Significance of histopathological features in differentiating autoimmune liver disease from nonautoimmune chronic liver disease in children

Comparative Evaluation of Simplified and Modified Histologic Criteria in the Diagnosis of Chronic Autoimmune Hepatitis

Background

The present study aimed at comparing simplified and modified histologic criteria alone and along with other indicators in the diagnosis of chronic autoimmune hepatitis (AIH).

Materials and Methods

In this cross-sectional study, 48 cases were selected from slides and paraffin blocks of patients suspected of chronic AIH according to clinical and laboratory data, including serology and autoantibody findings and viral hepatitis test results. Then, scores equal to 1 (compatible hepatitis), 2 (typical hepatitis), ≤6 (probable hepatitis), and ≥7 (definite hepatitis) were calculated based on the simplified histologic criteria, modified histologic criteria, and these two criteria, along with other indicators including antinuclear antibodies (Ab), smooth muscle Ab or liver-kidney microsomal Ab or soluble liver antigen (Ag) and serum immunoglobulin G (IgG) and absence of viral hepatitis.

Results

The results of this study revealed that based on the simplified histologic criteria, 43.8% and 56.3% of these cases were assigned a score of 1 and 2 points, respectively. However, calculating the total score using the simplified criteria along with other indicators showed that 60.4% and 39.6% of cases were assigned a score ≤6 and ≥7 points, respectively. Moreover, the modified histologic criteria indicated that 25% and 75% of cases were assigned a score of 1 and 2 points, respectively.

Conclusion

According to the findings of the present study, the modified histologic criteria compared to the simplified histologic criteria identified a higher percentage of patients assigned a score of 2 points. Moreover, modified histologic criteria, along with other indicators, were more accurate in detecting definite AIH (score ≥7 points).

Detection of polyreactive immunoglobulin G facilitates diagnosis in children with autoimmune hepatitis

OBJECTIVE

The detection of autoantibodies is essential to diagnose autoimmune hepatitis (AIH). Particularly in children, specificity of autoantibodies decreases due to lower titers being diagnostic and being present not only in AIH but also in other liver diseases. Recently, quantification of polyreactive IgG (pIgG) for detection of adult AIH showed the highest overall accuracy compared to antinuclear antibodies (ANA), anti-smooth muscle antibodies (anti-SMA), anti-liver kidney microsomal antibodies (anti-LKM) and anti-soluble liver antigen/liver pancreas antibodies (anti-SLA/LP). We aimed to evaluate the diagnostic value of pIgG for pediatric AIH.

DESIGN

pIgG, quantified using HIP1R/BSA coated ELISA, and immunofluorescence on rodent tissue sections were performed centrally. The diagnostic fidelity to diagnose AIH was compared to conventional autoantibodies of AIH in training and validation cohorts from a retrospective, European multi-center cohort from nine centers from eight European countries composed of existing biorepositories from expert centers (n = 285).

RESULTS

IgG from pediatric AIH patients exhibited increased polyreactivity to multiple protein and non-protein substrates compared to non-AIH liver diseases and healthy children. pIgG had an AUC of 0.900 to distinguish AIH from non-AIH liver diseases. pIgG had a 31-73% higher specificity than ANA and anti-SMA and comparable sensitivity that was 6-20 times higher than of anti-SLA/LP, anti-LC1 and anti-LKM. pIgG had a 21-34% higher accuracy than conventional autoantibodies, was positive in 43-75% of children with AIH and normal IgG and independent from treatment response.

CONCLUSION

Detecting pIgG improves the diagnostic evaluation of pediatric AIH compared to conventional autoantibodies, primarily owing to higher accuracy and specificity.

Comparison of four histological scoring systems for autoimmune hepatitis to improve diagnostic sensitivity

BACKGROUND/AIMS

The histological criteria in the 1999 and 2008 scoring systems proposed by the International Autoimmune Hepatitis Group (IAIHG) have their inherent limitations in diagnosing autoimmune hepatitis (AIH). In this study, we evaluated the histology components of four scoring systems (1. revised original scoring system ["1999 IAIHG"], 2. simplified scoring system ["2008 IAIHG"], 3. modified histologic criteria ["2017 UCSF"], and 4. a new histologic criteria proposed by the International AIH Pathology Group ["2022 IAHPG"]) in AIH patients.

