Clinical significance of organ- and non-organ-specific autoantibodies on the response to anti-viral treatment of patients with chronic hepatitis C

Autoimmune serology testing in clinical practice: An updated roadmap for the diagnosis of autoimmune hepatitis

Diagnosis of autoimmune hepatitis (AIH) is in most cases challenging for clinicians as there is not a single specific laboratory or histological marker to diagnose or exclude the presence of the disease. The clinical spectrum of AIH varies from completely asymptomatic to acute-severe or even rarely fulminant hepatic failure, while everybody can be affected irrespective of age, gender, and ethnicity. The old revised and the newer simplified diagnostic scores have been established by the International Autoimmune Hepatitis Group (IAIHG) in 1999 and 2008, respectively, which are based on several clinical, laboratory and histological parameters. Additionally, a thorough differential diagnosis from other diseases mimicking AIH is absolutely indicated. In this context, autoantibodies detection in patients with suspected AIH is mandatory -even though not pathognomonic- not only for AIH diagnosis but furthermore, for AIH classification (AIH-type 1 and AIH-type 2). Although autoimmune serology can be supportive of AIH diagnosis in ≥95% of cases if testing has been performed according to the IAIHG guidelines, this is not the case under real-life circumstances in routine clinical laboratories. Clinicians should be careful both for the importance of the required testing and how to interpret the results and therefore, they should communicate and discuss with the laboratory personnel to achieve the maximum benefit for the patient. Herein, a detailed and updated review of the diagnostic work-up for AIH diagnosis under real-life conditions is given to minimize the underestimation and misdiagnosis of AIH which can result in progression of the disease and unfavourable outcomes.

Impact of genetic and environmental factors on autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic non-resolving liver disease characterized by diffuse hypergammaglobulinemia, the presence of autoantibodies and characteristic histological findings. The disease can have catastrophic outcome with the development of end-stage liver disease if misdiagnosed/undiagnosed and left untreated. AIH pathogenesis remains obscure and the main hypothesis supports its development in genetically predisposed individuals after being exposed to certain environmental triggers. Genetic predisposition is linked to the presence of certain HLA alleles, mainly HLA-DR3 and HLA-DR4. However, a wide number of non-HLA epitopes have also been associated with the disease although data vary significantly among different ethnic groups. Therefore, it is likely that epigenetic alterations may also play a crucial role in disease's pathogenesis, although not yet extensively studied. The aim of this review was to summarize the genetic and environmental factors that have been associated with AIH, but also to open new insights towards the role of epigenetic modifications in the etiology of the disease.

Anti-rods/rings autoantibody and IMPDH filaments: an update after fifteen years of discovery

Autoantibodies to unknown subcellular rod and ring-shaped structures were first discovered in sera from hepatitis C patients in 2005. Early studies showed a strong association between these anti-rods/rings antibodies (anti-RR) and the standard of care interferon-α plus ribavirin combination therapy (IFN/RBV), suggesting that anti-RR are drug-induced autoantibodies. In the context of hepatitis C, anti-RR have been linked with relapse from or lack of response to IFN/RBV in some patient cohorts. However, examples of anti-RR in other diseases and healthy individuals have also been reported over the years, although anti-RR remains a rare autoantibody response in general. The advent of new direct-acting antiviral drugs for chronic hepatitis C and studies of anti-RR from different parts of the world are also beginning to change the perception of anti-RR. The nucleotide biosynthetic enzyme inosine monophosphate dehydrogenase (IMPDH) has been identified as the major autoantigen recognized by anti-RR. Coincidentally, the assembly of IMPDH into micron-scale rod and ring-shaped structures was discovered around the same time as anti-RR. Knowledge of the fundamental biological properties and cellular functions of these structures, referred to as "IMPDH filaments" by cell biologists, has advanced in parallel to anti-RR antibodies. Recent studies have revealed that IMPDH filament assembly is a mechanism to prevent feedback inhibition of IMPDH and is therefore important for the increased nucleotide production required in hyperproliferating cells, like activated T cells. Fifteen years later, we review the history and current knowledge in both the anti-RR autoantibody and IMPDH filament fields. TAKE-HOME MESSAGE: Anti-rods/rings are recognized as an example of a drug-induced autoantibody in hepatitis C patients treated with interferon and ribavirin, although new studies suggest anti-rods/rings may be detected in other contexts and may depend on unknown environmental or genetic factors in different populations. Recent data suggest that the assembly of IMPDH into rod and ring structures, the targets of anti-rods/rings autoantibody, is a mechanism for hyperproliferating cells, like activated T cells, to maintain increased guanine nucleotide levels to support rapid cell division.

