IgA Anti-b2GPI Antibodies in Patients with Autoimmune Liver Diseases

INTRODUCTION: Recently, we reported a high prevalence of immunoglobulin G and/or immunoglobulin M anticardiolipin antibodies (aCL) in patients with autoimmune liver diseases, namely, autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), and primary sclerosing cholangitis (PSC), which were independent of the respective isotypes of antibodies against beta2-glycoprotein I (anti-b2GPI). Immunoglobulin A (IgA) aCL and IgA anti-b2GPI are the least studied of the three specific isotypes either in antiphospholipid syndrome (APS) or in other conditions. METHODS: Therefore, we investigated the prevalence and clinical significance of IgA anti-b2GPI and IgA aCL by enzyme-linked immunosorbent assays in another set of Caucasian patients with autoimmune liver diseases (59 AIH, 96 PBC, and 37 PSC). The disease controls group consisted of 50 hepatitis C virus (HCV) patients, 50 hepatitis B virus (HBV), 30 alcoholic liver disease (ALD), 30 non-alcoholic steatohepatitis (NASH), and 110 healthy controls. RESULTS AND DISCUSSION: IgA anti-b2GPI prevalence was higher in AIH (50.8%) compared to PBC (p = 0.005), PSC (p = 0.008), NASH (p = 0.004), ALD (p = 0.01), and HCV (p = 0.002). The titers were also significantly higher in AIH compared to any other group of the study. IgA aCL prevalence was higher in AIH (33.9%) compared to PBC (p = 0.005), PSC (p = 0.014), NASH (p = 0.001), ALD (p = 0.004), and HCV (p < 0.001). IgA anti-b2GPI or IgA aCL were not associated with APS features in patients with liver autoimmunity. Of note, IgA anti-b2GPI and IgA aCL were associated with clinical and biochemical markers of disease severity in AIH and PBC. We demonstrated a high prevalence and high titers of IgA anti-b2GPI in patients with AIH compared to any other liver disease of the study. CONCLUSION: IgA anti-b2GPI and IgA aCL were associated with the severity and biochemical activity of AIH and PBC, but long-term prospective studies are needed to address whether this new finding is of clinical importance in AIH and PBC patients.     

Anti-Saccharomyces cerevisiae antibodies (ASCA) and autoimmune liver diseases

Antibodies to the baker's yeast Saccharomyces cerevisiae (ASCA), recently proposed as a serological marker of Crohn's disease, have also been detected in other autoimmune disorders. The aim of this study was to determine prevalence and clinical significance of ASCA in autoimmune liver disease. The presence of IgG and IgA ASCA was evaluated using a commercially available immunoassay in 215 patients with autoimmune liver disease (primary biliary cirrhosis, PBC, 123 cases; autoimmune hepatitis, AIH, 67 cases; primary sclerosing cholangitis, PSC, 25 cases), 48 with inflammatory bowel disease and 19 healthy blood donors. Anti neutrophil cytoplasmic antibodies with the perinuclear pattern (p-ANCA) were assessed by indirect immunofluorescence in PSC patients. The main clinical and biochemical parameters between ASCA-positive and negative patients were analysed and compared. ASCA are predominant in Crohn's disease (70%); among liver patients, PSC and AMA-negative PBC show the highest ASCA prevalence (53% and 44%). In PBC ASCA correlate with higher levels of circulating IgA (P < 0.05). In PSC the detection of either ASCA or p-ANCA is neither associated with any clinical or biochemical feature, nor with an underlying inflammatory bowel disease. ASCA can not be considered an additional serological marker of autoimmune liver disease, but the possibility of detecting such a reactivity in autoimmune liver disorders should be considered; their correlation with elevated IgA in PBC suggests that ASCA may be an indirect sign of enhanced mucosal immunity; in PSC patients neither ASCA nor p-ANCA predict the occurrence of a concomitant inflammatory bowel disease.     