METHODS

Medical records and liver biopsies were retrospectively reviewed for 68 patients from two independent medical institutions, diagnosed with AIH based on the 1999 IAIHG system between 2006 and 2016. The histological features were reviewed in detail, and the four histological scoring systems were compared.

RESULTS

Out of the 68 patients, 56 (82.4%) patients met the "probable" or "definite" AIH criteria of the 2008 IAIHG system, and the proportion of histologic score 2 (maximum) was 40/68 (58.8%). By applying the 2017 UCSF criteria, the number of histology score 2 increased to 60/68 (88.2%), and "probable" or "definite" AIH cases increased to 61/68 (89.7%). Finally, applying the 2022 IAHPG histology score resulted in the highest number of cases with histologic score 2 (64/68; 94.1%) and with a diagnosis of "probable" or "definite" AIH (62/68; 91.2%).

CONCLUSION

The recently proposed UCSF/IAHPG histological criteria increased the histology score of AIH. Substituting the histology component of the 2008 IAIHG system with the 2022 IAHPG criteria increased the sensitivity for diagnosing AIH (≥"Probable AIH") from 82.4% to 91.2%.

Seronegative autoimmune hepatitis in childhood

Comprehensive guidelines on seropositive autoimmune hepatitis have been published for both adults and children, although these guidelines comprise only limited knowledge about seronegative autoimmune hepatitis. Autoimmune hepatitis presents as an acute or chronic progressive disease and poor outcomes are inevitable if left untreated. The absence of autoantibody positivity, hypergammaglobulinemia and lack of comprehensive algorithms makes seronegative autoimmune hepatitis a mysterious disease. In general, seronegative autoimmune hepatitis often presents with acute hepatitis, and its treatment and prognosis similar to seropositive autoimmune hepatitis. The present review focuses on the known characteristics of seronegative autoimmune hepatitis in childhood, and those of which current knowledge is vague.

Autoimmmune hepatitis

Autoimmune hepatitis (AIH) is a T-cell mediated, inflammatory liver disease affecting all ages and characterized by female preponderance, elevated serum transaminase and immunoglobulin G levels, positive circulating autoantibodies, and presence of interface hepatitis at liver histology. AIH type 1, affecting both adults and children, is defined by positive anti-nuclear and/or anti-smooth muscle antibodies, while type 2 AIH, affecting mostly children, is defined by positive anti-liver-kidney microsomal type 1 and/or anti-liver cytosol type 1 antibody. While the autoantigens of type 2 AIH are well defined, being the cytochrome P4502D6 (CYP2D6) and the formiminotransferase cyclodeaminase (FTCD), in type 1 AIH they remain to be identified. AIH-1 predisposition is conferred by possession of the MHC class II HLA DRB1*03 at all ages, while DRB1*04 predisposes to late onset disease; AIH-2 is associated with possession of DRB1*07 and DRB1*03. The majority of patients responds well to standard immunosuppressive treatment, based on steroid and azathioprine; second- and third-line drugs should be considered in case of intolerance or insufficient response. This review offers a comprehensive overview of pathophysiological and clinical aspects of AIH.

Novel Diagnostic and Therapeutic Strategies in Juvenile Autoimmune Hepatitis

Juvenile autoimmune hepatitis (JAIH) is a rare, chronic, inflammatory disease of the liver characterized by a complex interaction between genetic, immunological, and environmental factors leading to loss of immunotolerance to hepatic antigens. It affects both children and adolescents, most commonly females, and its clinical manifestations are quite variable. JAIH is progressive in nature and if left untreated may lead to cirrhosis and terminal liver failure. Although JAIH was first described almost 50 years ago, there have been few significant advances in the clinical management of these patients, both in terms of available diagnostic tools and therapeutic options. Aminotransferase activity, class G immunoglobulins and autoantibodies are the biomarkers used to diagnose AIH and monitor treatment response alongside clinical and histological findings. Despite their utility and cost-effectiveness, these biomarkers are neither an accurate expression of AIH pathogenic mechanism nor a precise measure of treatment response. Current standard of care is mainly based on the administration of steroids and azathioprine. This combination of drugs has been proven effective in inducing remission of disease in the majority of patients dramatically improving their survival; however, it not only fails to restore tolerance to hepatic autoantigens, but it also does not halt disease progression in some patients, it is often needed life-long and finally, it has deleterious side-effects. The ideal therapy should be enough selective to contrast immune-mediated live damage while preserving or potentiating the ability to develop permanent tolerance vs. pathogenic autoantigens. By reviewing the state of the art literature, this article highlights novel diagnostic and therapeutic strategies for managing pediatric AIH with a special focus on new strategies of immunotherapy. These promising tools could improve the diagnostic algorithm, more accurately predict disease prognosis, and provide targeted, individualized treatment.

