Donor- and isolation-related predictive factors of in vitro secretory function of cultured human islets

Background and aims

Human islet preparations designated for research exhibit diverse insulin-secretory profiles. This study aims to assess the impact of donor- and isolation-related factors on in vitro islet secretory function.

Methods

A retrospective analysis of 46 isolations from 23 pancreata discarded for clinical transplantation was conducted. In vitro islet secretory function tests were performed on Day 1 and Day 7 of culture. Linear mixed-effects models (LMMs) were employed to investigate the relationships between various predictors characterizing the patient and donor characteristics as well as the isolation effectiveness and two functional outcomes including the islet stimulation index (SI) and area under the insulin curve (AUC). Fixed effects were introduced to represent the main effects of each predictor, and backward elimination was utilized to select the most significant fixed effects for the final model. Interaction effects between the timepoint (Day 7 vs. Day 1) and the predictors were also evaluated to assess whether predictors were associated with the temporal evolution of SI and AUC. Fold-change (Fc) values associated with each predictor were obtained by exponentiating the corresponding coefficients of the models, which were built on log-transformed outcomes.

Results

Analysis using LMMs revealed that donor body mass index (BMI) (Fc = 0.961, 95% CI = 0.927-0.996, p = 0.05), donor gender (female vs. male, Fc = 0.702, 95% CI = 0.524-0.942, p = 0.04), and donor hypertension (Fc = 0.623, 95% CI = 0.466-0.832, p= <0.01) were significantly and independently associated with SI. Moreover, donor gender (Fc = 0.512, 95% CI = 0.302-0.864, p = 0.02), donor cause of death (cerebrovascular accident vs. cardiac arrest, Fc = 2.129, 95% CI = 0.915-4.946, p = 0.09; trauma vs. cardiac arrest, Fc = 2.129, 95% CI = 1.112-7.106, p = 0.04), pancreas weight (Fc = 1.01, 95% CI = 1.001-1.019, p = 0.03), and islet equivalent (IEQ)/mg (Fc = 1.277, 95% CI = 1.088-1.510, p ≤ 0.01) were significantly and independently associated with AUC. There was no predictor significantly associated with the temporal evolution between Day 1 and Day 7 for both SI and AUC outcomes.

Conclusion

This study identified donor- and isolation-related factors influencing in vitro islet secretory function. Further investigations are essential to validate the applicability of these results in clinical practice.

In situ management of late thrombosis of a renal graft vein in a patient with Cockett syndrome

Late thrombosis of the renal graft vein is a rare complication that results in graft loss in the majority of cases. We describe the case of a 57-year-old female patient who had a kidney transplant 32 years ago and developed a late thrombosis of the graft vein, accompanied by extensive thrombosis in the common femoral and iliac veins. Risk factors included severe malnutrition, chronic inflammation due to an anal fistula, and Cockett syndrome. The treatment consisted of mechanical thrombectomy of the iliac vein, placement of a stent in the common iliac vein, partial thromboaspiration of the renal vein thrombus with local thrombolysis, followed by systemic anticoagulation. With this approach, renal function fully recovered without major complications.

Continuous vs. discontinuous purification of isolated human islets: functional and morphological comparison

Background

The COBE 2991 cell processor, commonly used for pancreatic islet isolation, is no longer distributed in Europe, leading to a search for alternative purification procedures with equivalent efficacy. The aim of this study was to evaluate the efficacy of an alternative method based on the discontinuous purification of islets.

Methods

The conventional isolation procedure using a standard continuous islet purification with COBE 2991 of n = 4 human pancreas was compared to n = 8 procedures using a discontinuous purification with a "bottle" method from donors of similar characteristics. Islet equivalents, purity, and dynamic glucose-stimulated insulin secretion were evaluated.

Results

A similar islet yield was obtained using continuous vs. discontinuous purification methods (76,292.5 ± 40,550.44 vs. 79,625 ± 41,484.46 islet equivalents, p = 0.89). Islets from both groups had similar purity (78.75% ± 19.73% vs. 55% ± 18.16%, p = 0.08) and functionality both in terms of stimulation index (3.31 ± 0.83 vs. 5.58 ± 3.38, p = 0.22) and insulin secretion (1.26 ± 0.83 vs. 1.53 ± 1.40 mean AUC, p = 0.73). Moreover, the size of the islets was significantly larger in the discontinuous vs. continuous purification group (19.2% ± 10.3% vs. 45.4% ± 18.8% of islets less than 100 µm, p = 0.0097 and 23.7% ± 5.3% vs. 15.6% ± 5.8% of 200-250 µm islet size, p = 0.03).

Conclusion

Compared to the conventional purification procedure, discontinuous purification with a bottle method shows similar results with regard to isolation yield and islet secretory function. Furthermore, this alternative technique allows for obtaining larger islets.

