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Histopathology is essential for the diagnosis and evaluation of disease activity of autoimmune hepatitis (AIH). We aimed to elucidate the characteristics of AIH from the localization of inflammation. We re-evaluated a nationwide survey that was performed in Japan in 2018 of AIH patients diagnosed between 2014 and 2017. A total of 303 patients were enrolled, and the clinical and treatment characteristics were compared between the patients with predominantly portal inflammation (230 patients) or lobular inflammation (73 patients). AIH patients with lobular inflammation had a higher probability of being diagnosed with acute hepatitis than those with portal inflammation. Liver enzyme levels were higher in patients with lobular inflammation, whereas immunoglobulin G levels were higher in patients with portal inflammation. The prevalence of an alanine aminotransferase level < 30 U/L after 6 months of treatment was significantly higher in patients with lobular inflammation than in those with portal inflammation (81.7% vs. 67.3%, P = 0.046). The localization of inflammation may be useful for evaluating the onset of AIH.

Background: Autoimmune hepatitis (AIH) is characterized by progressive inflammation and necrosis of hepatocytes and eventually leads to a variety of phenotypes, including acute liver dysfunction, chronic progressive liver disease, and fulminant hepatic failure. Although the precise mechanisms of AIH are unknown, environmental factors may trigger disease onset in genetically predisposed individuals. Patients with the recently established entity of AIH with acute presentation often display atypical clinical features that mimic those of acute hepatitis forms even though AIH is categorized as a chronic liver disease. The aim of this study was to identify the precise clinical features of AIH with acute presentation., Methods: Eighty-six AIH patients with acute presentation were retrospectively enrolled from facilities across Japan and analyzed for clinical features, histopathological findings, and disease outcomes., Results: Seventy-five patients were female and 11 were male. Patient age ranged from adolescent to over 80 years old, with a median age of 55 years. Median alanine transaminase (ALT) was 776 U/L and median immunoglobulin G (IgG) was 1671 mg/dL. There were no significant differences between genders in terms of ALT (P = 0.27) or IgG (P = 0.51). The number of patients without and with histopathological fibrosis was 29 and 57, respectively. The patients with fibrosis were significantly older than those without (P = 0.015), but no other differences in clinical or histopathological findings were observed. Moreover, antinuclear antibody (ANA)-positive (defined as × 40, N = 63) and -negative (N = 23) patients showed no significant differences in clinical or histopathological findings or disease outcomes. Twenty-five patients experienced disease relapse and two patients died during the study period. ALP ≥ 500 U/L [odds ratio (OR) 3.20; 95% confidence interval (CI) 1.12-9.10; P < 0.030] and GGT ≥ 200 U/L (OR 2.98; 95% CI 1.01-8.77; P = 0.047) were identified as independent risk factors of disease relapse., Conclusions: AIH with acute presentation is a newly recognized disease entity for which diagnostic hallmarks, such as ALT, fibrosis, and ANA, are needed. Further investigation is also required on the mechanisms of this disorder. Clinicians should be mindful of disease relapse during patient care.

Aims: Although liver biopsy is crucial to diagnose and guide treatment decisions, a detailed histological analysis of autoimmune hepatitis (AIH) with clinically acute presentations has not yet been performed. This study aimed to characterise the histological features and explore potential histological hallmarks to diagnose the acute presentation of AIH., Methods: We systematically evaluated liver specimens of 87 adult patients with acute presentation of AIH retrospectively enrolled from Japanese multicentre facilities. Each histological feature was predefined by consensus based on the diagnostic criteria., Results: Key findings were that acute presentation of AIH revealed histological features of both acute hepatitis and chronic hepatitis accompanying various degrees of fibrosis. The prominent features were lobular necrosis/inflammation (97.7%), plasma cell infiltration (96.4%), emperipolesis (89.3%), pigmented macrophages (84.5%), cobblestone appearance of hepatocytes (82.6%) and perivenular necroinflammatory activity, including centrilobular necrosis (81.4%)., Conclusions: The acute presentation of AIH represents the entire histological spectrum of acute hepatitis and chronic hepatitis with various activity grades and fibrosis stages that clinically correspond to acute-onset AIH and acute exacerbation of classic AIH, respectively. Although there are no pathognomonic features for the pathological diagnosis, the prominent presence of lobular and perivenular necroinflammatory activity, pigmented macrophages and cobblestone appearance of hepatocytes in addition to the classic AIH features, such as plasma cell infiltration and emperipolesis, are useful for the pathological diagnosis of the acute presentation of AIH., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: We proposed a new grading and staging system for primary biliary cirrhosis (PBC), which takes into account the degree of both chronic cholangitis activity (CA) and hepatitic activity (HA) for grading disease activity and that of fibrosis, bile duct loss, and chronic cholestasis for staging. In this study, we validated our new system., Methods: Using liver biopsy specimens from 166 cases of PBC, chronic cholangitis with mild periductal lymphoplasmacytic infiltration, including chronic nonsuppurative destructive cholangitis, and the combined activity of interface hepatitis and lobular hepatitis were categorized into 4 grades on the basis of their degree and distribution (CA0-3 and HA0-3, respectively). For staging, because orcein staining was not available in this study, 2 criteria (fibrosis and bile duct loss) were independently scored from 0 to 3 on the basis of their degrees, and a final stage score was created from the sum., Results: Although there was a relatively uniform distribution of CA0/1/2/3 cases, the cases of HA0/1/2/3 were distributed as 21%, 64%, 13%, and 3%, respectively, with a prominent number of cases categorized as having none or mild HA. The distribution of stages 1 to 4 using our system was considerably different from that using the classic system and, importantly, showed a correlation with patient outcome., Conclusions: Our system revealed that the activities of chronic cholangitis and hepatitis did not correlate with each other in terms of degree and that our staging system properly reflected the outcome of PBC patients. The present study could validate the effectiveness of this new system for characterizing the pathologic condition of PBC.

