Autoantibodies in the diagnosis and management of liver disease

Seronegative autoimmune hepatitis in children : A real diagnostic challenge

BACKGROUND AND AIM

Classical autoimmune hepatitis (AIH) is characterized by the presence of conventional autoantibodies (anti-smooth muscle, antinuclear and anti-liver-kidney-microsomal antibodies). The absence of such autoantibodies in some patients does not preclude AIH diagnosis or the need for its treatment. This group of patients was termed seronegative AIH. Whether non-conventional autoantibodies can identify this group of patients is still elusive. We aimed to study the prevalence of seronegativity of conventional autoantibodies and the occurrence of non-conventional autoantibodies in children with AIH.

METHODS

In this study, 55 children with AIH were investigated for non-conventional autoantibodies (anti-neutrophil cytoplasmic antibodies, antibodies to soluble liver antigen, anti-tissue transglutaminase and antiplatelet antibodies). All the patients received immunosuppressive therapy and were assessed for treatment response.

RESULTS

Of the patients 44 had classical AIH (type 1, 70.09%, type 2, 9.09%) and 20% were seronegative. The four studied non-conventional autoantibodies occurred in four patients, one for each. All non-conventional autoantibodies were exclusively associated with type 1 AIH. The clinical profile, ultrasonographic findings, liver biochemistry and histopathological findings were comparable in the classical and seronegative AIH. The majority of patients with classical (72.7%) and seronegative (54.5%) AIH were treatment responders.

CONCLUSION

Seronegative AIH represents a substantial percentage of pediatric patients diagnosed with AIH. They were even negative for non-conventional autoantibodies. Furthermore, apart from autoantibodies, seronegative AIH is almost indistinguishable from the classical AIH and the majority of patients were treatment responders. This favorable response to immunosuppression deserves sustainable efforts for considering such a diagnosis and start therapy to halt disease progression is worthwhile.

Autoimmunity and allergy control in adults submitted to complete thymectomy early in infancy

The contribution of the decline in thymic activity for the emergence of autoimmunity is still debatable. Immune-competent adults submitted to complete thymectomy early in life provide a unique model to address this question. We applied here strict criteria to identify adults lacking thymic activity based on sjTREC levels, to exclude thymic rebound and/or ectopic thymuses. In agreement, they featured severe naïve CD4 T-cell depletion and contraction of T-cell receptor diversity. Notwithstanding this, there was neither increased incidence of autoimmune disease in comparison with age-matched controls nor significant changes in their IgG/IgA/IgM/IgE autoreactivity profiles, as assessed through extensive arrays. We reasoned that the observed relative preservation of the regulatory T-cell compartment, including maintenance of naïve regulatory CD4 T-cells, may contribute to limit the emergence of autoimmunity upon thymectomy. Our findings have implications in other clinical settings with impaired thymic activity, and are particularly relevant to studies of autoimmunity in ageing.

Diagnosis and Management of Autoimmune Hepatitis: Current Status and Future Directions

Autoimmune hepatitis is characterized by autoantibodies, hypergammaglobulinemia, and interface hepatitis on histological examination. The features lack diagnostic specificity, and other diseases that may resemble autoimmune hepatitis must be excluded. The clinical presentation may be acute, acute severe (fulminant), or asymptomatic; conventional autoantibodies may be absent; centrilobular necrosis and bile duct changes may be present; and the disease may occur after liver transplantation or with features that suggest overlapping disorders. The diagnostic criteria have been codified, and diagnostic scoring systems can support clinical judgment. Nonstandard autoantibodies, including antibodies to actin, α-actinin, soluble liver antigen, perinuclear antineutrophil antigen, asialoglycoprotein receptor, and liver cytosol type 1, are tools that can support the diagnosis, especially in patients with atypical features. Prednisone or prednisolone in combination with azathioprine is the preferred treatment, and strategies using these medications in various doses can ameliorate treatment failure, incomplete response, drug intolerance, and relapse after drug withdrawal. Budesonide, mycophenolate mofetil, and calcineurin inhibitors can be considered in selected patients as frontline or salvage therapies. Molecular (recombinant proteins and monoclonal antibodies), cellular (adoptive transfer and antigenic manipulation), and pharmacological (antioxidants, antifibrotics, and antiapoptotic agents) interventions constitute future directions in management. The evolving knowledge of the pathogenic pathways and the advances in technology promise new management algorithms.

Diagnosis and management of autoimmune hepatitis

Autoimmune hepatitis is characterized by increased serum aminotransferase levels, autoantibodies, hypergammaglobulinemia, and interface hepatitis. Presentation can be acute, severe (fulminant), asymptomatic, or chronic. Diagnosis requires multiple findings and exclusion of similar diseases. Treatment with prednisone or prednisolone with azathioprine is recommended. Budesonide with azathioprine has normalized laboratory test with few side effects, but histologic resolution, durability of response, and target population are uncertain. Progressive worsening, incomplete improvement, drug intolerance, and relapse after drug withdrawal are suboptimal outcomes. Calcineurin inhibitors and mycophenolate mofetil are salvage agents in small series and liver transplantation is effective for liver failure.

PR3-ANCA: a promising biomarker in primary sclerosing cholangitis (PSC)

Background and Aims

The only recognized biomarker for primary sclerosing cholangitis (PSC) is atypical anti-neutrophil cytoplasmic antibodies (aANCA), which, in addition to having low sensitivity and specificity, is an indirect immunofluorescence (IIF) test lacking the advantages of high throughput and objectivity. Recent reports have shown that antibodies to proteinase-3 (PR3-ANCA) might add diagnostic value in inflammatory bowel disease (IBD), specifically in ulcerative colitis (UC). As PSC is associated with IBD, the objective of this study was to evaluate the frequency and clinical significance of PR3-ANCA in a large cohort of patients.