Intermittent Surface Oxygenation Results in Similar Mitochondrial Protection and Maintenance of Aerobic Metabolism as Compared to Continuous Oxygenation during Hypothermic Machine Kidney Machine Perfusion

Short bubble and subsequent surface oxygenation is an innovative oxygenation technique and alternative for membrane oxygenation during hypothermic machine perfusion (HMP). The metabolic effect of the interruption of surface oxygenation for 4 h (mimicking organ transport) during HMP was compared to continuous surface and membrane oxygenation in a pig kidney ex situ preservation model. After 30 min of warm ischemia by vascular clamping, a kidney of a ±40 kg pig was procured and subsequently preserved according to one of the following groups: (1) 22-h HMP + intermittent surface oxygenation (n = 12); (2) 22-h HMP + continuous membrane oxygenation (n = 6); and (3) 22-h HMP + continuous surface oxygenation (n = 7). Brief perfusate O₂ uploading before kidney perfusion was either obtained by direct bubble (groups 1, 3) or by membrane (group 2) oxygenation. Bubble oxygenation during minimum 15 min was as efficient as membrane oxygenation in achieving supraphysiological perfusate pO₂ levels before kidney perfusion. Metabolic tissue analysis (i.e., lactate, succinate, ATP, NADH, and FMN) during and at the end of the preservation period demonstrated similar mitochondrial protection between all study groups. Short bubble and subsequent intermittent surface oxygenation of the perfusate of an HMP-kidney might be an effective and cheap preservation strategy to protect mitochondria, eliminating the need/costs of a membrane oxygenator and oxygen source during transport.

Current Evidence and Future Perspectives to Implement Continuous and End-Ischemic Use of Normothermic and Oxygenated Hypothermic Machine Perfusion in Clinical Practice

The use of high-risk renal grafts for transplantation requires the optimization of pretransplant assessment and preservation reconditioning strategies to decrease the organ discard rate and to improve short- and long-term clinical outcomes. Active oxygenation is increasingly recognized to play a central role in dynamic preservation strategies, independent of preservation temperature, to recondition mitochondria and to restore the cellular energy profile. The oxygen-related decrease in mitochondrial succinate accumulation ameliorates the harmful effects of ischemia-reperfusion injury. The differences between normothermic and hypothermic machine perfusion with regard to organ assessment, preservation, and reconditioning, as well as the logistic and economic implications, are factors to take into consideration for implementation at a local level. Therefore, these different techniques should be considered complementary to the perfusion strategy selected depending on functional intention and resource availability. This review provides an overview of the current clinical evidence of normothermic and oxygenated hypothermic machine perfusion, either as a continuous or end-ischemic preservation strategy, and future perspectives.

First kidneys transplanted in man after brief bubble and subsequent surface oxygenation as alternative for membrane oxygenation during hypothermic machine perfusion

BACKGROUND

Active oxygen during hypothermic machine perfusion has the potential to improve mitochondrial preservation and subsequently decrease the harmful effects of ischemia reperfusion injury. Brief bubble, and subsequent surface oxygenation are an alternative oxygenation technique for membrane-oxygenated kidneys during hypothermic machine perfusion (HMP).

METHODS

Between March 20, 2022, and June 13, 2022, 5 kidney grafts originating from 3 donors after circulatory death were oxygenated by bubble and surface oxygenation during HMP.

RESULTS

No adverse events related to this new oxygenation technique were observed. All five recipients experienced no dialysis-dependency after transplantation with excellent initial graft function at 3 months after transplantation.

CONCLUSIONS

For the first time in human, this new oxygenation technique was successfully applied to 5 HMP-kidneys, originating from donation after circulatory death. If confirmed on larger scale cohorts, this innovative oxygenation technique, as alternative oxygenation technique for membrane-oxygenated kidneys, has the potential to be widely implemented because its simplicity and efficacy, and reducing economic and ecological costs by eliminating the need for a membrane oxygenator and oxygen source during transport.

Safety, Efficacy and Relapse of Nirmatrelvir-Ritonavir in Kidney Transplant Recipients Infected with SARS-CoV-2

Introduction

The efficacy of nirmatrelvir-ritonavir (NR; Paxlovid, Pfizer, New York, NY) to decrease the risk of progression to severe COVID-19 in high-risk patients has been demonstrated. However, evidence in infected kidney transplant recipients (KTRs) is lacking. Moreover, NR has significant and potentially harmful interactions with calcineurin inhibitors (CNIs).

Methods

In this single-center retrospective study, we included all KTRs treated with NR from April 28 to June 3, 2022. A standard management strategy of CNI dose adaptation (discontinuation of tacrolimus 12 hours before the start of NR and administration of 20% of the cyclosporine dose) and laboratory follow-up was applied.

Results

A total of 14 patients were included. Compared with day-0 (day before NR initiation), day-7 plasma creatinine concentrations and SARS-CoV-2 viral loads were similar (P = 0.866) and decreased (P = 0.002), respectively. CNI trough concentrations at the end of the treatment were satisfactory, nonetheless, with high individual variability. After a median follow-up time of 34 days, no death or viral pneumonia were observed. Nevertheless, 2 patients experienced early SARS-CoV-2 infection relapses (at day-10 and day-21) associated with an increase in SARS-CoV-2 viral loads.

Conclusion

NR can be used in KTRs but requires a strict protocol of drug adaptation. We observed 2 cases of early relapse after NR treatment that need further investigations.

Simultaneous nephrectomy during kidney transplantation for polycystic kidney disease does not detrimentally impact comorbidity and graft survival

BACKGROUND

The lack of space, as an indication for a native unilateral nephrectomy for positioning a future kidney graft in the absence of other autosomal dominant polycystic kidney disease-related symptoms, remains controversial.

