Chronic active hepatitis associated with antiliver/kidney microsome antibody type 1: a second type of "autoimmune" hepatitis

Autoantigen characterization in liver/kidney microsome positive hepatitis

Liver/kidney microsome autoantibodies are detectable in different forms of chronic hepatitis, namely autoimmune, viral, and drug-induced hepatitis and in hepatitis associated with Type 1 autoimmune polyglandular syndrome. Based on the aetiology of chronic hepatitis, liver/kidney microsome autoantibodies are directed against different enzymes with very little overlap. Thus, the simple Indirect Immunofluorescence test, which is universally used as a screening test to detect autoantibodies, does not allow subtyping of liver/kidney microsome autoantibodies. This brief review stresses the need to use methods such as Western-Blotting and enzyme-linked immunosorbent assay together with Indirect Immunofluorescence to characterize the liver/kidney microsome autoantibodies. Identification of the liver/kidney microsome target antigens, when possible, makes differential diagnosis easier and, at times, may help the clinician to choose the best approach to treatment.

Overlapping but distinct specificities of anti-liver-kidney microsome antibodies in autoimmune hepatitis type II and hepatitis C revealed by recombinant native CYP2D6 and novel peptide epitopes

Anti-liver-kidney microsome antibodies (anti-LKM) occur in autoimmune hepatitis (AIH) type II and in a subset of patients with hepatitis C. Anti-LKM1 in AIH are directed against cytochrome P4502D6 (CYP2D6), but conflicting data exist concerning the specificity of anti-LKM in hepatitis C. The aim of this study was to evaluate binding specificities of anti-LKM antibodies in both diseases using novel test antigens as well as their inhibitory capacity on CYP2D6 enzyme activity. Sera from 22 patients with AIH type II and 17 patients with hepatitis C being anti-LKM-positive in the immunofluorescence test were investigated for binding to native recombinant CYP2D6 and liver microsomes by ELISA and immunoblotting, and to synthetic peptides covering the region 254-339 (254-273, 257-269, 270-294, 291-310, 307-324, 321-339, 373-389) as well as the novel peptide 196-218 by ELISA. Furthermore, all sera were tested for inhibition of CYP2D6-dependent bufuralol 1'-hydroxylase activity. Twenty of the 22 AIH type II sera (91%) and nine of the 17 hepatitis C sera (53%) were positive for CYP2D6 by ELISA and/or immunoblotting. The previously described major peptide epitope comprising CYP2D6 amino acids 257-269 was recognized by 16 of the 22 AIH sera but by only one hepatitis C serum. A further epitope, 196-218, could be defined for the first time as another immunodominant epitope for AIH because it was recognized by 15 of the 22 AIH (68%) but only three of the 17 hepatitis C sera (18%). With the exception of the peptide 254-273, the other peptides showed no significant reactivity. Analysing the inhibitory properties of anti-LKM antibodies it emerged that 95% of AIH sera and 88% of hepatitis C sera inhibited enzyme function. These data indicate that anti-LKM antibodies in AIH and hepatitis C react with CYP2D6, as shown by their inhibitory activity, and that besides the known epitope 257-269 a further immunodominant epitope exists on CYP2D6 which is recognized by sera from patients with AIH II but hardly by sera from patients with hepatitis C.

Clinical significance of autoantibodies to soluble liver antigen in autoimmune hepatitis

BACKGROUND/AIMS

Classification of autoimmune hepatitis (AIH) into different subgroups according to autoantibody status has been proposed: type I (ANA/SMA), type II (LKM-1) and type III (anti-SLA). However, whether type III AIH forms a clinically distinct disease entity remains controversial. The aim of this study was to evaluate the subclassification of AIH into ANA/SMA and anti-SLA positive patients with regard to clinical, biochemical and histologic differences.

METHODS

Ninety-seven consecutive patients with a well-documented long-term course of AIH with ANA/SMA and/or anti-SLA autoantibodies were studied. Clinical, biochemical and histological features of patients with ANA/SMA and/or anti-SLA autoantibodies were compared in a secondary analysis of data acquired prospectively.

RESULTS

Anti-SLA autoantibodies were found in 21.6% of patients. Anti-SLA-positive patients tended to have lower transaminases (mean: 153 vs. 247 IU/l), gamma-globulins (25 vs. 31%) and bilirubin (1.8 vs. 3.3 mg/dl) in comparison to ANA/SMA positive patients, but there was a large overlap. HLA-type A1 B8 was more frequent in anti-SLA positive patients, while there was no difference in HLA DR3 and DR4 allotype. Response to immunosuppressive therapy was excellent, but relapse occurred frequently. Diagnosis of anti-SLA positive AIH was often delayed (mean: 68 months from first elevation of transaminases) since testing for anti-SLA autoantibodies is currently not generally available.

CONCLUSIONS

ANA/SMA and anti-SLA positive patients share most clinical, biochemical, histologic and prognostic features. Distinction between type I and type III AIH is therefore clinically not helpful. However, testing for anti-SLA autoantibodies helps in the diagnosis of AIH in many patients who may otherwise be misdiagnosed.

Frequency and nature of cytokine gene polymorphisms in type 1 autoimmune hepatitis

Genetic involvement in type 1 autoimmune hepatitis (AIH) is indicated by a marked female preponderance and strong, well-established, human leukocyte antigen (HLA) associations. These associations, however, are not universal and a number of genes outside the major histocompatibility complex may also play a role in susceptibility to type 1 AIH. Prime candidates at present are those polymorphic genes encoding the proinflammatory and immunoregulatory cytokines. The aim of this study was to investigate, for the first time, 2 members of the interleukin-1 (IL-1) family (IL-1B and IL-1RN), 3 polymorphic sites in the interleukin-10 (IL-10) gene promoter (positions -1082, -819, and -592), and 2 polymorphisms in the tumor necrosis factor-alpha (TNF-alpha) promoter (positions -308 and -238) in type 1 AIH. The study was performed on 2 independently collected DNA banks, each with appropriate controls, and throughout the analysis associations described in the first set were confirmed in the second set. Standard polymerase chain reaction (PCR)-based genotyping techniques were used. Overall there were no significant differences in the distributions of the IL-1B and IL-10 alleles, genotypes, or haplotypes in either study set. In contrast we report a significant association between type 1 AIH and TNF*2 (first set: 34% of controls vs. 49% of patients, Pc =.014 and second set: 26% vs. 56%, P =.00008). However, TNF*2 is found in strong linkage disequilibrium with the HLA A1-B8-DR3 haplotype and stratification analysis indicates that the association with TNF*2 is interdependent with HLA DRB1*0301. This is an indication that there is more than one susceptibility allele for type 1 AIH on chromosome 6p21.3.

Detection of anti-LKM-1(anti-CYP2D6) by an enzyme-linked immunosorbent assay in adult patients with chronic liver diseases

Anti-liver kidney microsome-1 (LKM-1) autoantibody, which is a serological marker for autoimmune hepatitis type II, recognizes Cytochrome P450 IID6 (CYP2D6). This autoantibody is also detected in a portion of patients with chronic hepatitis C. Anti-LKM-1 has been measured by indirect immunofluorescence (IF) using rat liver and kidney sections. However, this method has some problems in specificity and is so laborious to handle with many samples. In this study, in order to determine anti-LKM-1, we established an enzyme-linked immunosorbent assay (ELISA) for anti-CYP2D6 using a recombinant CYP2D6 fusion protein. We studied sera from 29 patients positive for anti-LKM-1 by the new ELISA. We further studied sera from a total of 301 patients with various liver diseases and 100 sera from normal controls negative for anti-LKM-1 by the new ELISA. The specificity of the ELISA was ascertained by absorption tests using sera positive for anti-LKM-1. In 29 sera from patients positive for anti-LKM-1 by IF, we found a good correlation between the logarithms of the antibody titers determined by IF and ELISA indexes obtained by our new method. Anti-CYP2D6 was positive in 12 of 12 (100%) patient with autoimmune hepatitis type II and 16 of 17(94.1%) with chronic hepatitis C positive for anti-LKM-1 by IF. In other 401 sera negative for anti-LKM-1 by IF, anti-CYP2D6 was all negative except a few sera. We established a new ELISA for anti-LKM-1 (anti-CYP2D6). This ELISA system is sensitive, antigen-specific and easy to be done. Therefore, this assay allows a routine test of many serum samples, especially for diagnosing autoimmune hepatitis type II.