Diagnosis and Management of Pediatric Autoimmune Liver Disease: ESPGHAN Hepatology Committee Position Statement

Paediatric autoimmune liver disease is characterized by inflammatory liver histology, circulating autoantibodies, and increased levels of IgG, in the absence of a known etiology. Three conditions have a likely autoimmune pathogenesis: autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis, and de novo AIH after liver transplantation. Two types of pediatric AIH are recognized according to seropositivity for smooth muscle and/or antinuclear antibody (AIH-1) or liver kidney microsomal type 1 and/or anti-liver cytosol type 1 antibodies (AIH-2).Pertinent issues addressing the diagnosis, treatment, and long-term follow-up were formulated by a core group of ESPGHAN members. They have commissioned the first authors with execution of this project. Initially, they have performed a systematic literature search on MEDLINE, ResearchGate, and Mendeley databases during the last 30 years and produced a document focusing on prospective and retrospective studies in children. The ESPGHAN core group and ESPGHAN Hepatology Committee members voted on each recommendation, using a formal voting technique.

Autoimmune hepatitis: review of histologic features included in the simplified criteria proposed by the international autoimmune hepatitis group and proposal for new histologic criteria

Simplified criteria for diagnosis of autoimmune hepatitis are based on autoantibodies, serum immunoglobulin G, histologic features, and negative viral serology. A score of 6 points is necessary for the designation of probable autoimmune hepatitis and 7 points or more for definite autoimmune hepatitis. The presence of three histologic features is required for categorizing a case as typical (2 points): interface hepatitis with portal lymphocytic/lymphoplasmacytic cells extending into lobule, emperipolesis, and rosettes. In the absence of all three features, a chronic hepatitis picture is considered compatible with autoimmune hepatitis (1 point). This study examines the validity of these histologic features for the diagnosis of autoimmune hepatitis. Clinical data and liver biopsies were reviewed for 88 autoimmune hepatitis, 20 primary biliary cholangitis, and 13 non-autoimmune acute hepatitis cases. Interface/lobular activity, number of plasma cells, copper/CK7 stains, and presence/absence of biliary features were assessed in autoimmune hepatitis and primary biliary cholangitis cases. The simplified criteria score was calculated. Modified histologic criteria were formulated on the basis of interface/lobular activity, number of plasma cells, and presence/absence of biliary features. Using the proposed histologic features, histologic score of 2 increased from 8 to 77%, while total simplified score of >6 increased from 69 to 86%. There was no increase in total simplified score for primary biliary cholangitis or non-autoimmune acute hepatitis. Rosettes and emperipolesis are difficult to interpret, and lack sensitivity and sensitivity for autoimmune hepatitis diagnosis. The current histologic criteria used in the current simplified score lead to underscoring of autoimmune hepatitis cases. The modified histologic criteria based on the inflammatory activity, extent of plasma cells, and results of copper/CK7 staining increased the histologic score in autoimmune hepatitis and led to a probable/definite diagnosis of autoimmune hepatitis in 17% of cases that would have otherwise been classified as non- autoimmune hepatitis by simplified score.

Activated hepatic stellate cells impair NK cell anti-fibrosis capacity through a TGF-β-dependent emperipolesis in HBV cirrhotic patients

Natural killer (NK) cells can induce liver fibrosis remission by killing hepatic stellate cells (HSCs) and producing interferon (IFN)-γ in a mouse model; however, their anti-fibrotic immune-characteristics and regulatory mechanisms by HSCs remain to be determined, especially in livers from HBV-infected liver cirrhosis (LC) patients. We analyzed frequency, phenotype and anti-fibrotic function of hepatic and peripheral NK subsets in 43 HBV-LC patients. We found that hepatic NK subsets from LC patients displayed a decreased frequency, activation status and anti-fibrotic activity compared with those from chronic hepatitis B patients, which were mainly mediated by increased intrahepatic tumour-growth factor (TGF)-β because blockade of TGF-β significantly reversed NK anti-fibrotic function in vitro. In vivo, hepatic NK cells were enriched in proximity to the α-smooth muscle actin (α-SMA+) area within mild fibrosis regions; while in severe fibrotic areas, they were either directly attached to or separated from the α-SMA+ region. NK cells from LC patients could enter HSCs to form emperipolesis (a cell-in-cell structure) and become apoptotic; anti-TGF-β treatment ameliorated this emperipolesis. This finding suggested a novel mechanism by which activated HSCs impair NK cells' anti-fibrosis capacity through a TGF-β-dependent emperipolesis in LC patients, providing an anti-fibrotic rational by enhancing NK cell activity.