Methods

A total of 244 PSC and 254 control [autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), hepatitis C viral infection (HCV), hepatitis B viral infection (HBV), and healthy controls] sera and their clinical correlations were retrospectively analyzed for PR3-ANCA determined by ELISA and a new chemiluminescence immunoassay (CIA). Testing was also performed for aANCA by IIF.

Results

When measured by CIA, PR3-ANCA was detected in 38.5% (94/244) of PSC patients compared to 10.6% (27/254) controls (p<0.0001). By ELISA, PR3-ANCA was detected in 23.4% (57/244) of PSC patients compared to 2.7% (6/254) controls (p<0.0001). PR3-ANCA in PSC patients was not associated with the presence or type of underlying IBD, and, in fact, it was more frequent in Crohn's disease (CD) patients with PSC than previously reported in CD alone. PR3-ANCA in PSC measured by CIA correlated with higher liver enzymes.

Conclusion

PR3-ANCA is detected in a significant proportion of PSC patients compared to other liver diseases including PBC and AIH. PR3-ANCA is associated with higher liver enzyme levels in PSC, and is not solely related to underlying IBD.

Anti-ribosomal P protein: a novel antibody in autoimmune hepatitis

BACKGROUND

Autoantibodies to ribosomal P proteins (anti-rib P) are specific serological markers for systemic lupus erythematosus (SLE) and are associated with liver involvement in this disease. The similarity in autoimmune background between autoimmune hepatitis (AIH) and SLE-associated hepatitis raises the possibility that anti-rib P antibodies might also have relevance in AIH.

AIMS

To evaluate the frequency and clinical significance of anti-rib P antibodies in a large AIH cohort.

METHODS

Sera obtained at diagnosis of 96 AIH patients and of 82 healthy controls were tested for IgG anti-ribosomal P protein by ELISA. All of the sera were also screened for other lupus-specific autoantibodies, three patients with the presence of anti-dsDNA (n = 1) and anti-Sm (n = 2) were excluded.

RESULTS

Moderate to high titres (>40 U) of anti-rib P antibody were found in 9.7% (9/93) of the AIH patients and none of the controls (P = 0.003). At presentation, AIH patients with and without anti-rib P antibodies had similar demographic/clinical features, including the frequency of cirrhosis (44.4 vs. 28.5%, P = 0.44), hepatic laboratorial findings (P > 0.05). Importantly, at the final observation (follow-up period 10.2 ± 4.9 years), the AIH patients with anti-rib P had a significantly higher frequency of cirrhosis compared with the negative group (100 vs. 60%, P = 0.04).

CONCLUSION

The novel demonstration of anti-rib P in AIH patients without clinical or laboratory evidence of SLE suggests a common underlying mechanism targeting the liver in these two diseases. In addition, this antibody appears to predict the patients with worse AIH prognoses.

Funktions- und Laboruntersuchungen

Zur Analyse abgeatmeter Gase muss endexspiratorische Luft gewonnen werden, ohne Vermischung mit frühexspiratorischer Luft (sonst Korrektur mit Messung des CO2-Partialdrucks, s. unten). Ältere Kinder blasen nach Anhalten der Atmung über 15 s durch tiefe Ausatmung über einen Strohhalm endexspiratorische Luft in ein Glasröhrchen, das dann luftdicht verschlossen wird (Vacutainer), oder über ein Mundstück oder eine Maske direkt in ein H2-Messgerät oder in Beutel. Bei Säuglingen und Kleinkindern kann mit einer Maske oder einer Sonde, die bis zum nasopharyngealen Übergang vorgeschoben wird, mit einer Spritze atemsynchron exspiratorische Luft abgesaugt und in Vacutainer oder direkt in das Messgerät eingegeben werden. In Vacutainern sind Proben über mehr als 30 Tage stabil und können auch zur Analyse verschickt werden.

Detection of anti-SP100 antibodies in primary biliary cirrhosis. Comparison of ELISA and immunofluorescence

Primary biliary cirrhosis (PBC) is, which a chronic, autoimmune liver disease. Some patients have antinuclear antibodies anti-Sp100, which are considered to be disease-specific. We compared an enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF) for detection of anti-Sp100. The sensitivity of anti-Sp100 determined by ELISA and IIF was 44% and 34%, respectively. Specificity was 99% for ELISA and 98% for IIF, respectively. The positive and negative predictive value (PPV, NPV) for anti-Sp100 determined by ELISA were 98%, 60% and 95%, 56% for IIF respectively. IIF required substantial experience in interpreting subjective patterns, whereas ELISA was more sensitive, cheaper, less time consuming, and produced clear-cut quantitative results.

TRAF1 gene polymorphism correlates with the titre of Gp210 antibody in patients with primary biliary cirrhosis

Background. Polymorphisms of TRAF1 (Tumor necrosis factor receptor-associated factor 1) are associated with rheumatoid arthritis (RA). Whether TRAF1 polymorphisms confer increased risk for primary biliary cirrhosis (PBC), an autoimmune liver disease which can co-exist with RA, is unknown. Aim of the Study. To assess the frequency of the RA-conferring susceptibility TRAF1 polymorphisms rs3761847 and rs2900180 in a cohort of PBC patients. The association of TRAF1 polymorphisms with clinical features and autoantibody markers was also analyzed. Methods. We studied 179 PBC patients and 300 controls. Samples were genotyped for TRAF1 gene polymorphisms by real-time PCR. Autoantibodies were tested by ELISA. Results. The frequency of rs3761847 and rs2900180 polymorphisms did not differ between patients and controls. Laboratory or clinical features were not associated with specific polymorphisms. Gp210 autoantibody titres were conspicuously higher among GG homozygotes of rs3761847 as compared with AA homozygotes (P = 0.02). In contrast, antichromatin titers were higher in AA compared to GG rs3761847 homozygotes (P = 0.04). Rheumatoid factor IgG titres were significantly higher in rs2900180 TT homozygotes than CC homozygotes (P = 0.02). Conclusions. TRAF1 polymorphisms occur with the similar frequency in PBC patients and in the general population, but their presence is probably involved in the regulation of specific PBC-related autoantibodies.

