The Value of Liver Biopsy and Histology in Liver Disease Diagnosis and Patient Care-a Pragmatic Prospective Clinical Practice Study

GOALS

We aimed to examine the correlation of pre-biopsy clinical diagnosis with hepatic histopathology.

BACKGROUND

Liver biopsy provides histologic information and informs physicians about the underlying clinical disease. We hypothesized that expert physicians' pre-biopsy clinical diagnoses may obviate the need for histopathological diagnosis.

STUDY METHODS

Patients undergoing liver biopsy to investigate a liver diagnosis were prospectively identified. In the 80 patients included, an anonymous validated questionnaire inquiring about the most likely clinical diagnosis and liver disease stage was completed prospectively by hepatologists before biopsy performance.

RESULTS

The most common pre-biopsy diagnoses were alcoholic liver disease (19 diagnoses), followed by non-alcoholic steatohepatitis and autoimmune hepatitis (18 each). Overall, the predicted histologic diagnosis was the same as the histologic diagnosis in 51/80 patients (64%), and thus a new liver disease diagnosis was made in 36% of patients. The diagnosis with the greatest pre-biopsy and post-biopsy diagnosis discrepancy was autoimmune hepatitis, with the correct diagnosis being predicted in 6/18 (33%) of patients (other diagnoses included the following: non-alcoholic steatohepatitis/non-alcoholic fatty liver disease (4), alcoholic liver disease (3), drug-induced liver injury (3), others (2)). For fibrosis staging, when grouped as no fibrosis (F0), fibrosis (F1-F3), or cirrhosis (F4), the fibrosis stage was correctly predicted in 68% of patients (54/80). Notably, 7 patients (9%) who were initially thought to have no or early-stage fibrosis had F4 fibrosis, and 6/80 (8%) patients who were considered to have a liver disease diagnosis before their biopsy had normal histology.

CONCLUSIONS

Although hepatology experts often predict the correct underlying liver disease diagnosis, histopathological diagnoses different from expected are common.

Comparison of the Safety of Transjugular and Percutaneous Liver Biopsies

PURPOSE

To compare adverse events (AEs) between the transjugular liver biopsy (TJLB) and percutaneous liver biopsy (PLB) approaches.

MATERIALS AND METHODS

A total of 1,300 patients who underwent liver biopsy between July 1, 2014 and January 31, 2018, were examined, and bivariate and multivariate analyses were used to determine predictors of the biopsy method used and AEs. To reduce bias in the comparison of the AE rates between patients who had TJLB or PLB, propensity score matching was used to control for baseline disease severity.

RESULTS

PLB and TJLB were performed in 601 and 699 patients, respectively. The mean Charlson Comorbidity Index score was 3 (±2), and antiplatelet or anticoagulation therapy at the time of biopsy was used in <10% of patients. Patients with suspected cirrhosis or portal hypertension (odds ratio [OR], 9.9), an international normalized ratio of >1.5 (OR, 5.9), or a platelet count of <100 × 103/mL (OR, 3.9) were more likely to undergo TJLB. After propensity matching, which identified a population of patients with a mean international normalized ratio of <1.5 and platelet count of >150 × 103/mL, the only difference in the AE rate was for pain, which was present in 8% and 10% of patients after TJLB and PLB, respectively (P < .001). Bleeding requiring transfusion occurred in 2 patients who underwent TJLB and 1 patient who underwent PLB. There was 1 case of death occurring after TJLB.

CONCLUSIONS

Severe/life-threatening AEs occurring after liver biopsy were uncommon, and the 2 liver biopsy approaches appeared to have similar safety profiles for low-risk patients. After matching for underlying disease severity, pain was the AE that was more likely to occur in patients who underwent PLB.

Structural insights into the career path between pre- and postgraduate physician-scientist training programs

The growing complexities of clinical medicine and biomedical research have clouded the career path for physician-scientists. In this perspective piece, we address one of the most opaque career stage transitions along the physician-scientist career path, the transition from medical school to research-focused internal medicine residency programs, or physician-scientist training programs (PSTPs). We present the perspectives of medical scientist training program (MSTP) and PSTP directors on critical features of PSTPs that can help trainees proactively align their clinical and scientific training for successful career development. We aim to provide both trainees and MSTP directors with a conceptual framework to better understand and navigate PSTPs. We also offer interview-specific questions to help trainees gather data and make informed decisions in choosing a residency program that best supports their career.