Emperipolesis mediated by CD8 T cells is a characteristic histopathologic feature of autoimmune hepatitis

Emperipolesis has been widely described in patients with autoimmune hepatitis, but the significance and the diagnostic value have not been quantitated. The goal of this study was to define the features and clinical significance of emperipolesis in autoimmune hepatitis (AIH). A retrospective histological evaluation of 101 patients with AIH and 184 controls was performed. Confocal staining for CD4, CD8, CD19, CD56, CD163, and CD11b, CK8/18 and cleaved caspase-3 was performed. Emperipolesis was observed in 65.3 % of the patients with AIH in haematoxylin and eosin (H&E)-stained slides, which was significantly higher than in patients with primary biliary cirrhosis (17.9 %), chronic hepatitis B (14.9 %), and drug-induced liver injury (25.6 %). Among AIH patients, the patients with emperipolesis had significantly higher serum (alanine aminotransferase/aspartate aminotransferase [ALT/AST]) levels. Histologically, emperipolesis was associated with more severe necroinflammatory features and more advanced fibrosis. The lymphocytes in hepatocytes were predominantly as CD8 T cells. Emperipolesis of CD8 T cells induced cleaved caspase-3 expression, and was prominent in areas apoptosis. Emperipolesis is a characteristic feature of AIH which is often seen in conjunction with interface hepatitis, plasmacytic infiltration and hepatocyte rosetting and is associated with more severe necroinflammatory and fibrotic changes. In AIH, emperipolesis is predominantly mediated by CD8 T cells, appears to induce apoptosis and may be another mechanism of autoimmune-mediated hepatocyte injury.

Assessment of the histopathological key features in autoimmune hepatitis

AIMS

In this study, we aimed to evaluate the use of typical histological features of both the revised original (1999) and simplified (2008) criteria in the diagnosis of autoimmune hepatitis (AIH) in clinical practice.

METHODS AND RESULTS

We performed a detailed histopathological evaluation of the pretreatment biopsies of 63 AIH patients, and used biopsies of 62 untreated chronic viral hepatitis patients [hepatitis B (n = 21) or hepatitis C (n = 41)] as a reference cohort. Biopsies were systematically reviewed for inflammation, fibrosis and the presence of interface hepatitis, plasma cells, rosettes and emperipolesis with a well-defined assessment method. AIH biopsies showed more interface hepatitis (87% versus 63%, P = 0.002), more plasma cell-rich infiltrates (48% versus 27%, P = 0.02), more rosettes (49% versus 23%, P = 0.004) and more emperipolesis (78% versus 50%, P = 0.001) than chronic viral hepatitis biopsies. Emperipolesis (P = 0.01) and rosettes (P < 0.01) were superior to plasma cells and interface hepatitis as independent predictors for AIH. Moderate to severe lymphocytic cholangitis was found in 28% of AIH patients.

CONCLUSIONS

Emperipolesis and rosette formation are superior histological predictors of AIH than the classic hallmark features of interface hepatitis and plasma cells. In addition, moderate to severe lymphocytic cholangitis does not preclude the diagnosis of AIH.

Tumour necrosis factor alpha (TNF-α) genetic polymorphisms and the risk of autoimmune liver disease: a meta-analysis