Prevalence and clinical significance of anticardiolipin antibodies in patients with type 1 autoimmune hepatitis

There are few case reports on the association between autoimmune hepatitis (AIH) and anticardiolipin antibodies (anti-CLAbs) and/or antiphospholipid syndrome (APLS). We studied the anti-CLAbs prevalence in AIH and other hepatic diseases. We also investigated whether anti-CLAbs are co-factor dependent and which is their avidity since co-factor dependency or increased resistance is associated with APLS. Fifty-nine AIH patients, 228 HCV, 50 HBV, 123 with other non-viral and non-autoimmune liver disorders (nV-nALD) and 267 healthy people were investigated for anti-CLAbs and antibodies against beta-2-glycoprotein I (anti-beta2-GPI). Resistance of IgG anti-CLAbs was evaluated using 2 M urea. IgG anti-CLAbs detected in 39% of AIH, 19.7% of HCV (p=0.006), 14% of HBV (p=0.01), 8.1% of nV-nALD (p=0.000) and 1.1% of healthy (p=0.000). IgG anti-CLAbs were associated with the presence of cirrhosis and active AIH while their resistance to urea was high. Anti-beta2-GPI was detected in two AIH patients. We demonstrated a significantly higher prevalence of anti-CLAbs in patients with AIH compared to other diseases and healthy people. Anti-CLAbs were associated with AIH stage but no association was found with APLS clinical manifestations (thrombosis, pregnancy morbidity, thrombocytopenia). However, their avidity was comparable with that of APLS indicating the need for prospective studies in order to address whether anti-CLAbs in AIH may contribute to the progression of liver disease or APLS development.     

Surgical treatment of primary biliary cirrhosis and primary sclerosing cholangitis

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are progressive cholestatic liver diseases of supposed auto-immune etiology. The clinical course is unpredictable and, in many patients, leads to end-stage liver disease or a poor quality of life. Conservative therapy only has a limited effect on the natural history, but orthotopic liver transplantation (OLT) offers a definitive therapeutic option. Retrospective analysis was performed for 38 patients with PBC and 17 patients with PSC who underwent OLT between January 1986 and June 2003 at our institution. Median follow-up after OLT was 72 mo. Cumulative survival at 5 yr post-OLT was 84% in the PBC group and 73% in the PSC group. Compared with OLT for other benign diseases, actuarial survival rates at 5 and 10 yr post-OLT were significantly better for patients with PBC, whereas there was no difference in survival after OLT for patients with PSC. Survival rate at 5 yr post-OLT was significantly increased for patients with PBC who had a Child-Pugh B liver cirrhosis (93%) compared with those who had Child-Pugh C cirrhosis (60%). Retransplantation rate was 18.2% (resulting from biliary complications in three cases). Surgical techniques had no effect on outcome after OLT in both groups. We concluded that liver transplantation represents a safe and beneficial therapy for patients with end-stage PBC. Cirrhotic patients with PSC also benefit from OLT, with an outcome comparable to that of liver cirrhosis of other etiologies.     

Anti-phospholipid antibodies in HIV infection and SLE with or without anti-phospholipid syndrome: comparisons of phospholipid specificity, avidity and reactivity with beta2-GPI.