Liver-infiltrating T cells play an essential role in the immunopathogenesis of autoimmune liver disease. Programmed death-1 (PD-1) and its ligands, B7-H1/PD-L1 and B7-DC/PD-L2, are new CD28-B7 family members that are involved in the regulation of immune responses. The ligation of PD-1 inhibits T-cell receptor-mediated T cell proliferation and cytokine production, and PD-1-deficient mice develop various organ-specific autoimmune diseases. To investigate the expressions of PD-1 and its ligands in autoimmune liver disease, in particular autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC), immunohistochemical analysis was performed. Liver biopsy specimens obtained from 17 patients with AIH and PBC were studied. PD-1 was expressed on more than half of the liver-infiltrating T cells within the portal tract. Some of the intrahepatic T cells expressed B7-H1 in patients with AIH and PBC. B7-H1 and B7-DC were mainly expressed on some Kupffer cells (KC) and liver sinusoidal endothelial cells (LSEC) within the sinusoids and their expression was upregulated in autoimmune liver disease. These results suggest that the interaction of PD-1 on T cells with increased expression of B7-H1 and B7-DC on KC and LSEC might be involved in the downregulation of autoreactive lymphocytes and result in the regulation of pathogenesis in autoimmune liver disease.

Vaccination of mice with dendritic cells loaded with Hepa1-6, well-differentiated hepatocellular carcinoma cell line (DC/Hepa1-6), induced cytotoxic T lymphocytes against Hepa1-6. Liver-specific inflammation was generated by vaccination of mice with DC/Hepa1-6 and subsequent administration of interleukin (IL)-12. Vaccination with DCs loaded with MC38 or B16 and administration of IL-12 did not generate significant liver-specific inflammation. Splenic T cells from DC/Hepa1-6-vaccinated mice showed proliferative response by stimulation with S-100 protein of the liver and showed cytotoxic activity to hepatocytes. Hepatic mononuclear cells from DC/Hepa1-6 + IL-12-treated mice also showed cytotoxic activity to hepatocytes. Adoptive transfer of splenocytes from DC/Hepa1-6-vaccinated mice produced hepatic inflammation in recipient mice that had been pretreated with IL-12. IL-12 upregulated the expression of adhesion molecules and chemokines in the liver. In conclusion, CTLs responsive to hepatocytes induced by DC/Hepa1-6 and enhanced expression of adhesion molecules and chemokines in the liver by IL-12 would produce autoimmune hepatic inflammation.

