Autoimmune acute liver failure: proposed clinical and histological criteria

Clinical Characteristics of Genuine Acute Autoimmune Hepatitis

Introduction

Autoimmune hepatitis (AIH) has a spectrum of symptoms ranging from asymptomatic disease to acute severe hepatitis, chronic hepatitis, and decompensated cirrhosis. The acute presentation is not rare and could represent genuine acute AIH (GAAIH) or acute exacerbation of chronic autoimmune hepatitis. We aimed to identify the prevalence, clinical features, and prognostic factors associated with GAAIH and compare these cases with acute exacerbation of chronic AIH.

Methods

This cross-sectional observational study evaluated patients with acute AIH presentation, defined as total bilirubin >5 times the upper limit of normality (xULN) and/or alanine aminotransferase >10 xULN, and no prior history of liver disease. Histology findings of acute disease defined GAAIH. Bivariate analyses were performed to identify factors associated with the GAAIH, when compared with acute exacerbation of chronic AIH.

Results

Seventy-two patients with acute presentation of AIH were included and six (8.3%) of them presented GAAIH. Comparative analysis between patients with GAAIH and patients with acute exacerbation of chronic AIH revealed that prothrombin activity (96% [74-100] vs. 61% [10-100]; p = 0.003) and albumin levels (3.9 ± 0.2 g/dL vs. 3.4 ± 0.5 g/dL; p < 0.001) were higher in patients with GAAIH. The International Autoimmune Hepatitis Group score was higher in patients with acute exacerbation of chronic AIH (18.5 [8-23] vs. 16.5 [15-17]; p = 0.010). Compared to 15.2% of acute exacerbation of chronic AIH, complete therapeutic response to treatment was achieved in 67.7% of cases with GAAIH (p = 0.018).

Conclusions

GAAIH was rare (8.3%), and patients with this presentation exhibited more preserved liver function tests, suggesting that most cases presenting with loss of function are acute exacerbation of chronic AIH. Additionally, patients with GAAIH had a better complete therapeutic response, suggesting a more preserved liver function at presentation, and early diagnosis has a positive therapeutic implication.

Severe acute liver disease in adults: Contemporary role of histopathology

Liver biopsies have consistently contributed to our understanding of the pathogenesis and aetiologies of acute liver disease. As other diagnostic modalities have been developed and refined, the role of biopsy in the management of patients with acute liver failure (ALF), acute-on-chronic liver failure (ACLF) and acute hepatitis, including acute liver injury (ALI), has changed. Liver biopsy remains particularly valuable when first-line diagnostic algorithms fail to determine aetiology. Despite not being identified as a mandatory diagnostic tool in recent clinical guidelines for the management of ALF or ACLF, many centres continue to undertake biopsies given the relative safety of transjugular biopsy in this setting. Several studies have demonstrated that liver biopsy can provide prognostic information, particularly in the context of so-called indeterminate hepatitis, and is extremely useful in excluding conditions such as metastatic tumours that would preclude transplantation. In addition, its widespread use of percutaneous biopsies in cases of less severe acute liver injury, for example in the establishment of a diagnosis of acute presentation of autoimmune hepatitis or confirmation of a probable or definite drug-induced liver injury (DILI), has meant that many centres have seen a shift in the ratio of specimens they are receiving from patients with chronic to acute liver disease. Histopathologists therefore need to be equipped to deal with these challenging specimens. This overview provides an insight into the contemporary role of biopsies (as well as explant and autopsy material) in diagnosing acute liver disease. It outlines up-to-date clinical definitions of liver injury and considers recent recommendations for the diagnosis of AIH and drug-induced, autoimmune-like hepatitis (DI-AIH).

Outcomes and management in paediatric autoimmune hepatitis presenting as acute liver failure: Individual patient data meta-analysis

BACKGROUND AND AIMS

Autoimmune hepatitis (AIH) in children presenting in acute liver failure (ALF) can be fatal and often requires liver transplantation (LTx). This individual patient data meta-analysis (IPD) aims to examine management and outcomes of this population, given the lack of large cohort studies on paediatric AIH first presenting as ALF (AIH-ALF).

METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses of IPD statement using PubMed and Excerpta Medica dataBASE, and included English studies published between 2000 and 2020. The study included patients under 21 years of age, diagnosed with type 1 or 2 AIH and presenting with ALF. Data extracted included clinical and biochemical characteristics, interventions, and outcomes.

RESULTS

Three hundred and thirty eligible patients from 61 studies were identified, with an additional five patients from our institution. The majority were female (66.8%), with a median age of 10. Overall, 59.7% achieved native liver survival (NLS), 35% underwent LTx, and 5% died before LTx. The use of corticosteroids with non-steroid immunomodulators increased the likelihood of NLS by 2.5-fold compared to corticosteroids alone. AIH-1 was associated with 3.3-fold odds for NLS, compared to AIH-2. However, on multivariate analysis, only AIH-1 was identified as an independent predictor for NLS (OR 3.8 [95% CI 1.03-14.2], p = .04).

CONCLUSION

While corticosteroids and non-steroid immunomodulators treatment may offer enhanced probability of achieving NLS, treatment regimens for AIH-ALF may need to consider patient-specific factors, especially AIH type. This highlights the potential for NLS in AIH-ALF and suggest a need to identify biomarkers which predict the need for combination immunosuppression to avoid LTx.

Advances in the evaluation and treatment of autoimmune hepatitis

PURPOSE OF REVIEW

The primary therapy of autoimmune hepatitis (AIH) has been established for over three decades. This review focuses on updates in the evaluation and management of patients with AIH.

RECENT FINDINGS

The evaluation of patients has recently been updated to include more definitive screening for other autoimmune diseases, including thyroid disease and celiac disease. Antibody detection by ELISA, an easier and more commonly available method, has been incorporated into the latest iteration of the AIH scoring system. Corticosteroids and AZA remain the backbone of AIH treatment, but there is growing evidence for mycophenolate mofetil as both first-line and second-line therapy, and growing inquiry into calcineurin inhibitors. Noninvasive markers of liver disease have now been validated in AIH, with the strongest evidence for VCTE in patients with minimal hepatic inflammation.

SUMMARY

Recent research of alternative immunosuppressant therapies, noninvasive markers of fibrosis, and updated society guidelines, have improved our ability to evaluate, treat, and follow patients with AIH.

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.

Autoimmune hepatitis: Brighton Collaboration case definition and guidelines for data collection, analysis, and presentation of immunisation safety data

This report introduces a Brighton Collaboration (BC) case definition for autoimmune hepatitis (AIH), which has been classified as a priority adverse event of special interest (AESI), as there were possible cases seen following COVID-19 vaccination. The case definition was developed by a group of subject matter and BC process experts to facilitate safety data comparability across pre- and post-licensure clinical trials, as well as pharmacovigilance activities in multiple settings with diverse resources and healthcare access. The usual BC case definition development process was followed in an expedited manner, and took two months to complete, including finalising the manuscript for publication, instead of the usual 1 year development time. It includes a systematic review of the literature and an expert consensus to define levels of diagnostic certainty for AIH, and provides specific guidelines for data collection and analysis. Histology, serological and biochemical tests and exclusion of alternate diagnosis were considered necessary to define the levels of certainty (definitive, probable and possible). AEFI reports of suspected AIH were independently classified by the WG members to test its useability and these classifications were used to finalise the case definition. The document underwent peer review by external AIH experts and a Reference Group of vaccine safety stakeholders in high-, low- and middle-income countries to ensure case definition useability, applicability, and scientific integrity. The expedited process can be replicated for development of other standardised case definitions for priority AESIs for endemics and epidemics. While applicable to cases reported following immunisation, the case definition is independent of lapsed time following vaccination and, as such, can also be used to determine background incidence for vaccinated and unvaccinated control groups in studies of causal association. While use of this case definition is also appropriate for the study of safety of other products including drugs, it is not meant to guide clinical case management.