AIM

To evaluate the surgical comorbidity and the impact on graft survival of an associated ipsilateral native nephrectomy during isolated kidney transplantation in patients with autosomal dominant polycystic kidney disease.

METHODS

One hundred and fifty-four kidney transplantations performed between January 2007 and January 2019 of which 77 without (kidney transplant alone (KTA) group) and 77 with associated ipsilateral nephrectomy (KTIN group), were retrospectively reviewed. Demographics and surgical variables were analyzed and their respective impact on surgical comorbidity and graft survival.

RESULTS

Creation of space for future graft positioning was the main reason (n = 74, 96.1%) for associated ipsilateral nephrectomy. No significant difference in surgical comorbidity (lymphocele, wound infection, incisional hernia, wound hematoma, urinary infection, need for blood transfusion, hospitalization stay, Dindo Clavien classification and readmission rate) was observed between the two study groups. The incidence of primary nonfunction and delayed graft function was comparable in both groups [0% and 2.6% (P = 0.497) and 9.1% and 16.9% (P = 0.230), respectively, in the KTA and KTIN group]. The 1- and 5-year graft survival were 94.8% and 90.3%, and 100% and 93.8%, respectively, in the KTA and KTIN group (P = 0.774). The 1- and 5-year patient survival were 96.1% and 92.9%, and 100% and 100%, respectively, in the KTA and KTIN group (P = 0.168).

CONCLUSION

Simultaneous ipsilateral native nephrectomy to create space for graft positioning during kidney transplantation in patients with autosomal dominant polycystic kidney disease does not negatively impact surgical comorbidity and short- and long-term graft survival.

Monoclonal Antibody Therapy in Kidney Transplant Recipients With Delta and Omicron Variants of SARS-CoV-2: A Single-Center Case Series

Rationale & Objective

Study Design

Setting & Participants

Results

Limitations

Conclusions

Pregnancy Outcomes After Kidney Transplantation and Long-Term Evolution of Children: A Single Center Experience

BACKGROUND

Pregnancies in women who underwent kidney transplants are at high risk compared with the general population.

METHODS

In this study, we aimed to retrospectively assess the obstetrical complications, delivery outcomes, and impact of pregnancy on kidney allograft function in a single-center cohort of kidney transplant recipients (KTRs). We provide data regarding the long-term evolution of children.

RESULTS

Thirty-two KTRs underwent a total of 57 pregnancies between 1994 and 2010. Fourteen pregnancies (24 %) did not survive caused by miscarriages (n = 9), stillborn (n = 1), ectopic pregnancies (n = 2), and medical abortion (n = 2). Live birth occurred in 76% of pregnancies. Delivery was by cesarean in 66%. The mean gestational age was 30.45 ± 11.3 weeks and 65% of newborns were premature. A low birth weight <2500g was noted in 46%. Obstetric complications were de novo hypertension in 4%, pre-eclampsia in 9%, and gestational diabetes in 2%. The 5- and 10-year post-delivery death-censored graft loss rates were 3.1% and 12.5%, respectively. Data on 21 children were collected via a self-questionnaire. After a median follow-up time of 17 years, they appeared in good medical and psychological health. None of them suffered from chronic disease (especially uronephrological condition) or was taking chronic medication.

CONCLUSIONS

Long-term evolution of children born to women who underwent kidney transplants seems favorable. Pregnancies in KTRs are successful in two-thirds of cases but are at increased risk of prematurity, delivery by cesarean, and low birth weight.

Disappointing Immunization Rate After 2 Doses of the BNT162b2 Vaccine in a Belgian Cohort of Kidney Transplant Recipients

Supplemental Digital Content is available in the text.

Simply Adding Oxygen during Hypothermic Machine Perfusion to Combat the Negative Effects of Ischemia-Reperfusion Injury: Fundamentals and Current Evidence for Kidneys

The use of high-risk renal grafts for transplantation requires optimization of pretransplant preservation and assessment strategies to improve clinical outcomes as well as to decrease organ discard rate. With oxygenation proposed as a resuscitative measure during hypothermic machine preservation, this review provides a critical overview of the fundamentals of active oxygenation during hypothermic machine perfusion, as well as the current preclinical and clinical evidence and suggests different strategies for clinical implementation.

Peripheral embolism as first and only clinical symptom of a true aneurysmal degeneration of the radial artery after ligation of a radiocephalic fistula

True aneurysmal degeneration of the inflow artery after arteriovenous fistula ligation is extremely rare. Pain is the most common symptom and surgical treatment by an autologous venous bypass is considered as the treatment of choice with good long-term results. We present a patient with peripheral embolism as first and only symptom leading to the diagnosis of a true aneurysmal degeneration of the entire left radial artery. It was discovered 5 years after the ligation of his radiocephalic fistula. As illustrated by this case, a conservative treatment by antiplatelet and anticoagulation therapy should be considered a satisfying alternative to the standard bypass surgery in patients with anatomical variations (e.g. an incomplete arterial palmar arch) since the latter include a higher risk of postoperative ischemic complications.

