Recent developments in autoimmune liver diseases

What is behind the presence of anti-neutrophil cytoplasmatic antibodies in chronic liver disease?

BACKGROUND

Anti-neutrophil cytoplasm antibodies (ANCA) have been detected in serum from patients affected by autoimmune CLD, and to a lesser extent, in serum of patients affected by non autoimmune CLD. The clinical significance of ANCA in these disorders is still unclear.

AIMS

To explore the clinical and diagnostic significance of ANCA in CLD.

MATERIALS AND METHODS

Forty-five sera from patients affected by HCV- and HBV-related CLD (group 1), 29 sera from patients affected by alcohol-related CLD (Group 2) and 33 sera from patients affected by autoimmune-related liver diseases including chronic autoimmune hepatitis (AIH), primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC), (Group 3) have been studied by using IIF and ELISA.

RESULTS

A low correspondence between the ANCA positivity obtained by IFI and ELISA was observed. The positivity for at least one ANCA antigen was observed in 60.0% of Group 1, in 44.8% of Group 2 and in 72.7% of Group 3. The relation between the aetiology of the disease and the number of positive ANCA tests in ELISA was not significant. The relation between the MELD score and the number of ANCA positivity in patients with cirrhosis in the autoimmune-related CLD and in the viral-related CLD has been investigated. In both Groups a significant worsening of MELD at increasing number of ANCA positivity was found. Moreover in patients without cirrhosis in Group 3 an increase in the ALT and AST activity in patients with at least one ANCA positivity was observed.

CONCLUSIONS

These data suggest that the finding of ANCA by ELISA is common not only in autoimmune CLD but, also in viral-related CLD. Patients with autoimmune-related CLD express more frequently a multiple antigen reactivity as compared to those with viral-related CLD. The positivity for ANCA might have a prognostic value in patients with viral-related as well as autoimmune-related cirrhosis since it is associated with worse MELD score.

Liver injury caused by antibodies against dengue virus nonstructural protein 1 in a murine model

Clinical manifestations of severe dengue diseases include thrombocytopenia, vascular leakage, and liver damage. Evidence shows that hepatic injury is involved in the pathogenesis of dengue infection; however, the mechanisms are not fully resolved. Our previous in vitro studies suggested a mechanism of molecular mimicry in which antibodies directed against dengue virus (DV) nonstructural protein 1 (NS1) cross-reacted with endothelial cells and caused inflammatory activation and apoptosis. In this study, the pathogenic effects of anti-DV NS1 antibodies were further examined in a murine model. We found, in liver sections, that anti-DV NS1 antibodies bound to naive mouse vessel endothelium and the binding activity was inhibited by preabsorption of antibodies with DV NS1. Active immunization with DV NS1 resulted in antibody deposition to liver vessel endothelium, and also apoptotic cell death of liver endothelium. Liver tissue damage was observed in DV NS1-immunized mice by histological examination. The serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were increased in mice either actively immunized with DV NS1 protein or passively immunized with antibodies obtained from DV NS1-immunized mice. Furthermore, histological examination revealed mononuclear phagocyte infiltration and cell apoptosis in mice passively immunized with antibodies obtained from mice immunized with DV NS1. Increased AST and ALT levels were observed in mice passively immunized with purified immunoglobulin G (IgG) from dengue patients compared with normal control human IgG-immunized mice. The increased AST and ALT levels were inhibited when dengue patient serum IgG was preabsorbed with DV NS1. In conclusion, active immunization with DV NS1 protein causes immune-mediated liver injury in mice. Passive immunization provides additional evidence that anti-DV NS1 antibodies may play a role in liver damage, which is a pathologic manifestation in dengue virus disease.

Animal models for autoimmune hepatitis

The liver is the target of adverse immune reactions in three putative autoimmune diseases: autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). These three diseases can be distinguished by clinical, histological, and immunological features. However, especially on the level of specific antibody formation an overlap can occur, which sometimes complicates diagnosis. In this review, we will concentrate on autoimmune hepatitis and the current state of animal models for this severe disease. AIH is characterized by the presence of interface hepatitis and portal plasma cell infiltration, hypergammaglobulinemia, and autoantibodies. The hallmark of type 2 AIH is the generation of autoantibodies of the LKM-1 type. The major target of these antibodies is the cytochrome P450 isoform 2D6 (CYP2D6). In the past several attempts have been made to develop a reliable animal model that reflects the persistent hepatic destruction that occurs in human AIH. However, most models were only successful in causing a transient form of hepatic damage and often used rather complex ways of disease induction.

