The Impact of Metabolic Health and Obesity on Liver Transplant Candidates and Recipients.

Poor metabolic health and obesity have significant impacts on the outcomes of patients suffering from chronic liver disease, particularly those with metabolic dysfunction-associated steatotic liver disease. Patients with such comorbidities who require liver transplant evaluation for advancing liver disease or liver failure require special consideration due to increased risk of cardiovascular disease, renal dysfunction, sarcopenic obesity, and cancer. Those who have had a history of prior bariatric surgery pose specific anatomical constraints and may also be at increased risk of alcohol use disorder. Pre-operative risk assessment as well as strict control of metabolic risk factors are essential to reduce intra-operative and post-liver transplant complications. As immunosuppressive therapy exacerbates metabolic dysfunction and risk for cancer, post-liver transplant care must focus on balancing the need to prevent rejection and the impact of progressive metabolic dysfunction in this unique, but growing, patient population.

Risk factors for renal dysfunction after isolated intestinal transplantation.

INTRODUCTION: Kidney dysfunction is a known complication of intestinal transplantation; however, the rate of development and risk factors for chronic kidney disease (CKD) remain poorly defined. METHODS: This was a single-center retrospective review of isolated adult intestinal allograft recipients from 2011 to 2019. Patients who died or experienced graft loss within 1-year or had a prior transplant were excluded. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation at 0-, 6- and 12-months post-transplant, and multivariable linear regression was performed to identify variables associated with adjusted eGFR at 1-year. Independent variables included age, ethnicity, BMI, history of diabetes/hypertension, vasopressor use, TPN and stoma days, urinary or bloodstream infections, intravenous contrast exposure, rejection, concomitant immunosuppression, and time above the therapeutic range of tacrolimus. Variables with a p < .1 in univariate analysis were considered for multivariable modeling. RESULTS: Thirty-three patients were included with a mean age of 43.9 ± 13.0. A mean 42.3% decline in eGFR was observed at 1-year post-transplant, with 15.2% of patients developing new stage 4/5 CKD. Factors associated with a greater decline in adjusted eGFR in the univariate model included increasing age, decreased BMI, stoma days, and vasopressor use. In the adjusted multivariable model patient age (ß = -.77, p < .01) and stoma days (ß = -.06, p < .01) remained significant. Tacrolimus and sirolimus exposure were not associated with decline in eGFR at 1 year. CONCLUSIONS: Renal dysfunction is common following intestinal transplantation. The need for stoma creation should be carefully considered, and reversal should be performed when feasible for renal protection.

Impact of Deceased-donor Acute Kidney Injury on Kidney Transplantation.

Even as record numbers of deceased donors are undergoing organ recovery, the global transplant community continues to struggle with a shortage of donor organs and a high organ discard rate. Acute kidney injury (AKI) occurs in many hospitalized patients, including up to 25% of patients in critical condition. Registry studies have shown a significant increase in nonrecovery or organ discard rates in AKI donors, despite most studies reporting similar clinical outcomes compared with non-AKI donors. This review aims to capture the salient information learned from these studies and to summarize the efforts that have been made to gain a more granular understanding of how kidneys from donors with AKI behave posttransplant. In particular, we reviewed the studies that analyzed the clinical outcomes in different stages of AKI and AKI in marginal donors, such as kidney donor profile index of >85%, older donors, and donation after circulatory death donors. We summarized studies investigating molecular biomarkers, transcriptomics, and possible future therapeutic targets for postdonation AKI.

Recurrent Intrahepatic Cholangiocarcinoma - Review.

Intrahepatic cholangiocarcinoma (ICC) is the second-most common primary liver malignancy after hepatocellular carcinoma. While surgical resection with negative margin is the only curative treatment, ICC has very high rate of recurrence, up to 60-70% after curative resection. We reviewed the current data available on risk factors for ICC recurrence, recurrence pattern (location and timing), treatment options, and future directions. The risk factors for recurrence include elevated preoperative CA19-9, presence of liver cirrhosis, nodal metastasis, positive margins, and vascular invasion. Understanding different recurrence patterns, timing course, and risk factors for early recurrence is important to tailor postoperative surveillance and select treatment strategies including systemic or locoregional therapy. Re-resection can be considered for a selected patient population at experienced centers, and can yield long-term survival. ICC remains a dismal disease given the high likelihood of recurrence. Advances in our understanding of the genomic landscape of ICC are beginning to identify targetable alterations in ICC in subsets of patients that allow for personalized treatment.

Lactate-mediated epigenetic reprogramming regulates formation of human pancreatic cancer-associated fibroblasts.