Towards the pathogenesis of autoimmune liver disease

There have been recent improvements in the clinical understanding and definition of the major types of autoimmune liver disease. However, still lacking is knowledge of their prevalence and pathogenesis. Three areas of study are in progress in our laboratory. First, in type 1 autoimmune hepatitis, the search continues to identify a liver/disease-specific autoantigenic reactant. Using hepatocyte membrane preparations, immunoblotting has underlined the problem of distinguishing, among multiple reactants, those that may be causally rather than consequentially related to hepatocellular damage. Second, in primary biliary cirrhosis (PBC), the need for population screening to ascertain prevalence and detect preclinical cases can be met by a rapid automated procedure for detection, by specific enzyme inhibition in microtitre wells, of antibody (anti-M2) to the pyruvate dehydrogenase complex E2 subunit (PDC-E2). Third, the structure of the conformational epitope within the inner lipoyl domain of PDC-E2 is being investigated by screening random phage-displayed peptide libraries using PBC sera. This has yielded phage clones in which the sequence of the peptide insert portrays the structure of this epitope, as judged by clustering of PBC-derived sequences to particular branches of a guide-tree that shows relatedness of peptides, and by reactivity of selected phage clones with anti-PDC-E2. Thus phage display identifies a peptide 'mimotope' of the antibody epitope in the inner lipoyl domain of PDC-E2.

Genetic heterogeneity in susceptibility to autoimmune hepatitis types 1 and 2

OBJECTIVE

Susceptibility to autoimmune hepatitis (AIH) type 1 has been associated with DRB1*03, DRB1*04, and DRB3 alleles in European and North-American whites, with DRB1*04 in Japan, and with DRB1*04 and DRB1*13 in Latin America. Very few studies have been performed on AIH type 2. The aim of the present study was to evaluate the association of AIH types 1 and 2 with HLA-DR and DQ loci.

METHODS

We performed HLA-DRB and -DQB1 typing by polymerase chain reaction amplification with sequence-specific primers (PCR-SSP) in 139 AIH patients. Most had AIH type 1 associated with circulating anti-smooth muscle antibody with F-actin specificity or antinuclear antibody. Twenty-eight patients presented AIH type 2 with anti-liver/kidney microsome type 1 or anti-liver cytosol type 1 antibodies.

RESULTS

We observed a significant increase of DRB1*13 (70% vs 26% of controls, p < 0.00001) and DRB3 (93% vs 69% of controls, p < 0.00001) in AIH type 1 patients. Analysis of patients without DRB1*13 disclosed a secondary association with DRB1*03 (70% vs 30% of controls, p = 0.0001) and either the DRB1*13 or the DRB1*03 alleles were present in the majority of these patients (91% vs 48% of controls, p = 0.001). Comparison of DRB1*13- and DRB1*03-positive subjects revealed that the former alleles conferred susceptibility to younger patients with AIH type 1. DQB1 typing showed a significant increase in DQB1*06 (68% vs 41% of controls, p = 0.00007) in strong linkage disequilibrium with DRB1*13, and a decrease in DQB1*0301 (8% vs 47% of controls, p(c) = 0.0003). On the other hand, HLA typing of patients with AIH type 2 disclosed a significant increase in the DRB1*07 (68% vs 20% of controls, p(c) < 0.00014), DRB4 (79% vs 43% of controls, p(c) = 0.004), and DQB1*02 (86% vs 42%, p = 0.00002) alleles. After exclusion of DRB1*07, a secondary association with HLA-DRB1*03 was further observed in these patients (78% vs 30%, p = 0.007) and most of them had either DRB1*07 or DRB1*03 (93% vs 44% of controls, p(c) < 0.0001).

CONCLUSIONS

Our data indicate that predisposition to AIH types 1 and 2 is associated, respectively, with the DRB1*13 or DRB1*03 and DRB1*07 or DRB1*03 alleles, and suggest that protection against type 1 disease may be conferred by DQB1*0301. In addition, the cluster of DRB1*13 in children with AIH type 1 also supports the concept that different HLA alleles might influence the onset of the disease.

Response to interferon alpha treatment and disappearance of cryoglobulinaemia in patients infected by hepatitis C virus

BACKGROUND

Mixed cryoglobulinaemia is closely associated with hepatitis C virus (HCV) infection.

AIM

To assess in a prospective open study the efficiency of interferon alpha treatment of cryoglobulinaemia, as reflected by the disappearance of cryoglobulins and clinical manifestations of the disease, and to analyse the factors predictive of a response to interferon.

METHOD

Eighty seven consecutive patients with chronic hepatitis C treated for the first time with interferon at a dose of 3 x 10(6) international units three times a week for six months were studied. Forty three patients had cryoglobulins, which were responsible for clinical manifestations in 12.

RESULTS

At the end of interferon treatment, cryoglobulins had disappeared in 39% of the patients. A clinical improvement (except for neuropathies) was observed in all patients. Six months after interferon treatment was stopped, the same rate of response (normal alanine aminotransferase values and undectable HCV RNA) was observed in patients with or without cryoglobulins. Only 14% of patients still had undetectable cryoglobulins, and all of them also had undetectable serum HCV RNA. The disappearance of cryoglobulins was found less frequently in patients with clinical symptoms than in asymptomatic ones, but the difference was not significant. Sustained responders were more often men, infected by genotype 2 or 3, with a lower pretreatment viral load.

CONCLUSION

The presence of cryoglobulins does not seem to affect the response to interferon in HCV infected patients. The improvement in cryoglobulinaemia is strongly associated with a virological response, reinforcing the hypothesis of a direct role for HCV in the pathogenesis of this disease.

Auto-antibodies in hepatitis C

Hepatitis C virus (HCV) has been implicated in the development of a variety of autoimmune phenomena, some of which are well documented and include a panel of auto-antibodies shared with autoimmune hepatitis (AIH). Anti-nuclear (ANA) and smooth muscle (SMA) antibodies (markers of AIH type 1 [AIH-1]), have been demonstrated in 9-38% and 5-91% of cases respectively, whereas anti-liver/kidney microsomal type 1 (anti-LKM-1) and anti-liver cytosol type 1 antibodies (anti-LC1) (markers of AIH type 2 [AIH-2]), are definitely rarer, especially in adults. The presence of these auto-reactivities in chronic hepatitis C generates clinical overlaps and dilemmas in the correct classification and treatment of such patients. The immunopathological characterization of the auto-antibodies, anti-nuclear and smooth muscle antibodies in particular, combined with internationally defined criteria for the diagnosis of AIH is helpful in this clinical process. Thyroid auto-antibodies and cryoprecitable rheumatoid factors are also commonly detected in hepatitis C, while the occurrence of other auto-antibodies still awaits confirmation.

Viral genotypes as determinants of autoimmune expression in chronic hepatitis C

OBJECTIVE

To correlate viral genotypes with the immune manifestations of chronic hepatitis C and evaluate the effect of immune features on disease expression and response to antiviral treatment.

