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.

Effectiveness of a two-stage strategy using the 16-item Prodromal Questionnaire (PQ16/fPQ16) and the Comprehensive Assessment of At Risk Mental States (CAARMS) in the early detection of Ultra High Risk (UHR) patients in Lebanon: a cross-sectional pilot study

OBJECTIVES

This study aims to identify the prevalence of Ultra High Risk (UHR) adults in a sample of patients in Lebanon and to compare screening and diagnostic tools.

METHODS

This is a cross-sectional pilot study which targeted patients aged 17-30 years willingly seeking psychiatric care in a university hospital in Beirut, Lebanon. Participants were invited to fill either the English or the French version of the Prodromal Questionnaire (respectively, PQ16 or fPQ16). The abbreviated version of the "Comprehensive Assessment of At-Risk Mental States" (CAARMS) was then administered to all participants. The latter were subsequently sorted into one of the three UHR groups - vulnerability group, attenuated psychosis (APS), intermittent psychosis (BLIPS) - or were diagnosed as suffering from a psychotic disorder.

RESULTS

Thirty-one patients participated in this study. The prevalence of positive screening on the PQ16/fPQ16 and positive diagnosis of UHR on the CAARMS were respectively of 61.29% and 45%. The APS group was the most prevalent (71.42%). A positive psychosis screening on PQ16/fPQ16 was statistically related to a UHR diagnosis on CAARMS (p-value: 0.011 on Chi2 test), OR=8.5 (95% CI: 1.4-50.9; p-value: 0.018). No relation was found between PQ16/fPQ16 results and risk stratification or between the number of "True" responses on PQ16/fPQ16 and the intensity of symptoms on CAARMS. PQ16/fPQ16 statements 5, 9, 11 and 16 predicted a UHR diagnosis on CAARMS (p-value of 0.045, 0.006, 0.045 and 0.045, respectively).

CONCLUSION

This two-stage strategy for identifying UHR patients can be adopted in a tertiary health care center.

Tacrolimus Pharmacokinetics is Associated with Gut Microbiota Diversity in Kidney Transplant Patients: Results from a Pilot Cross-Sectional Study

Clinical use of tacrolimus (TAC), an essential immunosuppressant following transplantation, is complexified by its high pharmacokinetic (PK) variability. The gut microbiota gains growing interest but limited investigations have evaluated its contribution to TAC PKs. Here, we explore the associations between the gut microbiota composition and TAC PKs. In this pilot cross-sectional study (Clinicaltrial.gov NCT04360031), we recruited 93 CYP3A5 non-expressers stabilized kidney transplant recipients. Gut microbiota composition was characterized by 16S rRNA gene sequencing, TAC PK parameters were computed, and additional demographic and medical covariates were collected. Associations between PK parameters or diabetic status and the gut microbiota composition, as reflected by α- and β-diversity metrics, were evaluated. Patients with higher TAC area under the curve AUC/(dose/kg) had higher bacterial richness, and TAC PK parameters were associated with specific bacterial taxa (e.g., Bilophila) and amplicon sequence variant (ASV; e.g., ASV 1508 and ASV 1982 (Veillonella/unclassified Sporomusaceae); ASV 664 (unclassified Oscillospiraceae)). Building a multiple linear regression model showed that ASV 1508 (co-abundant with ASV 1982) and ASV 664 explained, respectively, 16.0% and 4.6% of the interindividual variability in TAC AUC/(dose/kg) in CYP3A5 non-expresser patients, when adjusting for hematocrit and age. Anaerostipes relative abundance was decreased in patients with diabetes. Altogether, this pilot study revealed unprecedented links between the gut microbiota composition and diversity and TAC PKs in stable kidney transplant recipients. It supports the relevance of studying the gut microbiota as an important contributor to TAC PK variability. Elucidating the causal relationship will offer new perspectives to predict TAC inter- and intra-PK variability.

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.

Impact of thrice-weekly cotrimoxazole prophylaxis on creatinine and potassium plasma levels in kidney transplant recipients

INTRODUCTION

Cotrimoxazole (CTX) 800/160 mg daily or thrice-weekly is recommended as prophylaxis of Pneumocystis jirovecii pneumonia in kidney transplant recipients. Cotrimoxazole 800/160 daily elevates plasma creatinine and potassium levels but whether the thrice-weekly regimen does so is unknown.

METHODS

Medical records of 225 kidney transplant recipients at Cliniques Universitaires Saint-Luc were analyzed retrospectively. All received thrice-weekly CTX 800/160 for 6 months after transplantation. Monthly laboratory results, co-medications, and tacrolimus trough levels were compared. Standard statistical tests were used.