Even though pancreatic ductal adenocarcinoma (PDAC) is associated with fibrotic stroma, the molecular pathways regulating the formation of cancer associated fibroblasts (CAFs) are not well elucidated. An epigenomic analysis of patient-derived and de-novo generated CAFs demonstrated widespread loss of cytosine methylation that was associated with overexpression of various inflammatory transcripts including CXCR4. Co-culture of neoplastic cells with CAFs led to increased invasiveness that was abrogated by inhibition of CXCR4. Metabolite tracing revealed that lactate produced by neoplastic cells leads to increased production of alpha-ketoglutarate (aKG) within mesenchymal stem cells (MSCs). In turn, aKG mediated activation of the demethylase TET enzyme led to decreased cytosine methylation and increased hydroxymethylation during de novo differentiation of MSCs to CAF. Co-injection of neoplastic cells with TET-deficient MSCs inhibited tumor growth in vivo. Thus, in PDAC, a tumor-mediated lactate flux is associated with widespread epigenomic reprogramming that is seen during CAF formation.

U2AF1 mutations induce oncogenic IRAK4 isoforms and activate innate immune pathways in myeloid malignancies.

Spliceosome mutations are common in myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML), but the oncogenic changes due to these mutations have not been identified. Here a global analysis of exon usage in AML samples revealed distinct molecular subsets containing alternative spliced isoforms of inflammatory and immune genes. Interleukin-1 receptor-associated kinase 4 (IRAK4) was the dominant alternatively spliced isoform in MDS and AML and is characterized by a longer isoform that retains exon 4, which encodes IRAK4-long (IRAK4-L), a protein that assembles with the myddosome, results in maximal activation of nuclear factor kappa-light-chain-enhancer of B cells (NF-κB) and is essential for leukaemic cell function. Expression of IRAK4-L is mediated by mutant U2 small nuclear RNA auxiliary factor 1 (U2AF1) and is associated with oncogenic signalling in MDS and AML. Inhibition of IRAK4-L abrogates leukaemic growth, particularly in AML cells with higher expression of the IRAK4-L isoform. Collectively, mutations in U2AF1 induce expression of therapeutically targetable 'active' IRAK4 isoforms and provide a genetic link to activation of chronic innate immune signalling in MDS and AML.

Epigenetically Aberrant Stroma in MDS Propagates Disease via Wnt/ß-Catenin Activation.

The bone marrow microenvironment influences malignant hematopoiesis, but how it promotes leukemogenesis has not been elucidated. In addition, the role of the bone marrow stroma in regulating clinical responses to DNA methyltransferase inhibitors (DNMTi) is also poorly understood. In this study, we conducted a DNA methylome analysis of bone marrow-derived stromal cells from myelodysplastic syndrome (MDS) patients and observed widespread aberrant cytosine hypermethylation occurring preferentially outside CpG islands. Stroma derived from 5-azacytidine-treated patients lacked aberrant methylation and DNMTi treatment of primary MDS stroma enhanced its ability to support erythroid differentiation. An integrative expression analysis revealed that the WNT pathway antagonist FRZB was aberrantly hypermethylated and underexpressed in MDS stroma. This result was confirmed in an independent set of sorted, primary MDS-derived mesenchymal cells. We documented a WNT/ß-catenin activation signature in CD34+ cells from advanced cases of MDS, where it associated with adverse prognosis. Constitutive activation of ß-catenin in hematopoietic cells yielded lethal myeloid disease in a NUP98-HOXD13 mouse model of MDS, confirming its role in disease progression. Our results define novel epigenetic changes in the bone marrow microenvironment, which lead to ß-catenin activation and disease progression of MDS. Cancer Res; 77(18); 4846-57. ©2017 AACR.

The role of stromal cancer-associated fibroblasts in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer generally refractory to conventional treatments. Cancer-associated fibroblasts (CAFs) are cellular components of the desmoplastic stroma characteristic to the tumor that contributes to this treatment resistance. Various markers for CAFs have been explored including palladin and CD146 that have prognostic and functional roles in the pathobiology of PDAC. Mechanisms of CAF-tumor cell interaction have been described including exosomal transfer and paracrine signaling mediated by cytokines such as GM-CSF and IL-6. The role of downstream signaling pathways including JAK/STAT, mTOR, sonic hedge hog (SHH), and NFkB have also been shown to play an important function in PDAC-CAF cross talk. The role of autophagy and other metabolic effects on each cell type within the tumor have also been proposed to play roles in facilitating CAF secretory function and enhancing tumor growth in a low-glucose microenvironment. Targeting the stroma has gained interest with multiple preclinical and clinical trials targeting SHH, JAK2, and methods of either exploiting the secretory capability of CAFs to enhance drug delivery or inhibiting it to prevent its influence on cancer cell chemoresistance. This review summarizes the most recent progress made in understanding stromal formation; its contribution to tumor proliferation, invasion, and metastasis; its role in chemoresistance; and potential therapeutic strategies on the horizon.