Frequent occurrence of low-level positive autoantibodies in chronic hepatitis C

Evidence of autoimmune disease associated with hepatitis C virus (HCV)-infection has important clinical implications. A systematic profile of these autoantibodies in relevant clinical cohorts relative to healthy controls is needed to better inform current standard of care for chronic hepatitis C. Samples from an Australian cohort of chronic HCV-infected subjects (n=127) were tested for the presence of 19 diagnostic autoantibodies and compared with data available from a control cohort representing a general Caucasian population (n=198). Chronic HCV-infected individuals had a greater number of autoantibodies than controls (p<0.0001). Anti-nuclear antibodies (ANA) followed by anti-smooth muscle antibodies (SMA) were the most frequently detected autoantibodies within the HCV cohort and significantly more than in the control cohort (p<0.0001 and p=0.006, respectively). However, for most autoantibody assays the 95th percentile approximated the reference value for positivity. None of the autoantibodies were significantly associated with age or sex for the HCV cohort, except SMA positivity that was significantly higher in chronic HCV-infected male subjects (p<0.0001). Autoantibodies found in chronic HCV-infected subjects were commonly low positive and not disease-specific. Accordingly, general screening for autoimmunity in HCV-infected subjects should not be performed unless there is high clinical suspicion of an underlying autoimmune disease.

Resolution of HCV-Autoimmune Hepatitis Overlap Syndrome With Antiviral TreatmentA Paired Liver Biopsy Study

OBJECTIVES

To evaluate histologic changes occurring in patients having chronic hepatitis C and autoimmune hepatitis overlap (HCV-AIH), and who achieved virologic cure using direct-acting antiviral agents (DAA).

METHODS

Characteristics of HCV-AIH patients who underwent paired liver biopsies before and after receiving DAA treatment from 2011 to 2018 were evaluated.

RESULTS

Five HCV-AIH patients (three male; mean age, 60.4 years) underwent paired liver biopsies (average interval, 2.3 years) before and after achieving cure with DAA treatment. All patients showed virologic response, while four showed decreased inflammation, and three cases showed features of fibrosis regression. Immunohistochemical staining demonstrated significant decrease in plasma cell count in three patients (20.6 vs 11.9 plasma cells/high power field; P = .02, t test).

CONCLUSIONS

Histologic improvements in inflammation and fibrosis are noted in most HCV-AIH patients after DAA treatment, suggesting that the autoimmune component of the HCV-AIH overlap syndrome is merely a secondary phenomenon of viral infection.

Clinical relevance of serum non-organ-specific antibodies in patients with HCV infection receiving direct-acting antiviral therapy

BACKGROUND

Hepatitis C virus (HCV) infection is associated with production of different serum non-organ-specific antibodies (NOSA) and risk for developing autoimmune disorders. The clinical significance of these phenomena is not fully understood.

AIM

To assess non-organ-specific antibodies before and 24 weeks after the end of therapy with direct-acting antivirals in patients with HCV-related infection, to better clarify the clinical relevance of these antibodies in terms of treatment response and prognostic value.

METHODS

Patients enrolled (191) were considered non-organ-specific antibody-positive for titres ≥1:40 on at least two determinations before treatment.

RESULTS

At baseline, 46 patients were positive and 145 were negative for autoantibodies. The prevalence of autoimmune thyroiditis was significantly higher in non-organ-specific antibody-positive group than non-organ-specific antibody-negative group (P = 0.02). HCV-RNA 24 weeks after the end of antiviral therapy was 100% negative in patients with antibodies positivity and 98.6% in antibody-negative patients (P = 1.0). In the former group, autoantibodies disappeared in 30 of 46 patients (65.2%). On multivariate analysis, non-organ-specific antibody-negativity was significantly reduced in patients with hepatic hilar lymphadenopathy (OR = 0.17; 95% CI 0.02-0.94, P = 0.04). None of the adverse events occurring during antiviral therapy was related to autoimmune disorders.

