Transplant Dysfunction Research Articles

The use of metabolomics and machine learning algorithms to predict post-transplant diabetes mellitus in renal transplant patients on Tacrolimus therapy.

Tacrolimus (TAC) has significantly improved kidney graft survival following transplantation, though it is associated with adverse side effects. The most prevalent complication resulting from excessive TAC exposure is the onset of de novo diabetes mellitus (DM), a condition that can negatively impact both renal graft function and patient outcomes. De novo DM is linked to an increased risk of chronic transplant dysfunction, as well as cardiovascular morbidity and mortality. Although the underlying mechanisms remain unclear, emerging research in the field of omics shows promise. The aim of this study was to investigate the metabolomic profile of kidney transplant patients who developed de novo DM, in comparison to those who did not, following TAC exposure, using untargeted metabolomic analysis through ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) and machine learning algorithms. A cohort of 34 kidney transplant patients on a Tacrolimus regimen for at least 6 months was enrolled in the study, with serum samples collected from each patient. Comprehensive profiling of serum metabolites was performed, enabling the classification of patients into de novo diabetes mellitus and non diabetes groups. The metabolomic analysis of serum was conducted using UHPLC-MS. Of the 34 patients, 16 were diagnosed with TAC-induced diabetes. A total of 334 metabolites were identified in the serum samples, of which 10 demonstrated a significant correlation with the de novo diabetes mellitus group. Most of these metabolites were linked to alterations in lipid metabolism. The application of metabolomics in kidney transplant patients undergoing a Tacrolimus regimen is both feasible and effective in identifying metabolites associated with de novo diabetes mellitus. This approach may provide valuable insights into the metabolic alterations underlying TAC-induced diabetes.

Tumor characteristics in immunosuppressed and renal dysfunction populations

PurposeRenal transplantation and end-stage renal disease are increasingly common. Renal dysfunction and immunosuppression are two risk factors in the development of renal cell carcinoma. Carcinomas in these patients are thought to be more indolent, however data are limited and mixed. Our objective was to describe the histology of resected tumors from the transplant and renal dysfunction population and compare them to a control population. Materials and MethodsThis was a single-center retrospective cohort study of all patients who had a nephrectomy for a renal mass from 2009 to 2019. All transplant status and end-stage renal disease diagnoses were identified by diagnostic or procedural coding and confirmed by chart review. Our primary endpoint was the pathology for each patient's tumor. Tumors were classified into aggressive or nonaggressive categories based on their histology and grade. ResultsWe identified 1,150 radical and partial nephrectomies, of which 1,057 met inclusion criteria. Of these, 68 patients (6.4%) had renal dysfunction or a kidney transplant on immunosuppression at time of nephrectomy. After pathologic review, 270 (25%) tumors were classified as aggressive, and 673 (64%) tumors were pT1a or pT1b. On multivariable logistic regression controlling for age and gender, renal dysfunction was not associated with having an aggressive tumor (OR 1.24, 95%CI 0.72–2.15; P = 0.44). ConclusionsWe did not observe a relationship between renal dysfunction status and aggressive pathology. These data suggest that renal dysfunction and transplant patients are at similar risk for aggressive pathology as the general population and should be managed according to the same clinical guidelines.

The significance of serum lysozyme in predicting bacterial complications in patients after kidney transplantation

