Acute hepatitis and acute liver failure: Pathologic diagnosis and differential diagnosis

Cost-effective analysis of hepatitis A vaccination in Kerala state, India

Several hepatitis A outbreaks have recently been reported in Kerala state, India. To inform coverage decision of hepatitis A vaccine in Kerala, this study aimed to examine the cost-effectiveness of 1) hepatitis A vaccination among children aged 1 year and individuals aged 15 years, and 2) serological screening of individuals aged 15 years and vaccination of susceptible as compared to no vaccination or vaccination without serological screening. Both live attenuated hepatitis A vaccine and inactivated hepatitis A vaccine were considered in the analysis. A combination of decision tree and Markov models with a cycle length of one year was employed to estimate costs and benefits of different vaccination strategies. Analysis were based on both societal and payer perspectives. The lifetime costs and outcomes were discounted by 3%. Our findings indicated that all strategies were cost-saving for both societal and payer perspectives. Moreover, budget impact analysis revealed that vaccination without screening among individuals aged 15 years could save the government's budget by reducing treatment cost of hepatitis A. Our cost-effectiveness evidence supports the inclusion of hepatitis A vaccination into the vaccination program for children aged 1 year and individuals aged 15 years in Kerala state, India.

Acute liver failure histopathology: A 5-year retrospective study

BACKGROUND

Acute liver failure (ALF) is a rare, life-threatening disease of diverse etiology. It is defined as severe acute liver injury for fewer than 26 weeks' duration with encephalopathy and impaired synthetic function (international normalized ratio [INR] of 1.5 or higher) in a patient without cirrhosis or pre-existing liver disease. The diagnosis rests mainly on the clinical ground with wide range of pathological features. The present study seeks to explore the diverse histological patterns observed in cases for ALF and assess their usefulness in determining the underlying causes for the condition.

METHODOLOGY

A retrospective cross-sectional study was conducted among patients of ALF who underwent liver transplant and transjugular liver biopsy over a five-year period. From 1082 explant liver and 2446 liver biopsies, 22 cases of ALF (10 explants and 12 liver biopsies) were included in the study. Clinical and laboratory details were retrieved and histological findings were reviewed.

RESULT

Age ranged from 10 to 72 years (mean age, 40 years). There was a female predominance with a male:female ratio of 1:1.7. The commonest cause for ALF was virus-induced hepatocellular damage in 36.3% (eight patients), followed by autoimmune hepatitis in 22.7% (five patients), drug-induced liver injury (DILI) in 18.1% (four patients), cryptogenic in 13.6% (three patients) and ischemic injury secondary to large vein thrombosis in 9.0% (two) patients. The histological patterns identified were categorized into six categories. A more comprehensive morphological evaluation was conducted specifically for cases of ALF associated with autoimmune hepatitis (AIH) and compared with other cases of ALF.

CONCLUSION

In summary, our present study illustrates a morphological overlap in various patterns for the purpose of etiological assessment. In cases of AIH ALF, the presence of portal plasma cell infiltrate and central perivenulitis were identified as significant histological features to guide diagnosis.

Stem Cell-Based Strategies: The Future Direction of Bioartificial Liver Development

Acute liver failure (ALF) results from severe liver damage or end-stage liver disease. It is extremely fatal and causes serious health and economic burdens worldwide. Once ALF occurs, liver transplantation (LT) is the only definitive and recommended treatment; however, LT is limited by the scarcity of liver grafts. Consequently, the clinical use of bioartificial liver (BAL) has been proposed as a treatment strategy for ALF. Human primary hepatocytes are an ideal cell source for these methods. However, their high demand and superior viability prevent their widespread use. Hence, finding alternatives that meet the seed cell quality and quantity requirements is imperative. Stem cells with self-renewing, immunogenic, and differentiative capacities are potential cell sources. MSCs and its secretomes encompass a spectrum of beneficial properties, such as anti-inflammatory, immunomodulatory, anti-ROS (reactive oxygen species), anti-apoptotic, pro-metabolomic, anti-fibrogenesis, and pro-regenerative attributes. This review focused on the recent status and future directions of stem cell-based strategies in BAL for ALF. Additionally, we discussed the opportunities and challenges associated with promoting such strategies for clinical applications.

Emerging Pathogens Causing Acute Hepatitis

Acute hepatitis is defined as an inflammation or injury in the hepatocytes that continues for a short period of time (less than 6 months) [...].