CONCLUSIONS

Hepatitis C virus clearance frequently reduces non-organ-specific antibody positivity suggesting that they represent an epiphenomenon of the viral infection. However, in patients who did not become negative, long-term monitoring would establish whether they could hide an underlying process that may progress into a clear autoimmune or rheumatologic disease. (Trial registration number: NCT03566966).

Case Report: Patient with Hepatitis C, p-ANCA, and Cryoglobulin Antibodies Presenting with Necrotizing Crescentic p-ANCA Glomerulonephritis

Hepatitis C (HCV) infection has a prevalence of 3 million infected individuals in the United States, according to recent Center for Disease Control reports, and can have various renal manifestations. Cryoglobulins, antibodies that precipitate at colder temperatures in vitro, are a relatively common cause of renal disease in HCV infection. The cryoglobulin proteins can form occlusive aggregates in small glomerular capillary lumina or deposit in other areas of the glomerulus, resulting in hypocomplementemia, proteinuria, hematuria, and renal injury. The typical biopsy pattern is that of membranoproliferative glomerulonephritis (MPGN). There are, however, other HCV-related patterns of glomerular injury. Anti-neutrophil cytoplasmic antibodies (ANCA) are known to exist in HCV-infected patients. In many reported cases, ANCA serologic testing may appear positive due to cross-reactivity of the immune assays; however, the biopsy findings do not support ANCA-associated crescentic glomerulonephritis (GN)/vasculitis as the primary cause of glomerular injury. There are rare reports of microscopic polyangiitis (MPA) p-ANCA vasculitis, in patients with HCV infection. In comparison with the MPGN pattern of cryoglobulinemic glomerular injury, biopsies from these HCV-infected patients with concomitant MPA revealed a crescentic GN, associated with normal serum complement levels. We present a case of HCV-associated glomerular disease with the surprising biopsy finding of necrotizing and crescentic p-ANCA GN, with a background, low-grade mesangial immune complex GN. Thus, p-ANCA disease should also be considered in HCV-infected patients, in addition to the more typical lesions of MPGN or cryoglobulinemic GN.

Autoantibodies in Autoimmune Liver Diseases-Methods of Detection and Interpretation: An Update for the Reporting Pathologist

Autoimmune liver disease (AILD) is a type of chronic liver disease with autoimmune etiology. The diagnosis of the disease is multipronged and detection of autoantibodies in AILDs is an important diagnostic tool and it also helps in the classification of the disease. There are multiple autoantibodies that are detected in AILDs but none is diagnostic. Moreover, these autoantibodies are detected in many other pathological and nonpathological conditions. So the significance of seropositivity for these autoantibodies should be known by both the pathologists as well as the clinicians. In addition, there is prognostic significance associated with some of the antibodies and they also sometimes help in the disease monitoring. The whole array of antibodies detected in AILDs is discussed in detail in this review along with their clinical significance and interpretation.

Antineutrophil Cytoplasmic Antibody Induction due to Infection: A Patient with Infective Endocarditis and Chronic Hepatitis C

While antineutrophil cytoplasmic antibody (ANCA) is often used as a diagnostic marker for certain vasculitides, ANCA induction in the setting of infection is much less common. In the case of infective endocarditis, patients may present with multisystem disturbances resembling an autoimmune process, cases that may be rendered even trickier to diagnose in the face of a positive ANCA. Though not always straightforward, distinguishing an infective from an inflammatory process is pivotal in order to guide appropriate therapy. We describe an encounter with a 43-year-old male with chronically untreated hepatitis C virus infection who featured ANCA positivity while hospitalized with acute bacterial endocarditis. His case serves as a reminder of two of the few infections known to uncommonly generate ANCA positivity. We also summarize previously reported cases of ANCA positivity in the context of endocarditis and hepatitis C infections.

Cartilage oligomeric matrix protein: A novel non-invasive marker for assessing cirrhosis and risk of hepatocellular carcinoma

AIM

To assess serum cartilage oligomeric matrix protein (COMP) as a marker of cirrhosis and risk of progression to hepatocellular carcinoma (HCC).

