-OOHCA. Rates of ROSCCA and survival outcomes (ECPR-OOHCA only) were recorded and analysed according to the duration of no perfusion.

RESULTS

In NRP-DCDs, 12 of 410 articles identified by database searching were eligible for inclusion. There were no instances of ROSCCA recorded among 493 donors. In ECPR-OOHCA, eight of 947 screened articles were eligible for inclusion (254 patients). Where the absence of perfusion exceeded 5 min in ECPR-OOHCA, there were no survivors with a favourable neurological outcome.

CONCLUSION

ROSCCA is unlikely following commencement of NRP and has not occurred to date. Strict observance of the 5-min interval following asystole provides satisfactory assurance that ROSCCA will not occur following NRP.

Should End-of-Life Preferences Be Discussed Routinely before High-Risk Surgery?

Encapsulating peritoneal sclerosis (EPS) is a rare but devastating complication of peritoneal dialysis. It is characterized by peritoneal neovascularization, fibrosis, and calcification ultimately leading to intestinal obstruction and eventual failure. Surgery for EPS has a mortality approaching 50% and most patients require some form of postoperative life-sustaining therapy (LST) during their admission. A 43-year-old gentleman with progressive EPS and significant comorbidities was assessed for enterolysis after a failed first attempt at another center. Because of his comorbidities, postoperative mortality was quoted above 50%. The patient favored surgery to improve his survival and quality of life, but was reluctant to receive prolonged LST in the event of failure of surgical therapy. The surgical team, in conjunction with a palliative care physician, therefore held extensive discussions with the patient and his partner regarding LST and its limitations. Clinical parameters to trigger a transition to palliative care were identified and agreed. Limitations on LST that are directly expressed by patients can represent a contraindication to surgery for many surgeons. Surgical Buy-In is a concept described as a perceived contract, or covenant, between the patient and clinician regarding implied consent for postoperative LST. Currently, preoperative discussions regarding limitations of LST are infrequent, and there can be reticence among patients and surgeons to have these conversations, leading to dissatisfaction on behalf of the patient and their family. After the Montgomery legal ruling, the provision and perception of informed consent are particularly pertinent. The palliative care physician is uniquely placed to contribute to such discussions as part of the surgical multidisciplinary team.

Should End-of-Life Preferences Be Discussed Routinely before High-Risk Surgery?

Encapsulating peritoneal sclerosis (EPS) is a rare but devastating complication of peritoneal dialysis. It is characterized by peritoneal neovascularization, fibrosis, and calcification ultimately leading to intestinal obstruction and eventual failure. Surgery for EPS has a mortality approaching 50% and most patients require some form of postoperative life-sustaining therapy (LST) during their admission. A 43-year-old gentleman with progressive EPS and significant comorbidities was assessed for enterolysis after a failed first attempt at another center. Because of his comorbidities, postoperative mortality was quoted above 50%. The patient favored surgery to improve his survival and quality of life, but was reluctant to receive prolonged LST in the event of failure of surgical therapy. The surgical team, in conjunction with a palliative care physician, therefore held extensive discussions with the patient and his partner regarding LST and its limitations. Clinical parameters to trigger a transition to palliative care were identified and agreed. Limitations on LST that are directly expressed by patients can represent a contraindication to surgery for many surgeons. Surgical Buy-In is a concept described as a perceived contract, or covenant, between the patient and clinician regarding implied consent for postoperative LST. Currently, preoperative discussions regarding limitations of LST are infrequent, and there can be reticence among patients and surgeons to have these conversations, leading to dissatisfaction on behalf of the patient and their family. After the Montgomery legal ruling, the provision and perception of informed consent are particularly pertinent. The palliative care physician is uniquely placed to contribute to such discussions as part of the surgical multidisciplinary team.