The evolving phenotype of autoimmune hepatitis across the millennium: The 40-year experience of a referral centre in Italy

BACKGROUND AND AIMS

During recent years, there have been major insight into the pathogenesis, diagnosis and treatment of autoimmune hepatitis (AIH). We aim to evaluate modifications of the clinical-epidemiological phenotype of AIH patients from 1980 to our days.

METHODS

Single-centre, tertiary care retrospective study on 507 consecutive Italian patients with AIH. Patients were divided into four subgroups according to the decade of diagnosis: 1981-1990, 1991-2000, 2001-2010 and 2011-2020. We assessed clinical, laboratory and histological features at diagnosis, response to treatment and clinical outcomes. Acute presentation is defined as transaminase levels >10-fold the upper limit and/or bilirubin >5 mg/dL. Complete response is defined as the normalization of transaminases and IgG after 12 months. Clinical progression is defined as the development of cirrhosis in non-cirrhotic patients and hepatic decompensation/hepatocellular carcinoma development in compensated cirrhosis.

RESULTS

Median age at diagnosis increased across decades (24, 31, 39, 52 years, p < .001). Acute onset became more common (39.6%, 44.4%, 47.7%, 59.5%, p = .019), while cirrhosis at diagnosis became less frequent (36.5%, 16.3%, 10.8%, 8.7%, p < .001). Complete response rates rose (11.1%, 49.4%, 72.7% 76.2%, p < .001) and clinical progression during follow-up decreased (54.3%, 29.9%, 16.9%, 11.2%, p < .001). Anti-nuclear antibodies positivity increased (40.7%, 52.0%, 73.7%, 79.3%, p < .001), while IgG levels/upper limit progressively decreased (1.546, 1.515, 1.252, 1.120, p < .001). Liver-related death and liver transplantation reduced from 17.1% to 2.1% (p < .001).

CONCLUSIONS

In the new millennium, the typical AIH patient in Italy is older at diagnosis, more often presents with acute hepatitis, cirrhosis is less frequent and response to treatment is more favourable.

Onset of acute severe autoimmune hepatitis after severe acute respiratory syndrome coronavirus 2 infection: a case report

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can trigger autoimmune inflammation in the liver, leading to acute autoimmune hepatitis (AIH). We herein report a case involving a 39-year-old woman with a 23-day history of yellow skin and urine. Using the revised original scoring system of the International AIH Group, we definitively diagnosed the patient with acute severe AIH (AS-AIH). She began treatment with 80 mg/day intravenous methylprednisolone, which was gradually reduced and followed by eventual transition to oral methylprednisolone. The patient finally achieved a biochemical response after 30 days of therapy, and liver transplantation was avoided. Clinicians should be aware that the onset of AS-AIH after SARS-CoV-2 infection differs from the onset of conventional AIH with respect to its clinical and pathological features. Early diagnosis and timely glucocorticoid treatment are crucial in improving outcomes.

Implications of Gender on the Outcome in Patients With Autoimmune Hepatitis

BACKGROUND

Autoimmune hepatitis (AIH) is uncommon and predominantly affects females. Data on AIH from India are scanty. We retrospectively analyzed the spectrum and outcome of adults with AIH and compared it between male and female patients.

METHODS

AIH was diagnosed using a simplified AIH score. For suspected seronegative AIH, the revised score was used. Standard therapies for AIH and portal hypertension were administered and response was assessed at six months. Relapse rates and five-year mortality were also evaluated.

RESULTS

Of the 157 patients with AIH, 85 (male: female 25: 60) were included in the study. The median age at diagnosis was 46 (interquartile range (IQR) 32-55.5) years in males vs 45 (IQR 34.2-54) years in females (p=0.91). A similar proportion of male and female patients presented with cirrhosis, acute severe AIH, or AIH-related acute on chronic liver failure (ACLF); Extra-hepatic autoimmune diseases were less common in male patients (16% vs 35.5% p=0.02). Other laboratory and histological features were comparable in both groups. During the median follow-up period of 51 months (IQR 45-67 months). The biochemical and clinical response at six months were seen in 64% of male patients and 63.3% of female patients (p= 0.57). Of patients, 75% relapsed in the male AIH group (12 of 16 patients) after initial remission compared to 42% in the female group (p=0.02). Five-year mortality was 14.1%, and no patient developed hepatocellular carcinoma.

CONCLUSION

Male and female patients with AIH have similar clinical, biochemical, and histological profiles. More male patients relapsed after an initial response to therapy.

Autoimmune Hepatitis: A Diagnostic and Therapeutic Overview

Autoimmune hepatitis is an immune-mediated inflammatory condition of the liver of undetermined cause that affects both sexes, all ages, races, and ethnicities. Its clinical presentation can be very broad, from having an asymptomatic and silent course to presenting as acute hepatitis, cirrhosis, and acute liver failure potentially requiring liver transplantation. The diagnosis is based on histological abnormalities (interface hepatitis), characteristic clinical and laboratory findings (increased aspartate aminotransferase, alanine aminotransferase, and serum IgG concentration), and the presence of one or more characteristic autoantibodies. The large heterogeneity of these clinical, biochemical, and histological findings can sometimes make a timely and proper diagnosis a difficult task. Treatment seeks to achieve remission of the disease and prevent further progression of liver disease. First-line therapy includes high-dose corticosteroids, which are later tapered to decrease side effects, and azathioprine. In the presence of azathioprine intolerance or a poor response to the standard of care, second-line therapy needs to be considered, including mycophenolate mofetil. AIH remains a diagnostic and therapeutic challenge, and a further understanding of the pathophysiological pathways of the disease and the implementation of randomized controlled trials are needed.

Autoimmune Hepatitis: Epidemiology, Subtypes, and Presentation

Autoimmune hepatitis (AIH) is a chronic immunologic disorder in which the immune system targets the liver. The disease has a genetic basis and this accounts for the epidemiologic variation observed in serologic testing and clinical presentation across different populations. The incidence of AIH increases with age into the 70s and seems to be increasing in prevalence. Most patients test positive for antinuclear antibody, ASMA, or anti-LKM but about 20% of patients do not have these serologic markers. At clinical presentation, patients may be asymptomatic, symptomatic, have acute liver failure, or decompensated cirrhosis.

Diagnosis of Autoimmune Hepatitis

Autoimmune hepatitis (AIH) presents a diagnostic challenge because it is relatively rare and heterogenous in presentation. This article presents the currently adopted approach to AIH diagnosis and explores the challenges with accurately identifying this disease entity. AIH offers no pathognomonic findings, instead relies on clinical presentation, serology, and histology to make the diagnosis. Diagnostic scoring systems support clinical judgment and serve as valuable tools in diagnosis and research. Histological analysis remains the cornerstone of diagnosis and to this day biopsy is essential to make the diagnosis.

A Rare Presentation of Drug-Induced Autoimmune Hepatitis and the Role of Male Enhancement Supplements

Autoimmune hepatitis (AIH) is a condition characterized by an autoimmune response resulting in chronic inflammatory liver disease. Its presentation is marked by significant increases in serum immunoglobulins and the production of active autoantibodies that target liver tissue. AIH is often associated with other autoimmune disorders, which can lead to overlapping clinical syndromes. However, alternative theories propose that exposure to specific environmental triggers can initiate this autoimmune cascade. We present the case of a 45-year-old male who sought evaluation for abdominal discomfort and was subsequently diagnosed with drug-induced AIH (DIAIH) following prolonged use of an over-the-counter male-enhancing supplement.

