Hepatic Artery Thrombectomy After Orthotopic Liver Transplantation: A Stent Retriever and/or Aspiration Guided Catheter Approach.

Retransplantation has been the primary treatment for Hepatic artery thrombosis (HAT) in Orthotopic Liver Transplant (OLT) patients; however, due to scarcity of grafts, endovascular revascularization via mechanical thrombectomy offers an alternative to re-transplantation should it provide similar long term benefits. A series of 8 patients with hepatic artery thrombectomies across 10 procedures (1 Early HAT and 9 Late HAT) utilizing stent-retriever and/or suction catheter was collected. All had technically successful restoration of flow with stent placement of the anastomotic stenosis in 8 cases. Two patients required re-intervention for HAT at 18 and 701 days post-primary intervention, with the first expiring from liver failure but with a patent hepatic artery on explant. One case had a procedural related adverse event, hepatic artery dissection, SIR AE classification of 2. Technical success was achieved in all procedures, demonstrating promise in effectively treating HAT in OLT patients.

Chemical inhibition of DNA-PKcs impairs the activation and cytotoxicity of CD4+ helper and CD8+ effector T cells.

Modulation of T cell activity is an effective strategy for the treatment of autoimmune diseases, immune-related disorders and cancer. This highlights a critical need for the identification of proteins that regulate T cell function. The kinase DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is emerging as a potent regulator of the immune system, spurring interest in its use as a therapeutic target. In murine models of immune-related diseases including asthma and rheumatoid arthritis, treatment with small-molecule DNA-PKcs inhibitors decreased the disease severity. Additionally, DNA-PKcs inhibitors reduced T cell-mediated graft rejection in a murine allogenic skin graft model. These in vivo studies suggest the use of DNA-PKcs inhibitors as immunotherapy for autoimmune and T cell-mediated disorders. In this study, we sought to characterize further the effects of DNA-PKcs inhibitors on T cells to better understand their clinical potential. We determined that inhibition of DNA-PKcs using inhibitor NU7441 and the inhibitors currently in clinical trials for cancer therapy, M3184 and AZD7648, abrogated the activation of murine and human CD4+ and CD8+ T cells as evidenced by the reduced expression of the activation markers CD69 and CD25. Furthermore, inhibition of DNA-PKcs impeded metabolic pathways and the proliferation of activated T cells. This reduced the ability of OTI-CD8+ T cells to kill cancer cells and the expression of IFNγ and cytotoxic genes. These results highlight a critical role for DNA-PKcs in T cells and validate future studies using DNA-PKcs inhibitors as immune modulation therapy for the treatment of immune-related diseases.

DNA-PKcs kinase activity stabilizes the transcription factor Egr1 in activated immune cells.

DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is known primarily for its function in DNA double-stranded break repair and nonhomologous end joining (NHEJ). However, DNA-PKcs also has a critical yet undefined role in immunity impacting both myeloid and lymphoid cell lineages spurring interest in targeting DNA-PKcs for therapeutic strategies in immune-related diseases. To gain insight into the function of DNA-PKcs within immune cells, we performed a quantitative phosphoproteomic screen in T cells to identify phosphorylation targets of DNA-PKcs. Our results indicate that DNA-PKcs phosphorylates the transcription factor Egr1 (early growth response protein 1) at serine 301. Expression of Egr1 is induced early upon T cell activation and dictates T cell response by modulating expression of cytokines and key costimulatory molecules such as IL (interleukin) 2, IL6, IFNγ, and NFκB. Inhibition of DNA-PKcs by treatment with a DNA-PKcs specific inhibitor NU7441 or shRNA knockdown increased proteasomal degradation of Egr1. Mutation of serine 301 to alanine via CRISPR-Cas9 reduced EGR1 protein expression and decreased Egr1-dependent transcription of IL2 in activated T cells. Our findings identify DNA-PKcs as a critical intermediary link between T cell activation and T cell fate and a novel phosphosite involved in regulating Egr1 activity.

Comparable graft survival is achievable with the usage of donation after circulatory death liver grafts from donors at or above 70 years of age: A long-term UK national analysis.