Increased prevalence of anti-phospholipid antibodies (aPL) and increased levels of lipid peroxidation have been described in patients with HIV infection. To assess the binding specificity and avidity of aPL antibodies in HIV infection, sera from 44 HIV-1 infected patients were evaluated for antibodies to cardiolipin (aCL), phosphatidyl serine (aPS), phosphatidyl inositol (aPI) and phosphatidyl choline (aPC) using enzyme linked immunosorbent assay (ELISA) methods. Sera from 30 patients with systemic lupus erythematosus (SLE), but without features of anti-phospholipid syndrome (APS) (SLE/non APS), six with SLE and secondary APS, (SLE/APS) and 11 with primary APS (PAPS) were also evaluated as controls. The resistance of the aPL antibody binding to dissociating agents was evaluated by treating the ELISA wells, after serum incubation with 2 M urea or 0.6 M NaCl for 10 min. An anti-beta2-glycoprotein-I (beta2-GPI) ELISA was used to assess serum reactivity against beta2-GPI, a plasma protein considered as the true antigen of aCL antibodies occurring in APS and SLE patients. The prevalence of aCL, aPS, aPI and aPC antibodies in HIV-1 infection was 36%, 56%, 34% and 43% respectively, which was comparable to that found in SLE/APS and PAPS patients and significantly higher than that observed in SLE/non-APS patients. Anti-beta2-GPI antibodies occurred in 5% of HIV-1 infected vs. 17% in SLE/non-APS (P=0.11), 50% in SLE/APS (P=0.009) and 70% in PAPS patients (P=0.0014). A significant decrease of aPL binding after urea and NaCl treatment was observed in the sera of HIV-1-infected, compared to that of APS patients, indicating that aPL antibodies from HIV-1 infected individuals have low resistance to dissociating agents. In conclusion, aPL antibodies (1) occur in HIV-1 infection; (2) tend to recognize various phospholipids but not beta2-GPI; and (3) are of low resistance to dissociating agents-a finding probably reflecting low antibody avidity. Finally, these, like the autoimmune-type aCL antibodies, tend to recognize the oxidized CL-a finding probably indicating autoantibody generation as a result of neoepitope formation by oxidized PLs.     

The hepatitic/cholestatic "overlap" syndrome: an Italian experience

BACKGROUND: Patients with hepatitic and cholestatic autoimmune liver disease ("overlap syndrome") represent a diagnostic and therapeutic challenge. AIM: To evaluate the prevalence of the "hepatitic/cholestatic overlap" in a large series of consecutive patients with cholestatic autoimmune liver disease. METHODS: We re-evaluated the diagnosis of 235 patients with autoimmune liver disease, including 70 with type 1 autoimmune hepatitis (AIH), 142 with primary biliary cirrhosis (PBC), and 23 with primary sclerosing cholangitis (PSC), using the revised International Autoimmune Hepatitis Group (IAIHG) scoring system. Anti-mitochondrial, anti-nuclear, anti-smooth muscle, anti-liver kidney microsomal type 1, anti-liver cytosol type 1, perinuclear anti-neutrophil nuclear and anti-soluble liver antigen antibodies were evaluated in each patient. RESULTS: Ten patients (3 with a previous diagnosis of PBC and 7 of PSC) scored as "probable" or "definite" AIH. These patients did not have a specific autoantibody profile. CONCLUSIONS: Among patients with PBC, the occurrence of a PBC/AIH overlapping syndrome is rare (2.1%), whereas among patients with PSC an overlap between PSC and AIH is frequent (30.4%). Whether patients with the hepatitic/cholestatic overlap syndrome would benefit from a combination therapy with immunosuppression and ursodeoxycholic acid remains to be established.     

Role of liver biopsy in autoimmune liver disease

This article will review histological aspects of three chronic liver diseases – autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) – in which autoimmune mechanisms are thought to be involved. The changing role of liver biopsy in the diagnosis and management of patients with autoimmune liver disease will also be discussed. In the case of autoimmune hepatitis, histological assessments remain important in establishing a diagnosis, identifying prognostic features and monitoring therapeutic responses. By contrast, for many patients with PBC and PSC a diagnosis can now be made on the basis of biochemical, serological and/or radiological findings alone and histological confirmation may not be required. Liver biopsy can still be used to assess disease severity in such cases and remains important in establishing a diagnosis in patients with atypical features (e.g. AMA-negative PBC or the small-duct variant of PSC). Liver biopsy is also increasingly used in the assessment of patients suspected to have “overlap syndromes” involving AIH and PBC or PSC.     