METHODS

A COMP enzyme-linked immunosorbent assay was used to test 187 patients with chronic liver diseases at the time point of first evaluation. The selected patients included 72 with chronic hepatitis B infection, 75 with chronic hepatitis C infection, 22 with primary biliary cirrhosis, 7 with autoimmune hepatitis type 1, and 11 with alcoholic liver disease. Demographic, biochemical, histological and clinical characteristics of the patients were recorded at the first evaluation. One hundred and forty-seven patients were followed for a median [interquartile range (IQR)] duration of 96.5 (102) mo. The clinical, biochemical and histological data, as well as the development of cirrhosis, HCC according to internationally accepted criteria and in case of death, a liver-related cause during the follow-up period, were recorded at the electronic database of our clinic. COMP determination was also performed in 43 healthy individuals who served as the control study group.

RESULTS

COMP positivity (> 15 U/L) was detected in 22%-36% among chronic liver disease groups. Strikingly, almost 83% of COMP-positive patients were cirrhotic at baseline, independently of cause of liver disease. Among the patients who developed HCC during follow-up, 73.7% (14/19) were COMP positive at baseline. COMP positivity was significantly associated with older age (P < 0.001), advanced fibrosis (P = 0.001) and necroinflammatory activity (P = 0.001), higher aspartate aminotransferase (P < 0.001), alanine aminotransferase (P < 0.02), γ-glutamyl transpeptidase (P = 0.003), alkaline phosphatase (P = 0.001), bilirubin (P < 0.05), international normalized ratio (P = 0.002) and alpha-fetoprotein levels (P < 0.02), and lower albumin (P < 0.001), and platelet count (P = 0.008). COMP levels [median (IQR)] were significantly higher in cirrhotics compared to non-cirrhotics [13.8 (7.9) U/L vs 9.8 (4.6) U/L, respectively; P < 0.001]. On multivariate logistic regression analysis, COMP-positivity was independently associated only with cirrhosis (OR = 4.40, 95%CI: 1.33-14.69, P = 0.015). Kaplan-Meier analysis showed that COMP positivity was significantly associated with HCC development (P = 0.007) and higher incidence of liver-related death (P < 0.001).

CONCLUSION

Elevated COMP levels are strongly associated with cirrhosis and HCC progression. Serum COMP is a new promising non-invasive biomarker for HCC risk assessment in surveillance programs.

Autoantibodies in chronic hepatitis C: A clinical perspective

Non-organ-specific autoantibodies and thyroid autoantibodies have been frequently found in chronic carriers of hepatitis C virus (HCV). With respect to endomysial antibodies and tissue transglutaminase, it is controversial whether the prevalence of gluten-related seromarkers is higher in patients with HCV. In such cases, in addition to acknowledging any currently existing autoimmune disease, recognizing the risk of the patient developing an autoimmune disease during interferon (IFN)-based treatment must be a principle concern. From a clinical point-of-view, the presence of autoantibodies arouses suspicion that an autoimmune disease may be present or may be precipitated by IFN-based HCV treatment. In this paper, we review the prevalence of autoantibodies in individuals with hepatitis C, the clinical significance of these autoantibodies, and the approach recommended for such situations.

Anti-SLA/LP alone or in combination with anti-Ro52 and fine specificity of anti-Ro52 antibodies in patients with autoimmune hepatitis

BACKGROUND & AIMS

Antibodies (Abs) to soluble liver antigen/liver pancreas (anti-SLA/LP) are considered markers of worse prognosis and outcome in patients with autoimmune hepatitis (AIH) although this assumption has recently been attributed to their frequent co-expression with Abs against Ro52 (anti-Ro52). To assess the clinical significance of anti-SLA/LP Abs alone or in combination with anti-Ro52 in AIH patients and determine the immunodominant Ro52 epitopes according to the anti-SLA/LP status.

METHODS

Twenty-three anti-SLA/LP-positive and 106 anti-SLA/LP-negative AIH patients were included. Anti-SLA/LP were determined by ELISA using recombinant antigen, and confirmed by immunoblot using cytosolic rat liver fraction or HuH-7 extract. Anti-Ro52 Abs were determined by ELISA using recombinant antigen. Epitope mapping was assessed by ELISA using overlapping peptides covering the whole Ro52 protein in 26 AIH patients and 12 patients with Sjögren's syndrome.

RESULTS

Anti-SLA/LP positivity was not associated with the clinical, laboratory or histological characteristics of AIH patients. Treatment response, corticosteroid withdrawal, relapse after stopping treatment and outcome, were not associated with the presence of anti-SLA/LP, anti-Ro52 or double reactivity. Moreover, Ro52 epitope mapping revealed new epitopes unique for AIH and independent from anti-SLA/LP positivity.