MO939RECURRENCE AND OUTCOME OF ANTI-GLOMERULAR BASEMENT MEMBRANE GLOMERULONEPHRITIS AFTER KIDNEY TRANSPLANTATION: A BELGIAN MULTICENTER STUDY

Background and Aims

Recurrence of anti-glomerular basement membrane (anti-GBM) glomerulonephritis in the kidney graft is a rare event, described in limited case reports and registry analysis. The aim of this study was to evaluate in a large cohort of patients with detailed data collection and long follow-up the risk of recurrence of anti-GBM disease and graft loss caused by recurrence, the risk factors associated with clinical recurrence and the long-term patient and graft survival.

Method

Multicenter retrospective study. Inclusion criteria: patients with anti-GBM glomerulonephritis transplanted with a kidney between 1977 and 2015. Exclusion criteria: systemic vasculitis (except ANCA), lupus erythematosus and cryoglobulinemia. Clinical recurrence was defined as reappearance of signs of glomerulonephritis along with histological signs of proliferative glomerulonephritis and linear IgG staining on kidney biopsy, with or without anti-GBM antibodies.

Results

Fifty-three patients were included. Clinical recurrence in a first kidney transplant occurred in only one patient five years after transplantation -a prevalence rate of 1.9%- in the context of cessation of immunosuppressive drugs. The graft was lost due to recurrence. Histological recurrence with linear IgG staining on kidney biopsy in the absence of histologic signs of proliferative glomerulonephritis was observed in four patients, in the context of cellular rejection. Two patients lost their kidney graft from severe acute rejection; the others fully recovered. Patient survival was 100%, 94% and 89% at 5, 10 and 15 years, respectively. Overall, death-censored first graft survival rates were 88%, 83% and 79% at 5, 10 and 15 years, respectively.

Conclusion

Recurrence rate of anti-GBM glomerulonephritis after transplantation is very low, and associated with graft loss. The long-term patient and graft survival rates are excellent.

Recurrence and Outcome of Anti-Glomerular Basement Membrane Glomerulonephritis After Kidney Transplantation

Introduction

Recurrence of anti-glomerular basement membrane (anti-GBM) glomerulonephritis in the kidney graft is a rare event, described in limited reports. The aim of this study was to evaluate, in a large cohort of patients with long follow-up, the risk of recurrence of anti-GBM disease, the risk factors associated with clinical recurrence, and the long-term patient and graft survival.

Methods

This was a multicenter retrospective study. Inclusion criteria were patients with anti-GBM glomerulonephritis who underwent transplantation of a kidney between 1977 and 2015. Exclusion criteria were systemic vasculitis, lupus erythematosus, and cryoglobulinemia. Recurrence was defined as reappearance of clinical signs of glomerulonephritis along with histological signs of proliferative glomerulonephritis and linear IgG staining on kidney biopsy, with or without anti-GBM antibodies.

Results

A total of 53 patients were included. Recurrence of anti-GBM glomerulonephritis in a first kidney transplant occurred in only 1 patient 5 years after transplantation (a prevalence rate of 1.9%) in the context of cessation of immunosuppressive drugs, and resulted in graft loss due to recurrence. Linear IgG staining on kidney biopsy in the absence of histological signs of proliferative glomerulonephritis was observed in 4 patients, in the context of cellular rejection. Patient survival was 100%, 94%, and 89% at 5, 10, and 15 years, respectively. Death-censored first-graft survival rates were 88%, 83%, and 79% at 5, 10, and 15 years, respectively.

Conclusion

The recurrence rate of anti-GBM glomerulonephritis after transplantation is very low but is associated with graft loss. The long-term patient and graft survival rates are excellent.

Oxygenated End-Hypothermic Machine Perfusion in Expanded Criteria Donor Kidney Transplant: A Randomized Clinical Trial

Importance

Continuous hypothermic machine perfusion during organ preservation has a beneficial effect on graft function and survival in kidney transplant when compared with static cold storage (SCS).

Objective

To compare the effect of short-term oxygenated hypothermic machine perfusion preservation (end-HMPo2) after SCS vs SCS alone on 1-year graft survival in expanded criteria donor kidneys from donors who are brain dead.

Design, Setting, and Participants

In a prospective, randomized, multicenter trial, kidneys from expanded criteria donors were randomized to either SCS alone or SCS followed by end-HMPo2 prior to implantation with a minimum machine perfusion time of 120 minutes. Kidneys were randomized between January 2015 and May 2018, and analysis began May 2019. Analysis was intention to treat.

Interventions

On randomization and before implantation, deceased donor kidneys were either kept on SCS or placed on HMPo2.

Main Outcome and Measures

Primary end point was 1-year graft survival, with delayed graft function, primary nonfunction, acute rejection, estimated glomerular filtration rate, and patient survival as secondary end points.

Results

Centers in 5 European countries randomized 305 kidneys (median [range] donor age, 64 [50-84] years), of which 262 kidneys (127 [48.5%] in the end-HMPo2 group vs 135 [51.5%] in the SCS group) were successfully transplanted. Median (range) cold ischemia time was 13.2 (5.1-28.7) hours in the end-HMPo2 group and 12.9 (4-29.2) hours in the SCS group; median (range) duration in the end-HMPo2 group was 4.7 (0.8-17.1) hours. One-year graft survival was 92.1% (n = 117) in the end-HMPo2 group vs 93.3% (n = 126) in the SCS group (95% CI, -7.5 to 5.1; P = .71). The secondary end point analysis showed no significant between-group differences for delayed graft function, primary nonfunction, estimated glomerular filtration rate, and acute rejection.