APhL antibody ELISA as an alternative to anticardiolipin test for the diagnosis of antiphospholipid syndrome

Background

Persistent levels of antiphospholipid (aPL) antibodies [lupus anticoagulant (LA), anticardiolipin (aCL), anti-beta 2 glycoprotein I (aβ₂GPI) IgG and/or IgM] in association with clinical features of thrombosis and/or pregnancy associated morbidity are indicative of antiphospholipid syndrome (APS). Of the aPL antibodies, aCL is the most sensitive for APS, however, their lack of specificity constitute a laboratory and clinical challenge. IgG/IgM antibodies directed against APhL (a mixture of phospholipids) has been reported to predict APS more reliably than aCL tests. The main objective of this study was to evaluate the performance characteristics of the APhL IgG/IgM ELISA, relative to the aCL and aβ₂GPI tests.

Methods

Sixteen (16) clinically confirmed APS and 85 previously tested serum (PTS) samples for aCL and aβ₂GPI IgG/IgM antibodies were evaluated with the APhL IgG/IgM ELISA. Clinical specificity was determined in 100 serum samples (50 healthy and 50 infectious disease controls [parvo- and syphilis-IgG/IgM positive]).

Results

The IgG antibody prevalence for aCL and APhL in the APS and PST groups was comparable with marginal differences in clinical specificities. In contrast to the aCL IgM ELISA, the APhL test showed improved clinical specificities (72% aCL vs 94% APhL in the healthy controls; 38% aCL vs 78% APhL in the infectious disease controls) with implications for increased reliability in the diagnosis of APS. The overall agreement of the APhL with the aCL or aβ₂GPI for the IgG tests was 89% and 85% respectively, and that of the APhL IgM to the aCL or aβ₂GPI IgM tests was 72% and 86% respectively.

Conclusion

Routine use of the APhL IgG/IgM ELISA may substantially reduce the high number of false positives associated with the aCL test without loss in sensitivity for APS.     

The Hepatitic/Cholestatic "Overlap" Syndrome: An Italian Experience

Background: Patients with hepatitic and cholestatic autoimmune liver disease ("overlap syndrome") represent a diagnostic and therapeutic challenge. Aim: To evaluate the prevalence of the "hepatitic/cholestatic overlap" in a large series of consecutive patients with cholestatic autoimmune liver disease. Methods: We re-evaluated the diagnosis of 235 patients with autoimmune liver disease, including 70 with type 1 autoimmune hepatitis (AIH), 142 with primary biliary cirrhosis (PBC), and 23 with primary sclerosing cholangitis (PSC), using the revised International Autoimmune Hepatitis Group (IAIHG) scoring system. Anti-mitochondrial, anti-nuclear, anti-smooth muscle, anti-liver kidney microsomal type 1, anti-liver cytosol type 1, perinuclear anti-neutrophil nuclear and anti-soluble liver antigen antibodies were evaluated in each patient. Results: Ten patients (3 with a previous diagnosis of PBC and 7 of PSC) scored as "probable" or "definite" AIH. These patients did not have a specific autoantibody profile. Conclusions: Among patients with PBC, the occurrence of a PBC/AIH overlapping syndrome is rare (2.1%), whereas among patients with PSC an overlap between PSC and AIH is frequent (30.4%). Whether patients with the hepatitic/cholestatic overlap syndrome would benefit from a combination therapy with immunosuppression and ursodeoxycholic acid remains to be established.     

Overlap syndromes of cholestatic liver diseases and auto-immune hepatitis

Approximately 18% of patients with auto-immune liver disease present with features characteristic of a second auto-immune liver disease. These cases have been termed “overlap syndromes.” The pathogenesis of overlap syndromes is poorly understood, and few data are available regarding the clinical characteristics and outcome of this disease. Therefore, a consensus on the definition of overlap syndromes has not been reached. A common genetic background between auto-immune hepatitis (AIH) and its overlap with primary biliary cirrhosis (PBC) or primary sclerosing cholangitis (PSC) might confer susceptibility to a more inflammatory phenotype, probably requiring combined immunosuppressive treatment. This article focuses on the prevalence, diagnosis, and treatment of the overlap syndrome of AIH and PBC or PSC.     