Efficacy of therapeutic plasma exchange in pediatric cases of acute liver failure as an extracorporeal liver support system

BACKGROUND

Acute liver failure in the pediatric population is often accompanied by deranged metabolism, severe encephalopathy and coagulopathy. A liver transplant is the most viable option for the management of such patients. Therapeutic plasma exchange (TPE) is helpful in improving the liver biochemistry profile, thereby, increasing their likelihood of undergoing a liver transplant METHOD: The study was conducted over a period of 3 years (January 2018 to December 2021). Indications mainly consisted of ALF with hepatic encephalopathy, worsening liver parameters in spite of medical management, and candidacy for undergoing a liver transplant. Plasma exchange was performed daily or alternatively until the patient recovered, succumbed, or was stable enough to undergo a transplant. Biochemical parameters serum bilirubin, ALT, AST serum ammonia serum urea, serum creatinine were recorded before and after TPE sessions.

RESULTS

The study group comprised 14 patients of which a total of 28 TPE was performed. There were a total of 5 cases of cryptogenic ALF, 4 of Wilson disease, 2 cases each of infection-related ALF and autoimmune hepatitis, and a single case of drug-induced hepatitis. A total of 5 out of 14 patients underwent a liver transplant and amongst the 9 who did not undergo a transplant, 4 patients expired due to septic shock syndrome; the remaining 5 were discharged in a stable condition following TPE sessions. The disease-free survival was 78.9% and the transplant-free survival was 35.71%.

CONCLUSION

TPE plays a crucial role in improving the biochemistry profile of the liver in children with liver failure.

Future directions in acute liver failure

Acute liver failure (ALF) describes a clinical syndrome of rapid hepatocyte injury leading to liver failure manifested by coagulopathy and encephalopathy in the absence of pre-existing cirrhosis. The hallmark diagnostic features are a prolonged prothrombin time (ie, an international normalized ratio of prothrombin time of ≥1.5) and any degree of mental status alteration (HE). As a rare, orphan disease, it seemed an obvious target for a multicenter network. The Acute Liver Failure Study Group (ALFSG) began in 1997 to more thoroughly study and understand the causes, natural history, and management of ALF. Over the course of 22 years, 3364 adult patients were enrolled in the study registry (2614 ALF and 857 acute liver injury-international normalized ratio 2.0 but no encephalopathy-ALI) and >150,000 biosamples collected, including serum, plasma, urine, DNA, and liver tissue. Within the Registry study sites, 4 prospective substudies were conducted and published, 2 interventional ( N -acetylcysteine and ornithine phenylacetate), 1 prognostic [ 13 C-methacetin breath test (MBT)], and 1 mechanistic (rotational thromboelastometry). To review ALFSG's accomplishments and consider next steps, a 2-day in-person conference was held at UT Southwestern Medical Center, Dallas, TX, entitled "Acute Liver Failure: Science and Practice," in May 2022. To summarize the important findings in the field, this review highlights the current state of understanding of ALF and, more importantly, asks what further studies are needed to improve our understanding of the pathogenesis, natural history, and management of this unique and dramatic condition.

Juvenile Autoimmune Hepatitis: Recent Advances in Diagnosis, Management and Long-Term Outcome

Juvenile autoimmune hepatitis (JAIH) is severe immune-mediated necro-inflammatory disease of the liver with spontaneous progression to cirrhosis and liver failure if left untreated. The diagnosis is based on the combination of clinical, laboratory and histological findings. Prothrombin ratio is a useful prognostic factor to identify patients who will most likely require a liver transplant by adolescence or early adulthood. JAIH treatment consists of immune suppression and should be started promptly at diagnosis to halt inflammatory liver damage and ultimately prevent fibrosis and progression to end-stage liver disease. The risk of relapse is high especially in the setting of poor treatment compliance. Recent evidence however suggests that treatment discontinuation is possible after a prolonged period of normal aminotransferase activity without the need for liver biopsy prior to withdrawal.

Pathology of Acute and Acute-on-Chronic Liver Failure

Liver failure can develop as either acute liver failure in the absence of preexisting liver disease, or as acute-on-chronic liver failure in a patient with underlying chronic liver disease or cirrhosis. A timely liver biopsy is helpful to distinguish acute and chronic liver disease, identify precipitating factors, provide prognostic information based on pathologic changes, and aid in making appropriate decisions for patient management. This article will discuss the pathologic features of acute and acute-on-chronic liver failure. Developing an appreciation for the histopathologic patterns of injury observed in these entities is essential for a practical understanding of the diagnostic process.

Identifying the early predictors of non-response to steroids in patients with flare of autoimmune hepatitis causing acute-on-chronic liver failure

BACKGROUND AND AIMS

Early identification of non-response to steroids is critical in patients with autoimmune hepatitis (AIH) causing acute-on-chronic liver failure (ACLF). We assessed if this non-response can be accurately identified within first few days of treatment.

METHODS

Patients with AIH-ACLF without baseline infection/hepatic encephalopathy were identified from APASL ACLF research consortium (AARC) database. Diagnosis of AIH-ACLF was based mainly on histology. Those treated with steroids were assessed for non-response (defined as death or liver transplant at 90 days for present study). Laboratory parameters, AARC, and model for end-stage liver disease (MELD) scores were assessed at baseline and day 3 to identify early non-response. Utility of dynamic SURFASA score [- 6.80 + 1.92*(D0-INR) + 1.94*(∆%3-INR) + 1.64*(∆%3-bilirubin)] was also evaluated. The performance of early predictors was compared with changes in MELD score at 2 weeks.

RESULTS

Fifty-five out of one hundred and sixty-five patients (age-38.2 ± 15.0 years, 67.2% females) with AIH-ACLF [median MELD 24 (IQR: 22-27); median AARC score 7 (6-9)] given oral prednisolone 40 (20-40) mg per day were analyzed. The 90 day transplant-free survival in this cohort was 45.7% with worse outcomes in those with incident infections (56% vs 28.0%, p = 0.03). The AUROC of pre-therapy AARC score [0.842 (95% CI 0.754-0.93)], MELD [0.837 (95% CI 0.733-0.94)] score and SURFASA score [0.795 (95% CI 0.678-0.911)] were as accurate as ∆MELD at 2 weeks [0.770 (95% CI 0.687-0.845), p = 0.526] and better than ∆MELD at 3 days [0.541 (95% CI 0.395, 0.687), p < 0.001] to predict non-response. Combination of AARC score > 6, MELD score > 24 with SURFASA score ≥ - 1.2, could identify non-responders at day 3 (concomitant- 75% vs either - 42%, p < 0.001).

CONCLUSION

Baseline AARC score, MELD score, and the dynamic SURFASA score on day 3 can accurately identify early non-response to steroids in AIH-ACLF.

Acute Liver Failure Guidelines

Acute liver failure (ALF) is a rare, acute, potentially reversible condition resulting in severe liver impairment and rapid clinical deterioration in patients without preexisting liver disease. Due to the rarity of this condition, published studies are limited by the use of retrospective or prospective cohorts and lack of randomized controlled trials. Current guidelines represent the suggested approach to the identification, treatment, and management of ALF and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence was reviewed using the Grading of Recommendations, Assessment, Development and Evaluation process to develop recommendations. When no robust evidence was available, expert opinions were summarized using Key Concepts. Considering the variety of clinical presentations of ALF, individualization of care should be applied in specific clinical scenarios.

Autoimmune hepatitis presenting as acute liver failure: A 20-year retrospective review of North America

Autoimmune hepatitis is a common cause of acute liver failure. Treatment includes steroids for acute liver injury and liver transplantation in those who fail to respond or develop acute liver failure. The aim of this study is to further characterize acute liver failure secondary to autoimmune hepatitis and identify variables that predict 21-day transplant-free survival. This study included adults hospitalized with acute liver failure enrolled in the Acute Liver Failure Study Group Registry between 1998 and 2019 from 32 centers within the US. The etiology of all cases was reviewed by the Adjudication Committee, and all cases identified as autoimmune hepatitis were included. Acute liver injury was defined as an INR ≥2.0 without encephalopathy and acute liver failure as INR ≥ 1.5 with encephalopathy. Laboratory and clinical data were reviewed. Variables significantly associated with 21-day transplant-free survival were used to develop a multivariable logistic regression model.  A total of 193 cases of acute liver failure secondary to autoimmune hepatitis were identified and reviewed. There were 161 patients (83.4%) diagnosed with acute liver failure on enrollment, and 32 (16.6%) developed acute liver failure during hospitalization. At 21 days, 115 (59.6%) underwent liver transplantation, 28 (14.5%) had transplant-free survival, and 46 (23.8%) died before liver transplantation. Higher admission values of bilirubin, INR, and coma grade were associated with worse outcomes. A prognostic index incorporating bilirubin, INR, coma grade, and platelet count had a concordance statistic of 0.84. Acute liver failure secondary to autoimmune hepatitis is associated with a high short-term mortality. We developed a model specifically for autoimmune hepatitis that may be helpful in predicting 21-day transplant-free survival and early identification of patients in need of expedited liver transplant evaluation.