DESIGN

We undertook a retrospective analysis of 67 patients with chronic hepatitis C.

MATERIAL AND METHODS

Patients were selected for study if they had been screened for autoantibodies and concurrent immune diseases and if viral genotyping had been performed or was possible. Concurrent immune manifestations and responses to interferon therapy were determined.

RESULTS

Of the 67 patients, 18 (27%) had one or more immune features. Immune manifestations occurred as commonly in patients with genotype 1 as in those with other genotypes (30% versus 14%; P = 0.3). Concurrent immune features did not distinguish patients, and responses to interferon therapy were similar between patients with and those without immune manifestations. None of the 14 patients with concurrent immune diseases or high-titer autoantibodies (serum titers, 1:320 or more) entered remission during interferon treatment. In contrast, 6 of 53 patients without concurrent immune diseases and no or low-titer autoantibodies had treatment-related remission. These differences, however, were not statistically significant (0% versus 11%; P = 0.3).

CONCLUSION

Autoantibodies and concurrent immune diseases are not associated with a particular viral genotype, clinical profile, or treatment outcome. Larger studies are necessary for complete assessment of the influence of prominent immune manifestations on treatment response.

Case report: a rare association of primary biliary cirrhosis and systemic lupus erythematosus and review of the literature

We report a rare occurrence of systemic lupus erythematosus in a patient known to have had well-documented primary biliary cirrhosis for 10 years. The presentation was dramatic with pericardial tamponade, but responded well to high dose corticosteroid. There are only five such definite associations reported in the literature. In the present case, other possible causes were considered, such as drug-induced cholestasis, drug-induced lupus, autoimmune chronic active hepatitis and the overlap syndrome.

A novel assay for detecting antibodies to cytochrome P4502D6, the molecular target of liver kidney microsomal antibody type 1

Liver Kidney Microsomal type 1 (LKM1) antibody, the diagnostic marker of autoimmune hepatitis type 2, is also found in a proportion of patients with hepatitis C virus infection (HCV). It is detected conventionally by the subjective immunofluorescence technique. Our aim was to establish a simple and objective enzyme-linked immunosorbent assay (ELISA) that measures antibodies to cytochrome P4502D6 (CYP2D6), the target of LKM1. An indirect ELISA using eukaryotically expressed CYP2D6 was designed. Absorbance values obtained against a reference microsomal preparation were subtracted from those obtained against a microsomal preparation over-expressing CYP2D6, thus removing the non-CYP2D6-specific reaction. Sera from 51 LKM1 positive patients (21 autoimmune hepatitis and 30 with HCV infection), 111 LKM1 negative patients with chronic liver disease (including 20 with HCV infection) and 43 healthy controls were tested. Of 51 patients positive by immunofluorescence, 48 were also positive by ELISA while all the 154 LKM1 negative subjects were also negative by ELISA. There was a high degree of association between IFL and ELISA as demonstrated by a kappa reliability value of 0.96. The absorbance values by ELISA correlated with immunofluorescence LKM1 titres both in autoimmune hepatitis (r = 0.74, p < 0.001) and HCV infection (r = 0.67, p < 0.001). The simple, objective ELISA described has the potential to replace the standard immunofluorescence technique.

Formiminotransferase cyclodeaminase is an organ-specific autoantigen recognized by sera of patients with autoimmune hepatitis

BACKGROUND & AIMS

Anti-liver cytosol type 1 autoantibodies have been reported in association with anti-liver-kidney microsome type 1 autoantibodies in 30% of patients with autoimmune hepatitis type II. In 10% of cases, anti-liver cytosol type 1 antibodies are the only liver-related circulating autoantibodies. The liver cytosol antigen is a liver-specific 62-kilodalton protein present in the cell as an oligomer of approximately 240 kilodaltons. The aim of this study was to identify the antigen recognized by anti-liver cytosol antibody.

METHODS

To identify the liver cytosol antigen, an anti-liver cytosol type 1-positive serum was used for the screening of a complementary DNA library from HepG2 cells. Double immunodiffusion method was used to show the identity between the cytosolic and the cloned protein.

RESULTS

The sequence of two isolated clones showed 85.2% homology with the formiminotransferase cyclodeaminase (FTCD) enzyme from pig liver. Antibodies purified by affinity with the recombinant protein and sera from mice immunized with FTCD recognized a 62-kilodalton human cytosolic protein when tested by immunoblot. The identity of precipitation lines was found between the cytosolic antigen and FTCD.

CONCLUSIONS

This enzyme is a liver-specific antigen recognized by the sera of patients with autoimmune hepatitis.

Epitope mapping of cytochrome P4502D6 autoantigen in patients with chronic hepatitis C during alpha-interferon treatment

BACKGROUND/AIMS

Cytochrome P450 2D6 (CYP2D6) has been documented as the major target antigen of liver kidney microsomal autoantibodies type-1 (anti-LKM-1) in both autoimmune hepatitis type-2 (AIH-2) and hepatitis C (HCV). In HCV/anti-LKM-1-positive patients, the choice between alpha-interferon (alpha-IFN) or immunosuppression may be difficult. This study was conducted to evaluate the course and outcome of alpha-IFN therapy in HCV/anti-LKM-1-positive and -negative patients and the alterations in these autoantibody titers by the indirect immunofluorescence and a novel radioligand assay. Epitope mapping was also performed to screen for a potential shift in anti-LKM-1 binding towards small linear epitopes, which are more often detected in AIH-2 patients.

METHODS

Twenty-one patients with HCV infection received alpha-IFN. Seven patients were anti-LKM-1 positive (study group) and 14 patients were anti-LKM-1 negative (disease control group). Anti-CYP2D6 detection was based on immunoprecipitation of [35S]-methionine-labeled CYP2D6 recombinant protein (rCYP2D6) produced by in vitro transcription/translation.

RESULTS

Four out of seven (57%) patients in the study group and 5/14 (36%) in the disease control group initially responded, but subsequently relapsed. During follow-up, alanine aminotransferase significantly increased in the study group compared to the disease control group (p<0.01). A slight increase, followed by a plateau of autoantibody titers was recorded by the radioligand assay and by indirect immunofluorescence during therapy and follow-up in most cases. In one patient, however, gamma-globulins and anti-LKM-1 titers increased, reaching very high levels (1:40 960). alpha-IFN was interrupted and immunosuppression was started. HCV/anti-CYP2D6 positive sera recognized CYP2D6 expressed in E. coli and two truncated proteins (aa 250-494 and 321-494). Two out of seven sera, in addition reacted with a small linear epitope of aa 257-269 (one of which also reacted with a C-terminal domain of aa 350-494).

CONCLUSIONS

A rather mild deterioration in liver disease was observed in only 1/7 HCV/anti-LKM-1-positive patients during alpha-IFN treatment. This patient showed high anti-CYP2D6 titers before the initiation of therapy, a sharp increase in anti-LKM-1 titers during treatment, and reactivities to a small linear epitope and an infrequently recognized C-terminal domain of CYP2D6. After switching to immunosuppressive treatment, a complete and sustained response was recorded. Further prospective studies from many centers are needed to define whether these features have general, clinical significance or not.

Factors associated with progression of the disease before transplantation in patients with autoimmune hepatitis

AIMS/BACKGROUND

Studies on transplanted patients may provide clinically useful data on factors influencing progression of autoimmune hepatitis (AIH) since transplantation rather than death may now be considered as the most likely end-point of the disease. The aim of this work was to analyze risk factors related to progression of AIH before transplantation and provide guidelines for further prognostication with regards to the timing of transplantation.

