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Methylmalonic acidemia (MMAemia) is characterized by accumulation of methylmalonic acid (MMA) in all body tissues. To minimize disease-related complications, isolated kidney (KTx), liver (LTx) or combined liver-kidney transplantation (LKTx) have been suggested. However, the impact of these different transplant strategies on outcome are unclear.In this multicenter retrospective observational study, we compared plasma MMA levels and estimated glomerular filtration rate (eGFR) data of 83 patients. Sixty-eight patients (82%) had a mutsup0/sup-type MMAemia, one patient had a mutsup-/sup-type MMAemia, and seven (7.3%) had an inherited defect in cobalamin metabolism (cblA- or cblB-type MMAemia). Median observation period was 3.7 years (0-15.1 years).Twenty-six (31%) patients underwent KTx, 24 (29%) LTx and 33 (40%) LKTx. Posttransplant, mean plasma MMA concentration significantly decreased in all three cohorts; but at month 12, plasma MMA in KTx (1372 ± 1101 μmol/L) was 7.8-fold higher than in LTx (176 ± 103 μmol/L; Plt; 0.001) and 6.4-fold higher than in LKTx (215 ± 110 μmol/L; Plt; 0.001). Comparable data were observed at month 24. At time of transplantation, mean eGFR in KTx was 18.1 ± 24.3 mL/min/1.73 msup2/sup, in LTx 99.8 ± 29.9 mL/min/1.73 msup2/sup, and in LKTx 31.5 ± 21.2 mL/min/1.73 msup2/sup. At month 12 posttransplant, mean eGFR in KTx (62.3 ± 30.3 mL/min/1.73 msup2/sup) was 33.4% lower than in LTx (93.5 ± 18.3 mL/min/1.73 msup2/sup; P = 0.0053) and 25.4% lower than in LKTx (83.5 ± 26.9 mL/min/1.73 msup2/sup; P = 0.0403).In patients with isolated MMAemia, LTx and LKTx lead to markedly lower plasma MMA levels during the first 2 years posttransplant than KTx and are associated with a better preservation of kidney function. LTx should therefore be part of the transplant strategy in MMAemia.

BACKGROUND Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) are noninvasive surrogates for hepatic steatosis and fibrosis, respectively, and could help identify extended criteria donors in liver transplantation (LT). We aimed to determine the accuracy of CAP/LSM in deceased donors along with post-LT changes. METHODS Accuracy of preprocurement CAP/LSM to grade/stage steatosis/fibrosis was determined using liver biopsy as reference. Transplant outcomes, including primary nonfunction (PNF) and early allograft dysfunction (EAD), were recorded. Recipients underwent CAP/LSM as outpatients. Areas under the receiver operating characteristic curve (AUROC) and regression models were constructed to analyze data. RESULTS We prospectively evaluated 160 allografts (138 transplanted). Same-probe paired baseline/post-LT CAP was 231 dB/m (181-277) / 225 (187-261) (p=0.61), and LSM 7.6 kPa (6.3-10.8) / 5.9 (4.6-8.7) (p=0.002), respectively. CAP reading was affected by BMI and LSM by ALT, race and bilirubin. Although CAP did not correlate with steatosis from frozen sections (rho=0.08; p=0.47), it correlated with steatosis from permanent sections (rho=0.32; p

Currently, there is no consensus among pediatric kidney transplant centers regarding the use and regimen for immunosuppressive induction therapy.In this single center, retrospective cohort study, pediatric kidney transplant recipients transplanted between 1 May 2013 and 1 May 2018 with rabbit antithymocyte globulin (rATG) induction were included. We stratified patients based on immunological risk, with high risk defined as those with repeat transplant, preformed donor specific antibody, current panel-reactive antibodies 20%, 0 antigen match and/or African-American heritage. Outcome of interest was the incidence of biopsy proven acute rejection by 1 year.A total of 166 patients met inclusion criteria. Age of patients was 12 years (11 mo-21 y), (median, range), 21.5% received a living donor transplant and 50.6% were female. Low-immunologic-risk patients were divided into 2 groups, those who received the lower cumulative rATG dose of ≤ 3.5 mg/kg (n = 52) versus the higher cumulative dose of 3.5 mg/kg (n = 47). The median total dose in the lower dose group was 3.1 (IQR 0.3) and 4.4 (IQR 0.8) in the higher dose group, P 0.001. Rejection rate did not differ significantly between the 2 treatment groups (7/52 vs. 6/47). None in the lower dose group developed BK nephropathy versus 3 in the higher dose group. Graft loss due to BK nephropathy occurred in 1 patient in the higher dose group. Graft loss in the whole cohort at 12 months was a rare event (n = 1) with 99.5% graft survival and 100% patient survival.Reduced rATG dosing (≤ 3.5 mg/kg) when compared to higher dosing ( 3.5 mg/kg) is safe and effective in low-risk pediatric kidney transplant recipients without increasing risk of rejection. A higher resolution version of the Graphical abstract is available as Supplementary information.

Combined heart-liver transplant is an emerging option for patients with indications for heart transplantation and otherwise prohibitive hepatic dysfunction. Heart-liver transplantation is particularly relevant for patients with single ventricle physiology who often develop Fontan-associated liver disease and fibrosis. While only performed at a limited number of centers, several approaches to combined heart-liver transplantation have been described. The en bloc technique offers several potential advantages over the traditional sequential technique. Specifically, en bloc heart-liver transplantation may allow improved hemodynamics, decreased bleeding, reduced liver allograft ischemic time, and may result in reduced rates of graft dysfunction. Here we describe our center's en bloc heart-liver procurement technique in detail, with the aim of allowing broader use and standardization of this technique. Supplemental Visual Abstract; http://links.lww.com/TP/C147.

BACKGROUND Indications for a heart‒liver transplantation (HLT) for Fontan recipients are not well defined. We compared listing characteristics, post-operative complications, and post-transplant outcomes of Fontan recipients who underwent HLT with those of patients who underwent heart-only transplantation (HT). We hypothesized that patients who underwent HLT have increased post-operative complications but superior survival outcomes compared with patients who underwent HT. METHODS We performed a retrospective review of Fontan recipients who underwent HLT or HT at a single institution. Characteristics at the time of listing, including the extent of liver disease determined by laboratory, imaging, and biopsy data, were compared. Post-operative complications were assessed, and the Kaplan‒Meier survival method was used to compare post-transplant survival. Univariate regression analyses were performed to identify the risk factors for increased mortality and morbidity among patients who underwent HT. RESULTS A total of 47 patients (9 for HLT, 38 for HT) were included. Patients who underwent HLT were older, were more likely to be on dual inotrope therapy, and had evidence of worse liver disease. Whereas ischemic time was longer for the group who underwent HLT, post-operative complications were similar. Over a median post-transplant follow-up of 17 (interquartile range: 5–52) months, overall mortality for the cohort was 17%; only 1 patient who underwent HLT died (11%) vs 7 patients who underwent HT (18%) ( p = 0.64). Among patients who underwent HT, cirrhosis on pre-transplant imaging was associated with worse outcomes. CONCLUSIONS Despite greater inotrope need and more severe liver disease at the time of listing, Fontan recipients undergoing HLT have post-transplant outcomes comparable with those of patients undergoing HT. HLT may offer a survival benefit for Fontan recipients with liver disease.