Autoimmune Hepatitis and Fibrosis

Autoimmune hepatitis (AIH) is a chronic immune-inflammatory disease of the liver, generally considered a rare condition. The clinical manifestation is extremely varied and can range from paucisymptomatic forms to severe hepatitis. Chronic liver damage causes activation of hepatic and inflammatory cells leading to inflammation and oxidative stress through the production of mediators. This results in increased collagen production and extracellular matrix deposition leading to fibrosis and even cirrhosis. The gold standard for the diagnosis of fibrosis is liver biopsy; however, there are serum biomarkers, scoring systems, and radiological methods useful for diagnosis and staging. The goal of AIH treatment is to suppress fibrotic and inflammatory activities in the liver to prevent disease progression and achieve complete remission. Therapy involves the use of classic steroidal anti-inflammatory drugs and immunosuppressants, but in recent years scientific research has focused on several new alternative drugs for AIH that will be discussed in the review.

Diagnosis and management of autoimmune hepatitis

Autoimmune hepatitis is an inflammatory disease of the liver of unknown cause that may progress to liver cirrhosis and end stage liver failure if diagnosis is overlooked and treatment delayed. The clinical presentation is often that of acute hepatitis, sometimes very severe; less frequently, it can be insidious or completely asymptomatic. The disease can affect people of any age and is more common in women; its incidence and prevalence seem to be on the rise worldwide. An abnormal immune response targeting liver autoantigens and inducing persistent and self-perpetuating liver inflammation is the pathogenic mechanism of the disease. A specific set of autoantibodies, increased IgG concentrations, and histological demonstration of interface hepatitis and periportal necrosis are the diagnostic hallmarks of autoimmune hepatitis. Prompt response to treatment with corticosteroids and other immunomodulatory drugs is almost universal and supports the diagnosis. The aims of treatment are to induce and maintain long term remission of liver inflammation. Treatment can often even reverse liver fibrosis, thus preventing progression to advanced cirrhosis and its complications. Most patients need lifelong maintenance therapy, and repeated follow-up in experienced hands improves the quality of care and quality of life for affected patients.

Autoimmune Hepatitis with Acute Presentation: Clinical, Biochemical, and Histological Features of 126 Patients

INTRODUCTION

Autoimmune hepatitis (AIH) is a chronic liver disease with a relevant inflammatory component and an unknown etiology. Evidence for clinical characteristics and risk factors in large cohorts of patients with acute AIH (AAIH) is lacking. We clinically characterized patients with AAIH, the prevalence of a combined adverse outcome (death or liver transplantation (LT)), and its risk factors.

METHODS

A retrospective study of adult patients diagnosed with AAIH at three centers (Santiago, Chile; 2000-2018) was conducted. Clinical and laboratory characteristics were obtained. A liver biopsy was performed for all patients. Descriptive statistics and logistic regression models were used.

RESULTS

A total of 126 patients were admitted; 77% were female, 33 (26.2%) had a severe presentation, and 14 (11.1%) had a fulminant presentation. Overall, 24 patients (19.0%) lacked typical autoantibodies, and 26.2% had immunoglobulin G levels in the normal range. The most frequent histological findings were plasma cells (86.5%), interface hepatitis (81.7%), and chronic hepatitis (81.0%). Rosettes were uncommon (35.6%). Advanced fibrosis was present in 27% of patients. Combined adverse outcomes occurred in 7.9% of cases, all fulminant with histological cholestasis. Alkaline phosphatase, bilirubin, and prothrombin less than 50% were independent risk factors for in-hospital death or LT (p value <0.05). Although corticosteroid treatment was associated with better outcomes (OR 0.095, p value = 0.013), more severe patients were less likely to receive this therapy. Discussion. In this large cohort of patients with AAIH, clinical characteristics differ from those reported in patients with chronic AIH. Fulminant hepatitis, histological cholestasis, alkaline phosphatase, bilirubin, and prothrombin were associated with death/LT.

Management of Acute Liver Failure: Update 2022

Abbreviated pathogenesis and clinical course of the acute liver failure syndrome. The pathogenesis and clinical course of the syndrome of acute liver failure (ALF) differs depending upon the etiology of the primary liver injury. In turn, the severity of the liver injury and resulting synthetic failure is often the primary determinant of whether a patient is referred for emergency liver transplantation. Injuries by viral etiologies trigger the innate immune system via pathogen-associated molecular patterns (PAMPs), while toxin-induced (and presumably ischemia-induced) injuries do so via damage-associated molecular patterns (DAMPs). The course of the clinical syndrome further depends upon the relative intensity and composition of cytokine release, resulting in an early proinflammatory phenotype (SIRS) and later compensatory anti-inflammatory response phenotype (CARS). The outcomes of overwhelming immune activation are the systemic (extrahepatic) features of ALF (cardiovascular collapse, cerebral edema, acute kidney injury, respiratory failure, sepsis) which ultimately determine the likelihood of death.Acute liver failure (ALF) continues to carry a high risk of mortality or the need for transplantation despite recent improvements in overall outcomes over the past two decades. Optimal management begins with identifying that liver failure is indeed present and its etiology, since outcomes and the need for transplantation vary widely across the different etiologies. Most causes of ALF can be divided into hyperacute (ischemia and acetaminophen) and subacute types (other etiologies), based on time of evolution of signs and symptoms of liver failure; the former evolve in 3 to 4 days and the latter typically in 2 to 4 weeks. Both involve intense release of cytokines and hepatocellular contents into the circulation with multiorgan effects/consequences.Management involves optimizing fluid balance and cardiovascular support, including the use of continuous renal replacement therapy, vasopressors, and pulmonary ventilation. Early evaluation for liver transplantation is advised particularly for acetaminophen toxicity, which evolves so rapidly that delay is likely to lead to death.Vasopressor support, high-grade hepatic encephalopathy, and unfavorable (subacute) etiologies heighten the need for urgent listing for liver transplantation. Prognostic scores such as Kings Criteria, Model for End-Stage Liver Disease, and the Acute Liver Failure Group prognostic index take these features into account and provide reasonable but imperfect predictive accuracy. Future treatments may include liver support devices and/or agents that improve hepatocyte regeneration.

Autoimmune hepatitis with history of HCV treatment triggered by COVID-19 vaccination: case report and literature review

Although vaccines have been effective against the worldwide pandemic of Coronavirus Disease 19 (COVID-19), some case reports have described autoimmune hepatitis triggered by COVID-19 vaccination. Meanwhile, hepatitis C virus (HCV) is known to be related to autoimmune diseases. Here, we report a case of autoimmune hepatitis with history of HCV treatment triggered by COVID-19 vaccination. An 82-year-old woman was referred to our hospital for severe liver injury. She had received a COVID-19 vaccination 7 days prior. She had a history of HCV treatment with direct-acting antivirals 7 years previously. In her blood data, despite HCV antibody positivity, she was negative for HCV RNA by real-time RT-PCR. Anti-nuclear antibody was positive and IgG was elevated. Interface hepatitis and plasma cell infiltration were confirmed pathologically. She was diagnosed as autoimmune hepatitis and her liver injury quickly improved after initiation of steroid administration. This is a first case report of autoimmune hepatitis with history of HCV treatment triggered by COVID-19 vaccination.