Links between a biomarker profile, cold ischaemic time and clinical outcome following simultaneous pancreas and kidney transplantation

In sepsis, trauma and major surgery, where an explicit physiological insult leads to a significant systemic inflammatory response, the acute evolution of biomarkers have been delineated. In these settings, Interleukin (IL) -6 and TNF-α are often the first pro-inflammatory markers to rise, stimulating production of acute phase proteins followed by peaks in anti-inflammatory markers. Patients undergoing SPKT as a result of diabetic complications already have an inflammatory phenotype as a result of uraemia and glycaemia. How this inflammatory response is affected further by the trauma of major transplant surgery and how this may impact on graft survival is unknown, despite the recognised pro-inflammatory cytokines' detrimental effects on islet cell function. The aim of the study was to determine the evolution of biomarkers in omentum and serum in the peri-operative period following SPKT. The biochemical findings were correlated to clinical outcomes. Two omental biopsies were taken (at the beginning and end of surgery) and measured for CD68+ and CD206+ antibodies (M1 and M2 macrophages respectively). Serum was measured within the first 72 h post-SPKT for pro- and anti-inflammatory cytokines (IL -6, -10 and TNF-α), inflammatory markers (WCC and CRP) and endocrine markers (insulin, C-peptide, glucagon and resistin). 46 patients were recruited to the study. Levels of M1 (CD68+) and M2 (CD206+) macrophages were significantly raised at the end of surgery compared to the beginning (p = 0.003 and p < 0.001 respectively). Levels of C-peptide, insulin and glucagon were significantly raised 30 min post pancreas perfusion compared to baseline and were also significantly negatively related to prolonged cold ischaemic time (CIT) (p < 0.05). CRP levels correlated significantly with the Post-Operative Morbidity Survey (p < 0.05). The temporal inflammatory marker signature after SPKT is comparable to the pattern observed following other physiological insults. Unique to this study, we find that CIT is significantly related to early pancreatic endocrine function. In addition, this study suggests a predictive value of CRP in peri-operative morbidity following SPKT.

A prospective, proteomics study identified potential biomarkers of encapsulating peritoneal sclerosis in peritoneal effluent

Encapsulating peritoneal sclerosis (EPS) is a potentially devastating complication of peritoneal dialysis (PD). Diagnosis is often delayed due to the lack of effective and accurate diagnostic tools. We therefore examined peritoneal effluent for potential biomarkers that could predict or confirm the diagnosis of EPS and would be valuable in stratifying at-risk patients and driving appropriate interventions. Using prospectively collected samples from the Global Fluid Study and a cohort of Greek PD patients, we utilized 2D SDSPAGE/ MS and iTRAQ to identify changes in the peritoneal effluent proteome from patients diagnosed with EPS and controls matched for treatment exposure. We employed a combinatorial peptide ligand library to compress the dynamic range of protein concentrations to aid identification of low-abundance proteins. In patients with stable membrane function, fibrinogen γ-chain and heparan sulphate proteoglycan core protein progressively increased over time on PD. In patients who developed EPS, collagen-α1(I), γ-actin and Complement factors B and I were elevated up to five years prior to diagnosis. Orosomucoid-1 and a2-HS-glycoprotein chain-B were elevated about one year before diagnosis, while apolipoprotein A-IV and α1-antitrypsin were decreased compared to controls. Dynamic range compression resulted in an increased number of proteins detected with improved resolution of protein spots, compared to the full fluid proteome. Intelectin-1, dermatopontin, gelsolin, and retinol binding protein-4 were elevated in proteome-mined samples from patients with EPS compared to patients that had just commenced peritoneal dialysis. Thus, prospective analysis of peritoneal effluent uncovered proteins indicative of inflammatory and pro-fibrotic injury worthy of further evaluation as diagnostic/prognostic markers.

