Watt, Kymberly D.

Machine learning (ML) utilizes artificial intelligence to generate predictive models efficiently and more effectively than conventional methods through detection of hidden patterns within large data sets. With this in mind, there are several areas within hepatology where these methods can be applied. In this review, we examine the literature pertaining to machine learning in hepatology and liver transplant medicine. We provide an overview of the strengths and limitations of ML tools and their potential applications to both clinical and molecular data in hepatology. ML has been applied to various types of data in liver disease research, including clinical, demographic, molecular, radiological, and pathological data. We anticipate that use of ML tools to generate predictive algorithms will change the face of clinical practice in hepatology and transplantation. This review will provide readers with the opportunity to learn about the ML tools available and potential applications to questions of interest in hepatology.

Abstract Background Diffuse large B cell lymphoma post-transplant lymphoproliferative disorder (DLBCL-PTLD) represents a fatal complication after a solid organ transplant (SOT). Approximately 50% of DLBCL-PTLD can be related to Epstein Barr Virus (EBV) infection. However, the EBV status is not taken into account in the DLBCL-PTLD categorization, although increasing evidence suggests its critical role in biological, clinical and prognostic aspects of the disease. In this single center retrospective study, we compared clinical and histological features, as well as outcomes of DLBCL-PTLDs by EBV status. Methods This study focused on patients with SOT who were diagnosed with DLBCL-PTLD at Mayo Clinic (Rochester, MN). Patients were identified through the Mayo Clinic Lymphoma Data base and the University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER), between 1989 and 2017. The histology was re-reviewed (RLK) and classified according to the WHO Classification or Tumours of Haematopoietic and Lymphoid Tissues 2017. Cell of origin (COO) was performed by Hans algorithm. EBV RNA in situ hybridization (EBER) was performed. Cox proportional hazards models were used to assess the association of clinical factors in overall survival (OS). Results 148 DLBCL-PTLD were identified. The median age at SOT and at the time of PTLD diagnosis were 50 years (range: 15-71) and 56 years (range: 18-82), respectively. The median time to PTLD diagnosis from SOT was 38 months (range: 1-499). The types of SOT included renal (44%), liver (36%), cardiac (9%), renal/pancreas (5%), pancreas (8%), lung (7%) and multiorgan (4%). 62% were stage III-IV, 30% had elevated LDH and 67% had an IPI >1. 88% of patients presented with extranodal disease, and 16% had involvement of the grafted organ. Eighty-three (56%) cases were EBV positive. The COO information was available on 35 cases. The non-GCB subtype was identified in 24 cases and GCB subtype in 11 cases. The initial treatment was as follows: reduction in immunosuppression (12%), immunosuppression reduction with rituximab (26%), rituximab alone (5%), chemotherapy with or without rituximab (35%). Patients with EBV positive PTLD were more likely to have grafted organ involvement (20% vs. 8%, p=0.047) and late PTLD (occurring after 12 months from SOT - 60% vs. 8%, p<0.001) than patients with EBV negative PTLD. There was no association between EBV status and age, sex, stage, LDH, and extranodal site involvement. At a median follow-up of 80 months (range 9-269), 83 patients (56%) had died. The 5-year survival rate from PTLD diagnosis was 56% (95% CI: 48-65%). The median OS was 85 months (95% CI: 37-148). There was no difference in OS in patients with EBV positive PTLD (median OS=84.7 months, HR=1.21, 95% CI: 0.77-1.92) versus patients with EBV negative DLBCL-PTLD (median OS=85.4 months, p=0.41). Conclusion Our study assessed the impact of EBV status on the presentation and clinical outcome of DLBCL-PTLD in a 148-patient single-institution cohort. 56% of cases were EBV positive. EBV positivity was associated with grafted organ involvement and late PTLD diagnosis. Patients with EBV-negative and EBV-positive disease had similar survival from PTLD diagnosis. Disclosures Maurer: Celgene: Research Funding; Morphosys: Research Funding; Nanostring: Research Funding. Cerhan:Nanostring: Research Funding; Jannsen: Other: Scientific Advisory Board; Celgene: Research Funding.