Combined heart-liver transplant (CHLTx) remains the only option for long-term survival in patients with end-stage heart and hepatic failure. To date, there are a limited number of transplant centers in the United States that have conducted a CHLTx. Between July of 2009 and December 2019, our group has performed the largest series (N = 20) of en bloc CHLTx to date. En block combined heart-liver transplantation offers both grafts the opportunity to minimize dysfunction with shorter ischemic time compared to sequential heart-liver transplant. This technique simplifies the surgery in patients with complex venous anatomy such as heterotaxy patients and can be performed in dextrocardia or levocardia patients, irrespective of the side of inferior vena cava or superior vena cava. We describe our indications and detailed en block technique for combined heart-liver with its midterm outcome.

INTRODUCTION: Although the genome is often called the blueprint of an organism, it is perhaps more accurate to describe it as a parts list composed of the various genes that may or may not be used in the different cell types of a multicellular organism. Although nearly every cell in the body has essentially the same genome, each cell type makes different use of that genome and expresses a subset of all possible genes. This has motivated efforts to characterize the molecular composition of various cell types within humans and multiple model organisms, both by transcriptional and proteomic approaches. We created a human reference atlas comprising nearly 500,000 cells from 24 different tissues and organs, many from the same donor. This atlas enabled molecular characterization of more than 400 cell types, their distribution across tissues, and tissue-specific variation in gene expression. RATIONALE: One caveat to current approaches to make cell atlases is that individual organs are often collected at different locations, collected from different donors, and processed using different protocols. Controlled comparisons of cell types between different tissues and organs are especially difficult when donors differ in genetic background, age, environmental exposure, and epigenetic effects. To address this, we developed an approach to analyzing large numbers of organs from the same individual. RESULTS: We collected multiple tissues from individual human donors and performed coordinated single-cell transcriptome analyses on live cells. The donors come from a range of ethnicities, are balanced by gender, have a mean age of 51 years, and have a variety of medical backgrounds. Tissue experts used a defined cell ontology terminology to annotate cell types consistently across the different tissues, leading to a total of 475 distinct cell types with reference transcriptome profiles. The full dataset can be explored online with the cellxgene tool. Data were collected for the bladder, blood, bone marrow, eye, fat, heart, kidney, large intestine, liver, lung, lymph node, mammary, muscle, pancreas, prostate, salivary gland, skin, small intestine, spleen, thymus, tongue, trachea, uterus, and vasculature. Fifty-nine separate specimens in total were collected, processed, and analyzed, and 483,152 cells passed quality control filtering. On a per-compartment basis, the dataset includes 264,824 immune cells, 104,148 epithelial cells, 31,691 endothelial cells, and 82,478 stromal cells. Working with live cells, as opposed to isolated nuclei, ensured that the dataset includes all mRNA transcripts within the cell, including transcripts that have been processed by the cell’s splicing machinery, thereby enabling insight into variation in alternative splicing. The Tabula Sapiens also provided an opportunity to densely and directly sample the human microbiome throughout the gastrointestinal tract. The intestines from two donors were sectioned into five regions: the duodenum, jejunum, ileum, and ascending and sigmoid colon. Each section was transected, and three to nine samples were collected from each location, followed by amplification and sequencing of the 16S ribosomal RNA gene. CONCLUSION: The Tabula Sapiens has revealed discoveries relating to shared behavior and subtle, organ-specific differences across cell types. We found T cell clones shared between organs and characterized organ-dependent hypermutation rates among B cells. Endothelial cells and macrophages are shared across tissues, often showing subtle but clear differences in gene expression. We found an unexpectedly large and diverse amount of cell type–specific RNA splice variant usage and discovered and validated many previously undefined splices. The intestinal microbiome was revealed to have nonuniform species distributions down to the 3-inch (7.62-cm) length scale. These are but a few examples of how the Tabula Sapiens represents a broadly useful reference to deeply understand and explore human biology at cellular resolution.

Mesenchymal stromal cells (MSCs) have been a popular platform for cell‐based therapy in regenerative medicine due to their propensity to home to damaged tissue and act as a repository of regenerative molecules that can promote tissue repair and exert immunomodulatory effects. Accordingly, a great deal of research has gone into optimizing MSC homing and increasing their secretion of therapeutic molecules. A variety of methods have been used to these ends, but one emerging technique gaining significant interest is the use of ultrasound. Sound waves exert mechanical pressure on cells, activating mechano‐transduction pathways and altering gene expression. Ultrasound has been applied both to cultured MSCs to modulate self‐renewal and differentiation, and to tissues‐of‐interest to make them a more attractive target for MSC homing. Here, we review the various applications of ultrasound to MSC‐based therapies, including low‐intensity pulsed ultrasound, pulsed focused ultrasound, and extracorporeal shockwave therapy, as well as the use of adjunctive therapies such as microbubbles. At a molecular level, it seems that ultrasound transiently generates a local gradient of cytokines, growth factors, and adhesion molecules that facilitate MSC homing. However, the molecular mechanisms underlying these methods are far from fully elucidated and may differ depending on the ultrasound parameters. We thus put forth minimal criteria for ultrasound parameter reporting, in order to ensure reproducibility of studies in the field. A deeper understanding of these mechanisms will enhance our ability to optimize this promising therapy to assist MSC‐based approaches in regenerative medicine., Mesenchymal stromal cells (MSCs) are a promising platform for regenerative medicine, but their therapeutic efficacy still requires optimization. Ultrasound (US) can enhance MSC‐based therapies through a variety of strategies. When applied to MSCs in vitro, US modulates self‐renewal and differentiation. When applied to target organs in vivo, US enhances MSC homing by upregulating local cytokines and adhesion molecules.

Acute kidney injury (AKI) is characterized by a sudden failure of renal function, but despite increasing worldwide prevalence, current treatments are largely supportive, with no curative therapies. Mesenchymal stromal cell (MSC) therapy has been shown to have a promising regenerative effect in AKI but is limited by the ability of cells to home to damaged tissue. Pulsed focused ultrasound (pFUS), wherein target tissues are sonicated by short bursts of sound waves, has been reported to enhance MSC homing by upregulating local homing signals. However, the exact mechanism by which pFUS enhances MSC therapy remains insufficiently explored. In this study, we studied the effect of bone marrow-derived MSCs (BM-MSCs), in conjunction with pFUS, in a mouse model of cisplatin-induced AKI. Here, BM-MSCs improved kidney function, reduced histological markers of kidney injury, decreased inflammation and apoptosis, and promoted cellular proliferation. Surprisingly, whereas pFUS did not upregulate local cytokine expression or improve BM-MSC homing, it did potentiate the effect of MSC treatment in AKI. Further analysis linked this effect to the upregulation of heat shock protein (HSP)20/HSP40 and subsequent phosphatidylinositol 3-kinase (PI3K)/Akt signaling. In summary, our results suggest that pFUS and BM-MSCs have independent as well as synergistic therapeutic effects in the context of AKI., Graphical Abstract, Mesenchymal stromal cells (MSCs) have shown promise in kidney regeneration following acute kidney injury. However, their therapeutic efficacy still requires optimization, which may be accomplished using pulsed focused ultrasound (pFUS). Here, Ullah et al. show how MSCs and pFUS have both independent and synergistic roles in promoting kidney regeneration.