Conclusions and Relevance

Reconditioning of expanded criteria donor kidneys from donors who are brain dead using end-HMPo2 after SCS does not improve graft survival or function compared with SCS alone. This study is underpowered owing to the high overall graft survival rate, limiting interpretation.

Trial Registration

isrctn.org Identifier: ISRCTN63852508.

Brief O2 uploading during continuous hypothermic machine perfusion is simple yet effective oxygenation method to improve initial kidney function in a porcine autotransplant model

With oxygenation proposed as a resuscitative measure during hypothermic models of preservation, the aim of this study was to evaluate the optimal start time of oxygenation during continuous hypothermic machine perfusion (HMP). In this porcine ischemia-reperfusion autotransplant model, the left kidney of a ±40 kg pig was exposed to 30 minutes of warm ischemia prior to 22 hours of HMP and autotransplantation. Kidneys were randomized to receive 2 hours of oxygenation during HMP either at the start (n = 6), or end of the perfusion (n = 5) and outcomes were compared to standard, nonoxygenated HMP (n = 6) and continuous oxygenated HMP (n = 8). The brief initial and continuous oxygenated HMP groups were associated with superior graft recovery compared to either standard, nonoxygenated HMP or kidneys oxygenated at the end of HMP. This correlated with significant metabolic differences in perfusate (eg, lactate, succinate, flavin mononucleotide) and tissues (eg, succinate, adenosine triphosphate, hypoxia-inducible factor-1α, nuclear factor erythroid 2-related factor 2) suggesting superior mitochondrial preservation with initial oxygenation. Brief initial O₂ uploading during HMP at procurement site might be an easy and effective preservation strategy to maintain aerobic metabolism, protect mitochondria, and achieve an improved early renal graft function compared with standard HMP or oxygen supply shortly at the end of HMP preservation.

Eliminating Hepatitis C Virus From a Prevalent Kidney Transplant Recipient Population: A Single-Center Study in Belgium in the Direct-Acting Antivirals Era

BACKGROUND

Direct-acting antivirals (DAAs) have revolutionized the treatment of hepatitis C virus (HCV) infection. Although previous studies have reported positive results with DAAs after kidney transplantation (KT), their impact on the prevalence of HCV viremia (HCVv) in prevalent kidney transplant recipients (KTRs) remains ill defined.

METHODS

We retrospectively reviewed the HCV status of all patients followed at Cliniques Universitaires Saint-Luc, Brussels, Belgium, outpatient KT clinic between January 2014 and December 2018. We collected the clinical features of KTRs treated with DAAs during this period and calculated the annual prevalence of HCVv over this period.

RESULTS

Out of 1451 KTRs, 22 (1.52%) had HCVv in 2014 to 2018. From 2014 to 2018, the annual prevalence of HCVv dropped from 1.97% to 0.43%, (P < .001). Fourteen KTRs were treated with DAAs a median of 197 months (range: 5-374) after KT, mostly (79%) in 2017 after reimbursement restrictions of DAAs for KTRs in Belgium were removed. DAA treatment was safe with a sustained virological response rate at 12 weeks after treatment (SVR12) of 93%. Two patients died 14 months (lymphoma, despite SVR12) and 7 months (hepatocarcinoma, no SVR12) after DAAs initiation, respectively. Among HCVv KTRs not treated with DAAs (n = 8), 2 lost their graft, 5 died, and 1 is initiating therapy. The current prevalence of HCVv in the cohort is 0.08%, with a single patient currently on treatment.

CONCLUSION

Treatment with DAAs led to a dramatic decrease of HCVv prevalence in this KTR cohort. DAA use was safe and effective. Elimination of HCV is possible at KT clinics.

The effect on early renal function of various dynamic preservation strategies in a preclinical pig ischemia-reperfusion autotransplant model

The aims of this study were to determine the most optimal timing to start machine perfusion during kidney preservation to improve early graft function and to evaluate the impact of temperature and oxygen supply during machine perfusion in a porcine ischemia-reperfusion autotransplant model. The left kidney of an approximately 40-kg female Belgian Landrace pig was exposed to 30 minutes of warm ischemia via vascular clamping and randomized to 1 of 6 study groups: (1) 22-hour static cold storage (SCS) (n = 6), (2) 22-hour hypothermic machine perfusion (HMP) (n = 6), (3) 22-hour oxygenated HMP (n = 7), (4) 20-hour HMP plus 2-hour normothermic perfusion (NP) (n = 6), (5) 20-hour SCS plus 2-hour oxygenated HMP (n = 7), and (6) 20-hour SCS plus 2-hour NP (n = 6). Graft recovery measured by serum creatinine level was significantly faster for continuous HMP preservation strategies compared with SCS alone and for all end-ischemic strategies. The active oxygenated 22-hour HMP group demonstrated a significantly faster recovery from early graft function compared with the 22-hour nonactive oxygenated HMP group. Active oxygenation was also found to be an important modulator of a faster increase in renal flow during HMP preservation. Continuous oxygenated HMP applied from the time of kidney procurement until transplant might be the best preservation strategy to improve early graft function.