Seronegative autoimmune diseases: A challenging diagnosis

Autoimmune diseases (AID) are increasingly prevalent conditions which comprise more than 100 distinct clinical entities that are responsible for a great disease burden worldwide. The early recognition of these diseases is key for preventing their complications and for tailoring proper management. In most cases, autoantibodies, regardless of their potential pathogenetic role, can be detected in the serum of patients with AID, helping clinicians in making a definitive diagnosis and allowing screening strategies for early -and sometimes pre-clinical- diagnosis. Despite their undoubted crucial role, in a minority of cases, patients with AID may not show any autoantibody, a condition that is referred to as seronegative AID. Suboptimal accuracy of the available laboratory tests, antibody absorption, immunosuppressive therapy, immunodeficiencies, antigen exhaustion, and immunosenescence are the main possible determinants of seronegative AID. Indeed, in seronegative AID, the diagnosis is more challenging and must rely on clinical features and on other available tests, often including histopathological evaluation and radiological diagnostic tests. In this review, we critically dissect, in a narrative fashion, the possible causes of seronegativity, as well as the diagnostic and management implications, in several AID including autoimmune gastritis, celiac disease, autoimmune liver disease, rheumatoid arthritis, autoimmune encephalitis, myasthenia gravis, Sjögren's syndrome, antiphospholipid syndrome, and autoimmune thyroid diseases.

Whole Exome Sequencing Reveals Genetic Variants in HLA Class II Genes Associated With Transplant-free Survival of Indeterminate Acute Liver Failure

INTRODUCTION

Indeterminate acute liver failure (IND-ALF) is a rare clinical syndrome with a high mortality rate. Lacking a known etiology makes rapid evaluation and treatment difficult, with liver transplantation often considered as the only therapeutic option. Our aim was to identify genetic variants from whole exome sequencing data that might be associated with IND-ALF clinical outcomes.

METHODS

Bioinformatics analysis was performed on whole exome sequencing data for 22 patients with IND-ALF. A 2-tier approach was used to identify significant single-nucleotide polymorphisms (SNPs) associated with IND-ALF clinical outcomes. Tier 1 identified the SNPs with a higher relative risk in the IND-ALF population compared with those identified in control populations. Tier 2 determined the SNPs connected to transplant-free survival and associated with model for end-stage liver disease serum sodium and Acute Liver Failure Study Group prognostic scores.

RESULTS

Thirty-one SNPs were found associated with a higher relative risk in the IND-ALF population compared with those in controls, of which 11 belong to the human leukocyte antigen (HLA) class II genes but none for the class I. Further analysis showed that 5 SNPs: rs796202376, rs139189937, and rs113473719 of HLA-DRB5; rs9272712 of HLA-DQA1; and rs747397929 of IDO1 were associated with a higher probability of IND-ALF transplant-free survival. Using 3 selected SNPs, a model for the polygenic risk score was developed to predict IND-ALF prognoses, which are comparable with those by model for end-stage liver disease serum sodium and Acute Liver Failure Study Group prognostic scores.

DISCUSSION

Certain gene variants in HLA-DRB5, HLA-DQA1, and IDO1 were found associated with IND-ALF transplant-free survival. Once validated, these identified SNPs may help elucidate the mechanism of IND-ALF and assist in its diagnosis and management.

Early predictors of corticosteroid response in acute severe autoimmune hepatitis: a nationwide multicenter study

BACKGROUND AND AIMS

To assess whether corticosteroids improve prognosis in patients with AS-AIH, and to identify factors at therapy initiation and during therapy predictive of the response to corticosteroids.

METHODS

This was a retrospective cohort study including all patients with AS-AIH admitted to 13 tertiary centres from January 2002 to January 2019. The composite primary outcome was death or liver transplantation within 90 days of admission. Kaplan-Meier and Cox regression methods were used for data analysis.

RESULTS

Of 242 consecutive patients enrolled (mean age [SD] 49.7 [16.8] years), 203 received corticosteroids. Overall 90-day transplant-free survival was 61.6% (95% confidence interval [CI] 55.4-67.7). Corticosteroids reduced the risk of a poor outcome (adjusted hazard ratio [HR] 0.25; 95% CI 0.2-0.4), but this treatment failed in 30.5%. An internally validated nomogram composed of older age, MELD, encephalopathy and ascites at the initiation of corticosteroids accurately predicted the response (C-index 0.82; [95% CI 0.8-0.9]). In responders, MELD significantly improved from days 3 to 14 but remained unchanged in non-responders. MELD on day 7 with a cut-off of 25 (sensitivity 62.5%[95% CI: 47.0-75.8]; specificity 95.2% [95% CI: 89.9-97.8]) was the best univariate predictor of the response. Prolonging corticosteroids did not increase the overall infection risk (adjusted HR 0.75; 95% CI 0.3-2.1).

CONCLUSION

Older patients with high MELD, encephalopathy or ascites at steroid therapy initiation and during treatment are unlikely to show a favourable response and so prolonged therapy in these patients, especially if they are transplantation candidates, should be avoided.

Histopathologist and clinician interface in diagnosis and management of autoimmune hepatitis

Diagnosis of AIH is based on a combination of clinical, laboratory and histological information. It has been formalised by diagnostic scoring systems, to which liver biopsy contributes substantially. Diagnostic biopsy is thus, desirable in nearly all patients. An adequate biopsy size, provision by clinicians of adequate information to histopathologists and active discussion at regular meetings are all important for accurate histological diagnosis. Recently, the specificity of some features previously thought to suggest AIH has been questioned, and new recommendations for histological diagnosis have been proposed, although not yet validated. The histology of acutely presenting AIH and that of severe or fulminant AIH include some characteristic features. Primary biliary cholangitis, primary sclerosing cholangitis and non-alcoholic fatty liver disease may co-exist with AIH on biopsy. Liver biopsy also enables grading of severity of inflammation and staging of fibrosis. Presence of cirrhosis is a poor prognostic marker. Repeat liver biopsy after achieving biochemical remission, although not performed routinely, enables assessment of (a) histological remission, a favourable prognostic indicator and (b) fibrosis progression. It can thus help determine further management.

Prognostic Role of Liver Biopsy in Patients With Severe Indeterminate Acute Hepatitis

BACKGROUND AND AIMS

Severe indeterminate acute hepatitis (sIAH) is a poorly understood rare disease with no specific therapy. This study aims to define the clinicopathological characteristics of sIAH and the role of liver biopsy in determining prognosis.

METHODS

Patients with sIAH admitted to a single center between 2010 and 2019 were included. Histopathological patterns of liver biopsies were reviewed by 2 histopathologists, and key findings further were specified by multiplex immunofluorescence. Patients that died or underwent liver transplantation were analyzed as nonsurvivors.

RESULTS

Of 294 patients with acute hepatitis, 43 with sIAH were included. Seventeen (39.5%) underwent liver transplantation and 7 (16.2%) died within 3 months. Multilobular necrosis was the predominant histopathological feature, being significantly more frequent in nonsurvivors (62.5% vs 21.1%; P = .016). Necrotic areas showed low HNF4α and Ki67 expression but high expression of CK19 and cell death markers identifying areas of severe tissue injury and inadequate regenerative response. Patients with multilobular necrosis had higher international normalized ratio, Model for End-Stage Liver Disease, and Model for End-Stage Liver Disease-Sodium scores compared with those without (P values for all markers <.05). Multivariate Cox analysis revealed that multilobular necrosis (hazard ratio, 3.675; 95% confidence interval, 1.322-10.211) and lower body mass index (hazard ratio, 0.916; 95% confidence interval, 0.848-0.991) independently predicted death or transplantation.