Background Mortality and complications are not well defined nationally for emergency general surgery (EGS) patients presenting with underlying all-cause liver disease (LD). Study design We analyzed the 2012-2014 National Inpatient Sample for adults (aged ≥ 18 years) with a primary EGS diagnosis. Underlying LD included International Classification of Diseases, Ninth Revision, Clinical Modification codes for alcoholic and viral hepatitis, malignancy, congenital etiologies, and cirrhosis. The primary outcome was mortality; secondary outcomes included complications, operative intervention, and costs. Results Of the 6.8 million EGS patients, 358 766 (5.3%) had underlying LD. 59.1% had cirrhosis, 6.7% had portal hypertension, and 13.7% had ascites. Compared with other EGS patients, EGS-LD patients had higher mean costs ($12 847 vs $10 234, P < .001). EGS-LD patients were less likely to have surgery (26.1% vs 37.0%, P < .001) but for those who did, mortality was higher (4.8% vs 1.8%, P < .001). Risk factors for mortality included ascites (adjusted odds ratio [aOR] = 2.68, P < .001), dialysis (aOR = 3.44, P < .001), sepsis (aOR = 8.97, P < .001), and respiratory failure requiring intubation (aOR = 10.40, P < .001). Odds of death increased in both surgical (aOR = 4.93, P < .001) and non-surgical EGS-LD patients (aOR = 2.56, P < .001). Conclusions Underlying all-cause LD among EGS patients is associated with increased in-hospital mortality, even in the absence of surgical intervention.

Antibody-mediated rejection is a common cause of early kidney allograft loss but the specifics of antibody measurement, therapies and endpoints have not been universally defined. In this retrospective study, we assessed the performance of risk stratification using systematic donor-specific antibody (DSA) monitoring. Included in the study were children who underwent kidney transplantation between January 1, 2010 and March 1, 2018 at Stanford, with at least 12-months follow-up. A total of 233 patients were included with a mean follow-up time of 45 (range, 9–108) months. Median age at transplant was 12.3 years, 46.8% were female, and 76% had a deceased donor transplant. Fifty-two (22%) formed C1q-binding de novo donor-specific antibodies (C1q-dnDSA). After a standardized augmented immunosuppressive protocol was implemented, C1q-dnDSA disappeared in 31 (58.5%). Graft failure occurred in 16 patients at a median of 54 (range, 5–83) months, of whom 14 formed dnDSA. The 14 patients who lost their graft due to rejection, all had persistent C1q-dnDSA. C1q-binding status improved the individual risk assessment, with persistent; C1q binding yielding the strongest independent association of graft failure (hazard ratio, 45.5; 95% confidence interval, 11.7–177.4). C1q-dnDSA is more useful than standard dnDSA as a noninvasive biomarker for identifying patients at the highest risk of graft failure.

The development of chemotherapy drug resistance remains a significant barrier for effective therapy in several cancers including breast cancer. Bone marrow-derived mesenchymal stem cells (BMMSCs) have previously been shown to influence tumor progression and the development of chemoresistance. In the present study, we showed that when GFP labelled BMMSCs and RFP labelled HCC1806 cells are injected together in vivo, they create tumors which contain a new hybrid cell that has characteristics of both BMMSCs and HCC1806 cells. By labelling these cells prior to their injection, we were then able to isolate new hybrid cell from harvested tumors using FACS (DP-HCC1806:BMMSCs). Interestingly, when DP-HCC1806:BMMSCs were then injected into the mammary fat pad of NOD/SCID mice, they produced xenograft tumors which were smaller in size, and exhibited resistance to chemotherapy drugs (i.e. doxorubicin and 5-fluorouracil), when compared tumors from HCC1806 cells alone. This chemoresistance was shown to associated with an increased expression of tetraspanins (CD9, CD81) and drug resistance proteins (BCRP, MDR1). Subsequent siRNA-mediated knockdown of BMMSC-CD9 in DP-HCC1806:BMMSCs resulted in an attenuation of doxorubicin and 5-fluorouracil chemoresistance associated with decreased BCRP and serum cytokine expression (CCL5, CCR5, CXCR12). Our findings suggest that within the tumor microenvironment, CD9 is responsible for the crosstalk between BMMSCs and HCC1806 breast cancer cells (via CCL5, CCR5, and CXCR12) which contributes to chemoresistance. Hence, BMMSC-CD9 may serve as an important therapeutic target for the treatment of breast cancer.

Background BK virus (BKV) is a significant cause of nephropathy in kidney transplantation. The goal of this study was to characterize the course and source of BKV in kidney transplant recipients. Methods We prospectively collected pretransplant plasma and urine samples from living and deceased kidney donors and performed BKV polymerase chain reaction (PCR) and immunoglobulin G (IgG) testing on pretransplant and serially collected posttransplant samples in kidney transplant recipients. Results Among deceased donors, 8.1% (17/208) had detectable BKV DNA in urine prior to organ procurement. BK viruria was observed in 15.4% (6/39) of living donors and 8.5% (4/47) of deceased donors of recipients at our institution (P = .50). BKV VP1 sequencing revealed identical virus between donor–recipient pairs to suggest donor transmission of virus. Recipients of BK viruric donors were more likely to develop BK viruria (66.6% vs 7.8%; P < .001) and viremia (66.6% vs 8.9%; P < .001) with a shorter time to onset (log-rank test, P < .001). Though donor BKV IgG titers were higher in recipients who developed BK viremia, pretransplant donor, recipient, and combined donor/recipient serology status was not associated with BK viremia (P = .31, P = .75, and P = .51, respectively). Conclusions Donor BK viruria is associated with early BK viruria and viremia in kidney transplant recipients. BKV PCR testing of donor urine may be useful in identifying recipients at risk for BKV complications.

Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) are noninvasive surrogates for hepatic steatosis and fibrosis, respectively, and could help identify extended criteria donors in liver transplantation (LT). We aimed to determine the accuracy of CAP/LSM in deceased donors along with post-LT changes.Accuracy of preprocurement CAP/LSM to grade/stage steatosis/fibrosis was determined using liver biopsy as reference. Transplant outcomes, including primary nonfunction (PNF) and early allograft dysfunction, were recorded. Recipients underwent CAP/LSM as outpatients. Areas under the receiver operating characteristic curve and regression models were constructed to analyze data.We prospectively evaluated 160 allografts (138 transplanted). Same-probe paired baseline/post-LT CAP was 231 dB/m (181-277)/225 (187-261) (P = 0.61), and LSM 7.6 kPa (6.3-10.8)/5.9 (4.6-8.7) (P = 0.002), respectively. CAP reading was affected by BMI and LSM by ALT, race and bilirubin. Although CAP did not correlate with steatosis from frozen sections (ρ = 0.08, P = 0.47), it correlated with steatosis from permanent sections (ρ = 0.32, P0.001) and with oil red O histomorphometry (ρ = 0.35, P = 0.001). CAP identified moderate-to-severe steatosis with an areas under the receiver operating characteristic curve curve of 0.79 (0.66-0.91), for a negative predictive value of 100% at a cutoff value of 230 dB/m. LSM correlated with fibrosis staging (ρ = 0.22, P = 0.007) and it identified discarded allografts with advanced fibrosis/cirrhosis. Patients with no to minimal fibrosis had an LSM of 7.6 (6-10.1) kPa.Our results are proof-of-concept of the utility of CAP/LSM during organ procurement. Establishing the precise role of these noninvasive tools in the organ allocation process mandates confirmatory studies.

Combined heart-liver transplant is an emerging option for patients with indications for heart transplantation and otherwise prohibitive hepatic dysfunction. Heart-liver transplantation is particularly relevant for patients with single ventricle physiology who often develop Fontan-associated liver disease and fibrosis. Although only performed at a limited number of centers, several approaches to combined heart-liver transplantation have been described. The en bloc technique offers several potential advantages over the traditional sequential technique. Specifically, en bloc heart-liver transplantation may allow improved hemodynamics, decreased bleeding, reduced liver allograft ischemic time, and may result in reduced rates of graft dysfunction. Here we describe our center's en bloc heart-liver procurement technique in detail, with the aim of allowing broader use and standardization of this technique.

Liver transplant recipients (LTRs) are at risk for vancomycin-resistant Enterococcus (VRE) infections which can lead to significant morbidity or mortality. Antibiotic exposure, including vancomycin, is associated with greater risk of VRE infection. This study aimed to assess the appropriateness of vancomycin use and rates of VRE infection in this population. We performed a retrospective cohort study of 327 patients who underwent liver transplantation at our center from January 1, 2012 to June 30, 2017. Sixty (18.3%) LTRs had at least one VRE-positive culture between six-months pre-transplant and six-months post-transplant. LTRs with VRE had greater vancomycin exposure as compared to VRE-negative LTRs (p < 0.05) and were more likely to receive prolonged vancomycin courses (> 72 hours, p < 0.05). Overall appropriateness of vancomycin use > 72 hours among VRE-positive LTRs was only 26.8%. Inappropriate vancomycin use most commonly occurred in patients with presumed sepsis without an identifiable source or pneumonia with negative respiratory cultures. Our findings illustrate an opportunity to improve antibiotic stewardship and reduce vancomycin use in the transplant population

BackgroundEcological momentary assessment (EMA) enables individuals to self-report their subjective momentary physical and emotional states. However, certain conditions, including routine observable behaviors (eg, moods, medication adherence) as well as behaviors that may suggest declines in physical or mental health (eg, memory losses, compulsive disorders) cannot be easily and reliably measured via self-reports.ObjectiveThis study aims to examine a method complementary to EMA, denoted as peer-ceived momentary assessment (PeerMA), which enables the involvement of peers (eg, family members, friends) to report their perception of the individual’s subjective physical and emotional states. In this paper, we aim to report the feasibility results and identified human factors influencing the acceptance and reliability of the PeerMAMethodsWe conducted two studies of 4 weeks each, collecting self-reports from 20 participants about their stress, fatigue, anxiety, and well-being, in addition to collecting peer-reported perceptions from 27 of their peers.ResultsPreliminary results showed that some of the peers reported daily assessments for stress, fatigue, anxiety, and well-being statistically equal to those reported by the participant. We also showed how pairing assessments of participants and peers in time enables a qualitative and quantitative exploration of unique research questions not possible with EMA-only based assessments. We reported on the usability and implementation aspects based on the participants’ experience to guide the use of the PeerMA to complement the information obtained via self-reports for observable behaviors and physical and emotional states among healthy individuals.ConclusionsIt is possible to leverage the PeerMA method as a complement to EMA to assess constructs that fall in the realm of observable behaviors and states in healthy individuals.

The accuracy of liver biopsy to stage fibrosis due to Fontan-associated liver disease (FALD) remains unclear. We compared the results of biopsy pre-combined heart and liver transplantation (CHLT) to the results of whole liver explant. Liver biopsy and explants from 15 Fontan patients (ages 16-49, median 28 years) were retrospectively reviewed. Staging was as follows: stage 0: no fibrosis, stage 1: pericellular fibrosis, stage 2: bridging fibrosis, and stage 3: regenerative nodules. There is no stage 4. Clinical characteristics including Model of End-stage Liver Disease eXcluding INR and Varices, Ascites, Splenomegaly, and Thrombocytopenia (VAST) scores were collected, and descriptive statistics and Mann-Whitney U tests were used to analyze the data. All patients had biopsies with at least bridging fibrosis, and all had nodularity on explant; transjugular biopsy never overestimated fibrosis. Explant showed higher-grade fibrosis (stage 3) than pre-CHLT biopsy (stage 2) in 6 of 15 patients and equal grade of fibrosis (stage 3) in 9 of 15 patients. Though clinical characteristics varied significantly, VAST score was ≥2 in all but two patients. Transjugular liver biopsy does not overestimate and can underestimate fibrosis in Fontan patients undergoing CHLT, likely due to the patchy nature of fibrosis in FALD.

Liver transplantation (LT) is definitive treatment for end‐stage liver disease. This study evaluated factors predicting successful evaluation in patients transferred for urgent inpatient LT evaluation. Eighty‐two patients with cirrhosis were transferred for urgent LT evaluation from January 2016 to December 2018. Alcohol‐associated liver disease was the common etiology of liver disease (42/82). Of these 82 patients, 35 (43%) were declined for LT, 27 (33%) were wait‐listed for LT, 5 (6%) improved, and 15 (18%) died. Psychosocial factors were the most common reasons for being declined for LT (49%). Predictors for listing and receiving LT on multivariate analysis included Hispanic race (odds ratio [OR], 1.89; P = 0.003), Asian race (OR, 1.52; P = 0.02), non‐Hispanic ethnicity (OR, 1.49; P = 0.04), hyponatremia (OR, 1.38; P = 0.04), serum albumin (OR, 1.13; P = 0.01), and Model for End‐Stage Liver Disease (MELD)‐Na (OR, 1.02; P = 0.003). Public insurance (i.e., Medicaid) was a predictor of not being listed for LT on multivariate analysis (OR, 0.77; P = 0.02). Excluding patients declined for psychosocial reasons, predictors of being declined for LT on multivariate analysis included Chronic Liver Failure Consortium (CLIF‐C) score >51.5 (OR, 1.26; P = 0.03), acute‐on‐chronic liver failure (ACLF) grade 3 (OR, 1.41; P = 0.01), hepatorenal syndrome (HRS) (OR, 1.38; P = 0.01), and respiratory failure (OR, 1.51; P = 0.01). Predictors of 3‐month mortality included CLIF‐C score >51.5 (hazard ratio [HR], 2.52; P = 0.04) and intensive care unit (HR, 8.25; P