Autoantibody-negative autoimmune hepatitis

Autoimmune hepatitis has a variable clinical phenotype, and the absence of conventional autoantibodies does not preclude its diagnosis or need for treatment. The goals of this review are to describe the frequency and nature of autoantibody-negative autoimmune hepatitis, indicate its outcome after corticosteroid treatment, and increase awareness of the diagnosis in patients with unexplained acute and chronic hepatitis. The frequency of presumed autoantibody-negative autoimmune hepatitis in patients with acute and acute severe presentations is ≤7%, and its frequency in patients with chronic presentations is 1-34%. Patients with acute presentations can have normal serum γ-globulin levels, centrilobular zone 3 necrosis, and low pre-treatment international diagnostic scores. Liver tissue examination is essential for the diagnosis, and hepatic steatosis can be a co-morbid feature. The comprehensive international scoring system can support but never override the clinical diagnosis pre-treatment, and non-standard serological markers should be sought if the clinical diagnosis is uncertain or the diagnostic score is low. A 3-month treatment trial with corticosteroids should be considered in all patients, regardless of the serological findings, and improvements have occurred in 67-87% of cases. Autoantibody-negative autoimmune hepatitis may be associated with an autoantibody outside the conventional battery; it may have a signature autoantibody that is still undiscovered, or its characteristic autoantibodies may have been suppressed or have a delayed expression. The pathogenic mechanisms are presumed to be identical to those of classical disease. Autoantibody-negative autoimmune hepatitis is an infrequent but treatable disease that must be considered in unexplained acute and chronic hepatitis.

Cryptogenic chronic hepatitis and its changing guise in adults

Cryptogenic chronic hepatitis is a disease that is unexplained by conventional clinical, laboratory and histological findings, and it can progress to cirrhosis, develop hepatocellular carcinoma, and require liver transplantation. The goals of this review are to describe the changing phenotype of cryptogenic chronic hepatitis in adults, develop a diagnostic algorithm appropriate to current practice, and suggest treatment options. The frequency of cryptogenic hepatitis is estimated at 5.4%. Cryptogenic cirrhosis is diagnosed in 5-30% of patients with cirrhosis, and it is present in 3-14% of adults awaiting liver transplantation. Nonalcoholic fatty liver disease has been implicated in 21-63% of patients, and autoimmune hepatitis is a likely diagnosis in 10-54% of individuals. Viral infections, hereditary liver diseases, celiac disease, and unsuspected alcohol or drug-induced liver injury are recognized infrequently in the current cryptogenic population. Manifestations of the metabolic syndrome heighten the suspicion of nonalcoholic fatty liver disease, and the absence of hepatic steatosis does not discount this possibility. The diagnostic scoring system of the International Autoimmune Hepatitis Group can support the diagnosis of autoimmune hepatitis in some patients. Certain genetic mutations may have disease-specificity, and they suggest that some patients may have an independent and uncharacterized disease. Corticosteroid therapy is effective in patients with autoimmune features, and life-style changes and specific therapies for manifestations of the metabolic syndrome are appropriate for all obese patients. The 1- and 5-year survivals after liver transplantation have ranged from 72-85% to 58-73%, respectively.

Resistin is associated with breach of tolerance and anti-nuclear antibodies in patients with hepatobiliary inflammation

Resistin is a cysteine-rich protein, which is abundantly expressed at the site of inflammation, and acts as a regulator of the NF-kB-dependent cytokine cascade. The aim of this study was to evaluate resistin levels in relation to inflammatory mediators, disease phenotype and autoantibody status in a spectrum of pathological conditions of the gastrointestinal tract. Resistin levels were measured with an ELISA in sera originated from 227 patients and 40 healthy controls (HC). Fifty patients diagnosed with non-alcoholic fatty liver disease (NAFLD), 53 ulcerative colitis (UC), 51 Crohn's disease (CD), 46 autoimmune hepatitis (AIH) and 27 primary sclerosing cholangitis (PSC) were included. The sera were analysed with respect to biochemical parameters of systemic inflammation and liver function and to the presence of antibodies to nuclear antigens (ANA), mitochondria (AMA) and smooth muscle (SMA). Compared with HC, resistin levels were raised in AIH (P = 0.017) and PSC (P = 0.03); compared with NAFLD, levels were elevated in CD (P = 0.041), AIH (P < 0.001) and PSC (P < 0.001). Patients with elevated levels of resistin were more often treated with corticosteroids, but no difference was found between active disease and clinical remission. Resistin levels were significantly higher in ANA-positive individuals compared with ANA-negative (P = 0.025). Resistin levels were directly correlated with IL-6 (r = 0.30, P = 0.02) and IL-8 (r = 0.51, P < 0.001). Elevated levels of resistin were prominent in patients with hepatobiliary inflammation and were associated with breach of self-tolerance, i.e. ANA positivity. Thus, we propose that resistin may be an important marker of disease severity in autoantibody-mediated gastrointestinal inflammatory diseases.