Background: The role of nitric oxide synthase (NOS) in autoimmune disease is gaining increased attention because of the relationships between NOS activity and T-lymphocyte subpopulations and, in particular, the influence of NO on cytokine production by Th1 versus Th2 cells. In addition, there is evidence that both the liver and infiltrating hepatic T cells have inducible NOS-2 activity., Methods: We studied serum levels of nitrite (NO2-) and nitrate (NO3-) in groups of patients with liver disease secondary to hepatitis B, hepatitis C, autoimmune hepatitis and primary biliary cirrhosis (PBC). Simultaneously, in a nested subpopulation, we studied the liver expression of NOS-2., Results: Interestingly, there was a significant elevation both of nitrite and of nitrate in patients with PBC but not other liver diseases. Despite such increments, there was no correlation of the levels of nitrite and nitrate with sera levels of tumor necrosis factor-alpha, interferon-gamma, alanine aminotransferase, total bilirubin, alkaline phosphatase, gamma-glutamyl transpeptidase, platelet count, IgG, IgM, antimitochondrial antibodies or prothrombin time. These data were extended by demonstrating the expression of NOS-2 by immunohistochemistry in 13/14 patients with PBC, including in 9/14 patient hepatocyte populations and 4/14 bile duct cells. In contrast, NOS-2 expression was noted in hepatitis B and hepatitis C, but only found within mononuclear cells., Conclusion: Our data suggest that NO produced through NOS-2 may play a role in the pathogenesis of bile duct injury in some PBC patients., (Copyright 2002 Blackwell Science Asia Pty Ltd)

Background/aims: A nationwide survey of autoimmune hepatitis (AIH) was carried out in Japan., Methods: Four hundred and ninety-six patients were enrolled by questionnaires sent to 101 hospitals with hepatology specialists., Results: The clinical features of Japanese AIH were as follows: most patients were middle-aged women; serum autoantibodies, especially antinuclear antibody, were frequently positive, serum IgG level was high, and HLA-DR4 was the major HLA allotype. Liver-kidney microsomal type 1 antibody was positive in nine of 79 patients tested. Eight of these antibody positive patients were also positive for antinuclear antibody and five for anti-smooth muscle antibody. Ninety-two percent of the patients showed piecemeal necrosis and 60% bridging necrosis; plasma cell infiltration in the portal areas was observed in 50% of the patients. Only 12.3% were diagnosed as having liver cirrhosis. A favorable effect of corticosteroid, normalization of serum transaminases, was observed in 89% of 317 patients, who were treated with an initial dose of over 30 mg/day. Sixty-two patients were positive for hepatitis C virus (HCV) markers. In these patients, however, only one patient was liver-kidney microsomal type 1 antibody positive. Corticosteroid was effective in 30 (81%) of 37 HCV-marker-positive patients treated with this agent. Thus the efficacy of corticosteroid did not differ from that in AIH patients without HCV infection (90%). Similarly, interferon treatment was used in 20 patients, all of whom were positive for HCV-RNA, and resulted in 50% efficacy as determined by normalization of the serum transaminase level 6 months after treatment. The International Diagnostic Scoring System for the diagnosis of AIH worked well in these patients, except for HCV-infected individuals, that is, approximately 10% of the total of AIH patients.

In the present study, we investigated the role of the spleen in experimental hepatic ischemia/reperfusion in the rat. After a 90-min period of ischemia in the left and middle hepatic lobes, the ischemia was released and the liver was reperfused for up to 24 h. Plasma alanine aminotransferase reached a peak 3 h after the onset of reperfusion, and gradually decreased thereafter. A histological examination revealed evidence of hepatocellular necrosis and degeneration, especially 24 h after the onset of reperfusion. In addition, there was a noticeable accumulation of polymorphonuclear cells in the liver following ischemia/reperfusion. A splenectomy performed just prior to ischemia/reperfusion reduced both biochemical and histological hepatocellular injury. The number of polymorphonuclear cells in the liver following ischemia/reperfusion was significantly reduced in rats subjected to splenectomy, suggesting that the increase in polymorphonuclear cells may contribute to liver injury. The number of mononuclear cells also increased in the marginal zones of the spleen following ischemia/reperfusion, and appeared to be derived from the splenic monocyte/macrophage population, based on immunohistochemical studies. The spleen plays an important role in the pathogenesis of hepatic ischemia/reperfusion injury and the splenic monocyte/ macrophage population contributes to liver damage.

The expression of thrombomodulin on sinusoidal endothelial cells was studied using the immuno-peroxidase method and both light and electron microscopy in patients with chronic viral hepatitis (type B: four cases; type C: 28 cases). Thrombomodulin was found on sinusoidal endothelial cells, especially on the surface in both type B and type C chronic hepatitis. There was no correlation between the level of thrombomodulin expression and clinical data including serum level of transaminase, and coagulating factors. The supernatant of liver tissue homogenate obtained from the patients showed a clear 80 kDa single band by western blotting. We concluded that the expression of thrombomodulin might be related to hepatic inflammatory responses in chronic viral hepatitis.