Hyperbilirubinemia in hospitalized patients: Etiology and outcomes

There is little information on the differential diagnosis and prognosis of hospitalized patients with hyperbilirubinemia. Here, we hypothesized that hyperbilirubinemia in hospitalized patients is associated with specific diseases and outcomes. This retrospective cohort analysis included patients admitted to the Medical University of South Carolina with a total bilirubin >3 mg/dL from January 9, 2015 to August 25, 2017. Collected clinical data included demographics, primary diagnosis, Charlson Comorbidity Index (CCI), laboratory data, and clinical outcomes. We separated and analyzed the cohort into seven primary diagnostic groups. We identified 1693 patients with a bilirubin level >3 mg/dL. The cohort was 42% female, had an average age of 54, average CCI of 4.8, and average length of stay of 13 days. The causes of hyperbilirubinemia included the following: primary liver disease (868/1693; 51%) with cirrhosis being most common (385/1693; 23%), benign biliary obstruction (252/1693; 15%), hemolytic anemia (149/1693; 9%), malignant biliary obstruction (121/1693; 7%), unknown etiology (108/1693; 6%), primary liver cancer (74/1693; 4%), and metastatic cancer to the liver (57/1693; 3%). Overall, the mortality/discharge to hospice rate in patients with a bilirubin >3 mg/dL was 30%, and was proportional to the severity of hyperbilirubinemia, including when controlling for the underlying severity of illness. Mortality was highest in patients with primary liver disease and malignancy and was lowest in patients with non-cancerous obstruction or hemolytic jaundice. Hyperbilirubinemia in hospitalized patients is most often due to primary liver disease, and identifies patients with a poor prognosis, particularly when caused by primary liver disease or cancer.

Paxillin regulates liver fibrosis via actin polymerization and ERK activation in hepatic stellate cells

Liver injury leads to fibrosis and cirrhosis. The primary mechanism underlying the fibrogenic response is the activation of hepatic stellate cells (HSCs), which are 'quiescent' in normal liver but become 'activated' after injury by transdifferentiating into extracellular matrix (ECM)-secreting myofibroblasts. Given that integrins are important in HSC activation and fibrogenesis, we hypothesized that paxillin, a key downstream effector in integrin signaling, might be critical in the fibrosis pathway. Using a cell-culture-based model of HSC activation and in vivo models of liver injury, we found that paxillin is upregulated in activated HSCs and fibrotic livers. Overexpression of paxillin (both in vitro and in vivo) led to increased ECM protein expression, and depletion of paxillin in a novel conditional mouse injury model reduced fibrosis. The mechanism by which paxillin mediated this effect appeared to be through the actin cytoskeleton, which signals to the ERK pathway and induces ECM protein production. These data highlight a novel role for paxillin in HSC biology and fibrosis.

Natural History and Outcomes of Cavernous Transformation of the Portal Vein in Cirrhosis

BACKGROUND AND AIMS

Cavernous transformation of the portal vein can occur after portal vein thrombosis (PVT). In this study, we investigated clinical complications associated with cavernous transformation in the context of cirrhosis and PVT.

METHODS

In this retrospective cohort analysis, 204 patients with cirrhosis and PVT with or without cavernous transformation were identified using MUSC's Clinical Data Warehouse between January 1, 2013, through December 31, 2019. Complete demographic data, clinical history, and laboratory tests were abstracted from the electronic medical record.

RESULTS

Of 204 patients, 41 (20%) had cavernous transformation. MELD, Child-Pugh, and Charlson Comorbidity Index scores were similar among groups. There were no significant differences in the prevalence of esophageal varices (with or without bleeding), splenomegaly, or hepatic encephalopathy in patients with and without cavernous transformation, although ascites tended to be lower in patients with cavernous transformation (31/41 (76%) vs 142/163 (87%), p = 0.06). Patients with cavernous transformation were significantly less likely to have hepatocellular carcinoma (HCC) (13/41 (32%) vs 81/163 (50%), p < 0.05) and had significantly lower APRI (1.4 vs 2.0, p < 0.05) and Fib-4 (4.7 vs 6.5, p < 0.05). Patients with cavernous transformation had lower 5-year mortality (12/41 (29%) vs 81/163 (49%) died, p = 0.06). The 10-year mortality of patients with cavernous transformation without HCC was significantly lower than in those without cavernous transformation (8/28 (29%) vs 46/82 (56%), respectively, p < 0.05).