The aim of the study was to assess the UK donation after circulatory death (DCD) liver transplant experience from donors ≥70 years. Nationwide UK DCD retrospective analysis was conducted between 2001 and 2015 (n = 1163). Recipients were divided into group 1 vs. group 2 (donors 70≥ vs. <70 years, respectively). group 1 (n = 69, 5.9%) recipients were older (median 59 vs. 55 years, p = .001) and had longer waitlist time (128 vs. 84 days; p = .039). 94.2% of group 1 clustered in London and Birmingham, where the two busiest centers are located. group 1 allografts had higher UKDRI and UK DCD Risk Scores but similar WIT and CIT and were more likely to have been imported. Both groups had similar 1-, 3-, and 5-year graft survival (group 1, 90%, 81.4%, and 74% vs. group 2, 88.6%, 81.4%, and 78.6%, respectively; p = .54). Both groups had similar ICU stay length (p = .22), 3-month hepatic artery thrombosis rates (4.4% vs 4.0%; p = .9), and 12-month readmission rates for all biliary complications (20.3% vs 25.7%; p = .32). This study demonstrates that acceptable outcomes are achievable using older grafts in a highly selected cohort at experienced centers. Advanced age should not be an absolute contraindication to utilizing a DCD graft from donors aged ≥70 years.

Central venous pressure monitoring in living donor kidney recipients does not affect immediate graft function: A propensity score analysis.

BACKGROUND: During kidney transplantation, intraoperative fluid management can affect post-transplant graft function. It is unclear whether or not central venous pressure (CVP) monitoring is required to guide fluid therapy during kidney transplantation. METHODS: We compared post-transplant graft function in recipients of living donor kidney transplants between August 2006 and March 2009 based on the use or absence of intraoperative CVP monitoring. Graft function, assessed using the creatinine reduction ratio on postoperative day 2 (CCR2), was evaluated by multivariable linear regression analysis and in a propensity-matched cohort. RESULTS: Two hundred and ninety patients were included in the analysis. Central venous pressure was monitored in 84 patients (29%). There was no difference in post-transplant graft function, as measured by CCR2, between patients with and without CVP monitoring in both unadjusted and multivariable-adjusted analyses. There were also no statistically significant differences in CCR2, delayed graft function, or 3-month renal function between those monitored with CVP and those without, in the propensity-matched cohort. CONCLUSIONS: In this single-center analysis, immediate post-transplant renal function was not associated with the use of intraoperative CVP monitoring.

Smartphone-based machine learning model for real-time assessment of medical kidney biopsy.

Background: Kidney biopsy is the gold-standard for diagnosing medical renal diseases, but the accuracy of the diagnosis greatly depends on the quality of the biopsy specimen, particularly the amount of renal cortex obtained. Inadequate biopsies, characterized by insufficient cortex or predominant medulla, can lead to inconclusive or incorrect diagnoses, and repeat biopsy. Unfortunately, there has been a concerning increase in the rate of inadequate kidney biopsies, and not all medical centers have access to trained professionals who can assess biopsy adequacy in real time. In response to this challenge, we aimed to develop a machine learning model capable of assessing the percentage cortex of each biopsy pass using smartphone images of the kidney biopsy tissue at the time of biopsy. Methods: 747 kidney biopsy cores and corresponding smartphone macro images were collected from five unused deceased donor kidneys. Each core was imaged, formalin-fixed, sectioned, and stained with Periodic acid-Schiff (PAS) to determine cortex percentage. The fresh unfixed core images were captured using the macro camera on an iPhone 13 Pro. Two experienced renal pathologists independently reviewed the PAS-stained sections to determine the cortex percentage. For the purpose of this study, the biopsies with less than 30% cortex were labeled as inadequate, while those with 30% or more cortex were classified as adequate. The dataset was divided into training (n=643), validation (n=30), and test (n=74) sets. Preprocessing steps involved converting High-Efficiency Image Container iPhone format images to JPEG, normalization, and renal tissue segmentation using a U-Net deep learning model. Subsequently, a classification deep learning model was trained on the renal tissue region of interest and corresponding class label. Results: The deep learning model achieved an accuracy of 85% on the training data. On the independent test dataset, the model exhibited an accuracy of 81%. For inadequate samples in the test dataset, the model showed a sensitivity of 71%, suggesting its capability to identify cases with inadequate cortical representation. The area under the receiver-operating curve (AUC-ROC) on the test dataset was 0.80. Conclusion: We successfully developed and tested a machine learning model for classifying smartphone images of kidney biopsies as either adequate or inadequate, based on the amount of cortex determined by expert renal pathologists. The model's promising results suggest its potential as a smartphone application to assist real-time assessment of kidney biopsy tissue, particularly in settings with limited access to trained personnel. Further refinements and validations are warranted to optimize the model's performance.

A web-based tool for real-time adequacy assessment of kidney biopsies.