CONCLUSIONS

Neither anti-SLA/LP nor anti-Ro52 Abs or their combination could specify a distinct group of AIH patients in terms of clinical characteristics, treatment response and outcome. Further studies are needed to clarify whether the newly discovered immunodominant epitopes of Ro52 antigen which were associated specifically with AIH have any clinical or pathogenetic significance in AIH.

Autoantibodies in Chinese patients with chronic hepatitis B: Prevalence and clinical associations

AIM: To investigate the prevalence of autoantibodies and their associations with clinical features in Chinese patients with chronic hepatitis B (CHB).

METHODS: A total of 325 Chinese patients with CHB were enrolled in this retrospective, hospital-based study. Patients with chronic hepatitis C (CHC), autoimmune hepatitis (AIH), or primary biliary cirrhosis (PBC) were included, with healthy donors acting as controls. A panel of autoantibodies that serologically define AIH and PBC was tested by indirect immunofluorescence assay and line immunoassay. The AIH-related autoantibody profile included homogeneous anti-nuclear antibodies (ANA-H), smooth-muscle antibodies, anti-liver kidney microsome type 1, anti-liver cytosolic antigen type 1, and anti-soluble liver antigen/liver pancreas; the PBC-related antibodies were characterized by ANA-nuclear dots/membranous rim-like, anti-mitochondrial antibodies-M2 (AMA-M2), anti-BPO (recombinant antigen targeted by AMA-M2), anti-Sp100, anti-promyelocytic leukemia protein (anti-PML), and anti-gp210. The dichotomization of clustering was used to unequivocally designate the AIH or PBC profiles for each case. Anti-Ro52 antibodies were also tested.

RESULTS: The prevalence of any autoantibody in CHB amounted to 58.2%, which was similar to the 66.2% prevalence in CHC, significantly higher than the 6.7% in the healthy controls (P < 0.001), and lower than the 100% found in AIH and PBC (P = 0.004 and P < 0.001, respectively). There were more anti-PML and anti-gp210 antibodies among the CHB patients than the CHC patients (11.1% vs 0%, P = 0.003; 12.6% vs 0%, P < 0.001, respectively). The prevalence and titer of AMA, anti-BPO, anti-PML, and anti-gp210 were higher in PBC than in those with CHB. Among the CHB patients, the prevalence of ANA, especially ANA-H, was significantly lower in patients with compensated and decompensated cirrhosis compared with patients without cirrhosis. Thirty-eight cases of hepatocellular carcinoma (HCC) in CHB showed a significant difference compared with non-HCC patients in the prevalence of anti-PML (0% vs 12.5%, P = 0.013). Dichotomization of the autoantibodies revealed that the PBC profile was more prevalent in patients with CHB than in those with CHC, and that it was strongly correlated with both compensated and decompensated cirrhosis. In contrast, the prevalence of the AIH profile was significantly higher in non-cirrhosis patients with CHB than in those with compensated cirrhosis (18.5% vs 8.2%, P = 0.039). Moreover, the AIH profile was also closely associated with hepatitis B e-antigen positivity.

CONCLUSION: ANA-H could be an indicator of early-stage CHB. Dichotomizing the autoantibody profiles revealed that the PBC profile is strongly associated with cirrhosis in CHB.

Autoimmune hepatitis, one disease with many faces: Etiopathogenetic, clinico-laboratory and histological characteristics

Autoimmune hepatitis (AIH) is an unresolving progressive liver disease of unknown etiology characterized by hypergammaglobulinemia, autoantibodies detection and interface hepatitis. Due to the absence of specific diagnostic markers and the large heterogeneity of its clinical, laboratory and histological features, AIH diagnosis may be potentially difficult. Therefore, in this in-depth review we summarize the substantial progress on etiopathogenesis, clinical, serological and histological phenotypes of AIH. AIH has a global distribution affecting any age, both sexes and all ethnic groups. Clinical manifestations vary from asymptomatic to severe or rarely fulminant hepatitis. Hypergammaglobulinemia with selective elevation of IgG is found in most cases. Autoimmune attack is perpetuated, possibly via molecular mimicry, and favored by the impaired control of T-regulatory cells. Histology (interface hepatitis, emperipolesis and hepatic rosette formation) and autoantibodies detection although not pathognomonic, are still the hallmark for a timely diagnosis. AIH remains a major diagnostic challenge. AIH should be considered in every case in the absence of viral, metabolic, genetic and toxic etiology of chronic or acute hepatitis. Laboratory personnel, hepato-pathologists and clinicians need to become more familiar with disease expressions and the interpretation of liver histology and autoimmune serology to derive maximum benefit for the patient.