Epidemiological studies have evaluated the association between tumour necrosis factor alpha (TNF-α)- 308G/A and (TNF-α)- 238G/A polymorphisms, and the risk of autoimmune liver disease (AILD), yet the results are conflicting. To derive a more precise estimation of the relationship, we performed this meta-analysis. A systematic review was conducted to identify all eligible studies of TNF-α polymorphisms and AILD risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association between the two TNF-α polymorphisms and AILD risk. A total of 15 eligible studies were identified. Overall, positive associations of -308G/A polymorphism with AILD risk were found (A vs G allele: OR =1.45, 95%CI = 1.13- 1.86; AA vs GG: OR = 2.74, 95%CI = 1.51- 4.96; GA vs GG: OR = 1.46, 95%CI = 1.11- 1.92;dominant model: OR = 1.57, 95%CI = 1.18- 2.10; recessive model: OR = 2.22, 95%CI = 1.31- 3.76). In subgroup analysis by ethnicity, a significantly higher risk was found in Caucasians. In subgroup analysis by AILD category, significant association was observed in autoimmune hepatitis and primary sclerosing cholangitis, especially in Caucasians. Patients carrying TNF-α-238A allele had a slightly decreased risk of developing AILD (OR = 0.65, 95%CI = 0.48- 0.87). However, we found both TNF-α polymorphisms were not associated with primary biliary cirrhosis risk, even in subgroup analysis. Our meta-analysis suggests that the TNF-α-308G/A and -238G/A polymorphisms may contribute to AILD susceptibility in Caucasians,especially for autoimmune hepatitis and primary sclerosing cholangitis. Nevertheless, we found both TNF-α polymorphisms were unlikely to be associated with the risk of primary biliary cirrhosis

Clinicopathological study of primary biliary cirrhosis with interface hepatitis compared to autoimmune hepatitis

AIM: To investigate histological and immunohistochemical differences in hepatitis between autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) with AIH features.

METHODS: Liver needle biopsies of 41 PBC with AIH features and 43 AIH patients were examined. The activity of periportal and lobular inflammation was scored 0 (none or minimal activity) to 4 (severe), and the degree of hepatitic rosette formation and emperipolesis was semiquantatively scored 0-3. The infiltration of mononuclear cells positive for CD20, CD38, CD3, CD4, and CD8 and positive for immunoglobulins (IgG, IgM, and IgA) at the periportal areas (interface hepatitis) and in the hepatic lobules (lobular hepatitis) were semiquantitatively scored in immunostained liver sections (score 0-6). Serum aspartate aminotransferase (AST), immunoglobulins, and autoantibodies at the time of liver biopsy were correlated with the histological and immunohistochemical scores of individual lesions.

RESULTS: Lobular hepatitis, hepatitic rosette formation, and emperipolesis were more extensive and frequent in AIH than in PBC. CD3+, CD4+, and CD8+ cell infiltration scores were higher in the hepatic lobules and at the interface in AIH but were also found in PBC. The degree of mononuclear cell infiltration correlated well with the degree of interface and lobular hepatitis in PBC, but to a lesser degree in AIH. CD20+ cells were mainly found in the portal tracts and, occasionally, at the interface in both diseases. Elevated AST correlated well with the hepatocyte necroinflammation and mononuclear cell infiltration, specifically CD38+ cells in PBC. No correlation existed between autoantibodies and inflammatory cell infiltration in PBC or AIH. While most AIH cases were IgG-predominant at the interface, PBC cases were divided into IgM-predominant, IgM/IgG-equal, and IgG-predominant types, with the latter sharing several features with AIH.

CONCLUSION: These results suggest that the hepatocellular injuries associated with interface and lobular hepatitis in AIH and PBC with interface hepatitis may not be identical.

Persistent hypertransaminasemia in asymptomatic children: A stepwise approach

We aimed to examine the major causes of isolated chronic hypertransaminasemia in asymptomatic children and develop a comprehensive diagnostic flow diagram. A MEDLINE search inclusive of publications throughout August 2012 was performed. We found only a small number of publications that had comprehensively investigated this topic. Consequently, it was difficult to construct a diagnostic flowchart similar to those already available for adults. In children, a “retesting panel” prescription, including gamma-glutamyl transpeptidase and creatine kinase in addition to aminotransferases, is considered a reasonable approach for proficiently confirming the persistence of the abnormality, ruling out cholestatic hepatopathies and myopathies, and guiding the subsequent diagnostic steps. If re-evaluation of physical and historical findings suggests specific etiologies, then these should be evaluated in the initial enzyme retesting panel. A simple multi-step diagnostic algorithm incorporating a large number of possible pediatric scenarios, in addition to the few common to adults, is available. Accurately classifying a child with asymptomatic persistent hypertransaminasemia may be a difficult task, but the results are critical for preventing the progression of an underlying, possibly occult, condition later in childhood or during transition. Given the high benefit/cost ratio of preventing hepatic deterioration, no effort should be spared in diagnosing and properly treating each case of persistent hypertransaminasemia in pediatric patients.