Background Acute kidney injury (AKI) is characterized by rapid failure of renal function and has no curative therapies. Mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) are known to carry therapeutic factors, which have shown promise in regenerative medicine applications, including AKI. However, there remains an unmet need to optimize their therapeutic effect. One potential avenue of optimization lies in pulsed focused ultrasound (pFUS), where tissues-of-interest are treated with sound waves. pFUS has been shown to enhance MSC therapy via increased cell homing, but its effects on cell-free EV therapy remain largely unexplored. Methods We combine pFUS pretreatment of the kidney with MSC-derived EV therapy in a mouse model of cisplatin-induced AKI. Results EVs significantly improved kidney function, reduced injury markers, mediated increased proliferation, and reduced inflammation and apoptosis. While pFUS did not enhance EV homing to the kidney, the combined treatment resulted in a superior therapeutic effect compared to either treatment alone. We identified several molecular mechanisms underlying this synergistic therapeutic effect, including upregulation of proliferative signaling (MAPK/ERK, PI3K/Akt) and regenerative pathways (eNOS, SIRT3), as well as suppression of inflammation. Conclusion Taken together, pFUS may be a strategy for enhancing the therapeutic efficacy of MSC-derived EV treatment for the treatment of AKI.

The antigen-specific apoptotic DNA immunotherapeutic, ADi-100, is designed to suppress type 1 diabetes and consists of two DNA plasmids encoding genetic sequences of the apoptosis-inducing molecule, BAX, and the secreted form of the autoantigen, glutamic acid decarboxylase 65, that is CpG hyper-methylated to avoid inflammatory signaling (msGAD55). Upon a four-day treatment with ADi-100 of young female non-obese diabetic (NOD) mice, the frequency of various tolerogenic dendritic cell populations increased in draining lymph nodes; these cells lost the capacity to stimulate glutamic acid decarboxylase (GAD)-specific CD4+ T lymphocytes and were associated with the previously demonstrated enhancement of GAD-specific regulatory T cells. The efficacy of two ADi-100 formulations containing different proportions of BAX and msGAD55, 1:4 (10/40 µg) and 1:2 (17/33 µg), was evaluated in mildly hyperglycemic pre-diabetic NOD female mice. Both formulations suppressed the incidence of diabetes by 80% in an antigen-specific manner, while all untreated mice developed diabetes. However, treatment of pre-diabetic mice with significantly higher hyperglycemia, denoting progressive disease, showed that ADi-100 1:2 strongly suppressed diabetes incidence by 80% whereas the ADi-100 1:4 was less effective (50%). As an antigen-specific monotherapy, ADi-100 is highly efficacious in reversing elevated hyperglycemia to prevent diabetes, in which increasing apoptosis-inducing BAX content is a promising immune tolerance feature.

INTRODUCTION Urinary diversion in pediatric renal transplant candidates with bladders not amenable to primary reconstruction can be achieved by pre-transplant ileal conduit creation. We performed cutaneous ureterostomies to limit pre-transplant surgery, protect the peritoneum for dialysis, transplant patients sooner, and preserve ureter length for future surgical reconstruction. METHODS We compared four pediatric transplant recipients with ureterostomies to four recipients with ileal conduits from 2009 to 2017. RESULTS All patients with ileal conduits developed at least one urinary tract infection (UTI) within 1 year of transplant and three of four patients had recurrent UTIs within the first year. Two patients required ileal conduit revisions for redundant conduits and recurrent UTIs. Of the four ureterostomy patients, two patients had UTIs within one year of transplant. Two patients developed ureterostomy strictures requiring revision at the fascial level; one was associated with a UTI. CONCLUSION In our small case series, ureterostomy allowed for a single operative intervention with preservation of ureter length for later reconstruction. Ureterostomy is safe and recurrent UTI may be lower in the ureterostomy group. Long-term evaluation of ureterostomy for urinary diversion in pediatric kidney transplant is warranted.

The purpose of this study is to evaluate whether use of a standardized radiology report template would improve the ability of liver transplant surgeons to diagnose stage T2 hepatocellular carcinoma (HCC) and determine patient suitability to undergo orthotopic liver transplant (OLT).In this retrospective study, a standardized template was devised, and its use was mandated for reporting of liver CT findings for patients with cirrhosis and HCC. Two surgeons analyzed 200 reports (100 before and 100 after template implementation) for descriptions of cirrhosis, portal hypertension, lesion enhancement characteristics, tumor thrombus, portal and superior mesenteric vein patency, and Organ Procurement Transplantation Network (OPTN) class. Ability to determine Milan criteria and surgeon satisfaction were also assessed. Data obtained before and after template implementation were statistically analyzed using the Cochran-Mantel-Haenszel test.Template implementation increased the percentage of reports documenting the presence or absence of portal hypertension (74% to 88% for surgeon 1 and 86% to 87% for surgeon 2; p = 0.042); lesion number (76% to 88% for surgeon 2 [no change for surgeon 1]; p = 0.038), size (95% to 96% for surgeon 1 and 82% to 93% for surgeon 2; p = 0.03), and enhancement (93% to 94% for surgeon 1 and 80% to 91% for surgeon 2; p = 0.049); presence of tumor thrombus (10% to 57% for surgeon 1 and 31% to 63% for surgeon 2; p0.001); and OPTN class (8% to 82% for surgeon 1 and 2% to 81% for surgeon 2; p0.001). The surgeons were significantly more able to determine the presence of T2 disease and qualification for exception points after implementation of the template (increasing from 80% to 94%; p = 0.025). Satisfaction with reports also improved (p0.0001).The reporting template improved determination of patient suitability to undergo transplant according to the Milan criteria.