Liver Regeneration and Immunity: A Tale to Tell

The physiological importance of the liver is demonstrated by its unique and essential ability to regenerate following extensive injuries affecting its function. By regenerating, the liver reacts to hepatic damage and thus enables homeostasis to be restored. The aim of this review is to add new findings that integrate the regenerative pathway to the current knowledge. An optimal regeneration is achieved through the integration of two main pathways: IL-6/JAK/STAT3, which promotes hepatocyte proliferation, and PI3K/PDK1/Akt, which in turn enhances cell growth. Proliferation and cell growth are events that must be balanced during the three phases of the regenerative process: initiation, proliferation and termination. Achieving the correct liver/body weight ratio is ensured by several pathways as extracellular matrix signalling, apoptosis through caspase-3 activation, and molecules including transforming growth factor-beta, and cyclic adenosine monophosphate. The actors involved in the regenerative process are numerous and many of them are also pivotal players in both the immune and non-immune inflammatory process, that is observed in the early stages of hepatic regeneration. Balance of Th17/Treg is important in liver inflammatory process outcomes. Knowledge of liver regeneration will allow a more detailed characterisation of the molecular mechanisms that are crucial in the interplay between proliferation and inflammation.

Extreme Hyperferritinemia: Causes and Prognosis

The significance of extreme hyperferritinemia and its association with certain diagnoses and prognoses are not well characterized. We performed a retrospective analysis of adult patients with at least one total serum ferritin (TSF) measurement ≥ 5000 µg/L over 2 years, in three university hospitals. Conditions associated with hyperferritinemia were collected, and patients were classified into 10 etiological groups. Intensive care unit (ICU) transfer and mortality rates were recorded. A total of 495 patients were identified, of which 56% had a TSF level between 5000 and 10,000 µg/L. There were multiple underlying causes in 81% of the patients. The most common causes were infections (38%), hemophagocytic lymphohistiocytosis (HLH, 18%), and acute hepatitis (14%). For TSF levels > 10,000 µg/L, there were no solid cancer or hematological malignancy without another cause of hyperferritinemia. Isolated iron-overload syndromes never exceeded TSF levels > 15,000 µg/L. Extreme hyperferritinemia (TSF levels > 25,000 µg/L) was associated with only four causes: HLH, infections, acute hepatitis and cytokine release syndromes. A total of 32% of patients were transferred to an ICU, and 28% died. Both ICU transfer rate and mortality were statistically associated with ferritin levels. An optimized threshold of 13,405 μg/L was the best predictor for the diagnosis of HLH, with a sensitivity of 76.4% and a specificity of 79.3%. Hyperferritinemia reflects a variety of conditions, but only four causes are associated with extreme hyperferritinemia, in which HLH and acute hepatitis are the most common. Extreme hyperferritinemia has a poor prognosis with increased mortality.

Pediatric Acute Liver Failure: A Clinicopathological Perspective

Pediatric acute liver failure (PALF) is a life-threatening disorder characterized by acute hepatocellular injury occurring in children without recognized underlying liver disease. The clinicopathologic evaluation of PALF requires a different approach from that in adults. The diagnostic considerations differ depending on the age, personal and family history, geographical region, and clinical presentation. Distinct entities such as gestational alloimmune liver disease, herpes simplex virus infection, and metabolic disorders should be considered in neonates with acute liver failure, while acetaminophen toxicity and autoimmune hepatitis are more frequently seen in older children and adolescents. An identified cause for PALF despite a negative complete evaluation (indeterminate) is lacking in 30 to 50% of cases. Although not routinely performed in the setting of PALF, liver biopsy may be helpful in assessing the etiology, potential mechanisms of injury, determining the appropriateness of liver transplantation, and prognostication of the patients. In this article, we review the clinicopathologic characteristics of PALF with an emphasis on general approach of pathologic evaluation and histopathologic characteristic of selected entities.

Noninvasive imaging of hepatic dysfunction: A state-of-the-art review

Hepatic dysfunction represents a wide spectrum of pathological changes, which can be frequently found in hepatitis, cholestasis, metabolic diseases, and focal liver lesions. As hepatic dysfunction is often clinically silent until advanced stages, there remains an unmet need to identify affected patients at early stages to enable individualized intervention which can improve prognosis. Passive liver function tests include biochemical parameters and clinical grading systems (e.g., the Child-Pugh score and Model for End-Stage Liver Disease score). Despite widely used and readily available, these approaches provide indirect and limited information regarding hepatic function. Dynamic quantitative tests of liver function are based on clearance capacity tests such as the indocyanine green (ICG) clearance test. However, controversial results have been reported for the ICG clearance test in relation with clinical outcome and the accuracy is easily affected by various factors. Imaging techniques, including ultrasound, computed tomography, and magnetic resonance imaging, allow morphological and functional assessment of the entire hepatobiliary system, hence demonstrating great potential in evaluating hepatic dysfunction noninvasively. In this article, we provide a state-of-the-art summary of noninvasive imaging modalities for hepatic dysfunction assessment along the pathophysiological track, with special emphasis on the imaging modality comparison and selection for each clinical scenario.