CONCLUSIONS

The results of this study provide novel insights into the important role of liver biopsy in sIAH patients, suggesting that the presence of multilobular necrosis is an early indicator of poor prognosis.

Emergencies in paediatric hepatology

The aetiology of several liver diseases in children is age specific and many of these conditions have significant and potentially long-term clinical repercussions if not diagnosed early and managed in a timely fashion. We address 5 clinical scenarios that cover most of the diagnostic and therapeutic emergencies in children: infants with liver disease; acute liver failure; management of bleeding varices; liver-based metabolic disorders; and liver tumours and trauma. A wide spectrum of conditions that cause liver disease in infants may present as conjugated jaundice, which could be the only symptom of time-sensitive disorders - such as biliary atresia, metabolic disorders, infections, and haematological/alloimmune disorders - wherein algorithmic multistage testing is required for accurate diagnosis. In infantile cholestasis, algorithmic multistage tests are necessary for an accurate early diagnosis, while vitamin K, specific milk formulae and disease-specific medications are essential to avoid mortality and long-term morbidity. Management of paediatric acute liver failure requires co-ordination with a liver transplant centre, safe transport and detailed age-specific aetiological work-up - clinical stabilisation with appropriate supportive care is central to survival if transplantation is indicated. Gastrointestinal bleeding may present as the initial manifestation or during follow-up in patients with portal vein thrombosis or chronic liver disease and can be managed pharmacologically, or with endoscopic/radiological interventions. Liver-based inborn errors of metabolism may present as encephalopathy that needs to be recognised and treated early to avoid further neurological sequelae and death. Liver tumours and liver trauma are both rare occurrences in children and are best managed by a multidisciplinary team in a specialist centre.

Secular Trends in Severe Idiosyncratic Drug-Induced Liver Injury in North America: An Update From the Acute Liver Failure Study Group Registry

INTRODUCTION

Idiosyncratic drug-induced liver injury (DILI) is the second leading cause of acute liver failure (ALF) in the United States. Our study aims were to characterize secular trends in the implicated agents, clinical features, and outcomes of adults with DILI ALF over a 20-year period.

METHODS

Among 2,332 patients with ALF enrolled in the ALF Study Group registry, 277 (11.9%) were adjudicated as idiosyncratic DILI ALF (INR ≥ 1.5 and hepatic encephalopathy) through expert opinion. The 155 cases in era 1 (January 20, 1998-January 20, 2008) were compared with the 122 cases in era 2 (January 21, 2008-January 20, 2018).

RESULTS

Among 277 cases of DILI ALF, 97 different agents, alone or in combination, were implicated: antimicrobials, n = 118 (43%); herbal/dietary supplements (HDS), n = 42 (15%); central nervous system agents/illicit substances, n = 37 (13%); oncologic/biologic agents, n = 29 (10%); and other, n = 51 (18%). Significant trends over time included (i) an increase in HDS DILI ALF (9.7% vs 22%, P < 0.01) and decrease in antimicrobial-induced DILI ALF (45.8% vs. 38.5%, P = 0.03) and (ii) improved overall transplant-free survival (23.5%-38.7%, P < 0.01) while the number of patients transplanted declined (46.4% vs 33.6%, P < 0.03).

DISCUSSION

DILI ALF in North America is evolving, with HDS cases rising and other categories of suspect drugs declining. The reasons for a significant increase in transplant-free survival and reduced need for liver transplantation over time remain unclear but may be due to improvements in critical care, increased NAC utilization, and improved patient prognostication.

Presence of multilobular necrosis on liver biopsy identifies corticosteroid responsiveness in acute indeterminate hepatitis

BACKGROUND AND AIMS

Treatment of patients with severe indeterminate hepatitis (IAH) is an unmet need. Corticosteroids are often used in the management of these patients but criteria for the selection of patients for this intervention are arbitrary. The aims of this study were to analyse the clinical and pathological features of patients with IAH to define predictors of corticosteroid responsiveness.

METHODS

This study included consecutive patients with acute indeterminate hepatitis admitted to a single hospital and underwent a liver biopsy. The clinical manifestation and histopathological features of steroid and non-steroid groups were compared and their relationship with corticosteroids response was evaluated.

RESULTS

Forty-eight patients were included, 24 (50%) recovered and the other half underwent liver transplantation or died within 3-months. Of the 48 cases, 24 received corticosteroids (initial dose of 45 ± 12 mg prednisolone). Corticosteroids were initiated 2.7 ± 3.8 days after admission. Liver biopsy was performed 2-days (median, IQR 1-3) after admission. Fifteen (62.5%) patients receiving corticosteroids survived without transplantation compared with 9 (37.5%) that did not receive steroids (P = .149). In those with multilobular necrosis, 50% reduction in the death/transplantation rate was observed after steroid treatment (P = .018). In patients without multilobular necrosis and with or without perivenulitis, corticosteroids did not impact the outcome. Response to corticosteroids was independent of the MELD score.

CONCLUSIONS

The presence of multilobular necrosis on liver biopsy helps identify a subgroup of IAH cases who may benefit from the administration of corticosteroids.

Role of Corticosteroids in Drug-Induced Liver Injury. A Systematic Review

Introduction: Apart from cessation of the implicated agent leading to drug-induced liver injury (DILI), there is no standard therapy for DILI. Corticosteroids have been used in DILI, although their efficacy is unclear. Published data showed either beneficial effects or no improvement associated with steroid therapy. The aim of the current study was to perform a systematic review of the role of corticosteroids in the treatment of DILI.

Methods: A search was performed in PubMed, searching for the terms: “corticosteroids” and “drug-induced liver injury”. Observation studies were included, but case reports excluded.

Results: A total of 24 papers were retrieved. Most of these were observational studies on the effects of corticosteroids in moderate/severe DILI (n = 8), reports on the corticosteroid treatment in patients with drug-induced autoimmune hepatitis (DI-AIH) (n = 5), and effects of corticosteroids in drug-induced fulminant acute liver failure (ALF, n = 2). Furthermore, treatment of corticosteroids in patients with liver injury due to check point inhibitors (CPIs) was addressed in nine studies. In moderate/severe DILI, six out of eight studies suggested steroid treatment to be beneficial, whereas two studies showed negative results. All five observational studies on the effects of corticosteroids in DI-AIH showed good therapeutic response with rapid and long lasting effects after discontinuation of corticosteroids and without evidence of relapse. Steroid therapy was not associated with improved overall survival in patients with drug-induced fulminant ALF. CPIs-induced liver injury was found to improve spontaneously in 33–50% without corticosteroids, and the rate of patients who were treated responded to steroids in 33–100% (mean 72%).

Conclusions: The majority of studies analyzing the effects of corticosteroids in moderate/severe DILI have demonstrated beneficial effects. However, this was not the case in drug-induced fulminant ALF. Patients with DI-AIH had an excellent response to corticosteroids. The majority of those with CPIs-induced liver injury responded to corticosteroids; however, patients without treatment usually recovered spontaneously. The observational design and comparison with historical controls in these studies makes it very difficult to draw conclusions on the efficacy of corticosteroids in DILI. Therefore, there is a strong need for a randomized controlled trial to properly assess the role of corticosteroids in DILI.

E. coli and the etiology of human PBC: Antimitochondrial antibodies and spreading determinants

BACKGROUND AND AIMS

The increased frequency of urinary tract infections in patients with primary biliary cholangitis (PBC) and the cross-reactivity between the lipoyl domains (LD) of human pyruvate dehydrogenase complex (hPDC-E2) and Escherichia coli PDC-E2 (ePDC-E2) have long suggested a role of E. coli in causality of PBC. This issue, however, has remained speculative. We hypothesized that by generating specific constructs of human and E. coli PDC-E2, we would be able to assess the specificity of autoantibody responses and define whether exposure to E. coli in susceptible hosts is the basis for the antimitochondrial antibody (AMA) response.