Renal Allograft Failure After Ipilimumab Therapy for Metastatic Melanoma: A Case Report and Review of the Literature

Transplant recipients are at an increased risk of malignant melanoma, a result of chronic immunosuppression. Ipilimumab is a newer biological agent targeting T lymphocytes to potentiate an immune response against melanoma, and the use of this agent results in a new adverse effect profile that the clinician must be aware of while a patient is on therapy. We report the case of a male renal transplant recipient who developed graft failure while treated with ipilimumab and minimal immunosuppressive therapy for metastatic ocular melanoma, with biopsy evidence of glomerulonephritis and acute rejection. We highlight the immunological side effects that can manifest from ipilimumab therapy and conclude that it did influence graft function in this patient. Our case illustrates the importance of weighing the risks and benefits to graft function and long-term survival as well as the importance of considering other treatment modalities in this specific group of melanoma patients.

Kidney Transplant Recipients Requiring Critical Care Admission Within One Year of Transplant

OBJECTIVES

Kidney transplant is the gold standard for treatment of renal failure. With the increasing age of the recipient population, which carries significant comorbidities, and the use of more marginal organs, there is potential for increased critical care admissions. In this study, we investigated the incidence, indications, and outcomes of patients admitted to critical care within 1 year of transplant. We also aimed to identify any precipitating factors or events that may trigger these admissions, as well as establish variables that could affect mortality.

MATERIALS AND METHODS

We performed a retrospective analysis of kidney transplant recipients admitted to critical care within 1 year after transplant, between January 2009 and December 2013.

RESULTS

Of 1002 kidney transplants, 53 patients (5.3%) were admitted to critical care within 1 year, with patients separated into 2 groups. Group 1 comprised 32 patients (61%) who were admitted immediately postoperatively, mainly from cardiorespiratory derangements with mean stay of 3.7 days (range, 1-34 days) and 0 mortalities. Group 2 comprised 21 patients (39%) who were admitted later in the postoperative period, principally from sepsis-related complications with a mean stay of 18 days (range, 1-101 days). Most patients in group 2 required intensive therapy, including mechanical ventilation and immunosupprression reduction, incurring a hospital mortality rate of 48%. Hemorrhage with reexploration was higher in group 1. Diabetes mellitus, cardiac comorbidity, prolonged stay, nutritional support, nosocomial infections, and multiple organ failure were found at a higher rate in the group 2 patients who died.

CONCLUSIONS

The incidence of critical care admissions 1 year after kidney transplant was 5.3%. Most admissions occurred in the early postoperative period, mostly as preemptive measures for cardiorespiratory monitoring and support. This category of admission is potentially preventable with optimization of preoperative treatment. Later admissions were mostly consequential to sepsis-related complications, with patients having a high mortality rate due to multiple organ failure. Clinical management should therefore focus on the prevention of multiple organ failure to improve patient outcomes.

Incidence and Histologic Features of Transplant Graft Pancreatitis: A Single Center Experience

OBJECTIVES

Pancreas transplant is an effective long-term treatment modality for complicated type 1 diabetes mellitus. However, allograft failure or severe concomitant rejection remain an obstacle to successful transplant outcome, occurring in approximately 21% of recipients within 1 year. Most histologic studies investigating the cause of pancreas transplant failure have concentrated on the presence and severity of acute and chronic cellular or vascular rejection. After vascular thrombosis, graft pancreatitis is the second most frequent complication after transplant.

MATERIALS AND METHODS

We conducted a retrospective analysis, collecting information from a contemporaneously maintained database of patients after pancreas transplant.

RESULTS

We identified 44 patients with rejected allografts from a database of 196 pancreas transplant patients (44/196, 22%). In these identified rejected allografts, 27 patients (61%) had histopathology reports containing 1 or more terms associated with pancreatitis, with the most common histologic finding was being fat necrosis (21/27, 83%), followed by inflammatory or neutrophil infiltrate (13/27, 48%). Sixteen of these patients (60%) had two 2 or more terms histology terms descriptive of pancreatitis records. Ten of the 44 rejected allografts, 10 patients had histologic evidence of vascular or cellular rejection. There was no significant difference in the proportions showing evidence of rejection between groups with (2/27 patients [26%]) and without (3/17 patients [18%]) descriptions of pancreatitis in their medical records (P = .70). When time from transplant to pancreatectomy was analyzed, a larger proportion of pancreatectomies occurred late for patients with descriptions of pancreatitis in their medical records versus patients without (17/26 [65%] vs 4/16 [25%]; P = .05).