A Large Intraperitoneal Residual Volume Hampers Adequate Volumetric Assessment of Osmotic Conductance to Glucose

Background

In end-stage renal disease patients treated with peritoneal dialysis (PD), the osmotic conductance to glucose (OCG) represents the intrinsic ability of the membrane to transport water in response to a crystalloid osmotic gradient. A progressive loss of OCG in long-term PD patients indicates the development of fibrosis in the peritoneal interstitium, and helps identify patients at risk for encapsulating peritoneal sclerosis. The double mini-peritoneal equilibration test (PET) has been proposed as a simple method to assess OCG using the difference in initial ultrafiltration rates generated by 2 successive dwells using 1.36% and 3.86% glucose-based, 1-h PET. However, the presence of a large peritoneal residual volume (RV) may potentially interfere with the correct evaluation of drained volumes, limiting the reliability of OCG assessed by the double mini-PET.

Methods

We retrospectively reviewed data from 53 peritoneal function tests in 35 consecutive PD patients starting PD at our center between March 2013 and March 2017. The test consisted of a uni-PET (double mini-PET combined with a 3.86%, 4-h PET) performed at PD start, then yearly. In addition to peritoneal solute transport rate and net ultrafiltration, the tests provided information about osmotic water transport (OCG, sodium sieving, and free-water transport) as well as the RV estimated from albumin dilution.

Results

Contrary to sodium sieving, net ultrafiltration, and free-water transport, OCG did not correlate with any of the other parameters of osmotic water transport. In multivariate regression analyses, the RV was identified as the only determinant of OCG, while it did not alter the robust association between sodium sieving/free-water transport and their respective determinants. Considering only baseline tests or the whole series of tests, the presence of a large intraperitoneal RV was associated with discrepant values between OCG and sodium sieving, and with an artificial increase in OCG.

Conclusions

A large RV leads to significant overestimation of OCG using the double mini-PET, potentially reducing the ability of OCG to identify patients with progressive fibrosis in the peritoneal interstitium. On the other hand, sieving of the dialysate sodium, a biochemical surrogate for OCG, is independent of the RV and may therefore be more reliable. A call for caution is warranted in patients with a large RV to avoid misinterpretation of OCG values derived from the double mini-PET.

Unusual presentations of enlarged parathyroid cysts: two case reports

INTRODUCTION

Parathyroid cysts are infrequently encountered and have a variable presentation pattern depending on their size, location and secreting character.

PATIENTS AND METHODS

We report two cases of parathyroid cysts characterized by their uncommon clinical presentation.

RESULTS

In the first case the patient presented with a large cervical cystic mass without hypercalcemia, while in the second case, the patient experienced a hypercalcemic crisis associated with acute renal failure. The variable pattern of clinical manifestations is discussed.

CONCLUSION

Parathyroid cysts are a rare entity. Surgical resection is the key to therapy when hyperparathyroidism or local compression are identified.

Pharmacogenetic-based strategy using de novo tacrolimus once daily after kidney transplantation: prospective pilot study

Aim: The once daily tacrolimus formulation (Tac-OD) has been associated with better patient adherence and low variability in exposure. Patients carrying the CYP3A5*1 allele show accelerated clearance of Tac. Authors prospectively evaluate a simplified strategy for Tac-OD administration. Patients & methods: After grafting, 151 patients were divided into four groups and received a daily dose calculated according to CYP3A5 genotypes and unchanged for the first 3 days: CYP3A5*3/*3: 0.20 mg/kg/day, CYP3A5*3/*3: 0.25 mg/kg/day, CYP3A5*1/*3: 0.30 mg/kg/day and CYP3A5*1/*1: 0.35 mg/kg/day. The dose was adaptated on day 4 and remained unchanged a further three days and so on. Results: On day 3, median Cmin fell within the therapeutic range in all study groups. CYP3A5 expressors require significantly higher Tac-OD throughout the follow-up period to achieve a comparable Cmin. Conclusion: This simplified strategy does not hamper treatment efficacy.

Fourteen years of experience in uncontrolled organ donation after cardio-circulatory death

BACKGROUND

Since 1999, a protocol for uncontrolled donation after cardio-circulatory death (DCD) has been carried out in our institution. We aimed at evaluating those 14 years of local experience.

METHODS

We reviewed the charts of uncontrolled donors from 1999 till 2013. Potential donors with a no-flow period less than 30 minutes were considered. Kidneys were perfused by the use of a double balloon triple lumen catheter after at least a 2-minute period of no touch. We analyzed grafts outcome and warm and cold ischemia times.