METHODS

80 liver transplants in 68 patients with AIH were performed in our unit. The diagnosis was established on conventional clinical criteria. Parameters such as sex, age at diagnosis and transplantation or duration of the disease were evaluated in relation to: patient HLA DR status, disease presentation (aggressive or non-aggressive), presence of anti-LKM antibodies and concurrent immune disease.

RESULTS

AIH with concurrent immune disease occurred more commonly in females (90 vs. 61%; p = 0.0075) and was linked with markedly slower progression of the disease (125 vs. 66 mo; p = 0.002) as compared to subjects without such association. AIH without concurrent autoimmune disease occurred significantly more commonly in patients with DR3 phenotype (p = 0.01). Patients with positive anti-LKM autoantibodies were younger at transplantation (25.6 vs. 43.5 yr; p = 0.006) and had more rapid progression of their disease (14.3 vs. 103 mo; p = 0.001). Unlike previously reported series of non-transplanted patients, all anti-LKM positive subjects had no concurrent autoimmune disease.

CONCLUSIONS

Coincidence with another autoimmune disease is associated with a significantly longer disease history prior to transplantation and may possibly reflect greater responsiveness to immunosuppressive therapy before grafting. AIH without concurrent autoimmune disease, particularly if associated with DR4 negative phenotype, male sex and anti-LKM antibodies may characterize patients with rapid progression of the disease. None of these factors had a significant influence on 5 year survival after surgery.

Short-term cyclosporine induces a remission of autoimmune hepatitis in children

BACKGROUND/AIMS

The current immunosuppressive treatment of patients with autoimmune hepatitis consists of prednisone and azathioprine. High doses of prednisone used to obtain the remission of the disease are associated with serious adverse effects. To avoid harmful consequences of prednisone therapy, we proposed to treat patients with oral cyclosporine to obtain the remission of the inflammatory process.

METHODS

This is a pilot, multinational, multicenter, clinical trial involving children with autoimmune hepatitis. Thirty-two children were recruited, who according to international criteria were considered as having definite autoimmune hepatitis. Cyclosporine alone was administered for 6 months, followed by combined low doses of prednisone and azathioprine for 1 month, after which cyclosporine was discontinued. Biochemical remission of the disease was established by the follow-up of serum transaminase activity levels. Growth parameters and adverse effects of the treatment were recorded.

RESULTS

Two patients were withdrawn from the study: one for non-compliance and the other for liver failure which did not improve with cyclosporine. Of the 30 remaining patients, 25 normalized alanine aminotransferase activity levels by 6 months and all the patients by 1 year of treatment. Z-scores for height showed a trend towards improvement during treatment. Adverse effects of cyclosporine were mild and disappeared during weaning off the medication.

CONCLUSIONS

Cyclosporine induced the biochemical remission of the hepatic inflammatory/necrotic process in children with autoimmune hepatitis, with few and well-tolerated adverse effects.

Drug therapy in the management of type 1 autoimmune hepatitis

Prednisone alone or in combination with azathioprine is the treatment of choice for severe type 1 autoimmune hepatitis. The combination regimen is preferred, especially in the elderly, because of a lower incidence of corticosteroid-related complications. Only patients with sustained severe laboratory abnormalities, bridging necrosis or multilobular necrosis on histological assessment, and/or incapacitating symptoms, have absolute indications for treatment based on controlled clinical trials. The institution of therapy must be individualised in other patients, based mainly on symptoms and disease behaviour. Serum aspartate aminotransferase and gamma-globulin levels are the most useful indices to monitor during therapy. Liver tissue examination is the best method of evaluating completeness of response. Most patients enter remission, but relapse occurs in 50 to 86% after drug withdrawal. Maintenance therapy with low dosages of prednisone or azathioprine can be used long term in patients who have relapsed repeatedly. Inability to achieve remission after 3 years (incomplete response), deterioration during therapy (treatment failure) and drug toxicity are unsatisfactory responses that warrant alternative strategies. Liver transplantation is effective in managing decompensated disease, but recurrence of autoimmune hepatitis after transplantation is possible. Tacrolimus and budesonide are promising new drugs.

Successful treatment of refractory type 1 autoimmune hepatitis with methotrexate

BACKGROUND/AIMS

Autoimmune hepatitis is a heterogeneous disorder that typically responds to glucocorticoids with or without azathioprine. Treatment options for patients not responding to standard therapy are limited.

METHODS

We describe a 52-year-old female who presented with jaundice, marked elevation in liver enzymes, positive antinuclear antibody and a liver biopsy consistent with autoimmune hepatitis. Liver enzymes did not normalize with prednisone alone. When azathioprine was added, the disease flared. The patient refused cyclosporine. Methotrexate 7.5 mg po per week resulted in normalization of liver enzymes, improved liver histology, and has maintained remission with a steroid-sparing effect.

RESULTS/CONCLUSION

In this patient methotrexate was used successfully to treat type 1 autoimmune hepatitis. This suggests that methotrexate may have a role in treatment of autoimmune hepatitis refractory to standard therapy.

Argininosuccinate lyase: a new autoantigen in liver disease

Anti-liver cytosol 1 autoantibody (LC1) characterizes a severe form of autoimmune hepatitis (AIH), staining the cytoplasm of periportal hepatocytes and targeting an unidentified 60-kD liver cytosolic antigen. To identify its target, we used high-titre anti-LCI+ sera from two patients with AIH to screen 18 cytoplasm enzymes with periportal location by double immunodiffusion (DDI). Both sera gave a broad precipitin line against human liver cytosol, suggesting that they may recognize two distinct antigens, a possibility confirmed by the appearance of two precipitin lines when DDI conditions were optimized (0.8% agarose and 3% polyethylene glycol (PEG)). Experiments by DDI and Western blot (WB) identified a liver cytosolic autoantigen of 50 kD, different from LC1, giving a line of identity with argininosuccinate lyase (ASL). Reactivity to ASL was then investigated by DDI and WB in 57 patients with AIH, 17 with primary biliary cirrhosis (PBC), 15 with chronic hepatitis B virus (HBV) infection, 13 with alphal-antitrypsin deficiency, 17 with Wilson's disease, 18 with extrahepatic autoimmune disorders, and in 48 healthy controls. Anti-ASL was found in 16% of AIH and 23% of PBC patients by DDI and in 14% of AIH, 23% of PBC and 20% of HBV patients by WB. No argininosuccinate was present in the urine of four anti-ASL+ patients tested, excluding an inhibition of enzymatic activity by anti-ASL. The addition of anti-ASL+ serum to human fibroblast cultures induced a significant increase in ASL activity. ASL is a new autoantigen in liver disease and its clinical relevance warrants further investigation.

Rheumatologic manifestations of gastrointestinal diseases

One of the most significant extraintestinal manifestations of gastrointestinal diseases is rheumatologic disorders. The gastrointestinal diseases with rheumatologic manifestations can be divided into two major categories: intestinal disorders and disorders of the liver, biliary tree, and pancreas. The cause of diseases in each of these categories is different. Although intestinal permeability and immune responsiveness are frequently implicated in disorders of the intestine, diseases of the liver, biliary tree, and pancreas usually involve the production of autoantibodies, cytokines, or enzymes. Treatment of rheumatologic complications frequently involves therapy directed at the underlying gastrointestinal disease.