CONCLUSIONS

This case series demonstrates that 61% of rejected allografts over a span of 13 years at a single center had histologic features of graft pancreatitis, suggesting that pancreatitis may be a contributory mechanism to graft failure.

Encapsulating peritoneal sclerosis-a rare but devastating peritoneal disease

Encapsulating peritoneal sclerosis (EPS) is a devastating but, fortunately, rare complication of long-term peritoneal dialysis. The disease is associated with extensive thickening and fibrosis of the peritoneum resulting in the formation of a fibrous cocoon encapsulating the bowel leading to intestinal obstruction. The incidence of EPS ranges between 0.7 and 3.3% and increases with duration of peritoneal dialysis therapy. Dialysis fluid is hyperosmotic, hyperglycemic, and acidic causing chronic injury and inflammation in the peritoneum with loss of mesothelium and extensive tissue fibrosis. The pathogenesis of EPS, however, still remains uncertain, although a widely accepted hypothesis is the "two-hit theory," where, the first hit is chronic peritoneal membrane injury from long standing peritoneal dialysis followed by a second hit such as an episode of peritonitis, genetic predisposition and/or acute cessation of peritoneal dialysis, leading to EPS. Recently, EPS has been reported in patients shortly after transplantation suggesting that this procedure may also act as a possible second insult. The process of epithelial-mesenchymal transition of mesothelial cells is proposed to play a central role in the development of peritoneal sclerosis, a common characteristic of patients on dialysis, however, its importance in EPS is less clear. There is no established treatment for EPS although evidence from small case studies suggests that corticosteroids and tamoxifen may be beneficial. Nutritional support is essential and surgical intervention (peritonectomy and enterolysis) is recommended in later stages to relieve bowel obstruction.

Genetic Polymorphisms and Peritoneal Membrane Function

BACKGROUND

Outcomes for peritoneal dialysis (PD) patients are affected by the characteristics of the peritoneal membrane, which may be determined by genetic variants. We carried out a systematic review of the literature to identify studies which assessed the association between genetic polymorphisms, peritoneal membrane solute transport, and clinical outcomes for PD patients.

METHODS

The National Library of Medicine was searched using a variety of strategies. Studies which met our inclusion criteria were reviewed and data abstracted. Our outcomes of interest included: high transport status peritoneal membrane, risk for peritonitis, encapsulating peritoneal sclerosis (EPS), patient and technique survival. We combined data from studies which evaluated the same genetic polymorphism and the same outcome.

RESULTS

We evaluated 18 relevant studies. All studies used a candidate gene approach. Gene polymorphisms in the interleukin (IL)-6 gene were associated with peritoneal membrane solute transport in several studies in different ethnic populations. Associations with solute transport and polymorphisms in endothelial nitric oxide synthase and receptor for advanced glycation end product genes were also identified. There was evidence of a genetic predisposition for peritonitis found in 2 studies, and for EPS in 1 study. Survival was found to be associated with a polymorphism in vascular endothelial growth factor and technique failure was associated with a polymorphism in the IL-1 receptor antagonist.

CONCLUSIONS

There is evidence that characteristics of the peritoneal membrane and clinical outcomes for PD patients have genetic determinants. The most consistent association was between IL-6 gene polymorphisms and peritoneal membrane solute transport.