RESULTS

One month after CTX stop, creatinine level decreased by 0.11 mg/dl (8%, p = 0.029). This contrasts with its stability in previous and subsequent months. No co-medication change accounted for this decrease. The decrease averaged 0.17 mg/dl (p < 0.01) in the highest initial creatinine tertile. The higher the initial creatinine level, the greater the decrease after CTX stop (p < 0.001), and urea levels remained stable after CTX stop. Potassium levels decreased by 0.09 mmol/L (p = 0.021) one month after CTX stop, and decreased by 0.23 mmol/L (p < 0.01) in the highest initial potassium level tertile.

CONCLUSIONS

Our study pinpoints the impact of CTX 800/160 thrice-weekly on creatinine and potassium levels in kidney transplant recipients. This should be considered when interpreting the evolution of plasma creatinine over time, especially in patients with graft dysfunction. Thus, creatinine levels of cohorts with 6 months versus lifelong CTX require different interpretations.

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.

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.

BRAFV600E Expression in Thyrocytes Causes Recruitment of Immunosuppressive STABILIN-1 Macrophages

Simple Summary

Incidence of thyroid cancer, including papillary thyroid cancer, is rapidly increasing. Oncogenes, such as the BRAF^V600E, have been identified, and their effect on thyroid cancer cells have been studied in vitro and in mouse models. What is less understood is the impact of these mutations on thyroid cancer microenvironment and, in turn, the effect of changes in the microenvironment on tumor progression. We investigated the modifications in the cellular composition of thyroid cancer microenvironment using an inducible mouse model. We focused on a subpopulation of macrophages, expressing the STABILIN-1 protein, recruited in the thyroid tumor microenvironment following BRAF^V600E expression. CRISPR/Cas9 genetic inactivation of Stablin-1 did not change macrophage recruitment but highlighted the immunosuppressive role of STABILIN-1-expressing macrophages. The identification of a similar subpopulation of STABILIN-1 macrophages in human thyroid diseases supports a conserved role for these macrophages and offers an opportunity for intervention.

Abstract

Papillary thyroid carcinoma (PTC) is the most frequent histological subtype of thyroid cancers (TC), and BRAF^V600E genetic alteration is found in 60% of this endocrine cancer. This oncogene is associated with poor prognosis, resistance to radioiodine therapy, and tumor progression. Histological follow-up by anatomo-pathologists revealed that two-thirds of surgically-removed thyroids do not present malignant lesions. Thus, continued fundamental research into the molecular mechanisms of TC downstream of BRAF^V600E remains central to better understanding the clinical behavior of these tumors. To study PTC, we used a mouse model in which expression of BRAF^V600E was specifically switched on in thyrocytes by doxycycline administration. Upon daily intraperitoneal doxycycline injection, thyroid tissue rapidly acquired histological features mimicking human PTC. Transcriptomic analysis revealed major changes in immune signaling pathways upon BRAF^V600E induction. Multiplex immunofluorescence confirmed the abundant recruitment of macrophages, among which a population of LYVE-1+/CD206+/STABILIN-1+ was dramatically increased. By genetically inactivating the gene coding for the scavenger receptor STABILIN-1, we showed an increase of CD8+ T cells in this in situ BRAF^V600E-dependent TC. Lastly, we demonstrated the presence of CD206+/STABILIN-1+ macrophages in human thyroid pathologies. Altogether, we revealed the recruitment of immunosuppressive STABILIN-1 macrophages in a PTC mouse model and the interest to further study this macrophage subpopulation in human thyroid tissues.

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.

Two miRNAs enriched in plasma extracellular vesicles are potential biomarkers for thyroid cancer

Differential diagnosis of thyroid cancer and benign nodules is still one of the most challenging issues in the field of endocrinology. To overcome overdiagnosis of papillary thyroid carcinomas (PTC) and the consecutive overtreatment of multinodular diseases, the search for easily accessible, sensitive and accurate biomarkers is critical. Several micro-RNAs (miRNAs) freely circulating in peripheral blood or enclosed in extracellular vesicles (EVs) have been proposed as potential biomarkers from non-invasive liquid biopsies. However, protocols are rarely comparable and conflicting data exist in the literature. In this work, we aimed to assess the diagnostic value of six micro-RNAs by comparing their expression in thyroid tissue to their abundance in bulk plasma and in plasma-EVs, before and after thyroid surgery. Plasma-EVs were isolated using a sequential density- and size-based fractionation, followed by in-depth characterization, confirming EV purity. Micro-RNA levels were measured by RT-qPCR in thyroid tissue, plasma and plasma-EVs. Among the six candidates, only miR-146b-5p and miR-21a-5p displayed a significant differential abundance in purified plasma-derived EVs from patients with PTC and benign disease. However, no difference could be demonstrated in bulk plasma through our cohort of patients. Overall, our work supports the use of a well-defined protocol of plasma-EV miRNAs purification for biomarker discovery, rather than the use of freely circulating miRNAs in bulk plasma. Our work also demonstrates that standardized pre-analytical and analytical procedures as well as optimized EV-miRNAs detection methods are essential.