Demonstration of autoantibodies to recombinant human sulphite oxidase in patients with chronic liver disorders and analysis of their clinical relevance

It has been shown previously that sera from patients with cholestatic liver diseases react with sulphite oxidase (SO) prepared from chicken liver. In order to analyse this reactivity and the clinical relevance of anti-SO antibodies in more detail, we produced human recombinant SO. Human recombinant SO (60 kDa) was expressed in Escherichia coli and applied to enzyme-linked immunosorbent assay and Western blot. Sera from patients with autoimmune liver disorders [primary biliary cirrhosis (PBC) n = 96; autoimmune hepatitis (AIH) n = 77; primary sclerosing cholangitis (PSC) n = 39], and from patients with other hepatic (n = 154) and non-hepatic chronic inflammatory disorders (n = 113) were investigated. Highest incidence and activities of IgG-anti-SO antibodies were observed in PSC patients. Nine of 16 untreated (56%) and four of 23 PSC patients treated with ursodeoxycholic acid (UDCA) (17%) were positive. Antibody activity decreased significantly during UDCA treatment. Five per cent of PBC and 9% of AIH patients, but also 15% of patients with alcoholic liver disease, were IgG anti-SO-positive. In patients with viral hepatitis and non-hepatic disorders they could be hardly detected. Anti-SO antibodies are further anti-mitochondrial antibodies in chronic liver diseases. They occur predominantly in PSC, and UDCA treatment seams to decrease antibody activity. Whether these antibodies are primary or secondary phenomena and whether they are related to the aetiology or pathogenesis, at least in a subgroup of patients with chronic liver diseases, has still to be evaluated.     

Clinical significance and prevalence of anti-Saccharomyces cerevisiae antibody in Chinese patients with primary biliary cirrhosis

Clinical significance of anti-Saccharomyces cerevisiae antibody (ASCA) and its prevalence in Chinese primary biliary cirrhosis (PBC) patients have not been characterized and therefore needs to be defined. Enzyme-linked immunosorbent assay was used to test ASCA in sera from 198 PBC patients, 85 patients with other liver diseases (OLD) and 35 health controls (HC). Indirect immunofluorescence was used to detect anti-mitochondrial antibodies (AMA) in PBC. Results showed that the frequency of ASCA in PBC, 29.8 %, was higher than other disease groups. And ASCA occurred more frequently in PBC patients with positive anti-gp210 than the negative ones. Also, ASCA was detected in 7 out of 15 PBC negative for AMA. Some liver-related biochemical indices and inflammatory indices were significantly higher in PBC patients with positive ASCA (p < 0.05). In conclusion, the prevalence of ASCA in Chinese PBC patients is 29.8 %. PBC patients with positive ASCA are associated with more severe liver injury, and ASCA-IgA might be related to disease activity of PBC.     

Is there a relation between Chlamydia infection and primary biliary cirrhosis?