CONCLUSIONS

Patients with cavernous transformation appeared to have better outcomes than those without cavernous transformation.

Development and Validation of a Novel 1-year Mortality Risk Score That Includes the Use of Antithrombotic in Patients With Overt Gastrointestinal Bleeding

GOALS AND BACKGROUND

We aimed to develop a novel 1-year mortality risk-scoring system that includes use of antithrombotic (AT) drugs and to validate it against other scoring systems in patients with acute gastrointestinal bleeding (GIB).

STUDY

We developed a risk-scoring system from prospectively collected data on patients admitted with GIB between January 2013 and August 2020, who had at least 1- year of follow-up. Independent predictors of 1-year mortality were determined after adjusting for the following confounders: the age-adjusted Charlson Comorbidity Index (CCI) (divided into 4 groups: CCI-0=0, CCI-1=1 to 3, CCI-2=4 to 6, CCI-3 ≥7), need for blood transfusion, GIB severity, need for endoscopic therapy, and type of AT. The risk score was based on independent predictors.

RESULTS

Five hundred seventy-six patients were included and 123 (21%) died at 1-year follow-up. Our risk -score was based on the following: CCI-2 (2 points), CCI-3 (4 points), need for blood transfusion (1 point), and no use of aspirin (1 point), as aspirin use was protective (maximum score=6). Patients with higher risk scores had higher mortality. The model had a better predictive accuracy [AUC=0.82, 95% confidence interval (0.78-0.86), P <0.0001] than the Rockall score for upper GIB (Area Under the Curve (AUC)=0.68, P <<0.0001), the Oakland score for lower GIB (AUC=0.69, p =0.004), or the Shock Index for all (AUC=0.54, P <0.0001).

CONCLUSION

A simple and novel score that includes use of AT upon admission accurately predicts 1-year mortality in patients with GIB. This scoring system may help guide follow-up decisions and inform the prognosis of patients with GIB.

Takotsubo Cardiomyopathy Associated With Acute Pancreatitis

Takotsubo cardiomyopathy is classically associated with emotional stress in middle-aged women. In clinical practice, physical stressors are a more common cause of Takotsubo cardiomyopathy. Here, we present two patients who had acute pancreatitis as a physical stressor that caused Takotsubo cardiomyopathy, and an additional 13 cases identified in the literature. An important clinical feature of these cases is that because metabolic derangements are often encountered, close attention to electrolyte repletion with cardiac monitoring is indicated.

Accurate Identification of Patients with Cirrhosis and Its Complications in the Electronic Health Record

BACKGROUND

Cirrhosis represents a significant health burden; administrative data provide an important tool for research studies.

AIMS

We aimed to understand the validity of current ICD-10 codes compared to previously used ICD-9 codes to identify patients with cirrhosis and its complications.

METHODS

We identified 1981 patients presenting to MUSC between 2013 and 2019 with a diagnosis of cirrhosis. To validate the sensitivity of ICD codes, we reviewed the medical records of 200 patients for each associated ICD 9 and 10 codes. Sensitivity, specificity, and positive predictive value for each ICD code (individually or when combined) were calculated and univariate binary logistic models, for cirrhosis and its complications, predicted probabilities were used to calculate C-statistics.

RESULTS

Single ICD 9 and 10 codes were similarly insensitive for detection of cirrhosis, with sensitivity ranging from 5 to 94%. However, ICD-9 code combinations (when used as either/or) had high sensitivity and specificity for the detection of cirrhosis, with the combination of either 571.5 (or 456.21) or 571.2 codes having a C-statistic of 0.975. Combinations of ICD-10 codes were only slightly less sensitive and specific than ICD-9 codes for detection of cirrhosis (K76.6, or K70.31, plus K74.60 or K74.69, and K70.30 had a C-statistic of 0.927).