Hepatocyte cytotoxicity is facilitated by asialoglycoprotein receptor

It has been recently identified that hepatocytes can act as cytotoxic effectors and can kill contacted cells by way of CD95 ligand-CD95 and perforin-dependent pathways. However, it remained unknown whether hepatocyte-mediated cell killing is indiscriminant or is directed toward targets with particular cell surface characteristics, as well as whether hepatocytes have the capacity to directly eliminate contacted lymphocytes. In this study, we found that desialylation of surface glycoproteins significantly augments cell susceptibility to hepatocyte-mediated killing. Using asialofetuin as a competitive ligand, and by silencing gene transcription with specific small interfering RNA, we found that the asialoglycoprotein receptor (ASGPR) is involved in hepatocyte recognition of cells predestined for killing, including activated autologous T lymphocytes.

CONCLUSION

Hepatocytes are constitutively equipped in the molecular machinery capable of eliminating cells brought into contact with their surface in a manner that is reliant, at least in part, upon the recognition of terminally desialylated glycoproteins by hepatocyte ASGPR. The study adds a new dimension to the physiological role of hepatic ASGPR and provides further evidence that hepatocytes can actively contribute to intrahepatic immune regulation and moderation of the local inflammatory response.

Performance parameters of the conventional serological markers for autoimmune hepatitis

BACKGROUND

Autoimmune hepatitis is defined by a conventional battery of autoantibodies that may also be present in other liver diseases.

AIMS

To define the performance parameters of the conventional autoantibodies for autoimmune hepatitis, determine the diagnostic implications of simultaneous autoantibody production, and assess the performances of serological assays based on indirect immunofluorescence and enzyme immunoassay.

METHODS

In this study, 265 adults satisfying codified criteria for autoimmune hepatitis and 342 adults who satisfied conventional diagnostic criteria for another chronic liver disease were each assessed for the conventional autoantibodies.

RESULTS

Antinuclear antibodies, smooth muscle antibodies, and antibodies to liver kidney type 1 had sensitivities of only 32, 16, and 1%, respectively, for the diagnosis of autoimmune hepatitis, and their diagnostic accuracy ranged from 56 to 61%. The combination of antinuclear antibodies and smooth muscle antibodies at presentation had superior sensitivity (43%), specificity (99%), positive (97%) and negative (69%) predictabilities, and diagnostic accuracy (74%) than each marker alone. The occurrence of multiple autoantibodies was lower in other chronic liver diseases than in autoimmune hepatitis (8% versus 51%, p < 0.000001). The enzyme immunoassay for antinuclear antibodies had an accuracy that was not discriminative for autoimmune hepatitis (p = 0.06).

CONCLUSIONS

Isolated autoantibodies have a low diagnostic accuracy for autoimmune hepatitis. Concurrent antinuclear antibodies and smooth muscle antibodies have superior performance parameters. The enzyme immunoassay for antinuclear antibodies performs less well than the assay based on indirect immunofluorescence.

HLA-DRB1 as a risk factor in children with autoimmune hepatitis and its relation to hepatitis A infection

Background

The human leukocyte antigens (HLAs) are proteins found in the membranes of nearly all nucleated cells. People with certain HLA antigens are more likely to develop certain autoimmune diseases. The aim of this study was to determine the frequency of HLA-DRB1 in children with autoimmune hepatitis (AIH) as a risk factor for occurrence, its relation to preceding hepatitis A infection and treatment outcome.

Subjects and methods

25 children with AIH were subjected to HLA-DRB 1 typing performed by sequence specific oligonucleotide probe technique and compared to HLA-DRB1 found in 548 normal populations.

Results

The most frequent alleles found in our children with AIH were HLA-DRB1*13 (36%), HLA-DRB1*04 (18%) and HLA-DRB1*03 (14%). HLA-DRB1*13 was significantly more frequent in AIH patients compared to controls. In type I AIH patients HLA-DRB1*13 was the most frequent allele (32.4%), followed by HLA-DRB1*04 in (20.6%) and HLA-DRB1*03 in (14.7%), While in type II, the most frequent alleles were HLA-DRB1*13 in (40%), HLA-DRB1*07 (20%) and HLA-DRB1*15 in (20%). HLA-DRB1*12 was significantly more frequent in AIH patients with positive Hepatitis A IgM than in patients with negative hepatitis A IgM. No statistically significant difference between partial responders and complete responders to treatment as regards HLA-DRB1 subtypes.

Conclusion

It is concluded from the previous study that HLA-DRB1*13 may be a susceptibility allele for the occurrence of autoimmune hepatitis in our population. HLA-DRB1*07 and HLA-DRB1*15 may be susceptibility alleles for occurrence of autoimmune hepatitis type 2. HLA-DRB1*12 association with AIH in patients triggered by hepatitis A needs further studies.

Clinical and biologic importance of F-actin autoantibodies in HCV monoinfected and HCV-HIV coinfected patients

The purpose of this study was to evaluate the relationship between serum filamentous (F)-actin antibody titers and severity of hepatitis present in hepatitis C virus (HCV)-infected patients. Liver biopsy samples from 18 HCV monoinfected and 20 HCV-HIV coinfected patients were graded with respect to the degree of hepatitis activity and intensity of plasma cell infiltration using MUM-1 and CD138 immunostains. Of the 38 HCV-infected patients, 6 (16%) had F-actin antibody titers in excess of 30 enzyme-linked immunosorbent assay units. We found a positive trend between serum F-actin antibody levels and the mean number of plasma cells present in the portal tracts of patients with HCV infection (r = 0.31; P = .06) and a significant association between these factors in HCV-HIV coinfected patients (r = 0.64; P = .002). Our data suggest that elevated serum F-actin antibody titers are commonly encountered in HCV-infected patients and may reflect more active inflammation in liver biopsy samples, similar to autoimmune hepatitis.