Solid organ transplantation (SOT) treats over 1500 children/year in the US. While short-term outcomes have improved, long-term outcomes still remain poor. With the rare exception of monozygotic twins as donors, recipients require lifelong immunosuppression with its accompanying toxicities, the risk of nonadherence, and chronic rejection. Further, up to half of recipients require a second transplant. We have pioneered translational approaches that abrogate rejection and the need for post-transplant immunosuppression. Previous attempts in adult patients utilizing allogeneic hematopoietic stem cell transplantation (HSCT) to eliminate the need for post-SOT immunosuppression in non-histocompatible kidney transplant (KT) recipients have failed(Lowsky R, BMT 2019). The establishment of mixed lymphoid chimerism has permitted a reduction in the number of immunosuppressive drugs needed, but not their discontinuation, whereas complete donor engraftment after HSCT has resulted in fatal graft-versus-host disease in some patients (Leventhal JR, Eur J Pediatr 2000). The use of HSCT to eliminate the need for immunosuppression following pediatric KT has not been evaluated. We have pioneered sequential haploidentical HSCT followed by KT in three patients with Schimke immuno-osseous dysplasia (SIOD) to abrogate kidney rejection and the need for post-transplant immunosuppression. SIOD is a monogenic disorder with progressive nephropathy correctable by KT and a T-cell immunodeficiency curable by HSCT. All three patients received αβT-cell/CD19 B-cell depleted HSCT (αβhaplo-HSCT) from a parent prior to a KT from the same parental donor. The pre-HSCT reduced intensity preparative regimen consisted of fludarabine (a starting dose of 1 mg/kg x 4 days, which was adjusted based on AUC), total body irradiation (TBI) 200 cGy, cyclophosphamide 1200 mg/m 2, anti-thymocyte globulin (ATG) thymoglobulin® 7.5 mg/kg, and rituximab 200 mg/m 2. Immunosuppressive drugs were not prophylactically administered after HSCT. After confirmation of full donor lymphoid chimerism post-HSCT, the patients received a living donor KT from their parental HSCT donor. Post-KT immunosuppression included intraoperative methylprednisolone and post-operative low-dose oral prednisone (0.5 mg/kg/day with taper) and tacrolimus (target serum level of 3-5 ng/ml) to reduce potential reperfusion inflammation. All immunosuppressive drugs were tapered off by Day +30 post-KT. To demonstrate functional tolerance after KT, Mixed Lymphocyte Cultures (MLC) were performed between peripheral blood mononuclear cells (PBMC) and patient/parent-derived irradiated EBV transformed lymphoblastoid cells lines (EBV-LCL) as stimulators (Figure 1). PBMC were isolated from SIOD patients (n=3) by Ficoll Hypaque separation and were labelled with Invitrogen™ CellTrace Violet Proliferation Kit (CTV). EBV-LCL were established from SIOD patients, parents and healthy donors. The assay was performed in round bottom microtiter plates with 100,000 labelled PBMC as responder cells (R) and 50,000 irradiated (30gy) EBV-LCL in RPMI medium with 10% fetal calf serum. Cells were harvested on Day 6, and T-cell proliferation determined by CTV expression of CD3+ T cells using a Novocyte Penteon flow cytometer (Agilent). Donor-derived T cells isolated from the peripheral blood of all three recipients > 1-year post-HSCT/KT, did not respond to the donor cells, while they did proliferate to the non-donor parental and control cells (Fig. 1). These results demonstrate that post-HSCT/KT the circulating donor-derived T cells are functionally tolerant to the transplanted kidney and, therefore, are unable to mediate graft rejection even in the absence of immune suppression. We have achieved two goals: first, ablating the recipient immune system before HSCT we safely established a new donor-derived immune system - that could also, if required, cure a patient's underlying disease- and, second, functional tolerance to the transplanted kidney. At 12 to 24 months after KT, all patients have full donor lymphoid and myeloid chimerism, normal renal function without immunosuppression, MLC demonstrated tolerance towards donor cells, and normal proliferative responses to non-donor parental cells. These findings suggest that the combination of αβhaplo-HSCT and SOT could be extended to other solid transplantation like liver and small intestine. Figure 1 Figure 1. Disclosures Bertaina: Cellevolve Bio: Membership on an entity's Board of Directors or advisory committees; Neovii: Membership on an entity's Board of Directors or advisory committees; AdicetBio: Membership on an entity's Board of Directors or advisory committees. Shah: OrchardTherapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Dr. Shah currently serves on the medical advisory board for Orchard Therapeutics . Parkman: Jasper Biotech: Consultancy.

PURPOSE: To evaluate whether ultrasmall superparamagnetic iron oxide nanoparticle (USPIO)-enhanced magnetic resonance imaging (MRI) can detect allograft rejection in pediatric kidney transplant patients. PROCEDURES: The USPIO ferumoxytol has a long blood half-life and is phagocytosed by macrophages. In an IRB-approved single-center prospective clinical trial, 26 pediatric patients and adolescents (age 10–26 years) with acute allograft rejection (n = 5), non-rejecting allografts (n = 13), and normal native kidneys (n = 8) underwent multi-echo T2* fast spoiled gradient-echo (FSPGR) MRI after intravenous injection (p.i.) of 5 mg Fe/kg ferumoxytol. T2* relaxation times at 4 h p.i. (perfusion phase) and more than 20 h p.i. (macrophage phase) were compared with biopsy results. The presence of rejection was assessed using the Banff criteria, and the prevalence of macrophages on CD163 immunostains was determined based on a semi-quantitative scoring system. MRI and histology data were compared among patient groups using t tests, analysis of variance, and regression analyses with a significance threshold of p < 0.05. RESULTS: At 4 h p.i., mean T2* values were 6.6 ± 1.5 ms for native kidneys and 3.9 ms for one allograft undergoing acute immune rejection. Surprisingly, at 20–24 h p.i., one rejecting allograft showed significantly prolonged T2* relaxation times (37.0 ms) compared to native kidneys (6.3 ± 1.7 ms) and non-rejecting allografts (7.6 ± 0.1 ms). Likewise, three additional rejecting allografts showed significantly prolonged T2* relaxation times compared to non-rejecting allografts at later post-contrast time points, 25–97 h p.i. (p = 0.008). Histological analysis revealed edema and compressed microvessels in biopsies of rejecting allografts. Allografts with and without rejection showed insignificant differences in macrophage content on histopathology (p = 0.44). CONCLUSION: After ferumoxytol administration, renal allografts undergoing acute rejection show prolonged T2* values compared to non-rejecting allografts. Since histology revealed no significant differences in macrophage content, the increasing T2* value is likely due to the combined effect of reduced perfusion and increased edema in rejecting allografts.