CONCLUSIONS

ICD-9 and ICD-10 codes when used alone were inaccurate for identifying cirrhosis. ICD-10 and ICD-9 codes had similar performance characteristics. Combinations of ICD codes exhibited the greatest sensitivity and specificity for detection of cirrhosis, and thus should be used to accurately identify cirrhosis.

The role of artificial intelligence in hepatology research and practice

PURPOSE OF REVIEW

The use of artificial intelligence (AI) in examining large data sets has recently gained considerable attention to evaluate disease epidemiology, management approaches, and disease outcomes. The purpose of this review is to summarize the current role of AI in contemporary hepatology practice.

RECENT FINDINGS

AI was found to be diagnostically valuable in the evaluation of liver fibrosis, detection of cirrhosis, differentiation between compensated and decompensated cirrhosis, evaluation of portal hypertension, detection and differentiation of particular liver masses, preoperative evaluation of hepatocellular carcinoma as well as response to treatment and estimation of graft survival in patients undergoing liver transplantation. AI additionally holds great promise in examination of structured electronic health records data as well as in examination of clinical text (using various natural language processing approaches). Despite its contributions, AI has several limitations, including the quality of existing data, small cohorts with possible sampling bias and the lack of well validated easily reproducible models.

SUMMARY

AI and deep learning models have extensive applicability in assessing liver disease. However, multicenter randomized controlled trials are indispensable to validate their utility.

Timing of endoscopy for acute variceal bleeding in patients with cirrhosis (CHESS1905): A nationwide cohort study

BACKGROUND

Endoscopy plays an important role in the management of acute variceal bleeding (AVB) in patients with cirrhosis. This study aimed at determining the optimal endoscopy timing for cirrhotic AVB.

METHODS

Patients with cirrhosis with AVB across 34 university hospitals in 30 cities from February 2013 to May 2020 who underwent endoscopy within 24 hours were included in this study. Patients were divided into an urgent endoscopy group (endoscopy <6 h after admission) and an early endoscopy group (endoscopy 6-24 h after admission). Multivariable analysis was performed to identify risk factors for treatment failure. Primary outcome was the incidence of 5-day treatment failure. Secondary outcomes included in-hospital mortality, need for intensive care unit, and length of hospital stay. A propensity score matching analysis was performed. In addition, we performed an analysis, in which we compared the 5-day treatment failure incidence and the in-hospital mortality among patients with endoscopy performed at <12 hours and 12-24 hours.

RESULTS

A total of 3319 patients were enrolled: 2383 in the urgent endoscopy group and 936 in the early endoscopy group. After propensity score matching, on multivariable analysis, Child-Pugh class was identified as an independent risk factor for 5-day treatment failure (HR, 1.61; 95% CI: 1.09-2.37). The incidence of 5-day treatment failure was 3.0% in the urgent endoscopy group and 2.9% in the early group ( p = 0.90). The in-hospital mortality was 1.9% in the urgent endoscopy group and 1.2% in the early endoscopy group ( p = 0.26). The incidence of need for intensive care unit was 18.2% in the urgent endoscopy group and 21.4% in the early endoscopy group ( p = 0.11). The mean length of hospital stay was 17.9 days in the urgent endoscopy group and 12.9 days in the early endoscopy group ( p < 0.05). The incidence of 5-day treatment failure in the <12-hour group was 2.3% and 2.2% in the 12-24 hours group ( p = 0.85). The in-hospital mortality was 2.2% in the <12-hour group and 0.5% in the 12-24 hours group ( p < 0.05).

CONCLUSIONS

The data suggest that performance of endoscopy within 6-12 or within 24 hours of presentation among patients with cirrhosis with AVB led to similar treatment failure outcomes.

Review article: controversies surrounding the use of carvedilol and other beta blockers in the management of portal hypertension and cirrhosis

BACKGROUND

Advanced chronic liver disease is an increasing cause of premature morbidity and mortality in the UK. Portal hypertension is the primary driver of decompensation, including the development of ascites, hepatic encephalopathy and variceal haemorrhage. Non-selective beta blockers (NSBB) reduce portal pressure and are well established in the prevention of variceal haemorrhage. Carvedilol, a newer NSBB, is more effective at reducing portal pressure due to additional α-adrenergic blockade and has additional anti-oxidant, anti-inflammatory and anti-fibrotic effects.