Type 1 autoimmune hepatitis in Taiwan: diagnosis using the revised criteria of the International Autoimmune Hepatitis Group

Autoimmune hepatitis (AIH) is rare in Asian countries compared to the West, and an exceptionally low prevalence was noted previously in Taiwan. Using the revised criteria of the IAIHG, 48 cases of AIH patients were diagnosed. All patients were consecutively diagnosed over a period of 5 years. Detailed medical histories including disease onset, hepatitis B and C, alcohol, drugs, blood transfusion, and family history of autoimmune disease were recorded. Clinical manifestations, result of steroid therapy, outcome, and survival rate were investigated and analyzed. Clinical data on AIH patients with cirrhosis and without cirrhosis were compared and analyzed for their outcome. The statistical methods used were Fisher's exact test, Wilcoxon rank sum test, and Kaplan-Meier curve. Forty-eight patients were diagnosed as AIH type 1, with a median age of 58 years and a female:male ratio of 37:11. The most common clinical features at presentation were fatigue, jaundice, and anorexia. Ninety-eight percent of patients were ANA positive, and most of the patients showed elevated values of AST, ALT, serum globulin, and bilirubin. A substantial proportion of patients presented with poor liver function at entry and 35% of patients had liver cirrhosis, with relatively prolonged PT (P=0.001) and poorer outcome (P=0.005) compared to the noncirrhotics. As a whole there was a favorable treatment response and the overall survival rate was 85%. We conclude that the incidence of AIH in Taiwan is much higher than previously presumed and AIH type 1 is the predominant type of the disease. Although a substantial proportion of AIH patients presented with poor hepatic function at entry, as a whole there was a favorable clinical outcome.

Antimitochondrial antibody negative primary biliary cirrhosis in Japan: utilization of clinical data when patients applied to receive public financial aid

BACKGROUND

We examined patients who showed laboratory and histological evidence of primary biliary cirrhosis (PBC) in the absence of antimitochondrial antibody (AMA) to elucidate the characteristics of AMA negative PBC.

METHODS

From a total of 5,805 patients with symptomatic PBC, 2,419 cases (41.7%) were selected in the present study, who were diagnosed using the following criterion; chronic non-suppurative destructive cholangitis was histologically observed and laboratory data did not contradict PBC. The information collected from records included sex, age, symptoms, physical findings, and complicated autoimmune diseases. We then evaluated these data according to the positivity of AMA.

RESULTS

Of the total subjects, 470 cases (19.4%) were found to be negative for AMA. The proportion of female patients was higher among the AMA negative group than among the AMA positive one. Pruritus was found less frequently among patients with AMA negative PBC than among those with AMA positive PBC. Levels of alkaline phosphatase, γ-glutamyl transpeptidase, and IgM were significantly lower among patients with AMA negative PBC than among those with AMA positive PBC. Complications such as Sjögren’s syndrome, rheumatoid arthritis, and scleroderma, including CREST syndrome, were found with significantly higher frequency among patients with AMA negative PBC than among those with AMA positive PBC.

CONCLUSION

Considering serum level of IgM and frequencies of complicated autoimmune diseases, it is possible that Japanese patients with AMA negative PBC are consistent with the disease entity of autoimmune cholangitis reported in western countries.

Diagnosing clinical subsets of autoimmune liver diseases based on a multivariable model

BACKGROUND

Diagnosing autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), primary sclerosing cholangitis, and other autoimmune liver diseases remains an imperfect process. We need a more accurate, evidence-based diagnostic system.

METHODS

We conducted a national survey and identified 988 cases of liver disease which did not satisfy the inclusion criteria for any liver disease of known etiology. We expected these cases to include autoimmune liver disease (AILD) and its variant forms. We selected 269 prototype cases for which histological re-evaluation of liver biopsy by independent expert hepatopathologists and the original diagnosis coincided. We did a multiple logistic regression analysis to determine explanatory variables that would distinguish cases of AIH and PBC from those of non-AIH and non-PBC, respectively. We constructed a multivariable diagnostic formula that gave AIH and PBC disease probabilities and validated it in a study of an additional 371 cases (validation group).