RESULTS

Thirty-nine procedures were initiated: 19 were aborted because of family refusal (n = 7), medical reasons (n = 7), or canulation failures (n = 5) and 20 harvesting procedures were completed. Transplantation was considered for 35 kidneys (cold storage [n = 5] and hypothermic preservation system [n = 30]). The causes of withdrawal from transplantation were mostly macroscopic lesions (poor perfusion, macroscopic parenchyma or vascular lesions, or infectious risk). We transplanted 22 kidneys locally and 3 were shipped to another Eurotransplant center. Mean donor age was 40 ± 13 years. Among the 20 donors, 13 came from the emergency unit and 7 from the intensive care unit. Mean no-flow time for out-hospital management was 8.7 ± 3.6 minutes. Mean time of cardiopulmonary resuscitation was 71 ± 46 minutes. Mean cold ischemia time was 19 ± 5 hours. Primary nonfunction and delayed graft function occurred in 1 and 12 cases (4.5% and 54%), respectively. Graft survival was 86% at 1 year. Causes of graft loss during the entire follow-up were graft rejection (n = 3), ischemically damaged kidney (n = 2), and recurrence of focal segmental glomerulosclerosis (n = 1).

CONCLUSION

In our experience, uncontrolled donors represent a valuable source of kidney grafts, with a prognosis of graft function and survival similar to the literature. To increase the number of available DCD organs, new techniques, such as the use of Normothermic ExtraCorporeal Membrane Oxygenation (NECMO), as well as improvement of recruitment of out of hospital potential donors have to be considered.

Presentation and management of mycotic pseudoaneurysm after kidney transplantation

Pseudoaneurysms (PAs) developing at the site of vascular anastomosis after organ transplantation are a rare but serious complication. We report a series of 3 cases of PA observed in a single center over a period of 18 years. The mode of presentation was acute bleeding in 2 cases. In the third patient, who underwent combined kidney and pancreas transplantation, the PA on the renal graft was discovered by chance. Graft removal associated with iliac artery ligation and extra-anatomic femoro-femoral bypass represents the standard treatment. However, interposition of a venous homograft may allow preservation of inferior limb perfusion and possibly graft salvage.

Risk factors and surgical management of anastomotic biliary complications after pediatric liver transplantation

Biliary complications (BCs) still remain the Achilles heel of liver transplantation (LT) with an overall incidence of 10% to 35% in pediatric series. We hypothesized that (1) the use of alternative techniques (reduced size, split, and living donor grafts) in pediatric LT may contribute to an increased incidence of BCs, and (2) surgery as a first treatment option for anastomotic BCs could allow a definitive cure for the majority of these patients. Four hundred twenty-nine primary pediatric LT procedures, including 88, 91, 47, and 203 whole, reduced size, split, and living donor grafts, respectively, that were performed between July 1993 and November 2010 were retrospectively reviewed. Demographic and surgical variables were analyzed, and their respective impact on BCs was studied with univariate and multivariate analyses. The modalities of BC management were also reviewed. The 1- and 5-year patient survival rates were 94% and 90%, 89% and 85%, 94% and 89%, and 98% and 94% for whole, reduced size, split, and living donor liver grafts, respectively. The overall incidence of BCs was 23% (n = 98). Sixty were anastomotic complications [47 strictures (78%) and 13 fistulas (22%)]. The graft type was not found to be an independent risk factor for the development of BCs. According to a multivariate analysis, only hepatic artery thrombosis and acute rejection increased the risk of anastomotic BCs (P < 0.001 and P = 0.003, respectively). Anastomotic BCs were managed primarily with surgical repair in 59 of 60 cases with a primary patency rate of 80% (n = 47). These results suggest that (1) most of the BCs were anastomotic complications not influenced by the type of graft, and (2) the surgical management of anastomotic BCs may constitute the first and best therapeutic option.

Septuagenarian and octogenarian donors provide excellent liver grafts for transplantation

BACKGROUND

Wider utilization of liver grafts from donors ≥ 70 years old could substantially expand the organ pool, but their use remains limited by fear of poorer outcomes. We examined the results at our center of liver transplantation (OLT) using livers from donors ≥ 70 years old.

METHODS

From February 2003 to August 2010, we performed 450 OLT including 58 (13%) using donors ≥ 70 whose outcomes were compared with those using donors <70 years old.

RESULTS

Cerebrovascular causes of death predominated among donors ≥ 70 (85% vs 47% in donors <70; P < .001). In contrast, traumatic causes of death predominated among donors <70 (36% vs 14% in donors ≥ 70; P = .002). Unlike grafts from donors <70 years old, grafts from older individuals had no additional risk factors (steatosis, high sodium, or hemodynamic instability). Both groups were comparable for cold and warm ischemia times. No difference was noted in posttransplant peak transaminases, incidence of primary nonfunction, hepatic artery thrombosis, biliary strictures, or retransplantation rates between groups. The 1- and 5-year patient survivals were 88% and 82% in recipients of livers <70 versus 90% and 84% in those from ≥ 70 years old (P = .705). Recipients of older grafts, who were 6 years older than recipients of younger grafts (P < .001), tended to have a lower laboratory Model for End-Stage Liver Disease score (P = .074).

CONCLUSIONS

Short and mid-term survival following OLT using donors ≥ 70 yo can be excellent provided that there is adequate donor and recipient selection. Septuagenarians and octogenarians with cerebrovascular ischemic and bleeding accidents represent a large pool of potential donors whose wider use could substantially reduce mortality on the OLT waiting list.