AIM

To summarise the available evidence on the use of beta blockers, specifically carvedilol, in cirrhosis, focussing on when and why to start METHODS: We performed a comprehensive literature search of PubMed for relevant publications.

RESULTS

International guidelines advise the use of NSBB in primary prophylaxis against variceal haemorrhage in those with high-risk varices, with substantial evidence of efficacy comparable with endoscopic band ligation (EBL). NSBB are also well established in secondary prophylaxis, in combination with EBL. More controversial is their use in patients without large varices, but with clinically significant portal hypertension. However, there is gathering evidence that NSBB, particularly carvedilol, reduce the risk of decompensation and improve survival. While caution is advised in patients with advanced cirrhosis and refractory ascites, recent evidence suggests that NSBB can continue to be used safely, and that premature discontinuation may be detrimental.

CONCLUSIONS

With increasing evidence of benefit independent of variceal bleeding, namely retardation of decompensation and improvement in survival, it is time to consider whether carvedilol should be offered to all patients with advanced chronic liver disease.

Improved Mortality But Increased Economic Burden of Disease in Compensated and Decompensated Cirrhosis: A US National Perspective

INTRODUCTION

Cirrhosis remains a major burden on the health care system despite substantial advances in therapy and care. Studies simultaneously examining mortality, readmission, and cost of care are not available. Here, we hypothesized that improved patient care in the last decade might have led to improved outcomes and reduced costs in patients with cirrhosis.

MATERIALS AND METHODS

We identified compensated cirrhosis (CC) and decompensated cirrhosis (DC) patients using carefully chosen ICD-9/ICD-10 codes from the Nationwide Readmission Database (NRD) (years 2010 to 2016). We evaluated trends of 30-day all-cause mortality, 30-day readmission, and inflation-adjusted index hospitalization and readmission costs. Factors associated with mortality and readmission were identified using regression analyses.

RESULTS

A total of 3,374,038 patients with cirrhosis were identified, of whom nearly 50% had a decompensating event on initial admission. The 30-day inpatient mortality rate for both CC and DC patients decreased from 2010 to 2016. The 30-day readmission rate remained stable for DC and declined for CC. Over the study period, 30-day readmission costs increased for DC and remained unchanged for CC. The median cost for index hospitalization remained nearly unchanged, but the cost of readmission increased for both CC and DC groups. Gastrointestinal diseases and infections were the leading cause of readmission in CC and DC patient groups.

CONCLUSION

Inpatient mortality has decreased for CC and DC patients. Readmission has declined for CC patients and remained stable for DC patients. However, the economic burden of cirrhosis is rising.

Dosing of Rifaximin Soluble Solid Dispersion Tablets in Adults With Cirrhosis: 2 Randomized, Placebo-controlled Trials

BACKGROUND & AIMS

Cirrhosis-related complications are a major burden. Rifaximin soluble solid dispersion (SSD) tablets (immediate-release [IR]; sustained extended-release [SER]) were designed to increase rifaximin water solubility. These analyses evaluate dosing for prevention of cirrhosis complication-related hospitalizations/mortality and overt hepatic encephalopathy (OHE) treatment.

METHODS

Two phase II, randomized, double-blind, placebo-controlled trials were conducted. Trial 1: outpatients with early decompensated cirrhosis randomized to placebo or rifaximin SSD once-nightly: IR 40 or 80 mg, SER 40 or 80 mg, or IR 80 mg plus SER 80 mg, for 24 weeks. Trial 2: inpatients with OHE randomized to lactulose plus placebo or rifaximin SSD: IR 40 mg once or twice daily or SER 80 mg once or twice daily for ≤14 days. Primary efficacy endpoint: time to cirrhosis complication-related hospitalization/all-cause mortality (Trial 1) or time to OHE resolution (Trial 2).