RESULTS

Based on the results of the statistical analysis, we selected three laboratory tests and four histological features as independent variables correlated to the diagnosis of both AIH and PBC. For the validation group, assuming that the original diagnosis was correct, the sensitivity and specificity for AIH were 86.3% and 92.4%, respectively. For PBC the sensitivity and specificity were 82.5% and 63.7%, respectively. A detailed analysis of inconsistent cases showed that the diagnosis based on the formula had given the correct diagnosis, for either AIH or PBC, except for 5 cases (1.3%) in which disease probability was low for both.

CONCLUSIONS

A seven-variable formula based on three laboratory tests and four histological features gives significant information for the diagnosis of AILD.

Intravenous Immunoglobulin Plus Interferon-?? in Autoimmune Hepatitis C

BACKGROUND

Hepatitis C virus (HCV) may be associated with a variety of autoimmune phenomena causing a therapeutic dilemma for treatment with interferon-alpha (IFNalpha), which stimulates autoimmune symptoms, or with corticosteroids, which may lead to an increasing of viral load. To evaluate the possible role of intravenous immunoglobulins (IVIg) in the response of patients treated with IFNalpha, we administered IVIg plus IFNalpha and compared the results with a group of patients treated with IFNalpha alone.

METHODS

Forty-two patients affected by chronic hepatitis C with probable autoimmune disease were eligible for this open-label, randomised study. All patients tested positively for anti-nuclear antibodies, anti-smooth muscle antibodies, anti-liver/kidney microsomal antibodies and anti-mitochondrial antibodies. Patients were randomly assigned to one of two groups: group A received IVIg at a dosage of 400 mg/kg each day for 5 days, and then 3 MUI of leucocyte IFNalpha three times a week, while group B received physiological solution followed by the administration of leucocyte IFNalpha three times a week at the same dosage for 6 months. Complete biochemical response was defined as a sustained normalisation of alanine aminotransferase levels, and complete virological response was defined as complete clearance of virus throughout the entire 6-month follow-up period. Immunological response was measured in terms of Autoimmune Hepatitis (AIH) score, while histological response was based on a reduction in histological activity index (HAI) score.

RESULTS

Compared with patients receiving IFNalpha alone, a higher percentage of patients who received IFNalpha plus IVIg showed complete virological and histological responses (p = 0.04). More patients in the combination therapy group achieved biochemical and immunological responses, although the differences between the groups were not statistically significant at all time points.

CONCLUSIONS

Exogenously added Ig might modulate the immune network at various points. We propose that the immunomodulating action of IVIg acts synergistically with IFNalpha, achieving a better response to IFN treatment in patients with chronic HCV associated with autoimmunity. Data obtained from this preliminary study indicate a positive prospective for the clinical use of gamma globulins in patients with a high probability of autoimmune disorders associated with HCV infection.

Prevalence of autoimmune liver disease in Alaska Natives

OBJECTIVE

There is limited information on the prevalence of autoimmune liver disease in nonwhite populations. We conducted a population-based study on the prevalence of autoimmune liver diseases in Alaska natives.

METHODS

Clinical records from 1984 to July, 2000 were reviewed to identify Alaska natives with autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), primary sclerosing cholangitis, autoimmune cholangitis, and overlap syndromes of two of the above. AIH was defined as definite or probable, based on criteria established by the International Autoimmune Hepatitis Group. The diagnosis of PBC was based on a positive antimitochondrial antibody of > or = 1: 40, biochemical evidence of cholestasis, and compatible liver biopsy. Autoimmune cholangitis was defined as PBC but without a positive antimitochondrial antibody. Primary sclerosing cholangitis was diagnosed on the basis of cholangiogram.

RESULTS

Seventy-seven patients with possible autoimmune liver disease were identified. Of these, 42 had definite and seven probable AIH. At presentation, 34.7% of patients with AIH presented with acute icteric hepatitis, and 65.3% were asymptomatic. Persons presenting with mild or no symptoms were more likely to have moderate to severe fibrosis on liver biopsy than those presenting with jaundice. Eighteen persons were diagnosed with PBC, five with autoimmune cholangitis, five with overlap syndrome, and none with primary sclerosing cholangitis. The combined point prevalence of AIH Alaska natives was 42.9/100,000 (95% CI = 31-57.7). The prevalence of PBC was 16/100,000 (95% CI = 12.9-25.4).