Over the past two decades, a number of studies have failed to provide direct evidence of specific microbial chronic infection in primary biliary cirrhosis (PBC). However, a recent report suggests that there is a specific association of Chlamydia pneumoniae in patients with PBC and that C. pneumoniae or similar antigens might play a role in the pathogenesis of disease. To determine if Chlamydia infection is associated with PBC, we applied a combination of immunological and molecular approaches to investigate (a) the serological reactivity against two common Chlamydia human pathogens, C. pneumoniae and C. trachomatis, by immunoblotting, (b) the presence of Chlamydia in liver samples of patients with PBC and controls by PCR amplification of Chlamydia specific 16S rRNA and (c) the presence of Chlamydia proteins in liver samples of patients with PBC and controls by immunohistochemical staining. By immunoblotting, C. trachomatis and C. pneumoniae specific serological antibodies were found in 52/57 (91.2%) AMA positive PBC, 7/33 (21/2%) of AMA negative PBC, 1/25 (4%) PSC, 0/15 (0%) Sjorgen's syndrome and 0/20 (0%) systemic lupus erythematosus patients and 0/20 (0%) healthy volunteers at 1:200 sera dilution. PBC sera reacted to Chlamydia and E. coli lysates in western blots up to a maximum of 10(-4) dilution. However, PCR amplification of the Chlamydia specific 16S rRNA gene was negative in 25/25 PBC livers but positive in 1/4 PSC liver, 3/6 in other liver disease controls and 1/4 normal liver samples. While two commercially available specific monoclonal antibodies stained positive controls (Chlamydia infected HEp-2 cells) they failed to detect Chlamydia antigens in PBC livers. The detection of Chlamydia specific antibodies but not Chlamydia rRNA gene and Chlamydia antigens in PBC suggests that Chlamydia infection is not involved in PBC.     

Diagnostic Relevance and Clinical Significance of the New Enhanced Performance M2 (MIT3) ELISA for the Detection of IgA and IgG Antimitochondrial Antibodies in Primary Biliary Cirrhosis

Background/aims: Antimitochondrial antibodies (AMAs) are the serological hallmark of primary biliary cirrhosis (PBC). We evaluated the sensitivity and specificity of a new M2 enhanced performance enzyme-linked immunosorbent assay (ELISA) (MIT3) for the detection of IgG- and IgA-specific isotypes of AMA in PBC patients including a number of PBC patients negative for AMA by indirect immunofluorescence (IIF) as well as in patients with diverse, non-PBC disorders. We also investigated the clinical significance of IgG and IgA AMA in PBC. Methods: One hundred and three Greek PBC patients including 27 with AMA IIF-negative at the time of the investigation, 29 with autoimmune hepatitis-1 (AIH-1), 12 with primary sclerosing cholangitis (PSC), 26 with hepatitis C virus (HCV), 15 with hepatitis B virus (HBV), and 29 healthy were investigated for AMA (IgG and IgA) using the MIT3-based ELISAs (INOVA Diagnostics, San Diego, CA). The samples were also tested by conventional anti-M2 ELISA (INOVA Diagnostics, Inc.). Results: The IgG MIT3-based ELISA significantly increased AMA detection in the cohort of PBC patients, over 26% of whom were AMA IIF-negative, from 63.1% by the conventional anti-M2, and 73.7% by IIF to 79.6% by MIT3-based ELISA (p<0.001). IgA AMAs were detected in 47.6% patients. Overall, IgG/IgA AMAs were detected in 84/103 (81.6%). IgG MIT3-based ELISA detected 12/27 IIF AMA-negative samples (44.4%), while IgG/IgA MIT3-based ELISAs detected 13/27 IIF AMA-negative patients (48.1%). The specificities of MIT3-based ELISAs (IgG and IgA) were 82.8% and 89.7%, respectively, in AIH-1, 100% and 93.3%, respectively, in HBV, 100% in PSC, and 96% and 93.3%, respectively, in HCV. Patients positive for IgG AMA had significantly more severe disease as shown by worse histology and elevated biochemical markers; IgG and IgA AMA titers were associated positively with the Mayo risk score but none of the isotypes were able to predict disease outcome. Conclusions: The new IgG and IgA MIT3-based ELISAs seem to have higher specificity and sensitivity for AMA detection than IIF and the conventional anti-M2. Interestingly, these assays were able to unmask AMA presence in almost half of the AMA-negative samples by IIF. These findings may suggest the use of MIT3-based ELISAs as first-line investigation for AMA detection, particularly, when the laboratories are unfamiliar with the use and interpretation of the IIF patterns of AMA. The presence of IgG AMA seems to characterize PBC patients with more severe disease, but both IgG and IgA isotypes of AMAs were not predictive markers of disease outcome.     