The aim of the study was to conduct a comparative analysis of serum lysozyme activity and study its innovativeness in predicting bacterial complications after kidney transplantation. Material and methods. Lysozyme activity was studied in 99 patients after kidney transplantation and 81 practically healthy volunteers. Patients depending on period after surgery were divided into five groups: group 1 – 1st day after kidney transplantation (n = 6); group 2 – 1–5 months (n = 10); group 3 – 6–12 months (n = 21); group 4 – 2–5 years (n = 30); group 5 – 6–10 years (n = 32). An analysis of the correlation between serum lysozyme level, absolute leukocyte count and creatinine content was performed. Lysozyme activity was assessed in bacterial complications, transplant dysfunction and organ rejection. Results and discussion. On the 1st day after kidney transplantation lysozyme activity was minimal – 117.95 [60.80–133.51] µg/ ml (median [lower quartile – upper quartile]) (in healthy volunteers it was 243.80 [190.76–305.69] µg/ml, p < 0,001). One month after surgery, it returned to normal (292.08 [311.66–218.48] μg/ml) and did not differ from the value of the group of practically healthy volunteers for 5 months (p = 0,17). Lysozyme activity in serum of patients after kidney transplantation had inverse moderate correlation with creatinine content (r = –0,32, p < 0,05). The threshold value for the probability of bacterial infections for serum lysozyme was > 321,4 μg/ml (p = 0,003). Creatinine level > 0,11 mmol/l predicts graft dysfunction. Conclusions. On the first day after transplantation a low level of lysozyme indicates high risk of bacterial infection. One month after surgery lysozyme returned to normal which indicates restoration of humoral component of nonspecific immune resistance. Relationship between creatinine content and lysozyme activity as well as an increase in the latter in comparison with healthy group allows to use lysozyme as an additional diagnostic criterion for acute bacterial infection and creatinine – for prognosis of graft dysfunction.

Inter- and intra-individual differences regarding SARS-CoV-2 and influenza vaccination in pediatric kidney transplant recipients: An observational study.

In kidney transplant recipients (KTRs), viral infection can lead to antibody and/or T-cell mediated rejection, resulting in kidney transplant dysfunction. Therefore, it is critical to prevent infections. However, KTRs exhibit suboptimal responses to SARS-CoV-2 and/or influenza vaccines, partly due to immunosuppressant therapy. Inter- and intra-individual differences in the biological responses to vaccines may also affect patients' antibody production ability. This study included KTRs who received an messenger RNA SARS-CoV-2 vaccine (3 doses), and an inactivated quadrivalent influenza vaccine (1 or 2 doses). We measured the patients' total antibody titers against SARS-CoV-2 spike antigen, and hemagglutination inhibition (HI) titers against influenza A/H1N1, A/H3N2, B/Yamagata, and B/Victoria. Five patients were eligible for this study. Of these 5 KTRs, two produced anti-SARS-CoV-2 spike antibody titers to a seroprotective level, and also produced HI titers against A/H1N1 to a seroprotective level. Another 2 KTRs did not produce seroprotective anti-SARS-CoV-2 antibody titers, but produced seroprotective HI titers against A/H1N1. The remaining KTR produced a seroprotective anti-SARS-CoV-2 antibody titer, but did not produce a seroprotective HI titer against A/H1N1. The 2 KTRs who did not produce seroprotective anti-SARS-CoV-2 antibody titers following vaccination, later developed COVID-19, and this infection increased their titers over the seroprotective level. This study demonstrated that inter- and intra-individual differences in biological responses to vaccines should be considered in pediatric KTRs, in addition to immunosuppressant effects. Personalized regimens, such as augmented or booster doses of vaccines, could potentially improve the vaccination efficacy against SARS-CoV-2 and influenza.

#2859 Clinical and morphological characteristics of biopsy-proven kidney graft rejection in Latvia