Autoimmune polyglandular syndromes

Autoimmune polyglandular syndrome type 1 (APS1) is characterized by a variable combination of disease components: (1) mucocutaneous candidiasis; (2) autoimmune tissue destruction; (3) ectodermal dystrophy. The disease is caused by mutations in a single gene called APECED (autoimmune polyendocrinopathy-candidiasis-ectodermal-dystrophy) or AIRE (autoimmune regulator) coding for a putative transcription factor featuring two zinc-finger (PHD-finger) motifs. APS1 shows a penetrance of 100%, lack of female preponderance and lack of association with HLA-DR. Typically, onset of APS1 occurs in childhood and multiple autoimmune manifestations evolve throughout lifetime. Organ-specific autoantibodies associated with hypoparathyroidism, adrenal and gonadal failures, IDDM, hepatitis and vitiligo are discussed, and autoantibody patterns in APS1 patients are compared with autoantibodies in APS type 2 (APS2). APS2 is characterized by adult onset adrenal failure associated with IDDM and/or hyperthyroidism. APS2 is believed to be polygenic, characterized by dominant inheritance and association with HLA DR3.

Members of the glutathione S-transferase gene family are antigens in autoimmune hepatitis

BACKGROUND & AIMS

Autoimmmune hepatitis (AIH), a chronic liver disorder, can be classified into two subtypes on the basis of the specificities of circulating autoantibodies. Type I AIH is defined by antibodies to nuclear and/or smooth muscle antigens (SMA), and type II is characterized by antibodies to cytochrome P450IID6. There is an additional type of AIH characterized by antibodies to a cytosolic soluble liver antigen (SLA), which can occur alone or in combination with antinuclear antibodies and SMA. The aim of this study was to identify the reactive antigen in SLA, a heterogenous cytosolic fraction consisting of at least 100 extremely soluble proteins.

METHODS

Sera from 31 patients with AIH reacting with SLA and from 30 disease controls were tested. The immunoreactive antigens were determined using immunoprecipitation and immunoblotting after one- and two-dimensional polyacrylamide gel electrophoresis. The antigens were identified by microsequencing of the corresponding protein spots.

RESULTS

Twenty-five of 31 anti-SLA-positive sera (80, 7%) reacted with a set of proteins ranging from 25 to 27 kilodaltons that were identified as three subunits of glutathione S-transferases: Ya, Yb1, and Yc.

CONCLUSIONS

Glutathione S-transferase subunit proteins represent the major autoantigen in anti-SLA-positive AIH. This new finding permits the establishment of standardized immunoassays for routine diagnosis.

Hepatobiliary diseases in women

Most diseases of the hepatic and biliary systems affect both women and men. There are several disorders, however, that affect women differently than they affect men. Gallstones, primary biliary cirrhosis (PBC), and autoimmune liver disease occur more often in women. The impact of alcohol on the liver is worse in women. Chronic liver disease from any cause can affect fertility. In addition, oral contraceptive use and pregnancy can have specific effects on the liver.

Antibodies to P450IID6, SLA, PDH-E2 and BCKD-E2 in Japanese patients with chronic hepatitis

Auto-antibodies specific to various antigens in chronic hepatitis (CH) have been detected but their specificities and implications were uncertain. The aims of the present study were to investigate the frequency and the significance of seropositivity of antibodies to P450IID6 or liver/kidney microsome 1 (LKM1), soluble liver antigen (SLA), pyruvate dehydrogenase (PDH) and branched-chain keto acid dehydrogenase (BCKD) in 188 Japanese patients with different forms of CH by western blot or enzyme immunoassay (EIA). Anti-LKM1 was also measured by indirect immunofluorescent test. Anti-P450IID6 was found in 6/188 (3.2%) CH patients including 5/104 (4.8%) with hepatitis C virus (C) infection and 1/12 (8.3%) CH-C patients with antibodies to nuclear and smooth muscle antigens and hypergammaglobulinaemia (> 2.5 g/dL). This patient was the only one diagnosed with autoimmune hepatitis (AIH). All CH patients with hepatitis B (B), hepatitis non-B non-C (NBNC) and AIH were seronegative for anti-LKM1. Antibodies to soluble liver antigen were found in two of 188 (1%) patients, one with AIH and one with CH-B. Anti-BCKD-E2 but not anti-PDH-E2 was found in four patients (2.5%), one with AIH, two with CH-C, and one with NBNC. There was no obvious difference in age, sex ratio and laboratory findings in patients with or without anti-SLA and anti-BCKD-E2. Antibodies to P450IID6, SLA, PDH-E2 and BCKD-E2 are uncommon in adult CH-C, CH-B, CH-NBNC and AIH patients in Japan. Some of these patients positive for auto-antibodies appear to have autoimmune features and might require a careful follow up. The heterogeneity of these antibodies in CH preclude further justification for subtyping of AIH by the presence of the distinct auto-antibodies.

Chronic hepatitis C associated with anti-liver/kidney microsome-1 antibody is not a subgroup of autoimmune hepatitis

To determine whether "autoimmune hepatitis type IIb" should be categorized as a subgroup of autoimmune hepatitis, we conducted a clinicopathological study of 25 adult Japanese patients who were positive for anti-liver/kidney microsome-1 (anti-LKM-1) anti-body and infected with the hepatitis C virus (HCV). Anti-LKM-1 was determined by indirect immunofluorescence and by the double immunodiffusion assays we have developed. Twenty-two patients did not present any unusual symptoms or any associated diseases during the course of their chronic HCV infection. The spectrum of HCV genotypes of these patients did not significantly differ from that of anti-LKM-1-negative Japanese patients with chronic hepatitis C. Histological examination of liver biopsy specimens showed the usual characteristics of chronic hepatitis C and lack of characteristics of autoimmune hepatitis type I. No disease-specific HLA haplotypes were noted, and HLA-DR4, which is detectable in 88.7% of Japanese patients with autoimmune hepatitis type I, was detected in only 50.0% of our group, the same rate as the background frequency. Prednisolone was effective in none of the six patients treated, but interferon was effective in six of ten treated patients (60%). From these results, we conclude that "autoimmune hepatitis type IIb" should not be categorized as autoimmune hepatitis, and that this subgroup is essentially chronic hepatitis C in which an autoantibody has been produced during the course of chronic HCV infection.

Recent developments in autoimmune liver diseases

Several diseases are regarded as autoimmune liver diseases. Apart from the cholestatic liver diseases, primary biliary cirrhosis, primary sclerosing cholangitis, these include autoimmune hepatitis, hepatitis as part of the autoimmune polyendocrine syndrome type 1 (APS-1) and particular overlap syndromes such as autoimmune cholangitis (also called antimitochondrial antibody negative primary biliary cirrhosis [PBC]), overlap syndrome chronic active hepatitis (CAH)/PBC and the overlap syndrome primary sclerosing hepatitis (PSC)/CAH. In addition, auto-antibodies may be observed during the course of chronic viral hepatitis, in particular chronic hepatitis C and D. Finally, a small number of drug-induced liver diseases is immune mediated. The following article will review our recent progress in the field of autoimmune hepatitis including APS-1 and autoimmunity in viral hepatitis and immune-mediated drug-induced liver disease.

Chronic non-A, non-B, non-C hepatitis: is hepatitis G/GBV-C involved?

BACKGROUND

Hepatitis G virus/GBV-C is a recently discovered virus, and its relevance in chronic hepatitis is still debated.

METHODS

We have previously described 127 long-term-studied and well-characterized patients with chronic non-A, non-B hepatitis (NANBH). Ninety-one (71.7%) were positive for hepatitis C virus antibodies (anti-HCV) in a first-generation anti-HCV enzyme-linked immunosorbent assay (ELISA). We now reanalyzed the same group of patients and added a third-generation anti-HCV ELISA and recombinant immunoblot assay and, in negative patients, also polymerase chain reactions for hepatitis C virus RNA, hepatitis GBV-C RNA, and hepatitis B virus DNA. Additional tests for autoimmune hepatitis types 2 and 3 were also included.