Living with encapsulating peritoneal sclerosis (EPS): the patient's perspective

BACKGROUND

Although relatively rare, encapsulating peritoneal sclerosis (EPS) is nonetheless a major concern within the renal community. Risk of developing EPS is associated with long-term peritoneal dialysis (PD). High mortality was previously reported, although surgery has since improved outcomes. Research into EPS focuses on imaging and early detection methods, genetics, biomarkers and preventive strategies. No previous studies have examined patients' experiences of EPS.

AIMS

The aim of the present study was to explore the experience of patients who have undergone surgery for EPS in one center in the North of England.

METHODS

A qualitative phenomenological approach, involving in-depth interviews, was adopted. Nine participants were recruited out of a total of 18 eligible. Most participants were interviewed twice over a 12-month period (October 2009 to October 2010).

ANALYSIS

Interpretive data analysis was conducted, following the philosophical tradition of hermeneutics, to draw out themes from the data. Data collection and analysis took place concurrently and participants were sent a summary of their first interview to allow a period of reflection prior to the subsequent interview.

RESULTS

EPS presented the most serious challenge participants had faced since developing chronic kidney disease (CKD). Three major themes were identified, each with subcategories. The key issues for patients were related to identification of early symptoms and lack of understanding. The patients' sense of 'not being heard' by health care professionals led to a loss of trust and enhanced their feelings of uncertainty. The enormity of the surgery, the suffering, and what they had to endure had an enormous impact, but an overriding aspect of this experience was also the loss they felt for their independence and for the PD therapy over which they had control.

CONCLUSIONS

The findings of this study highlight a number of important issues relevant to clinical practice, including lack of information and understanding of EPS, particularly its early symptoms At the time patients transfer from peritoneal to hemodialysis, the provision of adequate information about the risks and potential early signs of EPS may not only improve their experiences, but may also assist in early detection.

Anthropometrics Identify Wasting in Patients Undergoing Surgery for Encapsulating Peritoneal Sclerosis

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INTRODUCTION

Encapsulating peritoneal sclerosis (EPS) is a serious complication of peritoneal dialysis in which gastrointestinal (GI) symptoms reduce appetite and dietary intake. Adequate nutrition is important, especially if surgery is required. Although the incidence of EPS is low, the present report is able to detail preoperative nutrition status and treatment in a large cohort of patients from a national EPS referral center. ♦

METHODS

Of 51 patients admitted to this EPS specialist center hospital for their first peritonectomy in the study period, 50 had a preoperative dietetic assessment, and 49 underwent upper-arm anthropometry. ♦

RESULTS

Mean body mass index (BMI) was 20.6 kg/m(2). Mean weight loss was 14% of body weight in the preceding 6 months, with 35 of 50 patients losing more than 10%. On anthropometry, 25 of 49 patients were below the 5th percentile for mid-arm circumference (MAC), 17 of 49 were below for triceps skinfold thickness (TSF), and 21 of 49 were below for mid-arm muscle circumference (MAMC). Mean handgrip strength (HGS) was 60% of normal, with 43 of 49 patients being below 85% of normal. Appetite was poor in 21 of 50 patients, and 37 of 50 had upper and 40 of 50 had lower GI symptoms. By subjective global assessment, 27 of 51 patients were graded as severely malnourished, and 5 of 51, as well-nourished. Mean serum albumin was 28 g/L and did not correlate with BMI, MAC, TSF, MAMC, or HGS. In most patients, C-reactive protein was elevated (mean: 111 mg/L). Preoperative parenteral nutrition was given to 46 of 51 patients for a mean of 21 days. ♦

DISCUSSION

Our findings demonstrate the poor nutrition status of patients admitted for EPS surgical intervention. Anthropometrics reveal depleted fat and lean body mass in EPS patients, which might be a result of anorexia and inflammation, and the reason that albumin was not an accurate marker of nutrition. Poor nutrition status is likely to negatively affect outcome in this patient group. ♦

CONCLUSIONS

Early recognition of GI symptoms may herald a diagnosis of EPS. Optimization of preoperative nutrition status with intensive nutrition support is needed.