CONCLUSIONS

This population-based study demonstrates that the prevalence rates of AIH and PBC in Alaska natives are comparable with reported rates in other populations.

Autoimmune hepatitis and overlap syndromes

Autoimmune hepatitis (AIH) is an immune-mediated, autodestructive liver disease with hepatocytes as target cells, mostly affecting young women. Primary biliary cirrhosis (PBC) is also regarded as an autoimmune liver disease with bile duct epithelia as the target cells, resulting in a continuous loss of bile ducts. Both diseases may occur simultaneously in their full manifestations in about 10% to 20% of cases, thus constituting an overlap syndrome with PBC directing the course of the disease. AIH may also occur simultaneously with primary sclerosing cholangitis (PSC), with a frequency of between 2% and 8% of patients with PSC. In most cases, AIH precedes manifestation of PSC. In children, the overlap syndrome of AIH and PSC seems to make up an entity of its own: autoimmune sclerosing cholangitis.

Long-term outcome of autoimmune hepatitis in children

BACKGROUND AND AIM

Autoimmune hepatitis (AIH) is a chronic disease of unknown etiology, which usually progresses to cirrhosis if not diagnosed and treated promptly. Data on long-term follow up in children with AIH are scant. The aim of this study is to assess the long-term outcome of autoimmune hepatitis in children with respect to clinical and laboratory features at presentation.

METHODS

Data were extracted from the medical records of patients presenting over a 28-year period (1972-2000) to the Royal Children's Hospital, Melbourne, Australia. Additional information was obtained by interviewing patients, and their current physicians. Of the 30 patients (22 females, mean age 9 years) identified, 18 had type I, three had type II, four had autoimmune-polyendocrinopathy syndrome type 1, one had infantile giant-cell hepatitis associated with Coomb's-positive hemolytic anemia, and four were seronegative (antinuclear antibody (ANA), smooth muscle antibody (SMA) and liver-kidney microsomal antibody (LKM)).

RESULTS

Clinical features at presentation included hepatomegaly (86%), jaundice (66%) and splenomegaly (50%). Initial investigations revealed a median serum bilirubin level of 55 micromol/L (range 6-425), median aspartate aminotransferase level of 678 IU (range 70-2548), and abnormal clotting in 33% of patients. Liver biopsies were performed on all patients at presentation and 11 showed cirrhosis (36%). The mean follow-up period was 10.0 +/- 7.8 years with 43% being followed for > 10 years. Only two patients died and one required transplantation. Fourteen (50%) patients continue to be on low dose prednisolone with azathioprine, two (7%) are on prednisolone alone, and six (21%) are on no therapy. When the cirrhotic and non-cirrhotic patients were compared, the albumin level at presentation was significantly lower in the cirrhotic group (P=0.01). Of the patients who were cirrhotic at presentation, six (54%) remain compensated with a mean follow-up period of 8 years. All 24 patients currently under follow up are engaged in age-appropriate activities including school, part- or full-time work.

CONCLUSION

Autoimmune hepatitis has a favorable long-term outcome with a transplant-free survival rate of 90% over a mean period of 10.0 +/- 7.8 years (range: 0.5-23), and a normal or near-normal lifestyle irrespective of presenting clinical, laboratory or histological features.

Autoimmune hepatitis in the Indian subcontinent: 7 years experience

BACKGROUND

Autoimmune hepatitis (AIH) is presumed to be rare in India. The present prospective study was carried out to determine the prevalence, clinical, biochemical and histological profile of patients with AIH in India.

METHODS

Consecutive patients with chronic liver disease suspected to be AIH, were screened for antinuclear antibodies (ANA), antismooth muscle antibodies (ASMA), antimitochondrial antibody (AMA), and anti-liver kidney microsomal antibodies (anti-LKM-1). Serum protein electrophoresis and liver biopsy were done. Autoimmune hepatitis was diagnosed according to the International Autoimmune Hepatitis Group criteria.