Review article: autoimmune hepatitis -- current management and challenges

BACKGROUND

Autoimmune hepatitis (AIH) is a disease of unknown aetiology characterised by interface hepatitis, hypergammaglobulinaemia, circulating autoantibodies and a favourable response to immunosuppression.

AIM

To review recent advancements in understanding aetiopathogenesis, clinical, serological and histological features, diagnostic criteria and treatment strategies of AIH.

METHODS

Published studies on AIH extracted mainly from PubMed during the last 15 years.

RESULTS

Autoimmune hepatitis has a global distribution affecting any age, both sexes and all ethnic groups. Clinical manifestations are variable ranging from no symptoms to severe acute hepatitis and only seldom to fulminant hepatic failure. Autoimmune attack is perpetuated, possibly via molecular mimicry mechanisms, and favoured by the impaired control of regulatory T-cells. A typical laboratory finding is hypergammaglobulinaemia with selective elevation of IgG, although in 15-25% of patients - particularly children, elderly and acute cases - IgG levels are normal. Liver histology and autoantibodies, although not pathognomonic, still remain the hallmark for diagnosis. Immunosuppressive treatment is mandatory and life-saving; however, to meet strict response criteria, the conventional therapy with prednisolone with or without azathioprine is far from ideal.

CONCLUSIONS

Autoimmune hepatitis remains a major diagnostic and therapeutic challenge. The clinician, the hepato-pathologist and the laboratory personnel need to become more familiar with different expressions of the disease, interpretation of liver histology and autoimmune serology. According to the strict definition of treatment response issued by the 2010 AASLD guidelines, many patients are nonresponders to conventional treatment. Newer immunosuppressive agents targeting pathogenetic mechanisms can improve patient management, which needs to be tailored on a case-by-case basis.

Clinical associations and potential novel antigenic targets of autoantibodies directed against rods and rings in chronic hepatitis C infection

Background

Chronic hepatitis C virus (HCV) infection is frequently associated with extrahepatic autoimmune disorders while interferon (IFN) and ribavirin treatment may exacerbate these conditions. Autoantibodies from HCV patients identify a novel indirect immunofluorescence (IIF) pattern on HEp-2 cells characterized by cytoplasmic rods and rings (RR). Our objectives were to determine the prevalence and clinical associations of RR autoantibodies in HCV patients, and identify related novel autoantibody targets.

Methods

Sera from 315 patients with HCV (301 treatment naive, 14 treated with interferon and/or ribavirin) were analyzed for the presence of RR antibodies by IIF on commercially available HEp-2 cell substrates. Antibodies to inosine monophosphate dehydrogenase 2 (IMPDH2) and cytidine triphosphate synthase 1 (CTPS1) were detected by addressable laser bead assay and other potential targets were identified by immunoscreening a protein microarray. Clinical and demographic data including HCV genotype, mode of infection, prior antiviral therapy, and histological findings were compared between RR antibody positive (RR+) and negative (RR-) patients.

Results

The median age of the HCV cohort was 51 years, 61% were male, and 76% were infected with HCV genotype 1 (G1). Four percent (n=14) had been treated with IFN-based therapy (IFN monotherapy, n=3; IFN/ribavirin, n=11); all had a sustained virologic response. In total, 15 patients (5% of the cohort) were RR+. RR+ and RR- patients had similar demographic and clinical characteristics including age, sex, mode of HCV infection, prevalence of the G1 HCV genotype, and moderate to severe fibrosis. Nevertheless, RR+ patients were significantly more likely than RR- cases to have been treated with IFN-based therapy (33% vs. 3%; adjusted odds ratio 20.5 [95% confidence interval 5.1-83.2]; P<0.0005). Only 1/10 RR positive sera had detectable antibodies to IMPHD2 and none had antibodies to CTPS1. Potentially important autoantibody targets identified on protein arrays included Myc-associated zinc finger protein (MAZI) and ankyrin repeat motif.