RESULTS

Anti-HCV were detected in 114 of the 123 evaluable patients (92.7%). Of the remaining nine anti-HCV-negative patients one had misdiagnosed primary biliary cirrhosis, and two had autoimmune hepatitis type 3. None of the anti-HCV-negative patients were hepatitis GBV-C RNA-, HCV RNA-, or HBV DNA-positive. Thus, 114 of 120 NANBH patients (95.0%) had chronic hepatitis C. None of the remaining six patients had received blood transfusions or was a drug addict, and two of them were successfully treated with steroids.

CONCLUSIONS

Hepatitis G/GBV-C as a single cause of chronic non-A, non-B hepatitis is uncommon, and in all patients with parenteral risk factors hepatitis C was detected.

Subfulminant hepatic failure in autoimmune hepatitis type 1: an unusual form of presentation

Autoimmune hepatitis type 1 is known to progress insidiously and in many cases cirrhosis is already established at the first presentation of symptoms. It affects mostly females, with peaks of incidence around 10 and 50 years of age. Subfulminant hepatic failure is an unusual initial form of presentation of AIH type 1 and it was observed in three post-pubertal female patients. Rapid disease evolution or no response to immunosuppressive therapy led to liver transplantation in all patients. Two did not have cirrhosis, and the third had focal cirrhosis. The occurrence of the unusual subfulminant form of autoimmune hepatitis in three latepubertal girls (Tanner V) suggests that estrogen may play a role in the severity of the disease.

Epidemiology and estimated population burden of selected autoimmune diseases in the United States

Autoimmune diseases cause significant and chronic morbidity and disability. The actual number of persons in the United States that are affected by autoimmune diseases and the resultant magnitude of their impact on the public's health are limited to a few specific diseases. In order to understand the clinical, public health and economic importance of these diseases it is necessary to have estimates of incidence and prevalence rates in the population. In this analysis, we estimate the number of persons affected by 24 autoimmune diseases in the United States by applying mean weighted prevalence and incidence rates obtained from published articles to U. S. Census data. The study was restricted to 24 autoimmune predefined diseases for which there was direct or indirect evidence for autoimmune pathogenesis. Subsequently, we used computerized search software and ancestry searching (bibliographies) to conduct a comprehensive search of articles published from 1965 to the present. Eligible studies included those which adhered to standard disease definitions and which included population-based estimates of incidence or prevalence rates. Mean weighted incidence and prevalence rates were calculated from eligible published studies with greater weight proportionately given to larger studies. The mean rates were then applied to the U.S. Census population figures to estimate the number of persons currently afflicted with each disease and the number of new cases occurring each year in the United States. Only U.S. and European studies were used to estimate prevalence and incidence rates when there were at least six eligible studies available for a disease. When there were fewer than six studies, all available studies were included, regardless of country of origin. The number of eligible incidence and prevalence studies found in the literature varied considerably between the 24 autoimmune diseases selected. The largest number of eligible prevalence studies were conducted on multiple sclerosis (MS), rheumatoid arthritis, and systemic lupus erythematosus (SLE) (>/=23), followed by insulin-dependent diabetes (IDDM), myasthenia gravis, primary biliary cirrhosis, and scleroderma (>/=7). There were only one to four eligible studies done on 11 other diseases, and no prevalence studies on 6 diseases. Incidence studies were less frequent but the largest number of studies were conducted on IDDM (n = 37) and MS (n = 28), followed by Graves' disease/hyperthyroidism, glomerulonephritis, primary biliary cirrhosis, rheumatic fever, rheumatoid arthritis, scleroderma, and SLE (>/=9). On the other 11 diseases, there were one to six eligible studies, and no studies on 5 diseases. There were no eligible incidence or prevalence studies on Goodpasture's syndrome, idiopathic thrombocytopenia purpura, or relapsing polychondritis. Overall we estimate that 8,511,845 persons in the United States or approximately 1 in 31 Americans are currently afflicted with one of these autoimmune diseases. The diseases with the highest prevalence rates were Graves'/hyperthyroidism, IDDM, pernicious anemia, rheumatoid arthritis, thyroiditis, and vitiligo, comprising an estimated 7,939, 280 people or 93% of the total number estimated. Glomerulonephritis, MS, and SLE added an estimated 323,232 people. The prevalence of the other diseases reviewed were rare, less than 5.14/100,000. Most diseases were more common in women. From the incidence data we estimate that 237,203 Americans will develop an autoimmune disease in 1996 and that approximately 1,186,015 new cases of these autoimmune diseases occur in the United States every 5 years. Women were at 2.7 times greater risk than men to acquire an autoimmune disease. After reviewing the medical literature for incidence and prevalence rates of 24 autoimmune diseases, we conclude that many autoimmune diseases are infrequently studied by epidemiologists. As a result the total burden of disease may be an underestimate. (ABSTRACT TRUNCATED)

Acute hepatitis caused by alverine associated with anti-lamin A and C autoantibodies

We report the case of a 67-year-old woman in whom onset and regression of acute hepatitis were closely related to the time of administration and withdrawal of the smooth muscle relaxant alverine. Antinuclear antibodies were positive, and their titer followed the course of hepatitis. They presented a smooth rim-like nuclear immunofluorescence staining pattern. Immunoblot assay showed that they were directed against lamin A and lamin C. This suggests that alverine should be added to the list of drugs known to produce acute hepatitis, and that drug-induced liver injury is a possible cause of antinuclear antibodies specific for lamin A and lamin C.

Viral hepatitis in Japan: update

Viral hepatitis is defined as a hepatitis virus infection in which hepatic inflammation and necrosis lead to a characteristic feature. It is caused by at least five viral agents with specific epidemiological attributes and distinctive immunoserologic findings. The well-characterized forms are hepatitis A, B, C, D and E viruses. Recent status and the current progress of viral hepatitis in Japan are discussed in the present article.

Present status of autoimmune hepatitis in Japan--correlating the characteristics with international criteria in an area with a high rate of HCV infection. Japanese National Study Group of Autoimmune Hepatitis

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.

Establishment of a novel radioligand assay using eukaryotically expressed cytochrome P4502D6 for the measurement of liver kidney microsomal type 1 antibody in patients with autoimmune hepatitis and hepatitis C virus infection

BACKGROUND/AIMS

Liver kidney microsomal type 1 antibody (LKM1) is the diagnostic marker of autoimmune hepatitis (AIH) type 2 and is also found in patients with hepatitis C virus (HCV) infection. Cytochrome P4502D6 (CYP2D6) is the documented target antigen of LKM1 in AIH, but not in HCV infection. To compare the reactivity in the two conditions, we established a radioligand assay using eukaryotically expressed CYP2D6 as target.

METHODS

A 1.2-kb human CYP2D6 cDNA was isolated from a human liver cDNA library and subcloned into an in vitro transcription vector pSP64 Poly(A). Recombinant CYP2D6 was then produced by in vitro transcription/translation, metabolically labelled with 35S methionine and used in the immunoprecipitation assay. Antibodies that bound radiolabelled CYP2D6 were immunoprecipitated and their levels assessed as cpm. Sera from 50 LKM1-positive patients (26 with AIH; 24 with HCV infection), 128 LKM1-negative patients and 57 normal controls were tested.

RESULTS

Reactivity to 35S labelled CYP2D6 was observed in all LKM1-positive sera from patients with AIH and HCV infection, but in none of the controls. The cpm in both conditions were significantly higher than in normal controls (p<0.0001), and were correlated with the immunofluorescence titres of LKM1 (r 0.87, p<0.001 and r=0.64, p<0.001 for AIH and HCV infection, respectively). Reactivity to 35S labelled CYP2D6 was inhibited by addition of an excess of eukaryotically expressed CYP2D6.