OBJECTIVES: Cardiovascular (CV) disease is the top cause of mortality in patients with nonalcoholic fatty liver disease (NAFLD). Female sex is protective against CV disease. We aimed to determine whether female sex remains a protective factor against CV disease (myocardial infarction, angina, and stroke) in NAFLD. METHODS: We identified all adults diagnosed with NAFLD in Olmsted County, Minnesota, between 1997 and 2014 and selected an age- and sex-matched (1:4) referent cohort from the general population. NAFLD was ascertained using a code-based algorithm with high validity tested by medical record review. The impact of female sex on incident CV events was examined using Cox proportional hazards regression analysis stratified by standard clinical risk factors. RESULTS: A total of 3,869 NAFLD and 15,209 age- and sex-matched referent subjects were identified. After a median follow-up time of 7 (range 1–20) years, 3,851 CV events were recorded. Female sex was protective for ischemic CV events in the general population (hazard ratio = 0.71, 95% confidence interval 0.62–0.80, P < 0.001), but the impact was significantly diminished among those with NAFLD (hazard ratio = 0.90, 95% confidence interval 0.74–1.08, P = 0.25), even after stratification by time-dependent CV risk factors and control for diagnostic testing (liver enzymes and ultrasound) during routine medical evaluations, as a surrogate of access to care. Among those with NAFLD, excess events were higher in women than in men: CV disease (18% vs 9%) and mortality (9% vs 6%). DISCUSSION: Women with NAFLD lose the CV protection conferred by the female sex, and their risk is underestimated by current estimating methods in clinical practice.

Cirrhotic cardiomyopathy (CCM) is cardiac dysfunction in patients with end‐stage liver disease in the absence of prior heart disease. First defined in 2005 during the World Congress of Gastroenterology, CCM criteria consisted of echocardiographic parameters to identify subclinical cardiac dysfunction in the absence of overt structural abnormalities. Significant advancements in cardiovascular imaging over the past 14 years, including the integration of myocardial deformation imaging into routine clinical practice to identify subclinical cardiovascular dysfunction, have rendered the 2005 CCM criteria obsolete. Therefore, new criteria based on contemporary cardiovascular imaging parameters are needed. In this guidance document, assembled by a group of multidisciplinary experts in the field, new core criteria based on contemporary cardiovascular imaging parameters are proposed for the assessment of CCM. This document provides a critical assessment of the diagnosis of CCM and ongoing assessment aimed at improving clinical outcomes, particularly surrounding liver transplantation. Key points and practice‐based recommendations for the diagnosis of CCM are provided to offer guidance for clinicians and identify gaps in knowledge for future investigations.

Background. Posttransplant diabetes mellitus (PTDM) affects up to 50% of solid organ transplant recipients and compromises long-term outcomes. The goal of this study was to investigate how immunosuppressants affect gene expression in a manner that increases diabetes risk, by performing integrative analysis on publicly available, high-throughput gene expression data. Methods. All high-throughput gene expression datasets of solid organ transplant recipients were retrieved from the Gene Expression Omnibus. Significantly dysregulated genes and pathways were determined, and those in common with type 2 diabetes were identified. THP-1 and HepG2 cells were exposed in vitro to tacrolimus, and validation of genes involved in insulin signaling and glucose metabolism was performed using specific arrays. These cells were then treated with the hypoglycemic agents, metformin, and insulin to assess for appropriate reversion of specific diabetogenic genes. Results. Insulin signaling and secretion were the most commonly dysregulated pathways that overlapped with diabetes in transplant recipients. KRAS, GRB2, PCK2, BCL2L1, INSL3, DOK3, and PTPN1 were among the most significantly upregulated genes in both immunosuppression and diabetes subsets and were appropriately reverted by metformin as confirmed in vitro. Conclusions. We discovered that the significantly dysregulated genes in the context of immunosuppression are implicated in insulin signaling and insulin secretion, as a manifestation of pancreatic β-cell function. In vitro validation confirmed key diabetes-related genes in the context of immunosuppression. Further analysis and in vitro validation revealed that metformin optimally reverts diabetogenic genes dysregulated in the context of immunosuppression. The optimal therapeutic management of posttransplant diabetes mellitus needs to be further investigated, taking into account the mechanistic impact of immunosuppressants.