Abstract Background and Aims Kidney transplantation is a treatment for many patients with end stage renal disease leading to increased quality of life. In last decades results in kidney transplantation have been improving, but allograft rejection remains an important clinical problem. Graft biopsy remains the gold standard to assess the cause of kidney transplant status. This study aimed to determine clinical and histopathological characteristics, treatment and short-term outcomes of biopsy-proved kidney graft rejection in Latvia. Method In this retrospective observational study all kidney allograft biopsies performed in Pauls Stradins Clinical University Hospital from January 2014 till December 2022 was reviewed. Biopsies with rejection, ≥7 glomeruli, patients ≥18 years old were included. Acute rejection was diagnosed according to clinical, laboratory and biopsy-proven acute rejection (BPAR) histological criteria. BPAR was classified and subdivided using Banff criteria. All recipients universally received either depleting or non-depleting induction therapy. Most of the patient (82%) for maintenance immunosuppression (MI) received triple therapy with calcineurin inhibitor, mycophenolate mofetil, and prednisone, others—in different combinations with above and mammalian target of rapamycin (mTOR), azathioprine. Graft function was evaluated according to glomerular filtration rate (GFR), calculated with the CKD-EPI Creatinine, 2021 equation. Treatment strategies, laboratory data at the time of biopsy and after 1 year follow-up were analysed. Repeated-control biopsies after receiving therapy were excluded. Data were analysed using descriptive statistics and T-test. Results From all 523 biopsies, further included and analysed were 153 (total 146 patients). 58% were males, average patient age was 45.5 years. Most 84% of the grafts were from deceased, 8%—living donors. Mean time from transplantation to biopsy was 32 months. Acute antibody-mediated rejection (AAMR) was diagnosed in 41% cases, chronic-active antibody mediated (CAAMR)—25%, followed by mixed 16%, acute cellular (ACR) 10% and borderline 8% rejection. Besides augmented MI for almost all patients, pulse steroids (GCS) were the most commonly 70% administered treatment, followed by plasma exchange 59% (PEX), rituximab (RTX) 50%, immunoglobulins (IG) 24% and anti-thymocyte globulin (ATG) 10% in different, mostly non-homogenous combinations. Non adherence, advanced fibrotic changes in biopsy and serious comorbidities were the main reasons patients did not receive specific treatment besides intensified MI. The most favourable outcomes were in ACR where mean allograft GFR increased +20.7 ml/min after one year, compared to the worst outcome CAAMR group where GFR decreased −4.7 ml/min (p = 0.03). In ACR group 92% graft function stayed the same or improved, moreover 54% graft function increased ≥20% from baseline; similarly in mixed and AAMR group GFR increase ≥20% were for 45% and 48%, compared to CAAMR where it was only for 6% of patient. Furthermore, the CAAMR group was with the most patients (48%) who returned to dialysis or died. In AAMR and mixed rejection groups mean GFR changes were close +13.4 ml/min and +12.9 ml/min (p = 0.95). There were no statistically significant associations between treatment outcomes in PEX+RTX+GCS vs PEX+RTX+GCS+IG in the AAMR group (p = 0.382). Overall, 3.9% of patients died. Conclusion Overall BPAR prevalence between kidney graft biopsies was high (29%). Antibody mediated rejection was diagnosed most often with least favourable short-term outcomes in CAAMR group. Despite various improvements in immunosuppression, CAAMR remains a serious cause of transplant dysfunction or loss.

Retrospective analysis of the perioperative outcome in living donor kidney transplantation with multiple renal arteries: does accessory vessel ligation affect the outcome?

PurposeAccurate surgical reconstruction of arterial vascular supply is a crucial part of living kidney transplantation (LDKT). The presence of multiple renal arteries (MRA) in grafts can be challenging. In the present study, we investigated the impact of ligation versus anastomosis of small accessory graft arteries on the perioperative outcome.MethodsClinical and radiological outcomes of 51 patients with MRA out of a total of 308 patients who underwent LDKT with MRA between 2011 and 2020 were stratified in two groups and analyzed. In group 1 (20 patients), ligation of accessory arteries (ARAs) and group 2 (31 patients) anastomosis of ARAs was performed.ResultsSignificant differences were observed in the anastomosis-, surgery-, and warm ischemia time (WIT) in favor of group 1. Students t-test showed comparable serum creatinine levels of 2.33 (± 1.75) to 1.68 (± 0.83) mg/dL in group 1 and 2.63 (± 2.47) to 1.50 (± 0.41) mg/dL in group 2, were seen from 1 week to 1 year after transplant. No increased rates of Delayed graft function (DGF), primary transplant dysfunction and transplant rejection were seen, but graft loss and revision rates were slightly higher when the ARAs were ligated. Analysis of Doppler sonography revealed that segmental perfusion deficits tend to regenerate during the clinical course.ConclusionLigation of smaller accessory renal arteries may not affect the outcome of living kidney transplantation, except for a minor increase in the reoperation rate. Segmental perfusion deficits of the graft seem to regenerate in most cases as seen in Doppler sonography.