The role of autoantibodies as diagnostic markers of autoimmune hepatitis

Autoantibody testing is the first step towards the diagnosis of autoimmune hepatitis, and it is essential in the evaluation of acute and chronic hepatitis of undetermined cause and allograft dysfunction following liver transplantation. A standard diagnostic repertoire has been promulgated, and other autoantibodies are emerging that may have prognostic value. Supplemental autoantibodies may prove useful in assessing patients who lack the standard markers or who are distinctive among those with conventional markers. Serologic testing will improve as assays are standardized by serum exchange workshops, core diagnostic batteries are codified and promulgated, and markers emerge that are tightly associated with pathogenic mechanisms, and closely reflect disease activity and outcome.

Markers of autoimmune liver diseases in postmenopausal women with osteoporosis

INTRODUCTION

Osteoporosis is a common complication of chronic liver diseases. However, there is limited information about autoimmune liver diseases as a factor of secondary osteoporosis. Therefore, we aimed to investigate the autoantibodies of autoimmune liver diseases in patients with osteoporosis.

METHODS

One hundred fifty female patients with postmenopausal osteoporosis were included. Bone mineral density was measured by dual energy X-ray absorptiometry. We analysized autoantibodies including antinuclear antibodies, liver membrane antibodies, anti-liver/kidney microsomal autoantibodies1, liver-specific protein, antismooth muscle antibodies, and anti-mitochondrial antibodies by indirect immunofluorescence. Serum was assayed for the levels of aminotransferases.

RESULTS

The mean age of the patients was 63,13 ± 8,6 years. The mean values of L1-L4 T-scores and femur total T-scores were -3,08 ± 0,58 and -1,53 ± 0,81, respectively. Among the 150 patients with osteoporosis, 14 (9.3%) were antinuclear antibodies, four (2.7%) were liver membrane antibodies, three (2.0%) were anti-liver/kidney microsomal autoantibodies1, and two (1.3%) were liver-specific protein positive. None of the patients had anti-mitochondrial antibodies or smooth muscle antibodies positivity. The mean values of levels of aminotransferases were within normal range.

CONCLUSIONS

The presence of liver membrane antibodies, liver-specific protein, and anti-liver/kidney microsomal autoantibodies1 has permitted us to see that there may be some suspicious clues of autoimmune liver diseases in patients with osteoporosis as a secondary risk factor. On the other hand, there is a need for comprehensive studies with a larger sample size and studies designed to compare the results with a normal population to understand the clinical importance of our findings.

Value of autoantibody analysis in the differential diagnosis of chronic cholestatic liver disease

BACKGROUND & AIMS

It is challenging to diagnose patients with chronic cholestatic liver diseases when all the classic criteria are not fulfilled. We evaluated the performance of the recently developed MIT3-based enzyme-linked immunosorbent assay (ELISA), which detects antimitochondrial autoantibodies (AMAs), together with ELISAs for other autoimmune liver disease-related antibodies in patients with chronic cholestatic liver disease.

METHODS

Sera from 281 patients with chronic cholestatic conditions, including primary biliary cirrhosis (PBC), primary sclerosing cholangitis, AMA-positive autoimmune hepatitis, and "undetermined cholangiopathy" were tested for the following PBC-associated autoantibodies: anti-gp210, anti-sp100, conventional anti-M2, anti-M2 (MIT3) IgG, anti-M2 (MIT3) IgA, as well as anti-centromere, anti-soluble liver antigen, and anti-chromatin.

RESULTS

Of 57 patients with PBC who were AMA-negative by conventional M2 ELISA, 14 were found to be AMA-positive by the MIT3-IgG assay. Furthermore, on the basis of the data from 3 tests (MIT3-IgG, gp210, and sp100), PBC was confirmed in 20 of 57 (35%) patients diagnosed with AMA-negative PBC. We confirmed that sp100 and gp210 antibodies were detected only in patients with PBC and AMA-positive autoimmune hepatitis, whereas gp210 was detected more frequently in patients known to have had a poor outcome. Of the 11 patients with an undetermined cholangiopathy, 3 (27%) tested positive for PBC with the MIT3-IgG assay. In contrast to previous findings, anti-centromere antibodies were not found to be associated with poor outcome in PBC.

CONCLUSIONS

ELISAs for AMAs and antinuclear antibodies are useful in diagnosis and prognosis of patients with features of PBC who lack conventional AMA and in patients with a cholangiopathy of undetermined etiology.

Study of nonstandard auto-antibodies as prognostic markers in auto immune hepatitis in children

Background

Antibodies to chromatin and soluble liver antigen have been associated with severe form of autoimmune hepatitis and/or poor treatment response and may provide guidance in defining subsets of patients with different disease behaviors. The major clinical limitation of these antibodies is their lower individual occurrence in patients with autoimmune hepatitis.

Aim

To estimate the value of detection of these non-standard antibodies in autoimmune hepatitis as prognostic markers.

Methods

Both antibodies were tested by enzyme immunoassay in 20 patients with autoimmune hepatitis.

Results

Antibodies to soluble liver antigen were not detected in any of our patients. On the other hand anti chromatin antibodies were present in 50% (10/20). Antibodies to chromatin occurred more commonly in females than males (8/14 versus 2/6). Of the 14 patients who relapsed 8(57%) had antichromatin antibodies while they were present in only 2 out of 6(33.3%) non relapsers. Antichromatin antibodies were found more in patients with antinuclear (3/4) and anti smooth muscle antibodies (9/13) more than in those with liver kidney microsomal antibodies (1/4) and those seronegative (1/4) i.e. they were +ve in patients with type I (8/12(66.6%)) more than those with type II (1/4(25%)) and those seronegative (1/4(25%)). Antibodies to chromatin are associated with high levels of γ globulin but yet with no statistical difference between seropositive and seronegative counterparts (p = 0.65).