The escalating incidence of kidney biopsies providing insufficient tissue for diagnosis poses a dual challenge, straining the healthcare system and jeopardizing patients who may require rebiopsy or face the prospect of an inaccurate diagnosis due to an unsampled disease. Here, we introduce a web-based tool that can provide real-time, quantitative assessment of kidney biopsy adequacy directly from photographs taken with a smartphone camera. The software tool was developed using a deep learning-driven automated segmentation technique, trained on a dataset comprising nephropathologist-confirmed annotations of the kidney cortex on digital biopsy images. Our framework demonstrated favorable performance in segmenting the cortex via 5-fold cross-validation (Dice coefficient: 0.788±0.130) (n=100). Offering a bedside tool for kidney biopsy adequacy assessment has the potential to provide real-time guidance to the physicians performing medical kidney biopsies, reducing the necessity for re-biopsies. Our tool can be accessed through our web-based platform: http://www.biopsyadequacy.org.

Development of VRE meningitis due to haematogenous spread while on high-dose daptomycin therapy.

Introduction: Vancomycin-resistant Enterococcus faecium (VRE) meningitis accounts for only 0.3%-4.0% of bacterial meningitis cases and typically occurs following neurosurgical intervention. We describe a rare case of a patient without neurological devices in situ or a recent neurological procedure who developed VRE meningitis via haematogenous spread. Optimal treatment for VRE meningitis is unknown. Case presentation: A 67-year-old male with end-stage liver failure underwent liver transplantation complicated by VRE bacteraemia and subsequently developed VRE meningitis while on high-dose daptomycin therapy (12 mg/kg/day). Due to clinical and microbiological failure with daptomycin, he was switched to linezolid and symptoms resolved rapidly. He completed 2 weeks of linezolid, fully recovered, and continued to do well without complications at the 5 month follow-up. Conclusions: This case highlights the severity of VRE infections in solid organ transplant recipients and raises concerns about daptomycin penetration into the CNS. Linezolid could be considered the preferred treatment for VRE CNS infections rather than high-dose daptomycin.

Incidence of Red Cell Antibody Formation Following Massive Transfusion Protocol: Experience of a Single Institution.

BACKGROUND: Injured patients in hemorrhagic shock have a survival benefit with massive transfusion protocol (MTP). While there are many published studies on the transfusion management of massively bleeding patients, the risk of alloimmunization in patients that have received products during an MTP activation is relatively unknown. Therefore, we sought to determine the frequency of new antibody formation in MTP patients that received blood products from an uncrossmatched megapack. MATERIALS AND METHODS: We conducted a retrospective data review of patients who underwent an MTP activation for trauma resuscitation between May 2014 and July 2020. Data were collected from patients who met the following criteria: MTP was activated, the patients received at least one unit of packed red blood cells, one unit of fresh frozen plasma, one unit of platelets, and had a repeat type and screen within 6 weeks of transfusion. These inclusion criteria resulted in 28 patients over the 6-year timeframe. RESULTS: Overall, the risk of alloimmunization secondary to MTP is 3.6% in our trauma patient population. The newly developed antibodies post-MTP are considered clinically significant, meaning they can cause hemolysis if exposed to donor red blood cells containing those antigens. DISCUSSION: Blood products should be given preferentially over crystalloids to acutely bleeding patients to prevent ischemic injury during an MTP activation despite the risk of alloimmunization. In our single-institution study, the alloimmunization rate in massive transfusions where patients receive uncrossmatched red blood cells is similar to those receiving crossmatched red blood cells.

Non-insulinoma pancreatogenous hypoglycemia syndrome due to nesidioblastosis following bariatric Roux-en-Y gastric bypass.

A 56-year-old woman with past medical history significant for bariatric Roux-en-Y gastric bypass 3 years prior presented for evaluation of an 8-month history of severe hypoglycemia relieved by intake of carbohydrates associated with syncopal episodes. Inpatient workup revealed endogenous hyperinsulinemia concerning for insulinoma vs. nesidioblastosis. She successfully underwent pancreaticoduodenectomy (Whipple procedure), and pathology report confirmed scattered low-grade intraepithelial neoplasia within the pancreatic parenchyma consistent with nesidioblastosis. The patient has had satisfactory control of glucose levels 30 days out from surgery.

Percutaneous Cholecystostomy Tubes versus Medical Management for Acute Cholecystitis.