RESULTS

Fifty of 1358 (3.43%) patients with chronic liver disease were diagnosed as autoimmune liver disease; 39 with AIH, two with overlap syndrome, five with primary sclerosing cholangitis, and four with primary biliary cirrhosis. Twenty-nine patients were categorized as definite AIH and 10 as probable AIH. Autoimmune hepatitis was common in females (males : females 1:3), with a mean age of 31 +/- 17 years. Patients often presented with fatigue, jaundice and anorexia. Skin lesions (58%), joint symptoms (30%), and menstrual abnormalities (26%) were not uncommon. Mildly elevated alkaline phosphatase and hyper gamma globulinemia were seen in 78 and 91% patients, respectively. Eighty percent of patients were type I AIH, while 20% of cases remained unclassified. Histopathological changes included piecemeal necrosis (100%), plasma cell infiltration (91%), rosette formation (82%), and cirrhosis (76%). Overall mortality was 25% during a mean follow up of 15.7 +/- 17.0 months.

CONCLUSIONS

Our results clearly demonstrate that: (i) AIH is not uncommon in India; and (ii) while the profile and spectrum of AIH resembles that seen in the West, Indian patients present late, often in a cirrhotic state.

The lymphoid liver: considerations on pathways to autoimmune injury

Immunologic injury in the liver involves immigrant T and B lymphocytes and a resident lymphoid population that comprises distinct lymphocytic cells and accessory cells. The forerunner to autoimmunity is breaching of natural self-tolerance and hence the disruption of a fundamental property of the immune system. Such breaching occurs by processes that include inflammatory activation of immunocytes and macrophages, spillage of intracellular constituents, and epitope mimicry by constituents of microorganisms, with these acting on a genetically conditional phenotype; compounding factors include aberrations of apoptosis, whether insufficient or excess. The downstream end requires specifically directed inflammatory leukocyte traffic as an essential component of autoimmune expressions in the liver. The culmination is an orchestrated attack on hepatocytes or biliary epithelial cells by multiple effector pathways. Progress in type 1 autoimmune hepatitis still requires knowledge of a disease-specific autoantigen(s) involved in T-cell reactivity, although such knowledge in type 2 autoimmune hepatitis, in which the known autoantigen is cytochrome P4502D6, has not yet been integrated into a clearly defined scheme of pathogenesis. For PBC there has been a very promising amalgamation of molecular knowledge of the mitochondrial autoantigens. Future insights require deeper analysis of molecular, genetic, macroenvironmental, and microenvironmental elements in predisposition.

Autoantibodies and overlap syndromes in autoimmune rheumatic disease

Many patients diagnosed with autoimmune rheumatic disease cannot be categorised easily into one of the established clinical entities such as systemic lupus erythematosus, dermatomyositis, or systemic sclerosis. The term "overlap syndrome" has been increasingly used to identify such patients and is useful in terms of clarifying prognosis and facilitating disease management. This article reviews overlap syndrome in autoimmune rheumatic disease, with particular emphasis on the associated serological markers.

Atypical antineutrophil cytoplasmic antibodies with perinuclear fluorescence in chronic inflammatory bowel diseases and hepatobiliary disorders colocalize with nuclear lamina proteins

Antineutrophil cytoplasmic antibodies (ANCA) are frequently associated with chronic inflammatory bowel diseases (IBD) and hepatobiliary disorders. However, their target antigens have not been identified yet. Recently, we observed an atypical perinuclear ANCA fluorescence (p-ANCA) together with an intranuclear staining using ANCA-positive sera from patients with IBD and hepatobiliary disorders. This observation suggests that the target antigens are localized within the nucleus of neutrophilic granulocytes. To further investigate this hypothesis, we examined sera from patients with ulcerative colitis, primary sclerosing cholangitis, autoimmune hepatitis or systemic vasculitis on ethanol or formaldehyde-fixed neutrophils using confocal laser scanning microscopy and immunoelectron microscopy. Counterstaining with propidium iodide, a DNA-specific dye, showed that ANCA-positive sera in IBD and heptobiliary disorders react with intranuclear antigens at the nuclear periphery of the neutrophils. Double immunolabeling techniques revealed that nuclear lamina proteins, lamins A, C and B1, and lamin B receptor were colocalized with the antigen(s) recognized by atypical p-ANCA. No colocalization was observed with classical p-ANCA and antibodies against histones (H1-H4). Our study showed that atypical p-ANCA are antinuclear antibodies reactive with granulocyte-specific antigens present in the nuclear lamina.