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.

Impact of temporary mechanical circulatory support on mortality in cardiogenic shock: an emulated target trial with a prospective, multicenter, French cohort study

Background

The field of temporary mechanical circulatory support (TMCS) has advanced in last decade justifying that TMCS is increasingly used for treatment of refractory cardiogenic shock (CS). Nevertheless, the efficacy of TMCS (extracorporeal life support (ECLS) and Impella) in CS remains controversial due to the lack of high-quality evidence. The aim of this prospective multicenter observational study simulating a randomized trial was to assess the impact of TMCS on the hospital mortality in patients with CS.

Methods

This study (ClinicalTrials.gov ID: NCT03528291) was conducted at 3 TMCS centers organized in a cardiac assistance network, one as a level 1 TMCS center (expert center), and 2 as level 2 centers (hub centers). The study was designed and led by the heart team of the expert center with input from the hub centers.

All patients admitted to an intensive care unit between July 2017 and May 2020 either directly at the TMCS centers or after transfer from a non-specialized hospital, were screened for TMCS indication provided they were admitted for CS. CS was defined according to the European Society of Cardiology criteria. Were excluded patients younger than 18 years, CS after cardiac surgery, or after cardiac arrest if it was refractory or with a no flow &gt;3 min and/or out-of-hospital cardiac arrest with non-shockable rhythm, or CS in the context of myocardial infarction complications, massive pulmonary embolism, and if TMCS was contraindicated

TMCS indication was decided after a multidisciplinary discussion carried out by the “heart team”. Implantation of TMCS resulted from an agreement of the heart team within the first 24 hours after admission mainly based on the initial severity of the CS, or if CS was refractory to the medical treatment.

The primary outcome was in-hospital survival. A propensity score-weighted analysis was done for treatment-effect estimation. This method, which weights each patient according to their propensity score, includes all participants in the analysis.

Results

246 patients with CS were included in the study: 121 in TMCS group (72% ECLS, 14% Impella, 14% both ECLS and Impella) and 125 in control group. After adjustment by a propensity score, hospital mortality was comparable in the two groups (32% TMCS group vs 27% control group; Odds ratio with TMCS, 1.28; 95% confidence interval, 0.87 to 1.88; p=0.21). Mortality at D180 was also similar in the two group (33% vs 30% respectively; p=0.51). Thromboembolic events were significantly higher in the TCMS group (14% vs 4%; p&lt;0.01) as well as the transfusion rate ((median (IQR); 4.0 (0.0; 9.0) vs 0.0 (0.0; 0.0); p&lt;0.01).

Conclusion

In our study, the use of TMCS does not seem to improve hospital survival in patients with cardiogenic shock. Thus, TMCS, which are iatrogenic side effects providers, should be reserved for the most severe patient and discussed by a multidisciplinary team.

Funding Acknowledgement

Type of funding sources: None. Flow chart

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.

Influence of secretory phenotype and preoperative preparation on surgical outcome in pheochromocytoma

OBJECTIVES

Surgery of pheochromocytomas (PCs) still carries a high risk of haemodynamic complications during the perioperative period. We aimed to evaluate the influence of their secretory phenotype and preoperative alpha-blocker treatment on surgical outcome.

DESIGN

A retrospective monocentric study at a tertiary medical centre.

PATIENTS

In this study, 80 consecutive patients operated by the same team for a PC between 1988 and 2018.

RESULTS

Diagnosis was based on typical symptoms and signs in 58 patients, genetic testing in 12 and work-up of an adrenal incidentaloma in 9. It was made during surgery in one patient. A genetic predisposition was found in one-third of index cases (21/62). The majority of the patients (73/79) had a secreting PC; more than 2/3 had an adrenergic phenotype and less than 1/3 a noradrenergic phenotype. The rate of perioperative haemodynamic complications was not influenced by the secretory phenotype, but persistent hypertension after surgery, recurrence and malignancy were more frequently observed in patients with a noradrenergic tumour. Preoperative alpha-blocker treatment was given for ≥ 14 days in 29 patients and, although being more symptomatic at diagnosis, these patients had less haemodynamic complications (3/29 vs 12/51 non-treated patients, P = 0.05).