Diagnosing Polyomavirus Nephropathy Without a Biopsy: Validation of the Urinary Polyomavirus-Haufen Test in a Proof-of-Concept Study Including Uromodulin Knockout Mice.

Polyomavirus (PyV) nephropathy (PyVN) leads to kidney transplant dysfunction and loss. Since a definitive diagnosis requires an invasive kidney biopsy, a timely diagnosis is often hampered. In this clinical dilemma the PyV haufen-test, centering around the detection of 3-dimensional PyV aggregates in the urine, might provide crucial diagnostic information. A multistep experimental design was used. The hypothesis was that PyV-haufen form within the kidneys under high concentrations of uromodulin, a kidney-specific protein and that PyV-haufen are, therefore, kidney-specific disease biomarkers. The first investigative step showed colocalization of uromodulin with aggregated PyV (1) in 10 kidneys with PyVN by immunohistochemistry, (2) in urine samples containing PyV-haufen by electron microscopy/immunogold labeling (n = 3), and (3) in urine samples containing PyV-haufen by immunoprecipitation assays (n = 4). In the in vitro experiments of the next step, only high uromodulin concentrations (≥1.25 mg/mL) aggregated PyV, as is expected to occur within injured nephrons. In contrast, in voided urine samples (n = 59) uromodulin concentrations were below aggregation concentrations (1.2-19.6 µg/mL). In the third investigative step, none of 11 uromodulin-/- knockout mice (0%) with histologic signs of PyVN showed urinary PyV-haufen shedding, compared with 10 of 14 uromodulin+/+ wild-type mice (71%). PyV-haufen form within kidneys under high uromodulin concentrations. Thus, PyV-haufen detected in the urine are specific biomarkers for intrarenal disease (ie, definitive PyVN).

Assessment of renal transplant dysfunction by doppler sonography: A systematic review and meta-analysis.

Doppler sonography parameters, particularly the resistive index (RI), have been identified as an essential tool for assessing renal transplant dysfunction (RTD). However, there is some ambiguity in the findings of previous research studies on this matter. Therefore, the objective of our study is to examine the relationship between changes in RI subsequent to RTD. This was a systematic review and meta-analysis study. We searched three electronic databases PubMed, Web of Science, and Scopus, from the year 2000 to 10 May 2022. The main effect size was considered as the mean RI differences of cases with RTD confirmed by biopsy with control patients with no RTD. We used random effect models to pool the effect size. Thirteen studies were included in our review. The pooled mean (95% CI) for the control group was calculated to be 0.71 (0.67, 0.75) and for patients with renal transplant dysfunction was 0.73 (0.68, 0.78), under a random effect model with high heterogeneity for both analyses (I2=98% and 97%, respectively). The pooled mean was significantly different between the control group and patients with RTD (P= 0.05), based on a t-test of pooled effect sizes. Based on the result of our study, we showed that there is a significant difference between RI in patients with kidney transplant dysfunction and the control group. However, RI cannot substitute kidney biopsy in the management and diagnosis of RTD.

TEN-YEAR OUTCOMES OF TIPS FOR BUDD-CHIARI SYNDROME: SYSTEMATIC REVIEW AND META-ANALYSIS.

Budd-Chiari syndrome (BCS) results from the obstruction of the hepatic venous flow, usually at the level of the hepatic vein or inferior vena cava. When left untreated, it can progress with several complications, including liver cirrhosis. Transjugular intrahepatic portosystemic shunt (TIPS) appears to be effective in a subgroup of BCS patients. To perform a systematic review and meta-analysis of TIPS effectiveness in BCS treatment, considering the survival rate, reduction in portosystemic pressure, need for liver transplantation, technical failure, and shunt dysfunction for up to 10 years of follow-up. We evaluated 17 studies published in PubMed, Science Direct, Web of Science, and SCOPUS databases, which used TIPS as a treatment for BCS, comprising 618 subjects between 18 and 78 years old. We assessed the bias risk by the NOS, NHI, and JBI scales for cohort stu-dies, before-after studies, and case series, respectively. We conducted the meta-analyses by extracting the number of events and the total patients evaluated to perform the proportion meta-analyses using the R software ("meta" package - version 4.9-6). The pooled results (95%CI) showed a 19% (25.9-12.5%) rate of portosystemic pressure reduction, 6% (1-12%) rate for the need for liver transplants despite the use of TIPS, 2% (1-6%) technical failure rate, 30% (18-46%) shunt dysfunction rate, and 88% (81-93%) for the mean frequency of patients alive between 1 and 10 years after the procedure. We stratified survival rate and found an 86% (74-93%) prevalence of living subjects during less than five years, 92% (83-97%) at five years, and a 77% frequency (68-83%) of patients alive ten years after the TIPS placement. TIPS is an effective treatment for BCS, providing a high 10-year frequency of living patients and a significant decrease in portosystemic pressure. The need for liver transplants after TIPS and the technical failure rate is low.