Conclusion

Antibodies to chromatin may be superior than those to soluble liver antigen in predicting relapse and may be useful as prognostic marker. Further studies with larger number of patients and combined testing of more than one antibody will improve the performance parameters of these antibodies and define optimal testing conditions for them before they can be incorporated into management algorithms that project prognosis.

Nonstandard Antibodies as Prognostic Markers in Autoimmune Hepatitis

BACKGROUND

Antibodies to actin, chromatin, soluble liver antigen/liver pancreas and liver cytosol type 1 have been ascribed prognostic value in autoimmune hepatitis.

AIM

Evaluate the performance parameters of these nonstandard autoantibodies and determine the critical battery for clinical application.

METHODS

All antibodies were tested concurrently by enzyme immunoassay in 106 patients who had reached a treatment outcome. Tests were repeated in 149 serum samples obtained later to assess durability of the findings.

RESULTS

Antibodies to chromatin and soluble liver antigen/liver pancreas were superior to the other markers in predicting relapse. Patients with antibodies to chromatin and/or soluble liver antigen/liver pancreas relapsed more frequently than patients without these markers (100 versus 79%, p < 0.0003). Maximum sensitivity and predictability for relapse required combined testing, and they were 54 and 60%, respectively. Antibody status remained stable in 60% of patients during 127 +/- 9 months of follow-up, and antibodies to soluble liver antigen/liver pancreas were less labile than antibodies to chromatin (frequency of status change, 4 versus 22%). None of the antibodies were associated with treatment failure, death from hepatic failure or requirement for liver transplantation.

CONCLUSIONS

Antibodies to chromatin and soluble liver antigen/liver pancreas are associated with relapse after corticosteroid withdrawal, and they may be useful prognostic markers. Combined testing improves but does not eliminate deficiencies in sensitivity, predictability and durability.

Atypical p-ANCA in PSC and AIH: a hint toward a "leaky gut"?

Primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH) are enigmatic chronic inflammatory diseases of the liver, which are frequently associated with chronic inflammatory bowel diseases. Both types of liver disease share various distinct autoantibodies such as atypical perinuclear antineutrophil cytoplasmic antibodies (p-ANCA), and thus are considered autoimmune disorders with atypical features. The discovery that atypical p-ANCA recognize both tubulin beta isoform 5 in human neutrophils and the bacterial cell division protein FtsZ has renewed the discussion on the potential role of microorganisms in the pathogenesis of both diseases. In this paper, we review the evidence for microbial infection in PSC and AIH and discuss new concepts how cross-recognition between microbial antigens in the gut and host components by the immune system along with stimulation of pattern recognition receptors might give rise to chronic hepatic inflammatory disorders with features of autoimmunity.

Serologic markers do not predict histologic severity or response to treatment in patients with autoimmune hepatitis

BACKGROUND & AIMS

Autoimmune hepatitis (AIH) is characterized by the presence of circulating autoantibodies, hypergammaglobulinemia, necroinflammatory histology, and a response to immunosuppressive drugs. The goal of this retrospective study was to determine whether the presence of antinuclear antibodies (ANAs) or anti-smooth muscle antibodies (ASMAs) in patients with AIH correlated with clinical presentation, histologic findings, or response to immunosuppressive therapy.

METHODS

Fifty-two patients diagnosed with AIH, on the basis of the revised scoring system of International Autoimmune Hepatitis group, were reviewed. Data on age, gender, aminotransferase levels, autoantibody titers, treatment regimens, and response to treatment were recorded. Seropositivity was defined as ANA >1:40 or ASMA >1:40. Percutaneous liver biopsies obtained at the initial presentation were reviewed.

RESULTS

Forty-two patients with AIH (81%) were seropositive, and 10 (19%) were seronegative. Both groups were similar with respect to demographics, treatment regimens, and response to therapy. Histologic parameters were similar among the 2 groups, including portal and lobular inflammation, piecemeal necrosis, and centrilobular necrosis. There were no significant differences in aminotransferase levels at diagnosis or after treatment.

CONCLUSIONS

The prevalence of ANAs or ASMAs did not correlate with the clinical or histologic severity of AIH at diagnosis. Furthermore, there was no correlation between antibody status and response to immunosuppressive therapy. Therefore, patients who meet the diagnosis of AIH on the basis of the revised scoring system of International Autoimmune Hepatitis Group should be given immunosuppressive therapy, regardless of antibody status.

Genetic factors affecting the occurrence, clinical phenotype, and outcome of autoimmune hepatitis

Autoimmune hepatitis is a polygenic disorder of unknown cause in which the genetic risk factors that affect occurrence, clinical phenotype, severity, and outcome still are being clarified. The susceptibility alleles in white North American and northern European patients reside on the DRB1 gene, and they are DRB1*0301 and DRB1*0401. These alleles encode a 6 amino acid sequence at positions 67-72 in the DRbeta polypeptide chain of the class II molecules of the major histocompatibility complex. This sequence is associated with susceptibility, and lysine at position DRbeta71 is the key determinant. Molecular mimicry between foreign and self-antigens may explain the loss of self-tolerance and the occurrence of concurrent immune diseases in anatomically distant organs. Disease severity is associated with the number of alleles encoding lysine at DRbeta71 (gene dose) and the number of polymorphisms, including those of the tumor necrosis factor-alpha gene, cytotoxic T lymphocyte antigen-4 gene, and tumor necrosis factor-receptor superfamily gene, that can modify the immune response. Individuals in different geographic regions may have different susceptibility alleles that reflect indigenous triggering antigens, and these may provide clues to the etiologic agent. Knowledge of the genetic predispositions for autoimmune hepatitis may elucidate pathogenic mechanisms, identify etiologic agents, characterize susceptible populations, foresee outcomes, and target new therapies. These lessons may be applicable to autoimmune disease in general.