Purpose While combined heart-liver transplant (HLT) is being performed for Fontan patients, outcomes and indications remain poorly defined. We compared listing characteristics and post-transplant outcomes of Fontan patients with HLT to those with heart-only transplant (HT). Methods We retrospectively reviewed all Fontan patients undergoing HT or HLT at our institution between 2006-2019. Pre-transplant liver disease at the time of listing, as determined by laboratory and radiology data, and MELD-XI, Child Pugh, and VAST scores, were compared between groups. The Kaplan Meier survival method was used to compare post-transplant survival and freedom from rejection (ISHLT Grade 2R+ or pAMR2+). Results Forty-two patients (33 HT, 9 HLT) were included. HLT patients were older, more likely to be on dual-inotrope therapy, had worse Child Pugh and VAST scores, and were more likely to have varices, ascites, splenomegaly, and cirrhosis on imaging (Table 1). While not significant, HLT patients tended to be more sensitized, had higher total bilirubin and creatinine, and lower platelet count. Over a median post-transplant follow-up of 22 (5, 62) months, overall mortality for the entire cohort was 19%; only one HLT patient died (11%) versus 7 (21%) HT patients (p=0.58, Figure 1). None of the HLT patients experienced rejection, whereas 11 (33%) HT patients had rejection (p=0.06). Conclusion Despite a greater inotrope need and more severe liver disease at time of listing, patients undergoing HLT have post-transplant outcomes that are comparable, if not better, than Fontan patients with HT. There appears to be a protective effect from rejection with HLT.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a fatal disorder characterized by progressive gastrointestinal dysmotility, peripheral neuropathy, leukoencephalopathy, skeletal myopathy, ophthalmoparesis, and ptosis. MNGIE stems from deficient thymidine phosphorylase activity (TP) leading to toxic elevations of plasma thymidine. Hematopoietic stem cell transplant (HSCT) restores TP activity and halts disease progression but has high transplant-related morbidity and mortality. Liver transplant (LT) was reported to restore TP activity in two adult MNGIE patients. We report successful LT in four additional MNGIE patients, including a pediatric patient. Our patients were diagnosed between ages 14 months and 36 years with elevated thymidine levels and biallelic pathogenic variants in TYMP. Two patients presented with progressive gastrointestinal dysmotility, and three demonstrated progressive peripheral neuropathy with two suffering limitations in ambulation. Two patients, including the child, had liver dysfunction and cirrhosis. Following LT, thymidine levels nearly normalized in all four patients and remained low for the duration of follow-up. Disease symptoms stabilized in all patients, with some manifesting improvements, including intestinal function. No patient died, and LT appeared to have a more favorable safety profile than HSCT, especially when liver disease is present. Follow-up studies will need to document the long-term impact of this new approach on disease outcome. Take Home Message: Liver transplantation is effective in stabilizing symptoms and nearly normalizing thymidine levels in patients with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) and may have an improved safety profile over hematopoietic stem cell transplant.

BACKGROUND Ecological momentary assessment (EMA) enables individuals to self-report their subjective momentary physical and emotional states. However, certain conditions, including routine observable behaviors (eg, moods, medication adherence) as well as behaviors that may suggest declines in physical or mental health (eg, memory losses, compulsive disorders) cannot be easily and reliably measured via self-reports. OBJECTIVE This study aims to examine a method complementary to EMA, denoted as peer-ceived momentary assessment (PeerMA), which enables the involvement of peers (eg, family members, friends) to report their perception of the individual’s subjective physical and emotional states. In this paper, we aim to report the feasibility results and identified human factors influencing the acceptance and reliability of the PeerMA METHODS We conducted two studies of 4 weeks each, collecting self-reports from 20 participants about their stress, fatigue, anxiety, and well-being, in addition to collecting peer-reported perceptions from 27 of their peers. RESULTS Preliminary results showed that some of the peers reported daily assessments for stress, fatigue, anxiety, and well-being statistically equal to those reported by the participant. We also showed how pairing assessments of participants and peers in time enables a qualitative and quantitative exploration of unique research questions not possible with EMA-only based assessments. We reported on the usability and implementation aspects based on the participants’ experience to guide the use of the PeerMA to complement the information obtained via self-reports for observable behaviors and physical and emotional states among healthy individuals. CONCLUSIONS It is possible to leverage the PeerMA method as a complement to EMA to assess constructs that fall in the realm of observable behaviors and states in healthy individuals.

Organismal aging involves the progressive decline in organ function and increased susceptibility to age-associated diseases. This has been associated with the aging of stem cell populations within the body that decreases the capacity of stem cells to self-renew, differentiate, and regenerate damaged tissues and organs. This review aims to explore how aging is associated with the dysregulation of stem cell-derived extracellular vesicles (SCEVs) and their corresponding miRNA cargo (SCEV-miRNAs), which are short non-coding RNAs involved in post-transcriptional regulation of target genes. Recent evidence has suggested that in aging stem cells, SCEV-miRNAs may play a vital role regulating various processes that contribute to aging: cellular senescence, stem cell exhaustion, telomere length, and circadian rhythm. Hence, further clarifying the age-dependent molecular mechanisms through which SCEV-miRNAs exert their downstream effects may inform a greater understanding of the biology of aging, elucidate their role in stem cell function, and identify important targets for future regenerative therapies. Additionally, current studies evaluating therapeutic role of SCEVs and SCEV-miRNAs in treating several age-associated diseases are also discussed.

Bilateral renal agenesis is associated with severe oligohydramnios and was considered incompatible with postnatal life due to severe pulmonary hypoplasia. The use of renal replacement therapy was limited by significant morbidity and mortality associated with dialysis in very young infants with major pulmonary pathology. In the United States, there is a tremendous controversy about whether or not the use of prenatal amniotic fluid infusions provides a benefit to fetuses with bilateral renal agenesis. One of the critical issues identified is that there are, as yet, no children reported who had achieved long-term survival. Previous reports all indicated these children died shortly after birth or after unsuccessful peritoneal dialysis. We present two infants with a prenatal diagnosis of bilateral renal agenesis whose mothers elected to undergo prenatal amnioinfusions. One was born at 28 weeks with a birthweight of 1230 g and the other born at 34 weeks with a birthweight of 1940 g. We present the details of both cases, with initial management on chronic peritoneal dialysis, which started shortly after birth, as a bridge to living related kidney transplants.

SummaryBackground Combined heart and liver transplantation (CHLT) in the pediatric population involves a complex group of patients, many of whom have palliated congenital heart disease (CHD) involving single ventricle physiology. Objective The purpose of this study was to describe the perioperative management of pediatric patients undergoing CHLT at a single institution and to identify management strategies that may be used to optimize perioperative care. Methods We did a retrospective database review of all patients receiving CHLT at a children's hospital between 2006 and 2014. Information collected included preoperative characteristics, intraoperative management, blood transfusions, and postoperative morbidity and mortality. Results Five pediatric CHLTs were performed over an 8-year period. All patients had a history of complex CHD with multiple sternotomies, three of whom had failing Fontan physiology. Patient age ranged from 7 to 23 years and weight from 29.5 to 68.5 kg. All CHLTs were performed using an en-bloc technique where both the donor heart and liver were implanted together on cardiopulmonary bypass (CPB). The median operating room time was 14.25 h, median CPB time was 3.58 h, and median donor ischemia time was 4.13 h. Patients separated from CPB on dopamine, epinephrine, and milrinone infusions and two required inhaled nitric oxide. All patients received a massive intraoperative blood transfusion post CPB with amounts ranging from one to three times the patient's estimated blood volume. The patient who required the most transfusions was in decompensated heart and liver failure preoperatively. Four of the five patients received an antifibrinolytic agent as well as a procoagulant (prothrombin complex concentrate or recombinant activated Factor VII) to assist with hemostasis. There were no 30-day thromboembolic events detected. Postoperatively the median length of mechanical ventilation, ICU stay and stay to hospital discharge was 4, 8, and 37 days, respectively. All patients are alive and free from allograft rejection at this time. Conclusion Combined heart and liver transplantation in the pediatric population involves a complex group of patients with unique perioperative challenges. Successful management starts with thorough preoperative planning and communication and involves strategies to deal with massive intraoperative hemorrhage and coagulopathy in addition to protecting and supporting the transplanted heart and liver and meticulous surgical technique. An integrated multidisciplinary team approach is the cornerstone for successful outcomes.