The impact of medical telecommunications on individual oral hygiene in children with end-stage chronic kidney disease

Objective. To evaluate the impact of medical telecommunication between pediatric oral surgeons in a hospital setting. Material and methods. The study involved 20 children with ESKD. Study participants were divided into 2 groups: 1st (n=10) – patients diagnosed according to ICD-10 “N18.0 End-stage chronic kidney disease” undergoing renal replacement therapy in the form of hemo- or peritoneal dialysis; 2nd (n=10) – patients diagnosed according to ICD-10 “T86.1 Kidney transplant dysfunction” who are on immunosuppressive therapy. hildren were given online oral hygiene lessons. To assess the effectiveness of oral hygiene, the Green-Vermillion index (oral hygiene index simplified – OHI-S) was calculated before and after training. In addition, for all study participants, the set of personal oral hygiene products was adjusted, taking into account the characteristics of the underlying disease and therapy. Results. All patients demonstrated a statistically significant decrease in IGR-U scores after completing distance learning (before training – 2.29±0.37; after training – 1.32±0.35; t=9.720; df=19). A comparison of the study groups showed that after training, IGR-U statistically significantly decreased in group 1 by almost 2 times (from 2.48±0.32 to 1.31±0.38; t=7.967; df=19; p <0.001), in group 2 – 1.5 times (from 2.09±0.31 to 1.33±0.35; t=7.343; df=19; p<0.001). Conclusion. Medical telecommunication between pediatric dentists, nephrologists, and patients with ESKD significantly improves the quality of individual oral hygiene in a hospital setting.

Methylxanthine Derivatives in the Treatment of Sinus Node Dysfunction: A Systematic Review.

While the chronotropic effects of theophylline and aminophylline are well-known, their clinical application in the treatment of sinus node dysfunction has not been established in a review. The purpose of this systematic review is to evaluate the efficacy and safety of methylxanthines in the treatment of bradyarrhythmias associated with sinus node dysfunction. A systematic review was conducted in accordance with PRISMA guidelines on Embase, PubMed, MEDLINE, Cochrane Central, Web of Science, SciELO, Korean Citation Index, Global Index Medicus, and CINAHL through June 2023. A total of 607 studies were identified through the literature search. After applying the inclusion and exclusion criteria, 14 studies were included in this review. The causes of bradyarrhythmias involving the sinoatrial node included acute cervical spinal cord injury, coronavirus disease of 2019, carotid sinus syncope, chronotropic incompetence, heart transplant, and chronic sinus node dysfunction. Theophylline and aminophylline were shown to be effective for increasing heart rate and reducing the reoccurrence of bradyarrhythmias. The data on symptom resolution was conflicting. While many case studies reported a resolution of symptoms, a randomized controlled trial reported no significant difference in symptom scores between the control, theophylline, and pacemaker groups in the treatment of sick sinus syndrome. The incidence of adverse effects was low across all study designs. The data suggests methylxanthines may be useful as an alternative or bridge to nonpharmacologic pacing; however, dosing has yet to be established for various indications. Overall, methylxanthines proved safe and effective as a pharmacologic therapy for bradyarrhythmic manifestations of sinus node dysfunction.