CONCLUSIONS

CYP2D6 is a major target antigen of both AIH and HCV infection. The novel radioligand assay is highly sensitive and specific.

Autoimmune hepatitis type 2 and hepatitis C virus infection: study of HLA antigens

BACKGROUND/AIMS

Markers for hepatitis C virus are often detectable in patients suffering chronic hepatitis with liver-kidney microsomal type 1 antibodies. Several authors have suggested that two subsets of those patients can be defined: a) hepatitis C virus negative and b) hepatitis C virus positive. The aim of this work was to further analyze the possible genetic association, HLA class I and II, in these two groups of patients.

METHODS

HLA was analyzed in 49 patients. Class I was studied using a standard lymphocytotoxicity test and in class II a reverse hybridization-based test for DRB1 typing and PCR-SSO for DQB1 typing were used. Sixty healthy Spanish subjects and 39 chronic hepatitis C subjects without anti-LKM1 antibodies were used as control groups for the "a" and "b" subsets, respectively.

RESULTS

No significant association was found with class I specificities in either group. DQB1 typing showed a very significant increase of DQ2 in the "a" group (93.3% vs. 48%; RR = 15; Pc = 0.0025), and DRB1 typing from the "b" group revealed a high association with DR7 (82.3% vs. 43.6%; RR = 6; Pc = 0.0086).

CONCLUSIONS

Our studies revealed a strong association with DQ2 for the "a" group and for the first time an extremely high association with DR7 antigen for the "b" subset. Hence it is possible to establish a different genetic profile in these two patient groups.

Systemic lupus erythmatosus associated with autoimmune hepatitis two cases with novel autoantibodies to transfer RNA-related antigens

Two cases of systemic lupus erythematosus (SLE) with autoimmune hepatitis are reported. Both patients had a mild form of SLE without central nervous system or renal involvement and showed a rapid response to corticosteroid therapy. Neither of them had antibodies to mitochondria, smooth muscle, and liver/kidney microsome-1 related to autoimmune hepatitis. Instead, novel autoantibodies which react with transfer RNA-related antigen were detected. These autoantibodies could be a useful marker for classification of SLE associated with autoimmune hepatitis.

Frequency and significance of antibodies to P450IID6 protein in Japanese patients with chronic hepatitis C

BACKGROUND/AIMS

The aims of the current study were to assess the frequency and the significance of antibodies to cytochrome P450IID6 protein (anti-P450IID6) in various diseases among Japanese patients.

METHODS

Sera from 541 patients were tested by indirect immunofluorescence, and the specificity of anti-P450IID6 was ascertained by either enzyme immunoassay (ELISA) or Western blot using recombinant antigen or rat liver microsomes.

RESULTS

Anti-P450IID6 was found in only 6 of 235 patients (2.6%) with chronic active hepatitis (CAH) positive for hepatitis C virus (HCV) antibody and quantitative HCV-RNA with genotypes II and IV. The predominant epitopes on immunoblots were 66 and 50KD, a 10KD band being the newly underfined microsomal antigen. Even in the patients negative for autoantibodies to nuclear antigens (ANA) by routine indirect immunofluorescence test, various ANA were detected by the newly developed recombinant ELISA. These patients were younger, with lower gamma-globulin and IgG levels than patients with autoimmune hepatitis. Three of five patients with anti-P450IID6 responded well to interferon therapy and one received prednisone when interferon was ineffective. Interestingly, only this patient was diagnosed as definite autoimmune hepatitis according to the criteria proposed by the International Autoimmune Hepatitis Group (IAHG). The other five patients who did not satisfy the IAHG criteria might be considered as CAH-C with autoimmune features. No autoimmune hepatitis patients positive for anti-P450IID6 were identified in the current study, indicating that the variant is very rare in Japan.

CONCLUSIONS

Anti-P450IID6 in CAH-C patients in Japan is not as rare as expected. Anti-P450IID6 among Japanese patients has uncertain significance and precludes further characterization of CAH-C with autoimmune features, which might require interferon therapy.

Absence of LKM-1 antibody reactivity in autoimmune and hepatitis-C-related chronic liver disease in Sweden. Swedish Internal Medicine Liver club

BACKGROUND

Type-2 autoimmune hepatitis is a subgroup of chronic hepatitis characterized by the presence of liver/kidney microsomal autoantibodies type 1 (LKM-1). A frequent association with chronic hepatitis C suggests that hepatitis virus might trigger autoimmune reactivity. LKM-1-positive chronic hepatitis is not uncommon in southern Europe but is rarely seen in the USA and the UK. The prevalence in Scandinavia is hitherto unknown.

METHODS

We used an automated prototype LKM-1 immunometry-based assay (IMx) to detect LKM-1 antibodies in sera from 350 Swedish patients with chronic liver diseases (100 with primary biliary cirrhosis, 80 with primary sclerosing cholangitis, 100 with hepatitis C, and 70 patients with various forms of chronic hepatitis, including 36 autoimmune cases), and from 17 children with autoimmune hepatitis. Sera reactive in the IMx assay were subjected to immunofluorescence testing.

RESULTS

No clearly LKM-reactive sera were detected. Serum samples from 29 patients were borderline reactive in the IMx assay but tested negative in the confirmatory immunofluorescence test. Positive tests in the former assay were likely caused by reactivity against microsomal antigens other than LKM-1/cytochrome P450IID6.

CONCLUSIONS

LKM-1-positive type-2 autoimmune hepatitis is very rare in Sweden. Furthermore, chronic hepatitis C did not trigger this type of autoimmune reactivity in our patients, probably owing to genetic insusceptibility.

Hepatotropic viruses and autoimmunity 1997

Autoimmune hepatitis is a disease of unknown cause. Apart from genetic markers such as HLA DR3 and HLA DR4, female predominance, hypergammaglobulinaemia and characteristic autoantibodies are diagnostic hallmarks. Several viruses have been discussed to induce autoimmune hepatitis, among them all major hepatotropic viruses, Epstein-Barr virus and herpes simplex virus. It seems that herpes viruses may be responsible in at least some cases of patients with autoimmune hepatitis type 2. Furthermore, hepatotropic viruses like hepatitis C and hepatitis D virus may cause autoimmune phenomena which are similar to those in idiopathic autoimmune hepatitis. LKM-1 antibodies in hepatitis C and LKM-3 antibodies in hepatitis D may cause diagnostic problems. LKM-1 antibodies in hepatitis C are directed either against cytochrome P450 2D6 or other yet unidentified microsomal antigens. As in hepatitis C the antimicrosomal autoantibody response in hepatitis D is more heterogeneous. These LKM-3 antibodies react with several epitopes on proteins of family 1 and 2 UDP-glucuronosyltransferases (UGT). Additional autoantibodies are seen in hepatitis D virus infection. Liver diseases are models to study autoimmune disease, drug-induced and virus-induced autoimmunity in humans.

[Autoimmune hepatitis treated with cyclosporin revealed by acute hepatocellular failure]

BACKGROUND

Autoimmune hepatitis (AIH), usually chronic hepatitis, can be revealed by an acute episode of hepatic failure not easily treatable.

CASE REPORT

A 4 year-old boy presented with severe acute hepatic failure (AHF) without hypergammaglobulinemia, revealing AIH. A triple immunosuppressive treatment (prednisolone, azathioprine, ciclosporine) was started when clinical and biological signs worsened (prothrombin time 18%, factor V 32%). Liver functions significantly improved within 10 days, although complications due to intensive immunosuppression occurred (Candida septicemia).