Acute severe hepatitis outbreak in children: A perfect storm. What do we know, and what questions remain?

During the first half of 2022, the World Health Organization reported an outbreak of acute severe hepatitis of unknown aetiology (AS-Hep-UA) in children, following initial alerts from the United Kingdom (UK) where a cluster of cases was first observed in previously well children aged <6 years. Sporadic cases were then reported across Europe and worldwide, although in most countries incidence did not increase above the expected baseline. There were no consistent epidemiological links between cases, and microbiological investigations ruled out known infectious causes of hepatitis. In this review, we explore the evidence for the role of viral infection, superimposed on a specific host genetic background, as a trigger for liver pathology. This hypothesis is based on a high prevalence of Human Adenovirus (HAdV) 41F in affected children, together with metagenomic evidence of adeno-associated virus (Adeno-associated viruses)-2, which is a putative trigger for an immune-mediated liver injury. Roles for superantigen-mediated pathology have also been explored, with a focus on the potential contribution of SARS-CoV-2 infection. Affected children also had a high frequency of the MHC allele HLA-DRB1*04:01, supporting an immunological predisposition, and may have been vulnerable to viral coinfections due to disruption in normal patterns of exposure and immunity as a result of population lockdowns during the COVID-19 pandemic. We discuss areas of ongoing uncertainty, and highlight the need for ongoing scrutiny to inform clinical and public health interventions for this outbreak and for others that may evolve in future.

Equine Parvovirus-Hepatitis Screening in Horses and Donkeys with Histopathologic Liver Abnormalities

There is strong evidence that equine parvovirus-hepatitis (EqPV-H) is associated with the onset of Theiler's disease, an acute hepatic necrosis, in horses. However, the impact of this virus on other hepatopathies remains unknown. The objective of this retrospective study was to evaluate the prevalence and quantify the viral loads of EqPV-H in formalin-fixed, paraffin-embedded equine and donkey livers with various histopathologic abnormalities. The pathologies included cirrhosis, circulatory disorders of the liver, toxic and metabolic hepatic diseases as well as neoplastic and inflammatory diseases (n = 84). Eight normal liver samples were included for comparison as controls. EqPV-H DNA was qualitatively and quantitatively measured by real-time PCR and digital PCR, respectively. The virus was detected in two livers originating from horses diagnosed with abdominal neoplasia and liver metastasis (loads of 5 × 10³ and 9.5 × 10³ genome equivalents per million cells). The amount of viral nucleic acids measured indicates chronic infection or persistence of EqPV-H, which might have been facilitated by the neoplastic disease. In summary, this study did not provide evidence for EqPV-H being involved in hepatopathies other than Theiler's disease.

Study protocol: epidemiological and clinical characteristics of acute viral hepatitis in Brazilian health services

INTRODUCTION

Acute viral hepatitis is a disease of great clinical importance. This study proposes actions to better characterise cases of acute hepatitis in Brazil and to provide relevant information to institutionalised health policies within the Unified Health System. Available data on acute hepatitis in Brazil need to be re-evaluated regarding the different hepatotropic agent (hepatitis A to E virus) frequencies, as well as other agents that can cause similar clinical conditions, such as Herpes Simplex Virus 1 and 2(HSV1, HSV2), Varicella Zoster Virus (VZV), Cytomegalovirus (CMV), Epstein Barr Virus (EBV), Human Herpes Virus 6 and 7 (HHV6, HHV7), arbovirus (yellow fever, dengue, chikungunya, Zika), parvovirus B19, adenovirus, parechovirus, enterovirus, HIV, leptospirosis, toxoplasmosis and syphilis, in addition to autoimmune hepatitis. In this context, the primary aim of this study is the clinical-epidemiological and molecular characterisation of acute viral hepatitis in Brazilian health services from all geographical regions of the country. The present article describes the study protocol.

METHODS AND ANALYSIS

This study will evaluate 2280 patients with symptoms and/or signs suggestive of acute liver disease in Brazilian health institutions in all five geographic Brazilian regions. Demographic, epidemiological and clinical data will be collected, as well as blood samples to be analysed at Hospital Israelita Albert Einstein Clinical Laboratory.

ETHICS AND DISSEMINATION

Ethics approval was obtained at the national research ethics committee (Conselho Nacional de Ética em Pesquisa- CONEP-CAAE 00952818.4.1001.0071) and at all participating sites. Results will be published in journals and presented at scientific meetings.