Overlap syndromes with autoimmune hepatitis in chronic cholestatic liver diseases

Conditions exhibiting features of two different autoimmune liver diseases are commonly designated overlap syndromes, although there is no current agreement on what constitutes an overlap syndrome or specific diagnostic criteria. As in the classic autoimmune liver diseases, such as autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC), the etiology is unknown but presumed to be related to alterations of immune regulation. Distinction of these clinical entities is important for management as outcomes may differ from outcomes of patients with diagnosis of classic autoimmune liver diseases. Due to their presumed rarity, no large therapeutic trials are available and treatment of overlap conditions is empirical and based upon extrapolation of data from the primary autoimmune liver diseases. PBC-AIH overlap is the most frequently described overlap syndrome and may be associated with a poor prognosis. This may represent an important and unrecognized cause of resistance to ursodeoxycholic acid in patients with PBC. PSC-AIH overlap is less commonly reported. Prognosis may be better than in patients with PSC alone; however, worse than in patients with AIH alone. Further studies are needed for determining diagnosis, natural history and optimal therapeutic strategies of overlap syndromes of autoimmune liver disease.

The significance of autoantibodies and immunoglobulins in acute liver failure: a cohort study

BACKGROUND/AIMS

The cause of cryptogenic ('seronegative') acute liver failure (ALF) is unknown; the presence of non-organ specific autoantibodies (NOSA) may indicate an autoimmune pathogenesis. We investigated the prevalence of autoimmune features including antibodies to soluble liver antigen (anti-SLA) determined by Radioligand assay (RLA) in ALF patients.

METHODS

The prevalence and relationship to the immunoglobulin (Ig) response of NOSA and anti-SLA were determined in 73 ALF patients of different causes. Patients were scored using the revised system for diagnosis of autoimmune hepatitis (AIH).

RESULTS

Autoantibodies were present in 23 (32%) patients; 16 had anti-SLA, 6 ANA, 4 ASM and 1 AMA. They were absent in paracetamol-related disease and present in 23 of 53 (43%) of non-paracetamol (NP) cases (p<0.0003). Two of 16 (13%) with NP drug-induced (NPDI), 9 of 21 (43%) viral and 5 of 16 (31%) cryptogenic cases had anti-SLA. NOSA and anti-SLA were not associated with liver injury severity or outcome. IgM was higher in those with viral disease (p<0.00001). AIH scores classified 50% of cryptogenic cases as 'probable autoimmune hepatitis'.

CONCLUSIONS

Autoantibodies are common in ALF; cryptogenic cases have features suggestive of an autoimmune pathogenesis. IgM is elevated in viral cases but infrequently in ALF of other causes.

Role of auto-antibodies for the diagnosis of chronic cholestatic liver diseases

Auto-antibodies are an integral part of the diagnostic armentarium in chronic cholestatic liver disorders, such as primary sclerosing cholangitis (PSC), primary biliary cirrhosis (PBC),auto-immune cholangitis, or overlap syndromes among these disorders. However, care should be taken not to overestimate the diagnostic specificity. Auto-antibodies to mitochondrial antigens(AMAs) with reactivity to the E2 subunit of the pyruvate dehydrogenase complex represent the hallmark antibody for the diagnosis of PBC, whereas antinuclear antibodies (ANAs)with low disease specificity are found in up to 50% of these sera. Antibodies that recognize nuclear envelope proteins exert a similarly high diagnostic specificity as AMA in PBC but occur at a rather low prevalence. The role of auto-antibodies is less well-studied for patients with PSC, but there is growing evidence that only antineutrophil cytoplasmic antibodies(ANCAs) are of relevant diagnostic significance. In contrast, auto-antibodies-particularlyAMAs-do not contribute to the diagnosis of auto-immune cholangitis, whereas ANCAs,ANAs, smooth muscle antibodies, and AMAs are of varying significance in PBC-auto-immune hepatitis (AIH) or PSC-AIH overlap syndromes. It has been widely accepted that the course of the auto-antibody serum end point titers are not suited for the clinical management of patients with chronic cholestatic liver disorders. Additionally, auto-antibodies in these disorders usually do not contribute to the immunopathogenesis of the disease.

Distinctive clinical phenotype and treatment outcome of type 1 autoimmune hepatitis in the elderly

Autoimmune hepatitis is classically a disease of young women. Our aims were to determine its occurrence, clinical phenotype, and outcome in elderly patients and contrast findings to young adults. Two-hundred-and-five white North American adults with definite type 1 autoimmune hepatitis were grouped according to age at presentation and the groups compared. Forty-seven patients (23%) were aged > or = 60 years (median age, 68 years), and 31 patients (15%) were aged < or = 30 years (median age, 25 years). The patients > or = 60 years had a higher frequency of cirrhosis at presentation than the patients < or = 30 years (33% versus 10%, P = .03). They also had thyroid or rheumatic diseases more commonly (42% vs. 13%, P = .006). HLA DR3 occurred more frequently in the patients < or = 30 years than in those > or = 60 years (58% vs. 23%, P = .004), and HLA DR4 occurred more often in the patients > or = 60 years (47% vs. 13%, P = .003). Patients aged > or = 60 years failed corticosteroid treatment less commonly than those aged < or = 30 years (5% vs. 24%, P = .03). Autoimmune hepatitis occurred in patients aged 18-30 years (15%), 31-39 years (15%), 40-49 years (21%), 50-59 years (25%), and > or = 60 years (23%). Differences in age distribution, HLA frequencies, and treatment outcome occurred after age > or = 40 years. In conclusion, elderly patients have a greater frequency of cirrhosis at presentation and HLA DR4 than patients < or = 30 years, and they have a lower occurrence of treatment failure. Transitions in clinical and genetic phenotypes occur after age > or = 40 years. Genetic susceptibilities may favor etiologic factors that are age-related.