CONCLUSIONS

The occurrence of haemodynamic complications during surgery was not significantly affected by the secretory phenotype in our study, but noradrenergic tumours show a worse post-surgical outcome. Our data also provide additional support in favour of a sufficient preoperative alpha-blockade in patients with pheochromocytoma.

Predictors of tacrolimus pharmacokinetic variability: current evidences and future perspectives

INTRODUCTION

In kidney transplantation, tacrolimus (TAC) is at the cornerstone of current immunosuppressive strategies. Though because of its narrow therapeutic index, it is critical to ensure that TAC levels are maintained within this sharp window through reactive adjustments. This would allow maximizing efficiency while limiting drug-associated toxicity. However, TAC high intra- and inter-patient pharmacokinetic (PK) variability makes it more laborious to accurately predict the appropriate dosage required for a given patient.

AREAS COVERED

This review summarizes the state-of-the-art knowledge regarding drug interactions, demographic and pharmacogenetics factors as predictors of TAC PK. We provide a scoring index for each association to grade its relevance and we present practical recommendations, when possible for clinical practice.

EXPERT OPINION

The management of TAC concentration in transplanted kidney patients is as critical as it is challenging. Recommendations based on rigorous scientific evidences are lacking as knowledge of potential predictors remains limited outside of DDIs. Awareness of these limitations should pave the way for studies looking at demographic and pharmacogenetic factors as well as gut microbiota composition in order to promote tailored treatment plans. Therapeutic approaches considering patients' clinical singularities may help allowing to maintain appropriate concentration of TAC.

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.

COVID-19 Infection in Kidney Transplant Recipients: A Single-Center Case Series of 22 Cases From Belgium

RATIONALE & OBJECTIVE

The world is facing a global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although kidney transplant recipients are at increased risk for viral infections, the impact of their chronic immunosuppressed status on the risk for acquiring coronavirus disease 2019 (COVID-19) and disease severity is unknown.

STUDY DESIGN

All cases of COVID-19 infection in our cohort of kidney transplant recipients were prospectively monitored. Clinical features, management, and outcomes were recorded. A standard strategy of immunosuppression minimization was applied: discontinue the antimetabolite drug and reduce trough levels of calcineurin or mammalian target of rapamycin inhibitors. Unless contraindicated, hydroxychloroquine was administered only to hospitalized patients.

SETTING & PARTICIPANTS

22 COVID-19 infections were diagnosed in our cohort of 1,200 kidney transplant recipients.

RESULTS

Most common initial symptoms included fever, cough, or dyspnea. 18 (82%) patients required hospitalization. Of those patients, 3 had everolimus-based immunosuppression. Computed tomography of the chest at admission (performed in 15 patients) showed mild (n = 3), moderate (n = 8), extensive (n = 1), severe (n = 2), and critical (n = 1) involvement. Immunosuppression reduction was initiated in all patients. Hydroxychloroquine was administered to 15 patients. 11 patients required supplemental oxygen; 2 of them were admitted to an intensive care unit (ICU) with mechanical ventilation. After a median of 10 days, 13 kidney transplant recipients were discharged, 2 were hospitalized in non-ICU units, 1 was in the ICU, and 2 patients had died.

LIMITATIONS

Small sample size and short follow-up.

CONCLUSIONS

The clinical presentation of COVID-19 infection was similar to that reported in the general population. A standard strategy of immunosuppression minimization and treatment was applied, with 11% mortality among kidney transplant recipients hospitalized with COVID-19 infection.

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.

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.

Tacrolimus Updated Guidelines through popPK Modeling: How to Benefit More from CYP3A Pre-emptive Genotyping Prior to Kidney Transplantation