Liver transplant dysfunction: outcomes and prospects for the prevention of liver cirrhosis in the recipient

Liver transplant dysfunction: outcomes and prospects for the prevention of liver cirrhosis in the recipient

Évaluation post-transplantation précoce de la dysfonction aiguë du greffon rénal

AbstractKidney transplantation is the best option in the treatment of end-stage kidney disease. Early acute kidney transplant dysfunction is a common complication that corresponds to acute renal failure (AKI) postoperatively after renal transplantation. When it occurs, it favors acute rejection and chronic dysfunction of kidney transplant. Incidence of this complication is constantly rising due to the increased use of grafts from extended criteria donors and from donors after circulatory death. This acute renal failure clinically results in a persistent elevation of serum creatinine and possibly a decrease in diuresis and the need for dialysis during the first postoperative week. However, these signs of renal damage are mostly inefficient and lead to a late diagnosis, limiting treatment efficiency. Therefore, it is essential to develop and use new methods for evaluating acute renal damage early after kidney transplantation. This review explores the various established or developing diagnostic modalities for early AKI after kidney transplantation, whether glomerular filtration rate (GFR) assessment methods or other approaches.

Outcomes With Belatacept Exposure During Pregnancy in Kidney Transplant Recipients: A Case Series.

Posttransplant fertility returns quickly, and female recipients of child-bearing age may conceive while on immunosuppression. However, pregnancy after transplantation confers risks to the recipient, transplant, and fetus, including gestational hypertension, preeclampsia, gestational diabetes, transplant dysfunction, preterm labor, and low birthweight infants. Additionally, mycophenolic acid (MPA) products are teratogenic. Literature evidence regarding belatacept, a selective T-cell costimulation blocker, during pregnancy and while breastfeeding is extremely limited. When female transplant recipients on a belatacept-based regimen are desirous of pregnancy or at the time of conception, transplant providers manage the immunosuppression regimen in 1 of 2 ways: (1) switch both belatacept and MPA to a calcineurin inhibitor-based regimen with or without azathioprine, which is the more common practice but requires several modifications, having potential negative outcomes; or (2) only switch MPA to azathioprine while continuing belatacept. This case series includes 16 pregnancies in 12 recipients with exposure to belatacept throughout pregnancy and while breastfeeding. Patient information was obtained from several sources, including Transplant Pregnancy Registry International, providers at Emory University, and Columbia University, as well as literature review. Pregnancy outcomes included 13 live births and 3 miscarriages. No birth defects or fetal deaths were reported in any of the live births. Seven infants were breastfed while their mothers continued belatacept. Outcomes appear comparable to those documented with the administration of calcineurin inhibitors. This case series provides data supporting the continued administration of belatacept during pregnancy. Additional research will assist in developing better guidelines to counsel female transplant recipients on belatacept desiring to pursue pregnancy.

The Association Between Frailty and Chronic Lung Allograft Dysfunction After Lung Transplantation.

After lung transplantation, both frailty and chronic lung allograft dysfunction (CLAD) commonly develop, and when they do, are associated with poorer outcomes. Given their potential shared mechanisms, we sought to explore the temporal relationship between frailty and CLAD onset. In a single center, we prospectively measured frailty by the short physical performance battery (SPPB) repeatedly after transplant. Because of the nature of the relationship between frailty and CLAD is unknown, we tested the association between frailty, modeled as a time-dependent predictor, and CLAD development as well as CLAD development, modeled as a time-dependent predictor, and frailty development. To do so, we used Cox proportional cause-specific hazards and conditional logistic regression models adjusted for age, sex, race, diagnosis, cytomegalovirus serostatus, posttransplant body mass index, and acute cellular rejection episodes as time-dependent covariates. We tested SPPB frailty as a binary (≤9 points) and continuous predictor (12-point scale); as an outcome, we defined frailty as SPPB ≤9. The 231 participants were a mean age of 55.7 y (SD 12.1). After adjusting for covariates, the development of frailty within 3 y after lung transplant was associated with cause-specific CLAD risk (adjusted cause-specific hazard ratio: 1.76; 95% confidence interval [CI], 1.05-2.92 when defining frailty as SPPB ≤9 and adjusted cause-specific hazard ratio: 1.10, 95% CI, 1.03-1.18 per 1-point worsening in SPPB). CLAD onset did not appear to be a risk factor for subsequent frailty (odds ratio, 4.0; 95% CI, 0.4-197.0). Studying the mechanisms underlying frailty and CLAD could provide new insights into the pathobiology of both and potential targets for intervention.