Hepatoblastoma is the most common malignant liver tumor in childhood. It has been associated with a variety of constitutional syndromes and gene mutations. However, there are very few reports of associations with pediatric hepatocellular adenomas (HCAs) and no reported associations with pigmented HCAs (P-HCAs). We present a unique case of hepatoblastoma arising in a background of 2 β-catenin-activated HCAs, one of which is pigmented, in a 4-year-old child. The gross, histologic, and immunohistochemical features are described for each tumor. In addition, the literature is reviewed with specific emphasis on the clinical and pathologic features of B-HCAs. Although the potential of β-catenin-activated HCAs to progress to hepatocellular carcinoma has been well documented, there are very few reports of their potential to progress to hepatoblastoma. We not only present such a case, but, to our knowledge, we also present the first case of a P-HCA in a child.

Acute kidney injury (AKI) is the abrupt loss of renal function, for which only supportive therapies exist. Mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) have been shown to be therapeutically effective in treating AKI by spurring endogenous cell proliferation and survival while suppressing inflammation. Pre-treating kidneys with pulsed focused ultrasound (pFUS) has also been shown to enhance MSC therapy for AKI, but its role in MSC-derived EV therapy remains unexplored. Using a mouse model of cisplatin-induced AKI, we show that combination therapy with pFUS and EVs restores physiological and molecular markers of kidney function, more so than either alone. Both pFUS and EVs downregulate heat shock protein 70 (HSP70), the NLRP3 inflammasome, and its downstream pro-inflammatory cytokines IL-1&beta, and IL-18, all of which are highly upregulated in AKI. In vitro knockdown studies suggest that HSP70 is a positive regulator of the NLRP3 inflammasome. Our study therefore demonstrates the ability of pFUS to enhance EV therapy for AKI and provides further mechanistic understanding of their anti-inflammatory and regenerative effects.

Diseases of the kidney contribute a significant morbidity and mortality burden on society. Localized delivery of therapeutics directly into the kidney, via its arterial blood supply, has the potential to enhance their therapeutic efficacy while limiting side effects associated with conventional systemic delivery. Targeted delivery in humans is feasible given that we can access the renal arterial blood supply using minimally invasive endovascular techniques and imaging guidance. However, there is currently no described way to reproduce or mimic this approach in a small animal model. Here, we develop in mice a reproducible microsurgical technique for the delivery of therapeutics directly into each kidney, via its arterial blood supply. Using our technique, intra-arterially (IA) injected tattoo dye homogenously stained both kidneys, without staining any other organ. Survival studies showed no resulting mortality or iatrogenic kidney injury. We demonstrate the therapeutic potential of our technique in a mouse model of cisplatin-induced acute kidney injury (AKI). IA injection of mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) successfully reversed AKI, with reduced physiological and molecular markers of kidney injury, attenuated inflammation, and restoration of proliferation and regeneration markers. This reproducible delivery technique will allow for further pre-clinical translational studies investigating other therapies for the treatment of renal pathologies.

Allogeneic hematopoietic stem cell transplantation (HSCT) from an HLA-matched donor, either related or unrelated, has been extensively used to treat patients with genetic disorders. However, only 25% of patients eligible to receive allogeneic HSCT have an HLA-identical sibling, and an HLA-matched unrelated donor can be identified for less than 60% of other patients. Mismatched HSCT has been associated with a high risk of graft loss, graft-versus-host disease (GvHD), and transplant-related mortality. Graft manipulation strategies have been used over the last decade to reduce these risks. HLA-haploidentical HSCT after ab T-cell/CD19 B-cell depletion (abhaplo-HSCT) has been shown to be effective in curing up to 90% of children with a variety of non-malignant disorders [Bertaina A, Blood 2014]. However, a scarcity of data are available for patients with rare and complex genetic diseases, including Tregopathies, an emerging new class of primary immunodeficiencies. Here we report preliminary data on the single center experience developed at Lucile Packard Children's Hospital, Stanford, CA, USA on the use of abhaplo-HSCT for rare and complex monogenic diseases (Table 1). All the cell products were manufactured at the Laboratory for Cell and Gene Medicine (LCGM) at Stanford (Table 2). Between 05/2018 and 08/2019, 5 patients with complex monogenic disorders were referred to our Center for HSCT including: a 23 year-old with Fanconi Anemia, two with Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) and two with Schimke Immuno-Osseous Dysplasia (SIOD). Remarkably, all these patients were previously considered not eligible for a HSCT, and one of the IPEX patients was in palliative care. At a median follow-up of 240 days (range 39-520), all patients are alive and disease-free. One patient (SIOD) developed Grade I/stage II skin only graft-versus-host disease (GvHD), while none of the evaluable patients had developed chronic GvHD. Five months after abhaplo-HSCT and with 100% of the circulating T cells being donor derived, the first SIOD patient received a living kidney transplant from the stem cell donor (mother) using minimal immunosuppression with tacrolimus and steroid. Four weeks after the kidney transplant all immunosuppression was stopped, and the patient remains off immunosuppression 12 weeks post-kidney transplantation. Our preliminary data on the use of abhaplo-HSCT in patients with rare and complex monogenic diseases provide a strong rationale for expanding this therapeutic approach to diseases not previously considered as an indication for allogeneic HSCT, to patients in very poor clinical condition and to patients requiring both HSCT and solid organ transplant.

Patients with failing Fontan physiology and liver cirrhosis are being considered for combined heart and liver transplantation. We performed a retrospective review of our experience with en bloc combined heart and liver transplantation in Fontan patients > 10 years old from 2006 to 18 per Institutional Review Board approval. Six females and 3 males (median age 20.7, range 14.2-41.3 years) underwent en bloc combined heart and liver transplantation. Indications for heart transplant included ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, and/or lymphatic abnormalities. Indication for liver transplant included portal hypertension and cirrhosis. Median Fontan/single ventricular end-diastolic pressure was 18/12 mm Hg, respectively. Median Model for End-Stage Liver Disease excluding International Normalized Ratio score was 10 (7-26), eight patients had a varices, ascites, splenomegaly, thrombocytopenia score of ≥ 2, and all patients had cirrhosis. Median cardiopulmonary bypass and donor ischemic times were 262 (178-307) and 287 (227-396) minutes, respectively. Median intensive care and hospital stay were 19 (5-96) and 29 (13-197) days, respectively. Survival was 100%, and rejection was 0% at 30 days and 1 year post-transplant. En bloc combined heart and liver transplantation is an acceptable treatment in the failing Fontan patient with liver cirrhosis.