The prevalence of antibodies to reovirus type 3 in adults with idiopathic cholestatic liver disease

Recent evidence suggests that neonatal infection with Reovirus type 3 (Reo-3) may play an important role in the pathogenesis of certain idiopathic cholestatic liver diseases of children. Whether this virus is of pathogenetic importance in similar diseases seen in adults is unclear. In this study, sera from 22 adults with idiopathic cholestatic liver disease (16 primary biliary cirrhosis (PBC) and six primary sclerosing cholangitis (PSC] were tested for antibody to Reo-3 virus by a standard hemagglutination inhibition assay. The results were compared to antibody prevalence in ten adults with various other causes of chronic liver disease and 11 healthy volunteers. Although patients with idiopathic cholestatic liver disease had a high prevalence of anti Reo-3 antibodies (20/22, 91%), similar prevalence rates were found in the two control populations (7/10, 70% in chronic liver disease controls and 11/11, 100% in healthy volunteers). Moreover, the geometric mean titres of antibody to Reo-3 virus were similar in all study groups. While these results do not exclude a pathogenetic role for Reo-3 viral infection, they do imply that some genetic predisposition must exist if Reo-3 infection is truly of pathogenetic importance in idiopathic cholestatic liver disease of adults.     

HLA-DR Allele Frequencies in Mexican Mestizos with Autoimmune Liver Diseases Including Overlap Syndromes

Autoimmune liver diseases are sometimes difficult to differentiate from hepatic overlap syndromes (OS). The objective of this study was to use polymorphic genetic markers to better distinguish clinical heterogeneity in autoimmune liver disease. Since autoimmunity is the result of autoantibody production we studied HLA-DR alleles in 20 patients with autoimmune hepatitis (AIH), 16 with primary biliary cirrhosis (PBC), 10 with OS, and in 99 ethnically matched healthy individuals. Patients with OS had significantly higher alkaline phosphatase and total bilirubin levels than patients with AIH. OS patients had a higher prevalence of positive antinuclear antibodies and a higher AIH score than patients with PBC. Patients with OS also had higher total immunoglobulin levels (IgG isotype) as compared to patients with PBC. We found in PBC patients a higher gene frequency of HLA-DR4 and DR1 as compared to healthy controls (p = 0.03, OR = 2.2 and p = 0.004, OR = 4.3, respectively) and to OS patients (p = 0.01, OR = 6.8, and p = 0.004, OR = 10.0, respectively). On the other hand, the gene frequency of HLADR5 was significantly decreased in the total group of patients as compared to healthy controls suggesting a protective role of this allele for developing autoimmune liver disease.     

The role of complement activation in autoimmune liver disease

IntroductionThe complement system, an essential part of the innate immune system, is involved in various autoimmune diseases. Activation of the complement system by autoantibodies results in immune activation and tissue damage. At the moment little is known about the role of the complement system in autoimmune liver disease, including primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH). Since inhibition of the complement system is currently being tested in several autoimmune diseases as a therapeutic option, its role in autoimmune liver disease requires further clarification.MethodsA review of the literature was performed on studies investigating complement activation in PBC, PSC and AIH. Since data on AIH were lacking immunohistochemical staining for IgG, C1q, C3d, C4d and C5b9 was performed on liver tissue of nine AIH patients, two healthy controls and one positive control (acute liver failure caused by paracetamol intoxication).ResultsImmunohistochemical analysis in AIH revealed increased production of C3 and C4 by hepatocytes. Despite a strong staining for IgG in the immune infiltrate in AIH, C3d, C4d and C5b9 deposition was only present in one AIH patient and the deposition was restricted to the interface between portal tracts and liver parenchyma. No deposition was found in all other AIH patients or healthy controls.Literature review showed raised plasma C3 and C4 levels in AIH, PBC and PSC patients compared to healthy controls. For PBC and PSC no complement depositions at the bile ducts were reported.Conclusion and discussionAlthough complement is involved in various autoimmune diseases, the role of complement in autoimmune liver disease seems limited. Therefore it is unlikely that complement inhibition will become a novel treatment option for these diseases.     