RESULTS

In Trial 1 (n = 516), no significant difference in time to cirrhosis complication-related hospitalization/all-cause mortality vs placebo. In a post hoc analysis, time to all-cause hospitalization/all-cause mortality was improved with IR 40 mg vs placebo (15.4% [12/78] vs 27.7% [26/94]; P = .03). A Trial 2 prespecified interim analysis (n = 71) showed lactulose plus rifaximin SSD IR 40 mg bid significantly reduced median time to OHE resolution (21.1 hours) vs lactulose plus placebo (62.7 hours; P = .02). Trial 2 was subsequently terminated.

CONCLUSION

Rifaximin SSD IR 40 mg may reduce hospitalizations in patients with cirrhosis and shorten duration of OHE during hospitalization-considered a negative finding, yet also hypothesis-generating. (ClinicalTrials.govNCT01904409; NCT03515044).

An AI Approach for Identifying Patients With Cirrhosis

GOAL

The goal of this study was to evaluate an artificial intelligence approach, namely deep learning, on clinical text in electronic health records (EHRs) to identify patients with cirrhosis.

BACKGROUND AND AIMS

Accurate identification of cirrhosis in EHR is important for epidemiological, health services, and outcomes research. Currently, such efforts depend on International Classification of Diseases (ICD) codes, with limited success.

MATERIALS AND METHODS

We trained several machine learning models using discharge summaries from patients with known cirrhosis from a patient registry and random controls without cirrhosis or its complications based on ICD codes. Models were validated on patients for whom discharge summaries were manually reviewed and used as the gold standard test set. We tested Naive Bayes and Random Forest as baseline models and a deep learning model using word embedding and a convolutional neural network (CNN).

RESULTS

The training set included 446 cirrhosis patients and 689 controls, while the gold standard test set included 139 cirrhosis patients and 152 controls. Among the machine learning models, the CNN achieved the highest area under the receiver operating characteristic curve (0.993), with a precision of 0.965 and recall of 0.978, compared with 0.879 and 0.981 for the Naive Bayes and Random Forest, respectively (precision 0.787 and 0.958, and recalls 0.878 and 0.827). The precision by ICD codes for cirrhosis was 0.883 and recall was 0.978.

CONCLUSIONS

A CNN model trained on discharge summaries identified cirrhosis patients with high precision and recall. This approach for phenotyping cirrhosis in the EHR may provide a more accurate assessment of disease burden in a variety of studies.

β-PIX cooperates with GIT1 to regulate endothelial nitric oxide synthase in sinusoidal endothelial cells

Previous studies have demonstrated that G protein-coupled receptor kinase interacting-1 protein (GIT1) associates with endothelial nitric oxide synthase (eNOS) to regulate nitric oxide production in sinusoidal endothelial cells (SECs). Here, we hypothesized that GIT1's tightly associated binding partner, β-PIX (p21-activated kinase-interacting exchange factor β, ARHGEF7) is specifically important in the regulation of eNOS activity. We examined β-PIX expression in normal rat liver by immunohistochemistry and explored β-PIX protein-protein interactions using immunoprecipitation and immunoblotting. The role of β-PIX in regulating eNOS enzymatic activity was studied in GIT1-deficient SECs. Finally, structural analysis of interaction sites in GIT1 and β-PIX required to regulate eNOS activity were mapped. β-PIX was expressed primarily in SECs in normal liver and was either absent or expressed at extremely low levels in other liver cells (stellate cells, Kupffer cells, and hepatocytes). β-PIX interacted with GIT1 and eNOS to form a trimolecular signaling module in normal SECs and was important in stimulating eNOS activity. Of note, GIT1-β-PIX interaction led to synergistic enhancement of eNOS activity, and β-PIX-driven increase in eNOS activity was GIT1 dependent. Disruption of β-PIX or GIT1 in normal SECs using β-PIX siRNA or GIT1-deficient SECs led to reduced eNOS activity. Finally, specific GIT1 domains [Spa2 homology domain (SHD) and synaptic localization domain (SLD), aa 331-596] and the β-PIX COOH terminal (aa 496-555) appeared to be critical in the regulation eNOS activity. The data indicate that β-PIX regulates eNOS phosphorylation and function in normal SECs and highlight the importance of the GIT1/β-PIX/eNOS trimolecular complex in normal liver SEC function.NEW & NOTEWORTHY β-PIX is a multidomain protein known to be a GIT1 binding partner. We report here that in the normal liver, the distribution and cellular localization of β-PIX are restricted largely to sinusoidal endothelial cells. Furthermore, β-PIX interacts with eNOS and GIT1 promotes eNOS activity and NO production and therefore exerts a novel posttranslational regulatory function on eNOS activity in sinusoidal endothelial cells. We also have identified specific molecular domains important in GIT1 and β-PIX's interaction with eNOS, which may represent novel therapeutic targets in the control of sinusoidal blood flow and intrahepatic resistance.