Tacrolimus (Tac) is a profoundly effective immunosuppressant that reduces the risk of rejection after solid organ transplantation. However, its use is hampered by its narrow therapeutic window along with its highly variable pharmacological (pharmacokinetic [PK] and pharmacodynamic [PD]) profile. Part of this variability is explained by genetic polymorphisms affecting the metabolic pathway. The integration of CYP3A4 and CY3A5 genotype in tacrolimus population-based PK (PopPK) modeling approaches has been proven to accurately predict the dose requirement to reach the therapeutic window. The objective of the present study was to develop an accurate PopPK model in a cohort of 59 kidney transplant patients to deliver this information to clinicians in a clear and actionable manner. We conducted a non-parametric non-linear effects PopPK modeling analysis in Pmetrics^®. Patients were genotyped for the CYP3A4^∗22 and CYP3A5^∗3 alleles and were classified into 3 different categories [poor-metabolizers (PM), Intermediate-metabolizers (IM) or extensive-metabolizers (EM)]. A one-compartment model with double gamma absorption route described very accurately the tacrolimus PK. In covariate analysis, only CYP3A genotype was retained in the final model (Δ-2LL = -73). Our model estimated that tacrolimus concentrations were 33% IC_95%[20–26%], 41% IC_95%[36–45%] lower in CYP3A IM and EM when compared to PM, respectively. Virtually, we proved that defining different starting doses for PM, IM and EM would be beneficial by ensuring better probability of target concentrations attainment allowing us to define new dosage recommendations according to patient CYP3A genetic profile.

Outcome of hepatitis B and C virus-associated hepatocellular carcinoma occurring after renal transplantation

Kidney transplant recipients (KTR) are subjected to immunosuppressive therapy that can enhance hepatitis B and C virus replication, leading to cirrhosis and hepatocellular carcinoma (HCC). The aim of this study was to assess the prevalence and outcome of HCC in KTR. Case-control study. Patients with chronic HBV and/or HCV infection who underwent kidney transplantation between 1976 and 2011 and subsequently developed HCC were compared to a control group of patients with chronic HBV and/or HCV infection, matched for gender and age at HCC diagnosis, who did not receive kidney transplantation. Among 2944 KTR, 330 had hepatitis B and/or C. Fourteen developed HCC, a period prevalence of 4.2%. Age at HCC diagnosis was 52.6 ± 6.5 years (53.5 ± 5.7 in controls, P=.76). Time between transplantation and HCC diagnosis was 16.7 ± 2.7 years. Six HCCs were related to HBV, six to HCV and two to co-infection with HBV and HCV. Immunosuppressive therapy was comparable in HBV, HCV and HBV+HCV patients. At diagnosis, 71% of patients met Milan criteria (65% in the control group, P=.4). Alpha-fetoprotein levels, tumour characteristics and treatment modalities were comparable between both groups. Patient survival 2 years after HCC diagnosis was 28% in KTR, compared to 68% in controls (P=.024). Survival after HCC diagnosis is significantly worse in KTR compared to nontransplanted patients with HBV and/or HCV. Prevention is crucial and should be based on viral eradication/suppression before or after transplantation.

Pioglitazone, a PPARγ Agonist, Upregulates the Expression of Caveolin-1 and Catalase, Essential for Thyroid Cell Homeostasis: A Clue to the Pathogenesis of Hashimoto's Thyroiditis

BACKGROUND

Peroxisome proliferator-activated receptor γ (PPARγ) is a transcription factor that regulates the expression of multiple target genes involved in several metabolic pathways as well as in inflammation. The expression and cell localization of caveolin-1 (Cav-1), thyroperoxidase (TPO), and dual oxidase (DUOX), involved in extracellular iodination, is modulated by Th1 cytokines in human normal thyroid cells and in Hashimoto's thyroiditis (HT).

OBJECTIVES

The objectives of this study were (i) to analyze the PPARγ protein and mRNA expression at the follicular level in HT versus controls in correlation with the one of Cav-1; (ii) to study the effects of Th1 cytokines on PPARγ and catalase expression in human thyrocyte primary cultures; and (iii) to study the effects of pioglitazone, a PPARγ agonist, on thyroxisome components (Cav-1, TPO, DUOX) and on catalase, involved in antioxidant defense.

RESULTS

Although the global expression of PPARγ in the whole gland of patients with HT was not modified compared with controls, there was great heterogeneity among glands and among follicles within the same thyroid. Besides normal (type 1) follicles, there were around inflammatory zones, hyperactive (type 2) follicles with high PPARγ and Cav-1 expression, and inactive (type 3) follicles which were unable to form thyroxine and did not express PPARγ or Cav-1. In human thyrocytes in primary culture, Th1 cytokines decreased PPARγ and catalase expression; pioglitazone increased Cav-1, TPO, and catalase expression.

CONCLUSION

PPARγ may play a central role in normal thyroid physiology by upregulating Cav-1, essential for the organization of the thyroxisome and extracellular iodination. By upregulating catalase, PPARγ may also contribute to cell homeostasis. The inhibitory effect of Th1 cytokines on PPARγ expression may be considered as a new pathogenetic mechanism for HT, and the use of PPARγ agonists could open a new therapeutic approach.