Circulating non-coding RNAs in chronic kidney disease and its complications.

Post-transcriptional regulation by non-coding RNAs (ncRNAs) can modulate the expression of genes involved in kidney physiology and disease. A large variety of ncRNA species exist, including microRNAs, long non-coding RNAs, piwi-interacting RNAs, small nucleolar RNAs, circular RNAs and yRNAs. Despite early assumptions that some of these species may exist as by-products of cell or tissue injury, a growing body of literature suggests that these ncRNAs are functional and participate in a variety of processes. Although they function intracellularly, ncRNAs are also present in the circulation, where they are carried by extracellular vesicles, ribonucleoprotein complexes or lipoprotein complexes such as HDL. These systemic, circulating ncRNAs are derived from specific cell types and can be directly transferred to a variety of cells, including endothelial cells of the vasculature and virtually any cell type in the kidney, thereby affecting the function of the host cell and/or its response to injury. Moreover, chronic kidney disease itself, as well as injury states associated with transplantation and allograft dysfunction, is associated with a shift in the distribution of circulating ncRNAs. These findings may provide opportunities for the identification of biomarkers with which to monitor disease progression and/or the development of therapeutic interventions.

Arteriovenous fistula in a renal allograft with gross hematuria and subsequent acute kidney injury due to urinary tract obstruction: a case report

BackgroundArteriovenous fistula (AVF) due to renal allograft biopsy is mechanical trauma resulting from the penetration of small arteries and veins by a core needle. Most AVFs are reported to resolve asymptomatically and spontaneously. This report presents a patient with acute kidney injury (AKI) due to urinary tract obstruction caused by a bleeding AVF in a renal allograft.Case presentationA 22-year-old Japanese woman who underwent living-donor kidney transplantation (KT) at 3 years due to end-stage renal disease caused by focal segmental glomerulosclerosis (FSGS) presented with a renal transplant AVF (gourd-shaped; 42 × 19 × 20 mm). The AVF was unexpectedly discovered by ultrasound before a surveillance biopsy at 10 years after KT. The patient had a history of recurrent FSGS, had undergone several renal allograft biopsies after KT, and did not experience symptoms or growth of the AVF for years. Nineteen years after KT, the patient developed AKI with sudden, asymptomatic, gross hematuria and anuria. Plain computed tomography revealed a hematoma in the pelvis of the renal allograft and bladder tamponade. The AVF was successfully treated by coil embolization. Hemodialysis was performed for AKI, and graft function was gradually recovered.ConclusionsUnexpected bleeding from a renal transplant AVF may lead to transplant dysfunction. Angiographic embolization against the ruptured renal transplant AVF may prevent rebleeding and rescue the renal allograft.

Pre-Existing Intrarenal Parvovirus B19 Infection May Relate to Antibody-Mediated Rejection in Pediatric Kidney Transplant Patients.

Viral infections can lead to transplant dysfunction, and their possible role in rejection is described. In total, 218 protocol biopsies performed in 106 children at 6, 12 and 24 months after transplantation were analyzed according to Banff '15. RT-PCR for cytomegalovirus, Epstein-Barr virus, BK virus and Parvovirus B19 was performed on blood and bioptic samples at the time of transplant and each protocol biopsy. The prevalence of intrarenal viral infection increases between 6 and 12 months after transplantation (24% vs. 44%, p = 0.007). Intrarenal Parvovirus B19 infection is also associated with antibody-mediated rejection (ABMR) (50% ABMR vs. 19% T-cell-mediated rejection, p = 0.04). Moreover, Parvovirus infection is higher at 12 months of follow-up and it decreases at 48 months (40.4% vs. 14%, p = 0.02), while in 24% of grafts, Parvovirus is already detectable at the moment of transplantation. Intrarenal Parvovirus B19 infection seems to be related to ABMR in pediatric kidney recipients. The graft itself may be the way of transmission for Parvovirus, so performance of a PCR test for Parvovirus B19 should be considered to identify high-risk patients. Intrarenal Parvovirus infection presents mainly during the first-year post-transplantation; thus, we recommend an active surveillance of donor-specific antibodies (DSA) in patients with intrarenal Parvovirus B19 infection during this period. Indeed, it should be considered a treatment with intravenous immunoglobulins in patients with intrarenal Parvovirus B19 infection and DSA positivity, even in the absence of ABMR criteria for kidney biopsy.