Autoantibodies in autoimmune liver disease

Autoantibodies indicate an immune reactive state, but in liver disease they lack pathogenicity and disease specificity. Antinuclear antibodies, smooth muscle antibodies, antibodies to liver/kidney microsome type 1, antimitochondrial antibodies, and perinuclear antineutrophil cytoplasmic antibodies constitute the standard serological repertoire that should be assessed in all liver diseases of undetermined cause. Antibodies to soluble liver antigen/liver pancreas, asialoglycoprotein receptor, actin, liver cytosol type 1, nuclear antigens specific to primary biliary cirrhosis, and pore complex antigens constitute an investigational repertoire that promises to have prognostic and diagnostic value. These autoantibodies may emerge as predictors of treatment response and outcome. Antibodies to histones, doubled-stranded DNA, chromatin, and lactoferrin constitute a supplemental repertoire, and they support the immune nature of the liver disease. Final diagnoses and treatment strategies do not depend solely on serological markers. Autoantibodies are floating variables, and their behavior does not correlate closely with disease activity. There are no minimum levels of significant seropositivity, especially in children. Over-interpretation is the major pitfall in the clinical application of the serological results. New autoantibodies will emerge as the search for target antigens and key pathogenic pathways continues.

Autoimmune hepatitis in children

Autoimmune hepatitis (AIH) remains an enigmatic condition that affects children of all ages. Although much knowledge has emerged over the past four decades regarding autoimmune diseases, the lack of a spontaneous animal model has hindered a more complete understanding of the pathophysiology of AIH. Serum autoimmune markers, combined with biochemical and histologic evidence of hepatocellular injury and absent other diagnostic considerations, are necessary to diagnose AIH. The clinical spectrum ranges from asymptomatic elevation of aminotransferase levels to acute liver failure. Patients with AIH type 1 are more likely to be older and have cirrhosis at the time of diagnosis, whereas those with AIH type 2 may have a more fulminant course and require life-long immunosuppressant medications. Overlap syndromes occur in children but are rare. Treatment with prednisone and azathioprine, alone or in combination, reverses the clinical course and improves biochemical abnormalities. Should liver transplantation be necessary, autoimmune injury may recur in the allograft.

The nuclear pore complex protein Tpr is a common autoantigen in sera that demonstrate nuclear envelope staining by indirect immunofluorescence

We studied the autoantigen targets of 75 human sera that had antibodies to the nuclear envelope (NE) as identified by indirect immunofluorescence (IIF) on HEp-2 cells. Several different IIF staining patterns could be identified when antibodies to different components of the nuclear membrane (NM) and nuclear pore complexes (NuPC) were identified: a smooth membrane pattern characteristic of antibodies to nuclear lamins, a punctate pattern typical of antibodies to the nuclear pore complex and more complex patterns that included antibodies to nuclear and cytoplasmic organelles. Western immunoblotting of isolated nuclear and NE proteins and immunoprecipitation of radiolabelled recombinant proteins prepared by using the full-length cDNAs of the Translocated promoter region (Tpr), gp210 and p62 were used to identify specific autoantibody targets. Fifty-two of the 75 (70%) sera bound to Tpr, 25 (33%) bound to lamins A, B or C, 15 (20%) reacted with gp210 and none reacted with p62. Sixteen (21%) did not react with any of the NE components tested in our assays. The clinical features of 37 patients with anti-NE showed that there were 34 females and three males with an age range of 16-88 years (mean 59 years). The most frequent clinical diagnosis (9/37 = 24%) was autoimmune liver disease (ALD; two with primary biliary cirrhosis), followed by seven (19%) with systemic lupus erythematosus (SLE), four (11%) with a motor and/or sensory neuropathy, three (8%) with anti-phospholipid syndrome (APS), two with systemic sclerosis (SSc), two with Sjögren's syndrome (SjS), and others with a variety of diagnoses. This report indicates that Tpr, a component of the NuPC, is a common target of human autoantibodies that react with the NE.

Autoantigens of the nuclear pore complex

The nuclear envelope (NE) is one of many intracellular targets of the autoimmune response in patients with autoimmune liver disease, systemic lupus erythematosus, and related conditions. In eukaryotic organisms the NE consists of five interconnected regions: an outer nuclear membrane (ONM) that is continuous with the endoplasmic reticulum, an intermembrane or perinuclear space, an inner nuclear membrane (INM) with a unique set of integral membrane proteins, the underlying nuclear lamina, and the pore domains that are regions where the ONM and INM come together. The pore domains are sites of regulated continuity between the cytoplasm and nucleus that are occupied by supramolecular structures, termed nuclear pore complexes (NPCs). Human autoantibodies identified to date bind to specific components in three of the five NE compartments. Autoantigen targets include the lamins A, B, and C of the nuclear lamina, gp210, p62 complex proteins, Nup153, and Tpr within the NPC, and LBR, MAN1, LAP1, and LAP2 that are integral proteins of the INM. Autoantibodies to these NE targets have been shown to be correlated with various autoimmune diseases such as primary biliary cirrhosis, other autoimmune liver diseases and systemic rheumatic diseases. Now that the proteome of the NE is more clearly defined, other autoantibodies to components in this cell compartment are likely to be defined.