BACKGROUND: Cholecystitis is one of the most common infections treated surgically in the United States. Surgical risk is prohibitive in some patients, leading to alternative therapeutic strategies, including medical management (antibiotics) with or without percutaneous cholecystostomy tube (PCT) drainage. MATERIALS AND METHODS: Using the Healthcare Cost and Utilization Project (HCUP) National Readmission Database (NRD), we performed a retrospective review to compare medically managed patients with or without PCT placement by evaluating 60-day readmissions rates, health care costs, and hospital length of stay (LOS). Both study groups were matched using the Elixhauser comorbidity index, age, and sex. Univariate and multivariate statistical analyses were performed using STATA. RESULTS: 776,766 patients were included in the analysis. The population receiving PCT placement was on average 16 years older (69.9 vs 53.6 years; P < .01), less likely to be female (40.7% vs 59.3%; P < .01), and had almost twice as many comorbidities (3.36 vs 1.81; P < .01) compared to the population receiving medical management. After matching our data to account for these incongruities, PCT patients were still 10.4 times more likely to be readmitted, had a 11.6% increase in the cost of care, and a 37.6% increase in LOS compared to those managed medically. DISCUSSION: Percutaneous cholecystostomy tube placement for cholecystitis is associated with a higher readmission rate, increased charges, and increased LOS compared to antibiotic therapy alone, even after correcting for age, sex, and comorbidities.

Disparities in the Use of Older Donation After Circulatory Death Liver Allografts in the United States Versus the United Kingdom.

BACKGROUND: This study aimed to assess the differences between the United States and the United Kingdom in the characteristics and posttransplant survival of patients who received donation after circulatory death (DCD) liver allografts from donors aged >60 y. METHODS: Data were collected from the UK Transplant Registry and the United Network for Organ Sharing databases. Cohorts were dichotomized into donor age subgroups (donor >60 y [D >60]; donor ≤60 y [D ≤60]). Study period: January 1, 2001, to December 31, 2015. RESULTS: 1157 DCD LTs were performed in the United Kingdom versus 3394 in the United States. Only 13.8% of US DCD donors were aged >50 y, contrary to 44.3% in the United Kingdom. D >60 were 22.6% in the United Kingdom versus 2.4% in the United States. In the United Kingdom, 64.2% of D >60 clustered in 2 metropolitan centers. In the United States, there was marked inter-regional variation. A total of 78.3% of the US DCD allografts were used locally. One- and 5-y unadjusted DCD graft survival was higher in the United Kingdom versus the United States (87.3% versus 81.4%, and 78.0% versus 71.3%, respectively; P < 0.001). One- and 5-y D >60 graft survival was higher in the United Kingdom (87.3% versus 68.1%, and 77.9% versus 51.4%, United Kingdom versus United States, respectively; P < 0.001). In both groups, grafts from donors ≤30 y had the best survival. Survival was similar for donors aged 41 to 50 versus 51 to 60 in both cohorts. CONCLUSIONS: Compared with the United Kingdom, older DCD LT utilization remained low in the United States, with worse D >60 survival. Nonetheless, present data indicate similar survivals for older donors aged ≤60, supporting an extension to the current US DCD age cutoff.

COVID-19 Mortality in Vaccinated vs. Unvaccinated Liver & Kidney Transplant Recipients: A Single-Center United States Propensity Score Matching Study on Historical Data.

Introduction: Existing studies report variable impact of vaccination on Coronavirus Disease (COVID-19) morbidity and mortality in solid organ transplant (SOT) recipients. This study aimed to perform a propensity score matching (PSM) analysis on COVID-19 survival of vaccinated and unvaccinated SOT patients who contracted the disease at a single US academic transplant center. Methods: All consecutive COVID-19 positive cases on adult liver, kidney or combined liver-kidney recipients were identified and demographics, comorbidities, immunosuppression, COVID-19 treatment and hospitalization status, COVID-19 vaccination status, and early mortality recorded. PSM study was performed on age and sex for completed vaccination status at time of infection, followed by multivariable analysis and survival curve plotting. Results: 144 SOT patients were diagnosed with COVID-19, with 98 unvaccinated. PSM reduced study number to 101. Matched data multivariable analysis for 60-day mortality identified age and post-kidney transplant status to significantly increase 60-day mortality odds (OR 1.22, p < 0.001 and OR 40.93, p < 0.001, respectively). Kaplan−Meier analysis showed inferior post-infection survival in the unvaccinated group [(30 days; vaccinated vs. unvaccinated 97.8% vs. 89.1%, respectively; p = 0.089) (60 days; 97.8% vs. 83.6%, respectively; p = 0.019)]. Conclusions: Matched data survival analysis demonstrated inferior survival in the unvaccinated group, supporting COVID-19 vaccination in SOT recipients.

Impact of Prolonged Cold Ischemia Time on One Year Kidney Transplant Outcomes.