APPROACH AND RESULTS

Importantly, the reactivity of hPDC-E2 LD (hPDC-E2LD) affinity-purified antibodies against hPDC-E2LD could only be removed by prior absorption with hPDC-E2LD and not ePDC-E2, suggesting the presence of unique human PDC-E2 epitopes distinct from E. coli PDC-E2. To identify the autoepitope(s) present in hPDC-E2LD, a more detailed study using a variety of PDC-E2 constructs was tested, including the effect of lipoic acid (LA) on ePDC-E2 conformation and AMA recognition. Individual recombinant ePDCE2 LD domains LD1, LD2 and LD3 did not react with either AMA or antibodies to LA (anti-LA), but in contrast, anti-LA was readily reactive against purified recombinant LD1, LD2, and LD3 expressed in tandem (LP); such reactivity increased when LP was precultured with LA. Moreover, when the three LD (LD1, LD2, LD3) domains were expressed in tandem in pET28a or when LD1 was expressed in another plasmid pGEX, they were lipoylated and reactive to PBC sera.

CONCLUSIONS

In conclusion, our data are consistent with an exposure to E. coli that elicits specific antibody to ePDC-E2 resulting in determinant spreading and the classic autoantibody to hPDC-E2LD. We argue this is the first step to development of human PBC.

Follistatin-controlled activin-HNF4α-coagulation factor axis in liver progenitor cells determines outcome of acute liver failure

BACKGROUND AND AIMS

In patients with acute liver failure (ALF) who suffer from massive hepatocyte loss, liver progenitor cells (LPCs) take over key hepatocyte functions, which ultimately determines survival. This study investigated how the expression of hepatocyte nuclear factor 4α (HNF4α), its regulators, and targets in LPCs determines clinical outcome of patients with ALF.

APPROACH AND RESULTS

Clinicopathological associations were scrutinized in 19 patients with ALF (9 recovered and 10 receiving liver transplantation). Regulatory mechanisms between follistatin, activin, HNF4α, and coagulation factor expression in LPC were investigated in vitro and in metronidazole-treated zebrafish. A prospective clinical study followed up 186 patients with cirrhosis for 80 months to observe the relevance of follistatin levels in prevalence and mortality of acute-on-chronic liver failure. Recovered patients with ALF robustly express HNF4α in either LPCs or remaining hepatocytes. As in hepatocytes, HNF4α controls the expression of coagulation factors by binding to their promoters in LPC. HNF4α expression in LPCs requires the forkhead box protein H1-Sma and Mad homolog 2/3/4 transcription factor complex, which is promoted by the TGF-β superfamily member activin. Activin signaling in LPCs is negatively regulated by follistatin, a hepatocyte-derived hormone controlled by insulin and glucagon. In contrast to patients requiring liver transplantation, recovered patients demonstrate a normal activin/follistatin ratio, robust abundance of the activin effectors phosphorylated Sma and Mad homolog 2 and HNF4α in LPCs, leading to significantly improved coagulation function. A follow-up study indicated that serum follistatin levels could predict the incidence and mortality of acute-on-chronic liver failure.

CONCLUSIONS

These results highlight a crucial role of the follistatin-controlled activin-HNF4α-coagulation axis in determining the clinical outcome of massive hepatocyte loss-induced ALF. The effects of insulin and glucagon on follistatin suggest a key role of the systemic metabolic state in ALF.

Cirrosis hepática o falla hepática crónica agudizada: definición y clasificación

La cirrosis se considera el estadio crónico e irreversible de la lesión hepática. Su etiología es diversa y abarca causas como las infecciones víricas, tóxicos como el alcohol, medicamentos, patologías autoinmunes y otras. La descompensación de la cirrosis hepática es consecuencia de cambios fisiopatológicos que se dan con el tiempo como ascitis, peritonitis bacteriana espontánea, hemorragia del tubo digestivo, síndrome hepatorrenal, encefalopatía hepática o hipertensión portopulmonar, mientras que la falla hepática crónica agudizada debe considerarse como una entidad que debe diferenciarse de la anterior, ya que es una falla multiorgánica de curso rápido, por lo regular en pacientes hospitalizados en unidad de cuidado intensivo, a menudo secundaria a desencadenantes como estados de choque. El clínico debe identificarlas para su abordaje y evaluación. El método actual adecuado para estadificar esta entidad es el puntaje CLIFF SOFA, que evalúa la mortalidad a 28 y 90 días, permitiendo intervenciones adecuadas en cada caso.

Case report: A case of severe acute hepatitis of unknown origin

According to analyses of etiology, clinical features, diagnostic methods, and treatment strategies by summarizing a case of unexplained acute hepatitis recently experienced, we are aiming to provide some information to enrich the clinical experience in diagnosis and treatment of severe acute hepatitis of unknown etiology in young children. A boy, aged 10 years and 6 months old, was admitted to the hospital due to acute abdominal pain, jaundice, and exceptionally high levels of ALT and AST. A range of measures, including patient history, physical examination, and routine laboratory testing, were performed. Furthermore, strategies such as trio-based next-generation sequencing (Trio-NGS) and liver biopsy, as well as metagenomic NGS (mNGS) of blood and liver samples were also performed. In summary, this case was an acute severe non-A-E hepatitis that is a probable case with hepatitis of unknown origin. Immunohistochemical analysis showed an immune injury in liver tissues. Torque teno virus (TTV) sequences were detected by mNGS assay. As for treatment strategies, in addition to general treatment, this patient also underwent plasmapheresis and methylprednisolone treatment due to disease deterioration. The patient's liver function was improved afterward and discharged after one month of treatment. Taken together, this work reported the clinical feature and treatment of severe acute hepatitis with non-A-E hepatitis in detail. The potential mechanism of liver damage might be due to an immune attack in which TTV might play a role as a co-factor.

Kupffer Cell Hyaline Globules in Children With Autoimmune Hepatitis

BACKGROUND

Hyaline globules (HGs) in the cytoplasm of Kupffer cells (KCs) have been appraised for being a typical feature of autoimmune hepatitis (AIH). This study aimed to determine how useful Kupffer cell hyaline globules (KCHGs) are in diagnosing AIH vs. other causes of pediatric chronic liver diseases (PCLDs).

MATERIALS AND METHODS

This retrospective study recruited 124 children; 58 with AIH, 50 with chronic hepatitis C virus (HCV) infection, and 16 with Wilson's disease (WD). Two pathologists retrieved paraffin blocks of liver biopsies and prepared new cut sections for Periodic acid-Schiff-Diastase (PAS-D) stain. They independently examined liver biopsies before starting treatment. Two pediatricians reviewed medical records for demographic, clinical, laboratory, and serological findings.

RESULTS

Females represented 48.6% of the studied children with a median age of 5.8 (4.9) years. Pathologists identified KCHGs in 67.24%, 12.5%, and 6.0% of AIH, WD, and HCV affected children respectively, P < 0.001. A significantly higher proportion of seropositive than seronegative AIH patients had KCHGs (77.5% vs. 50.0%), (P < 0.05). In multivariate analysis, KCHGs and prolonged prothrombin time were the only significant predictors that differentiate between AIH and the other studied PCLDs. The odds ratio of having AIH increased 68 times if KCHGs were seen. Among children with AIH, the presence of KCHGs was associated with higher median levels of direct bilirubin 2.2 (1.3) vs. 1.2 (2.2), and immunoglobulin G 3.2 (1.9) vs. 2.0 (1.7), (P < 0.05), but not to histopathological findings or hepatic fibrosis and activity.

CONCLUSIONS

KCHGs are key indicators that can differentiate between AIH and other PCLDs, and between seropositive and seronegative AIH.