CONCLUSION

AIH must be evocated in each case of AHF. Some observations of AIH treated with ciclosporine are published but protocols of its administration are variable: ciclosporine is used alone or associated with other drugs, in first intention or secondarily, when the classical treatment is contra-indicated or fails. Controlled studies are needed to precise ciclosporine indications in AIH and to propose the best protocol.

Non-organ specific autoantibodies in children with chronic hepatitis C

BACKGROUND/AIMS

Recent studies in adult patients have established a relationship between hepatitis C virus infection and the presence of liver-kidney microsomal autoantibody type 1 (LKM1). Conversely, little is known regarding the relationship between hepatitis C and autoimmunity in children. In this study, we investigated non-organ specific autoantibodies in 40 otherwise healthy Italian children with chronic hepatitis C.

METHODS

All but four patients included in the study were asymptomatic. Liver histology, obtained in 35, showed features ranging from minimal to mild chronic hepatitis. Autoantibodies were investigated by indirect immunofluorescence. HCV RNA was assayed by the polymerase chain reaction in 34 cases and viral genotypes were determined.

RESULTS

Antinuclear antibodies were detected in three (7.5%) cases, one with a homogeneous pattern; smooth muscle autoantibodies in seven (17.5%) cases, always with V (vessels only) specificity and LKM1 in four (10%), at titers ranging from 1:20 and 1:2560. Clinical and virologic features did not significantly differ between autoantibody positive and negative cases, although infections with HCV genotypes 1a and 2 were more frequent in LKM1-positive patients. During observation, the child with the highest LKM1 titre was unsuccessfully treated with alpha interferon but responded to steroids. Twelve LKM1 negative children were also treated with interferon and one developed low LKM1 titers concomitant with an alanine aminotransferase flare. The sera of the five LKM1-positive children with investigated by immunoblotting with a human microsomal fraction and peptide 257-269 of cytochrome P450IID6. Only the serum of the child with the highest LKM1 titers was reactive.

CONCLUSIONS

These results show that a consistent proportion of children with chronic hepatitis C circulate non-organ specific autoantibodies. The prevalence of LKM1 is greater than in adults and this could raise problems for the treatment of the disease with interferon. The analysis of LKM1 target antigens might help to identify putative cases of "true" autoimmune hepatitis with concomitant HCV infection that could benefit from steroid treatment.

Low hepatitis C viremia levels in patients with anti-liver/kidney microsomal antibody type 1 positive chronic hepatitis

BACKGROUND/AIMS

The majority of adult patients positive for anti-liver-kidney microsomal antibody are also positive for anti-hepatitis C virus and serum HCV RNA. In these patients the role played by hepatitis C virus infection in the progression of liver damage and its relationship with anti-liver-kidney microsomal antibody are, however, still a matter of debate.

METHODS

To clarify this point we have compared hepatitis C viremia in sera from 31 hepatitis C virus-related chronic hepatitis patients positive for anti-liver-kidney microsomal antibody with that of 31 patients with hepatitis C virus-related chronic hepatitis without autoantibodies using a newly developed competitive reverse transcription-polymerase chain reaction technique. Reverse transcription-polymerase chain reaction was performed using a synthetic competitor of a length similar to that of wild template (71 bp vs 86 bp).

RESULTS

The results obtained have been related to hepatitis C virus genotypes. Anti-liver-kidney microsomal antibody/anti-HCV positive patients show a median value of hepatitis C virus genome molecules (626829/ml, range 9780-25651424), significantly lower than anti-liver-kidney microsomal antibody negative/anti-HCV positive patients (10158314/ml, range 101822-67429974) (p < 0.001). No hepatitis C virus genotype was significantly associated with anti-liver-kidney microsomal antibody, although a predominance of genotype 1 (subtypes a and b) has been observed in these patients.

CONCLUSIONS

Since a low hepatitis C viremia has been observed in anti-liver-kidney microsomal antibody positive patients with disease severity comparable to that of patients without autoantibodies, it is conceivable that in them autoimmune mechanisms may cooperate with viral infection in sustaining disease activity.

Autoimmune hepatitis. Definition--classification--histopathology--immunopathogenesis

Autoimmune hepatitis (AIH) is a distinct form of acute and chronic inflammatory liver disease in which immune reactions against host antigens are found to be the major pathological mechanism. If left untreated it carries an unfavourable prognosis, and the diagnosis should be made as soon as possible. The diagnostic approach has been greatly facilitated by the establishment of a panel of marker autoantibodies, which do not define distinct therapeutic groups of AIH, but do allow a subgrouping based on differences in patient populations, some clinical features and prognosis. The characterization of organ-specific components of the liver cell surface as targets of cellular and humoral autoimmune reactions give new insights into the pathogenesis of the disease, even though the primary event triggering the disease remains to be defined. The most important disease-promoting factor seems to be a genetically determined background for autoimmunity. Without this different environmental factors, including viruses, toxins, cytokines and drugs, are only able to induce transient autoimmune phenomena and not autoimmune disease. The histopathology of AIH is in keeping with the present pathogenetic concept. Although there is no pathognomonic feature distinguishing this type of hepatitis from virus-induced forms, some distinct morphological lesions are regarded as characteristic. Clinical research on AIH has benefited greatly from observations of experimental AIH in mice. Recognition of the critical role of autoreactive T-lymphocytes in the pathogenesis and the observation of spontaneous recovery from AIH in the animal model associated with antigen-specific and antigen-non-specific T-cell suppression have made basic contributions to our improved understanding of the natural course of AIH in humans.

Diagnosis and therapy of autoimmune liver disease

The diagnostic criteria for autoimmune hepatitis have been codified by international consensus. Standardized clinical criteria or a scoring system that grades each relevant feature secure the diagnosis. Three types of autoimmune hepatitis have been proposed based on immunoserologic markers, but various forms exist. Multiple autoantibodies have diagnostic capability, but their clinical relevancy remains uncertain. Prednisone alone or in combination with azathioprine is effective therapy in most patients. Poor outcomes justify alternative strategies and evaluation of promising new drugs.

Frequency and significance of antibodies to asialoglycoprotein receptor in type 1 autoimmune hepatitis

Antibodies to asialoglycoprotein receptor have diagnostic specificity for autoimmune hepatitis, but it is uncertain if they are complementary or redundant markers of the disease. Our aims were to assess their frequency and significance in type 1 autoimmune hepatitis and determine their contribution to the evaluation of these patients. Sera from 54 well-characterized patients were evaluated for antibodies to asialoglycoprotein receptor by a radioimmunofiltration assay based on rabbit-derived protein. Forty-four patients (82%) were seropositive. Seropositive patients were distinguished from seronegative counterparts by having higher serum gamma globulin (3.7 +/- 0.2 g/dl vs 2.3 +/- 0.3 g/dl, P = 0.0007) and immunoglobulin G levels (3707 +/- 179 mg/dl vs 2203 +/- 263 mg/dl, P = 0.0005) at presentation and a greater frequency of relapse after drug withdrawal (88% vs 33%, P = 0.01). Seropositivity for smooth muscle and/or antinuclear antibodies did not define treatment outcomes and antinuclear antibodies occurred less frequently than the other markers. Concurrent testing for antibodies to asialoglycoprotein receptor and smooth muscle identified all patients. We conclude that antibodies to asialoglycoprotein receptor are common in type 1 autoimmune hepatitis and they identify patients with a high frequency of relapse after corticosteroid withdrawal. Concurrent testing for these antibodies and smooth muscle antibodies has the same diagnostic sensitivity as testing for antinuclear and smooth muscle antibodies but a greater prognostic implication.