Prevalence of antibody to hepatitis C virus in HBsAg-negative chronic liver disease in Hong Kong using different assays.

The prevalence of anti-HCV antibodies in Chinese patients with HBsAg-negative chronic liver diseases was studied retrospectively. Anti-HCV was detected by two different ELISAs. In 97 patients with HBsAg-negative chronic liver disease, 26 (27%) were anti-HCV positive. Of 157 control subjects, only 1 (0.6%) was anti-HCV positive (P less than 0.001). Anti-HCV was detected in 18 of 27 (67%) patients with post-transfusion non-A, non-B (PTNANB) chronic hepatitis or cirrhosis, 5 of 25 (20%) patients with cryptogenic chronic hepatitis or cirrhosis, 2 of 33 (6%) patients with alcoholic liver disease, 1 of 5 (20%) patients with autoimmune chronic active hepatitis (AICAH), none of 4 patients with primary biliary cirrhosis (PBC), and none of 3 patients with fatty liver. The prevalence in this group of patients was lower when compared to reports from other countries. The addition of a urea washing step reduced false-positivity in alcoholic and AICAH groups. The ELISA that employs three recombinant HCV antigens confirmed all positive results by another ELISA with the exception of one weakly positive result in the AICAH group and one in the alcoholic group. One patient in the PTNANB group was detected in addition by the second generation assay. In conclusion, ELISA with a urea wash proved to be useful in reducing false-positivity, and the second generation assay proved to be a sensitive and specific test for anti-HCV antibody.     

Medical treatment of primary biliary cirrhosis and primary sclerosing cholangitis

Chronic cholestasis is the main feature of primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC), the most common chronic cholestatic liver diseases in adults. Although the etiology of both diseases remains poorly understood, auto-immune processes appear to be important, particularly in PBC. PBC and PSC usually slowly progress to cirrhosis, liver failure, and death, unless liver transplantation is performed. Ursodeoxycholic acid (UDCA), a hydrophilic dihydroxy bile acid, is the only drug currently approved for the treatment of patients with PBC and is also used in patients with PSC. In addition to UDCA, patients with PSC should be referred to endoscopic dilatation of major bile duct stenoses. Several potential mechanisms of action of UDCA have been proposed, including intracellular modulation of signaling events and secretion. Various immunosuppressive drugs have been evaluated alone or in combination with UDCA—especially for the treatment of PBC. Of these drugs, the topical corticosteroid budesonide, together with UDCA, appears promising in the treatment of early stage PBC, but data remain insufficient to warrant use of budesonide outside of controlled studies.     

Autoantibodies to histones and their subfractions in chronic liver diseases

Sera of 78 patients with different chronic liver diseases were examined for the presence of anti-histone activity using an enzyme-linked immunosorbent assay. Eighteen patients had primary biliary cirrhosis (PBC), 20 had chronic active hepatitis, and 40 had cirrhosis. Anti-histone antibodies were detected in 34 patients (43.6%), distributed among all liver disease entities studied. When antibodies of specific isotypes (IgG, IgM, and IgA) were measured, even higher frequencies were noted--50% for IgG and 53.8% for IgA. Antibodies to histone subfractions H1, H2a, H2b, H3, and H4 were also observed in all liver disorders investigated (in 22-32% of patients)--H1 and H3 being the prominent fractions involved. Of the various disease entities examined PBC was the one disclosing the highest frequency of anti-histone antibodies.