Predictors associated with mortality of veno-venous extracorporeal membrane oxygenation therapy.

The use of veno-venous extracorporeal membrane oxygenation (V-V ECMO) has rapidly increased in recent years. Today, applications of V-V ECMO include a variety of clinical conditions such as acute respiratory distress syndrome (ARDS), bridge to lung transplantation and primary graft dysfunction after lung transplantation. The purpose of the present study was to investigate in-hospital mortality of adult patients undergoing V-V ECMO therapy and to determine independent predictors associated with mortality. This retrospective study was conducted at the University Hospital Zurich, a designated ECMO center in Switzerland. Data was analyzed of all adult V-V ECMO cases from 2007 to 2019. In total, 221 patients required V-V ECMO support (median age 50 years, 38.9% female). In-hospital mortality was 37.6% and did not statistically vary significantly between indications (P=0.61): 25.0% (1/4) for primary graft dysfunction after lung transplantation, 29.4% (5/17) for bridge to lung transplantation, 36.2% (50/138) for ARDS and 43.5% (27/62) for other pulmonary disease indications. Cubic spline interpolation showed no effect of time on mortality over the study period of 13 years. Multiple logistic regression modelling identified significant predictor variables associated with mortality: age [odds ratio (OR), 1.05; 95% confidence interval (CI): 1.02-1.07; P=0.001], newly detected liver failure (OR, 4.83; 95% CI: 1.27-20.3; P=0.02), red blood cell transfusion (OR, 1.91; 95% CI: 1.39-2.74; P<0.001) and platelet concentrate transfusion (OR, 1.93; 95% CI: 1.28-3.15; P=0.004). In-hospital mortality of patients receiving V-V ECMO therapy remains relatively high. Patients' outcomes have not improved significantly in the observed period. We identified age, newly detected liver failure, red blood cell transfusion and platelet concentrate transfusion as independent predictors associated with in-hospital mortality. Incorporating such mortality predictors into decision making with regards to V-V ECMO use may increase its effectiveness and safety and may translate into better outcomes.

Alloreactive T cells to Assess Acute Rejection Risk in Kidney Transplant Recipients.

Samples from 103 consecutive kidney transplant recipients (2018-2019) were obtained pretransplantation and at time of for-cause biopsy sampling within 6 mo of transplantation. The number of donor-reactive interferon gamma (IFN-γ) and interleukin (IL)-21-producing memory T cells was analyzed by enzyme-linked immunosorbent spot (ELISPOT) assay. Of the 63 patients who underwent a biopsy, 25 had a biopsy-proven acute rejection (BPAR; 22 aTCMR and 3 aAMR), 19 had a presumed rejection, and 19 had no rejection. Receiver operating characteristic analysis showed that the pretransplant IFN-γ ELISPOT assay distinguished between patients who later developed BPAR and patients who remained rejection-free (area under the curve [AUC] 0.73; sensitivity 96% and specificity 41%). Both the IFN-γ and IL-21 assays were able to discriminate BPAR from other causes of transplant dysfunction (AUC 0.81; sensitivity 87% and specificity 76% and AUC 0.81; sensitivity 93% and specificity 68%, respectively). This study validates that a high number of donor-reactive memory T cells before transplantation is associated with the development of AR after transplantation. Furthermore, it demonstrates that the IFN-γ and IL-21 ELISPOT assays are able to discriminate between patients with AR and patients without AR at the time of biopsy sampling.