Characterization of focal adhesion proteins in rodent hepatic stellate cells

Ongoing liver injury leads to fibrosis and ultimately cirrhosis, a leading cause of death worldwide. The primary mechanism underlying the fibrogenic response is the activation of cells known as hepatic stellate cells (HSCs) which are "quiescent" in the normal liver but become "activated" after injury by transdifferentiating into extracellular matrix-secreting myofibroblasts. Since integrins (extracellular matrix binding receptors) are important mediators of HSC activation and fibrogenesis, we hypothesized that focal adhesion (FA) proteins, which link integrins to the intracellular protein machinery, may be important in the activation process. Therefore, using both an in vitro model of activation in primary rat HSCs and an in vivo model of liver injury, we examined three FA proteins: vinculin, FAK, and talin. All three proteins were significantly upregulated during HSC activation at both the messenger RNA (mRNA) and protein levels. Confocal microscopy demonstrated that the proteins had a widespread expression throughout HSCs with prominent localization at the end of actin filaments. Finally, we stimulated HSCs with the profibrotic ligands endothelin-1 (ET-1) and transforming growth factor beta (TGF-β) and observed an increase in the size of vinculin-containing FAs and the cell area occupied by them. The data indicate that HSCs possess a broad array of FA proteins, and given their upregulation during activation, this raises the possibility that they play a role in the fibrogenic response to injury.

A novel quantitative computer-assisted drug-induced liver injury causality assessment tool (DILI-CAT)

Background and aims

We hypothesized that a drug’s clinical signature (or phenotype) of liver injury can be assessed and used to quantitatively develop a computer-assisted DILI causality assessment-tool (DILI-CAT). Therefore, we evaluated drug-specific DILI-phenotypes for amoxicillin-clavulanate (AMX/CLA), cefazolin, cyproterone, and Polygonum multiflorum using data from published case series, to develop DILI-CAT scores for each drug.

Methods

Drug specific phenotypes were made up of the following three clinical features: (1) latency, (2) R-value, and (3) AST/ALT ratio. A point allocation system was developed with points allocated depending on the variance from the norm (or “core”) for the 3 variables in published datasets.

Results

The four drugs had significantly different phenotypes based on latency, R-value, and AST/ALT ratio. The median cyproterone latency was 150 days versus < 43 days for the other three drugs (median: 26 for AMX/CLA, 20 for cefazolin, and 20 for Polygonum multiflorum; p<0.001). The R-value for the four drugs was also significantly different among drugs (cyproterone [median 12.4] and Polygonum multiflorum [median 10.9]) from AMX/CLA [median 1.44] and cefazolin [median 1.57; p<0.001]). DILI-CAT scores effectively separated cyproterone and Polygonum multiflorum from AMX/CLA and cefazolin, respectively (p<0.001). As expected, because of phenotypic overlap, AMX/CLA and cefazolin could not be well differentiated.

Conclusions

DILI-CAT is a data-driven, diagnostic tool built to define drug-specific phenotypes for DILI adjudication. The data provide proof of principle that a drug-specific, data-driven causality assessment tool can be developed for different drugs and raise the possibility that such a process could enhance causality assessment methods.

The natural history of patients with compensated cirrhosis and elevated hepatic venous pressure gradient

Aims

Portal hypertension is a major complication of liver cirrhosis. Hepatic venous pressure gradient (HVPG) appears to be one of the best surrogates of clinical outcomes. However, the utility of elevated HVPG in predicting subsequent clinical decompensation is unclear.