BACKGROUND: Prolonged cold ischemia times (CIT) of kidney allografts remains a significant reason for graft refusal in the new allocation system. We sought to investigate the effect of prolonged CIT on kidney transplant outcomes at a center without an international airport. METHODS: Retrospective study of kidney transplant patients treated at an academic medical center from January 1, 2018 to May 1, 2020. The 117 patients were divided into 2 categories. Fifty-four patients (46%) had CIT of 30-35.99 hours, and 63 (54%) had CIT of 36± hours. Kidney function was evaluated using creatinine and at 12 months, which was the primary endpoint. RESULTS: All of the transplanted allografts were carefully selected and had ≤ 20% glomerulosclerosis and an average kidney donor profile index of 54%. Among the 117 patients analyzed in this study, there was no significant difference in creatinine at 12 months between groups with CIT above 36 hours and < 35.99 hours (2.07 vs 1.78; P value .2339). There were a total of 18 rejection events (15%) and no cases of primary non-function in either group. Patients that were able to be maintained on calcineurin inhibitors had improved graft function at 12 months (1.69 vs 2.96; P value .0267). CONCLUSIONS: Our study indicated that prolonged CITs over 36 hours were not associated with poorer patient outcomes at 1 year when using creatinine as an endpoint. They also had similar rates of rejection, consistent with previously published rates for kidney transplantation.

Fetal intracranial hemorrhage associated with maternal coagulopathy and vitamin K deficiency after biliary drain placement: A case report and literature review.

INTRODUCTION: Fetal intracranial hemorrhage (ICH) is a rare but serious prenatal diagnosis. Predisposing factors include maternal trauma and fetal coagulation dysfunction. Maternal vitamin K deficiency has been described as an etiology. We present a case of maternal vitamin K deficiency associated with fetal ICH after percutaneous biliary drain (PBD) placement in a complicated cholecystectomy with injury to the common bile duct. CASE PRESENTATION: A 21-year-old woman, G2P1, presented at 23 weeks and 3 days of gestation with epigastric pain, nausea and vomiting. Right upper quadrant ultrasound diagnosed cholelithiasis. The patient was managed conservatively and discharged. She returned four days later, at 24 weeks of gestation, with worsening symptoms and ultrasound showing acute cholecystitis. She underwent laparoscopic cholecystectomy. Increasing bilirubin and imaging showed a transected biliary duct that required percutaneous biliary drain (PBD) placement. The patient was discharged and followed up at a high-risk obstetric clinic. Prenatal ultrasound showed bilateral ventriculomegaly with features of ICH. Maternal vitamin K deficiency was confirmed with PIVKA-II testing. The patient received vitamin K supplementation with normalization of the coagulopathy. Delivery occurred at 36 weeks of gestation via cesarean delivery after preterm premature rupture of membranes for fetal macrocrania. The neonate was discharged to a hospice. DISCUSSION: Maternal and neonatal etiologies for ICH include malabsorption and coagulopathy. Maternal vitamin K deficiency should be considered when coagulopathy is present. This case highlights that maternal vitamin K deficiency due to biliary diversion and malabsorption increases the risk of fetal ICH, which impacts pregnancy and neonatal outcomes.

DNA-PKcs Inhibition Extends Allogeneic Skin Graft Survival.

BACKGROUND: Organ transplantation is life-saving and continued investigations into immunologic mechanisms that drive organ rejection are needed to improve immunosuppression therapies and prevent graft failure. DNA-dependent protein kinase catalytic subunit, DNA dependent-protein kinase catalytic subunit (DNA-PKcs), is a critical component of both the cellular and humoral immune responses. In this study, we investigate the contribution of DNA-PKcs to allogeneic skin graft rejection to potentially highlight a novel strategy for inhibiting transplant rejection. METHODS: Fully MHC mismatched murine allogeneic skin graft studies were performed by transplanting skin from BalbC mice to C57bl6 mice and treating with either vehicle or the DNA-PKcs inhibitor NU7441. Graft rejection, cytokine production, immune cell infiltration, and donor-specific antibody formation were analyzed. RESULTS: DNA-PKcs inhibition significantly reduced necrosis and extended graft survival compared with controls (mean survival 14 d versus 9 d, respectively). Inhibition reduced the production of the cytokines interleukin (IL)-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ and the infiltration of CD3+ lymphocytes into grafts. Furthermore, DNA-PKcs inhibition reduced the number of CD19+ B cells and CD19+ CD138+ plasma cells coinciding with a significant reduction in donor-specific antibodies. At a molecular level, we determined that the immunosuppressive effects of DNA-PKcs inhibition were mediated, in part, via inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells signaling through reduced expression of the p65 subunit. CONCLUSIONS: Our data confirm that DNA-PKcs contributes to allogeneic graft rejection and highlight a novel immunologic function for DNA-PKcs in the regulation of nuclear factor kappa-light-chain-enhancer of activated B cells and concomitant cytokine production.