Conclusion

The majority of HCV patients with RR autoantibodies previously received IFN/ribavirin antiviral therapy. Further studies are necessary to determine the genesis of intracellular RR and elucidate the clinically relevant autoantigens as well as the clinical and prognostic significance of their cognate autoantibodies.

Autoantibodies in liver disease: important clues for the diagnosis, disease activity and prognosis

It has been well established that numerous kinds of autoantibodies have been detected in liver disease. Some kinds of autoantibodies may be helpful in the diagnosis of autoimmune liver diseases including autoimmune hepatitis, primary biliary cirrhosis or primary sclerosing cholangitis. However, these autoantibodies are present even in sera of patients with viral hepatitis, drug-induced hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease and hepatocelluar carcinoma as well as in sera of patients with autoimmune liver diseases. Other kinds of autoantibodies are recognized as predictive hallmarks for disease activity or prognosis in liver diseases. On the other hand, treatment with interferon initiates the production of several types of autoantibodies in patients with chronic hepatitis C virus infection. Some of autoantibodies induced by interferon may postulate the treatment outcome in those patients. Recent studies also revealed the close correlation between oxidative stress and the production of autoantibodies in liver diseases. This article primarily reviews the recent advances of autoantibodies in the liver diseases and discusses the clinical significance of these autoantibodies.

Differential reactivity to IMPDH2 by anti-rods/rings autoantibodies and unresponsiveness to pegylated interferon-alpha/ribavirin therapy in US and Italian HCV patients

PURPOSE

Autoantibodies to cytoplasmic structures called rods and rings (RR) are primarily specific to patients with hepatitis C virus (HCV) infection treated with pegylated interferon-alpha/ribavirin (IFN/R). Our aim is to examine anti-RR antibodies specificity and correlation with the response to IFN/R therapy in two independent cohorts (US and Italy) of HCV patients.

METHODS

Sera from the US cohort (n = 47) and the Italian cohort (n = 46) pre-selected for anti-RR antibodies were analyzed by immunofluorescence and radioimmunoprecipitation. The prevalence and titers of anti-RR were analyzed for correlation with the response to IFN/R therapy.

RESULTS

In the US cohort, anti-RR antibodies were more frequently non-responders to IFN/R (71 % vs 29 % responders). Titers in responder patients (n = 11) were ≤1:3200, whereas titers in non-responder patients (n = 27) reached 1:819,200 (p = 0.0016). In the Italian cohort, anti-RR titers ranged from 1:200 to >1:819,200 and only relapsers had the highest anti-RR titers. Radioimmunoprecipitation demonstrated that anti-RR autoantibodies were mainly anti-inosine monophosphate dehydrogenase 2 (IMPDH2) - 96 % in the Italian cohort vs. 53 % in the US cohort.

CONCLUSIONS

In the two cohorts analyzed, the anti-IMPDH2 response as a component of the anti-RR response is much more prominent in the Italian cohort. The reason for the difference between the US and Italian cohorts is unclear but it possibly illustrates the heterogeneity in response and the overall negative correlation between the production of these autoantibodies and response to IFN/R therapy. Patients with high titer anti-RR antibodies are either relapsers (Italian) or non-responders/relapsers (US).

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Anti-α actinin antibodies as new predictors of response to treatment in autoimmune hepatitis type 1

BACKGROUND

We reported that combined presence of autoantibodies (Abs) against filamentous-actin (AFA) and α-actinin are specific for autoimmune hepatitis type 1 (AIH-1) diagnosis.

AIM

To explore our data and assess whether anti-α-actinin and AFA Abs could be used as indicators of response to treatment and predictors of AIH-1 flares in a large cohort of AIH-1 patients.

METHODS

Seven hundred and sixty-four serial serum samples of 86 consecutive AIH-1 patients, 509 pathological and 110 normal controls were tested for the presence of anti-α-actinin and AFA Abs by an in-house IgG-specific ELISA and a standardised commercially available ELISA respectively. Patients sera were divided into baseline group (active disease before treatment initiation, n = 86) and then according to treatment response into group A-responders (n = 40 patients), group B-relapsers/incomplete responders (n = 37 patients) and group C-not-treated (n = 9 patients).