AbstractBackgroundStudies have suggested transplantation using older donor livers results in similar short‐term outcomes as younger donor livers; however, little data exist on long‐term patient/graft outcomes of the octogenarian liver recipient.MethodsRetrospective data were collected from 2 centers, (Valencia, Spain and Rochester, MN, USA) of all recipients of octogenarian donor liver allografts from 2000 to 2011 with follow‐up to 2016. The aim was to compare long‐term patient/graft survival as well as metabolic outcomes of the recipient with the octogenarian liver vs younger than 60 years donor.Results78 recipients of older liver allografts were compared to 78 matched controls. No difference in 10‐year patient mortality was demonstrated (P = 0.074). Octogenarian livers were associated with 3‐fold higher likelihood of graft failure (P = 0.002) but no increase in the risk of post‐LT cardiovascular disease (P = 0.60), hypertension (P = 0.33), vascular complications (P = 0.53), or malignancy (P = 0.14). In multivariate analysis, elder livers remained a significant factor associated with rejection (P = 0.034) with a trend not reaching statistical significance for graft failure (P = 0.052).ConclusionsFor appropriately selected recipients, receiving an octogenarian liver does not clearly influence patient survival but does impact early graft survival with a notable increase in early posttransplant rejection rates and re‐transplantation. Over 1.5 decades, older allografts have not adversely affected metabolic outcomes.

Sarcopenia is a common complication of cirrhosis and is defined as a progressive and generalized loss of skeletal muscle mass, strength, and function. Sarcopenia is associated with poor prognosis and increased mortality. How sarcopenia and muscle wasting relate to such poor outcomes requires looking beyond the overt muscle loss and at this entity as a systemic disease that affects muscles of vital organs including cardiac and respiratory muscles. This review explores the pathophysiological pathways and mechanisms that culminate in poor outcomes associated with sarcopenia. This provides a launching pad to identify potential targets for therapeutic intervention and optimization to improve patient outcomes.

AbstractAutoimmune hepatitis (AIH) is a rare immune‐mediated liver disease with few major advances in treatment options over the last several decades. Available options are effective in most patients albeit are imprecise in their mechanisms. Novel and more tolerable induction regimens and alternative options for management of patients intolerant or with suboptimal response to traditional therapies including in the post‐transplant setting remain an important unmet need. This review aims to summarize recent data on pharmacological options and investigational drugs in development for patients with AIH. Standard therapy using prednisone with or without azathioprine remains the mainstay of therapy and is effective in most patients. Budesonide may be considered for induction in early disease and in those with mild fibrosis, but has not been approved for maintenance therapy. Mycophenolate mofetil (MMF) in combination with steroids might be an alternative first‐line therapy, but results from a randomized trial are awaited. MMF as a second‐line maintenance agent has moderate efficacy though more frequent adverse events in patients with cirrhosis may be seen. Tacrolimus may be an equally effective second‐line option particularly in non‐responders, but data remain limited. Management of recurrent AIH post‐liver transplantation remains controversial with insufficient data to support long‐term steroid use. Moving forward, expanding the scope of therapeutic options to include biologics including B‐cell depleting agents may be a promising step. Recent insights in understanding the pathogenesis of AIH could serve as a basis for future therapies, including the elucidation of different immunoregulatory pathways and the potential role of the intestinal microbiome.

Summary Background Sarcopenia is associated with both increased wait‐list mortality and mortality following liver transplantation. Aims To determine the course of sarcopenia from transplant evaluation until 1 year post‐transplant, and its implications on hospitalisation and mortality following liver transplantation. Methods Two hundred and ninety‐three transplant recipients from 2002 to 2006 had pre‐transplant CT scans analysed at the third lumbar region for sarcopenia, myosteatosis and abdominal visceral fat content. Half the recipients had post‐transplant CT scan for interpretation (161/293). Results Sarcopenia was present in 146/293 (50%) of the patients pre‐transplant. There was a significant decrease in muscle mass (loss 2.0 ± 4.9 cm 2 /m 2 ; P < 0.001), and an increase in myosteatosis while awaiting liver transplantation. There was no significant change in abdominal visceral fat. For every 1 cm 2 /m 2 decrease in muscle mass there was an increase in post‐transplant length of stay by 0.36 days ( P = 0.005). Post‐transplant, 98/161 (61%) of patients with CT imaging had sarcopenia (25 de novo and 73 persistent), with continued increase in myosteatosis, lower Hounsfield units (−5.0 [IQR −8.6 to 0.1]; P < 0.001) and an increase in abdominal visceral fat (4.9 [IQR −4.4 to 15.6] cm 2 /m 2 ; P < 0.001). There was no statistically significant difference in 1‐year mortality in patients with de novo sarcopenia compared to patients with sarcopenia both pre‐ and post‐transplant (HR 1.88; P = 0.088). Conclusions Sarcopenia progresses up to 1 year following liver transplantation and is associated with an increase in post‐transplant length of stay.