North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Position Paper on the Diagnosis and Management of Pediatric Acute Liver Failure

ABSTRACT

Pediatric acute liver failure (PALF) is a rare, rapidly progressive clinical syndrome with significant morbidity and mortality. The phenotype of PALF manifests as abrupt onset liver dysfunction, which can be brought via disparate etiology. Management is reliant upon intensive clinical care and support, often provided by the collaborative efforts of hepatologists, critical care specialists, and liver transplant surgeons. The construction of an age-based diagnostic approach, the identification of a potential underlying cause, and the prompt implementation of appropriate therapy can be lifesaving; however, the dynamic and rapidly progressive nature of PALF also demands that diagnostic inquiries be paired with monitoring strategies for the recognition and treatment of common complications of PALF. Although liver transplantation can provide a potential life-saving therapeutic option, the ability to confidently determine the certainness that liver transplant is needed for an individual child has been hampered by a lack of adequately tested clinical decision support tools and accurate predictive models. Given the accelerated progress in understanding PALF, we will provide clinical guidance to pediatric gastroenterologists and other pediatric providers caring for children with PALF by presenting the most recent advances in diagnosis, management, pathophysiology, and associated outcomes.

Safety, Feasibility, Yield, Diagnostic and Prognostic Implications of Transjugular Liver Biopsy in Children and Adolescents

OBJECTIVES

The objectives of the study were to evaluate the indications, feasibility, complications and clinical implications of transjugular liver biopsy (TJLB) in children.

METHODS

Data of all TJLB performed in children <18 years old was retrieved from the computerized hospital information system. TJLB was done using a 19 G quick-core needle biopsy system with 20 mm throw length. Hepatic venous pressure gradient was additionally measured in children with portal hypertension. A single pathologist reviewed all the biopsies again and provided structured information.

RESULTS

A total of 102 children, including 5 with acute liver failure underwent TJLB with technical success in 101 (99%). A mean of 2.3 ± 0.9 passes (range: 1-5) was taken for the biopsy. The most common indications for TJLB in our cohort were elevated international normalized ratio >1.5 (66, 64.7%), ascites (46, 45.1%) and thrombocytopenia (platelet count < 60,000/mm3) (42, 41.2%). Mean size of the tissue received was 14.5 ± 5.6 mm with an average of 10.2 ± 4.7 portal tracts. Only one child developed major (category D) complication (hemobilia) and 12 (11.8%) developed minor complications post-procedure. Etiological diagnosis could be made in a total of 64 (63.9%) children undergoing TJLB, the most common diagnosis being autoimmune hepatitis (n = 31), non-cirrhotic portal fibrosis (n = 16) and drug-induced liver injury (n = 4).

CONCLUSION

TJLB is well tolerated, feasible and helps make a diagnosis in close to 64% children allowing timely medical and/or surgical intervention. It is especially useful for diagnosis of autoimmune liver diseases, drug-induced liver injury and non-cirrhotic portal fibrosis.

Hepatic Adenosine Triphosphate Reduction Through the Short-Chain Fatty Acids-Peroxisome Proliferator-Activated Receptor γ-Uncoupling Protein 2 Axis Alleviates Immune-Mediated Acute Hepatitis in Inulin-Supplemented Mice

How liver tolerance is disrupted in immune-mediated liver injury is currently unclear. There is also insufficient information available regarding susceptibility, precipitation, escalation, and perpetuation of autoimmune hepatitis. To explore how dietary fiber influences hepatic damage, we applied the concanavalin A (ConA)-induced acute immune-mediated liver injury model in mice fed a diet supplemented with 6.8% inulin, a water-soluble fermentable fiber. Twelve hours after ConA administration, inulin-supplemented diet-fed mice demonstrated significantly alleviated hepatic damage histologically and serologically, with down-regulation of hepatic interferon-γ and tumor necrosis factor and reduced myeloperoxidase (MPO)-producing neutrophil infiltration. Preconditioning with an inulin-supplemented diet for 2 weeks significantly reduced hepatic adenosine triphosphate (ATP) content; suramin, a purinergic P2 receptor antagonist, abolished the protective effect. Of note, the portal plasma derived from mice fed the inulin-supplemented diet significantly alleviated ConA-induced immune-mediated liver injury. Mechanistically, increased portal short-chain fatty acid (SCFA) levels, such as those of acetate and butyrate, by inulin supplementation leads to up-regulation of hepatic γ-type peroxisome proliferator-activated receptor (Pparg) and uncoupling protein 2 (Ucp2), which uncouples mitochondrial ATP synthesis downstream of PPARγ. Pparg down-regulating small interfering RNA cancelled the protective effect of inulin supplementation against MPO-producing neutrophil infiltration and the subsequent immune-mediated liver injury, suggesting that the SCFA-PPARγ-UCP2 axis plays a key role in the protective effect by inulin supplementation. Moreover, significant changes in the gut microbiota, including increased operational taxonomic units in genera Akkermansia and Allobaculum, also characterized the protective effect of the inulin-supplemented diet. Conclusion: There is a possible unraveled etiopathophysiological link between the maintenance of liver tolerance and dietary fiber. The SCFA-PPARγ-UCP2 axis may provide therapeutic targets for immune-mediated liver injury in the future.

Acute (fulminant) liver failure: a clinical and imaging review

Acute liver failure (ALF) is a rare clinical entity with high morbidity and mortality frequently requiring liver transplantation for survival. Imaging, particularly with ultrasound, plays an important role, especially to distinguish patients with underlying chronic liver disease who have lower transplant priority. We discuss the clinical and imaging findings in the three subtypes of ALF using a multi-modality approach with an emphasis on ultrasound.

Early liver transplantation for corticosteroid non-responders with acute severe autoimmune hepatitis: The SURFASA score

BACKGROUND & AIMS

In acute severe autoimmune hepatitis (AS-AIH), the optimal timing for liver transplantation (LT) remains controversial. The objectives of this study were to determine early predictive factors for a non-response to corticosteroids and to propose a score to identify patients in whom LT is urgently indicated.

METHODS

This was a retrospective, multicenter study (2009-2016). A diagnosis of AS-AIH was based on: i) Definite or probable AIH based on the simplified IAIHG score; ii) international normalized ratio (INR) ≥1.5 and/or bilirubin >200 μmol/L; iii) No previous history of AIH; iv) Histologically proven AIH. A treatment response was defined as LT-free survival at 90 days. The evolution of variables from corticosteroid initiation (day-D0) to D3 was estimated from: Δ%3 = (D3-D0)/D0.

RESULTS

A total of 128 patients were included, with a median age of 52 (39-62) years; 72% were female. Overall survival reached 88%. One hundred and fifteen (90%) patients received corticosteroids, with a LT-free survival rate of 66% at 90 days. Under multivariate analysis, D0-INR (odds ratio [OR] 6.85; 95% CI 2.23-21.06; p <0.001), Δ%3-INR ≥0.1% (OR 6.97; 95% CI 1.59-30.46; p <0.01) and Δ%3-bilirubin ≥-8% (OR 5.14; 95% CI 1.09-24.28; p <0.04) were predictive of a non-response. The SURFASA score: -6.80+1.92∗(D0-INR)+1.94∗(Δ%3-INR)+1.64∗(Δ%3-bilirubin), created by combining these variables, was highly predictive of LT or death (AUC = 0.93) (88% specificity; 84% sensitivity) with a cut-off point of <-0.9. Below this cut-off, the chance of responding was 75%. With a score higher than 1.75, the risk of dying or being transplanted was between 85% and 100%.

CONCLUSION

In patients with AS-AIH, INR at the introduction of corticosteroids and the evolution of INR and bilirubin are predictive of LT or death. Within 3 days of initiating corticosteroids, the SURFASA score can identify non-responders who require a referral for LT. This score needs to be validated in a prospective cohort.

LAY SUMMARY

The management of patients with acute severe autoimmune hepatitis is highly challenging, particularly regarding their early referral for liver transplantation. We found that international normalized ratio at the initiation of corticosteroid therapy and the evolution of international normalized ratio and bilirubin values after 3 days of therapy were highly predictive of liver transplantation or death. We are thus proposing a score that combines these variables and identifies patients in whom liver transplantation is urgently required.