Methods

We analyzed 410 patients who underwent HVPG assessment between 2014 and 2018. Of these, we identified and analyzed 20 patients with HVPG >12 mmHg without evidence of clinical decompensation (defined as ascites, non-bleeding esophageal varices or bleeding esophageal varices, hepatic encephalopathy, hepato-pulmonary syndrome, or hepatic hydrothorax). Additionally, we compared this group to 40 randomly selected cirrhotic patients with HVPG >12 mmHg with signs of clinical decompensation. Clinical events were subsequently assessed (mean = 33 months) after HVPG measurement.

Results

Patients with high HVPG without evidence of clinical decompensation had significantly lower model for end stage liver disease (MELD) scores (8 ± 4) compared to decompensated patients (13 ± 8, P = 0.05). HVPG measurements were similar in compensated (17 ± 6 mmHg) and decompensated (18 ± 4 mmHg) patients. Over follow-up for 33 months, 8/20 compensated patients had a decompensating event and neither MELD (8 and 8, respectively) nor HVPG (17 mmHg and 18 mmHg, respectively) differentiated patients who remained compensated vs. those that decompensated. Serum albumin at the time of HVPG measurement was significantly higher in patients who remained compensated than those with a decompensating event (3.5 g/dL vs. 2.6 g/dL, respectively, P = 0.05).

Conclusions

A small, unique, population of cirrhotic patients with substantially elevated HVPG appear to remain free of complications over long term follow-up.

Fibroblast fate determination during cardiac reprogramming by remodeling of actin filaments

Fibroblasts can be reprogrammed into induced cardiomyocyte-like cells (iCMs) by forced expression of cardiogenic transcription factors. However, it remains unknown how fibroblasts adopt a cardiomyocyte (CM) fate during their spontaneous ongoing transdifferentiation toward myofibroblasts (MFs). By tracing fibroblast lineages following cardiac reprogramming in vitro, we found that most mature iCMs are derived directly from fibroblasts without transition through the MF state. This direct conversion is attributable to mutually exclusive induction of cardiac sarcomeres and MF cytoskeletal structures in the cytoplasm of fibroblasts during reprogramming. For direct fate switch from fibroblasts to iCMs, significant remodeling of actin isoforms occurs in fibroblasts, including induction of α-cardiac actin and decrease of the actin isoforms predominant in MFs. Accordingly, genetic or pharmacological ablation of MF-enriched actin isoforms significantly enhances cardiac reprogramming. Our results demonstrate that remodeling of actin isoforms is required for fibroblast to CM fate conversion by cardiac reprogramming.

The impact of red blood cell transfusion practices on inpatient mortality in variceal and non-variceal gastrointestinal bleeding patients: a 20-year US nationwide retrospective analysis

BACKGROUND

Previous studies in upper gastrointestinal (GI) bleeding have reported inconsistent outcomes about packed red blood cell (PRBC) transfusion practices.

AIM

To assess whether PRBC transfusion is more likely to be dangerous in variceal bleeding than in non-variceal bleeding due to concern of over-transfusion leading to elevated portal pressure.

METHODS

We used the Nationwide Inpatient Sample (1999-2018). We identified patients with upper GI bleeding using an algorithmic approach, categorising bleeding from non-variceal or variceal sources. Our primary outcome was all-cause inpatient mortality. To control for the severity of bleeding, we performed propensity matching of baseline features, including age, gender, the presence of shock, the need for ICU care and co-morbidities. We also examined PRBC transfusion, inpatient mortality and hospitalisation rates for both populations.

RESULTS

We included 10,228,524 upper GI bleeding discharges; 755,135 patients had variceal bleeding. After propensity matching, PRBC transfusion in variceal bleeders was associated with a 22% increase in inpatient mortality, whereas non-variceal bleeders had a 9% increase in inpatient mortality. Compared to non-variceal bleeders receiving blood transfusion, variceal bleeders had nearly four-fold higher odds of inpatient mortality (propensity-matched OR: 3.8; 95% CI: 3.7-3.8; p < 0.001). Notably, PRBC transfusion rates in both groups have declined since 2011, although it has remained higher in variceal bleeders. Mortality for upper GI bleeding has been declining since 1999.

CONCLUSIONS

Although decreased over the last decade, PRBC transfusion rates remain high for variceal bleeders. In addition, PRBC transfusion appears to be more detrimental in variceal bleeders than in non-variceal bleeders.