Tacrolimus trough levels, rejection and renal impairment in liver transplantation: a systematic review and meta-analysis

We hypothesized that current trough concentrations of tacrolimus after liver transplantation are set too high, considering that clinical consequences of rejection are not severe while side effects are increased.We systematically reviewed 64 studies (32 randomized controlled trials and 32 observational studies) to determine how lower tacrolimus trough concentrations than currently recommended affect acute rejection rates and renal impairment. Among randomized trials the mean of tacrolimus trough concentration during the first month was positively correlated with renal impairment within 1 year (r = 0.73; p = 0.003), but not with acute rejection, either defined using protocol biopsies (r = -0.37; p = 0.32) or not (r = 0.11; p = 0.49). A meta-analysis of randomized trials directly comparing tacrolimus trough concentrations (five trials for acute rejection [n = 957] and two trials for renal impairment [n = 712]) showed that "reduced tacrolimus" trough concentrations (<10 ng/mL) within the first month after liver transplantation were associated with less renal impairment at 1 year (RR = 0.51 [0.38-0.69]), with no significant influence on acute rejection (RR = 0.92 [0.65-1.31]) compared to "conventional tacrolimus" trough levels (>10 ng/mL). Lower trough concentrations of tacrolimus (6-10 ng/mL during the first month) would be more appropriate after liver transplantation. Regulatory authorities and the pharmaceutical industry should allow changes of regulatory drug information.

The multicenter Belgian survey on liver transplantation for hepatocellular failure after bariatric surgery

The prevalence of obesity has grown dramatically over the last decades, with nonalcoholic steatohepatitis increasingly observed. Therapeutic options for morbid obesity include bariatric surgery. Fatal liver failure (LF) has been recorded after jejunoileal bypass (JIB) but is controversial after biliopancreatic diversion (BPD, Scopinaro operation). We performed a survey on the frequency of liver transplantation (LT) after bariatric surgery in Belgium. An enquiry was sent to all Belgian liver transplant centers to investigate the occurrence of subacute and chronic LF after bariatric surgery. After weight-reduction surgery, 10 patients in 3 Belgian transplant centers were listed for LT due to severe hepatocellular failure. Nine of them had undergone a Scopinaro operation and 1 a jejunoileal bypass. The median time to develop LF was 5 years. The patient with JIB developed chronic LF after 25 years. Seven patients were transplanted; two died awaiting a graft and one is still on the waiting list. After LT, 1 patient developed rapid reappearance of LF at 10 months, requiring retransplantation. Two recipients died after LT because of multiorgan failure shortly after transplantation. In another case, a de novo cancer was fatal at 6 years' follow-up. The remaining recipients were doing well. According to this survey, the BPD operation carries a potential risk of LF. However, because there were only 10 cases, we remain unaware of the actual incidence of Scopinaro operation-induced LF. We advise strict follow-up of liver function and timely dismantling of BPD.

Repetitive episodes of cryptogenic septicaemia in a patient with cirrhosis: a case of "heavy metal"

Endotipsitis or primary infection of a TIPS-stent, is an uncommon but possible life- threatening condition by its potential evolution to sepsis and death. Diagnosis should be suspected in patients with a TIPS-stent presenting with stent-dysfunction associated with fever or relapsing episodes of bacteremia/sepsis without any other alternative focus. A certain diagnosis is made by post-factum histopathological and/or microbiological examination of the TIPS-stent which is only possible after liver transplantation or at autopsy, whereas it can be highly suspected in case of repetitive positive blood-cultures without any other focus in a patient with a TIPS-stent. The microorganisms responsible for endotipsitis are most frequently of Gram-negative enteric origin. The regimen and duration of the treatment should be individualized and depends on multiple factors like the antibiotic sensitivity of the organism and the patients condition. In case of a fungal infection, longer treatment is recommended.

Thrombotic microangiopathy following intestinal transplantation: a single center experience

BACKGROUND

Transplant-related thrombotic microangiopathy (TMA) is a well-recognized complication of all types of transplantations. Despite its known relationship with immunosuppressive therapy, only a few cases have been reported following intestinal transplantation.

METHODS

We retrospectively reviewed the medical files of nine consecutive intestinal transplant patients between 2000 and 2008.

RESULTS

The diagnosis of TMA was established in 3 patients (33%). At diagnosis the immunosuppressive therapy consisted of tacrolimus (n = 3), combined with azathioprine (n = 1) or sirolimus (n = 2) and steroids (n = 2). The median time between transplantation and TMA was 104 days (range, 55-167 days). Levels of ADAMTS13, a von Willebrand protease, were within normal ranges in all 3 patients. Treatment consisted of stopping/tapering of tacrolimus, together with initiation of plasma therapy, leading to complete remission in all 3 patients. During further follow-up, all 3 patients showed severe graft rejection necessitating more profound immunosuppressive therapy, leading to graft loss in 1 patient and infection-related death in the 2 others. At a median follow-up of 52 months (range, 9-100 months) all remaining TMA-free patients (n = 6) were alive with functioning grafts under minimal immunosuppression.

CONCLUSION

Herein we have described 3 intestinal transplant patients who were diagnosed with transplantation-related TMA. Despite excellent disease control the final outcomes were dismal, which clearly contrasts with the outcome among TMA-free patients, who were all well with functioning grafts at last follow-up.