RESULTS

Anti-α-actinin and AFA levels were significantly higher at baseline. Double reactivity against α-actinin and AFA was associated with disease activity (OR 4.9; 95% CI: 2.7-9). Anti-α-actinin optical densities (ODs) before treatment decreased significantly at first remission (P < 0.05). Treatment response was associated with anti-α-actinin Abs negativity before treatment (OR 3.4; 95% CI: 1.3-8.9) and absence of double positivity for anti-α-actinin and AFA Abs before treatment (OR 3.8; 95% CI: 1.4-10.4). Responders had lower baseline levels of anti-α-actinin than relapsers and/or incomplete responders (P = 0.002). Binary logistic regression revealed lower levels of anti-α-actinin as the only independent predictors of response (P = 0.05).

CONCLUSIONS

Anti-α-actinin Abs at baseline appear to predict treatment response and therefore they might be used for monitoring treatment outcome in AIH-1.

Cytoplasmic rods and rings autoantibodies developed during pegylated interferon and ribavirin therapy in patients with chronic hepatitis C

BACKGROUND

Serum autoantibodies are frequently detected in patients with chronic HCV infection, reflecting the wide spectrum of immune reactions related to this virus. In the present study, a novel autoantibody to cytoplasmic rods and rings (RR) in chronic HCV patients was characterized.

METHODS

Sera from 75 previously untreated HCV patients were investigated by indirect immunofluorescence using HEp-2 cell substrate before and during pegylated interferon (PEG-IFN)/ribavirin (RBV) therapy. HEp-2 cells were cultured and fixed either following standard protocols or with the addition of RBV in culture medium.

RESULTS

In 15 out of 75 (20%) patients, analysis revealed the presence of antibodies to rod-like cytoplasmic structures ranging approximately 3-10 μm in length and rings approximately 2-5 μm in diameter. These RR structures became detectable in >95% of cells after addition of RBV in culture medium, whereas they were absent in untreated cells. Anti-RR antibodies were found in sera collected during PEG-IFN/RBV treatment only, but never detected before antiviral therapy nor in control groups. More importantly, these anti-RR antibodies were more often detected in non-responder/relapsers than in responder patients (33% versus 11%; P-value =0.037).

CONCLUSIONS

An RBV-induced autoantibody was identified to a new cytoplasmic autoantigenic structure developed in HCV patients after PEG-IFN/RBV and this same structure can be induced by RBV in in vitro culture. Owing to the onset of anti-RR antibodies in PEG-IFN/RBV-treated patients and their association with a treatment failure, studies are deemed necessary to clarify whether anti-RR plays a role in the response to PEG-IFN/RBV therapy.

Autoantibodies in patients with chronic hepatitis C virus infection: pitfalls for the diagnosis of rheumatic diseases

Hepatitis C virus infection (HCV) is one of the best mimes in medicine. About 40-70% of patients suffering from this disorder develop at least one extra-hepatic disorder that can have a rheumatic nature (arthralgias, arthritis, vasculitis and sicca syndrome) and must be differentiated from the primitive rheumatic diseases. In addition, HCV infection can also alter the laboratory tests. Several alterations of first line laboratory tests can be usually found in both chronic HCV infection and chronic inflammatory rheumatic disorders. In the present review we analyze the interference of HCV in tests more specifically used in rheumatology: rheumatoid factor and other autoantibodies (ANA, anti-ENA, ANCA, anti-DNA, antiphospholipid, anti-CCP). In patients suffering from HCV infection, the diagnosis of connective tissue diseases (CTD) or rheumatoid arthritis (RA) should be made only when the detected symptoms or laboratory data are not inducible by HCV, otherwise only a diagnosis of "possible CTD" or "possible RA" should be considered.

Hepatitis C virus and autoimmunity

Hepatitis C virus infection is associated with several extrahepatic manifestations. About 60% of patients infected with HCV develop at least one extrahepatic manifestation. The majority of these diseases seem to be triggered through autoimmune mechanisms, such as autoantibody production, autoreactive T cells and complex autoimmune mechanisms leading to systemic autoimmune disorders. In this review we categorize these diseases into three groups according to the main pathogenetic process involved, in particular B-cell-mediated, T-cell-mediated and complex autoimmune systemic diseases.

Antinuclear antibody positivity in patients with chronic hepatitis C: clinically relevant or an epiphenomenon?

BACKGROUND

Serum autoantibodies such as antinuclear antibody (ANA) are frequently detected in patients with chronic hepatitis C virus (HCV) infection, but its relevance is a matter of discussion.

AIM

To assess the association of ANA positivity with clinical and histological features, and with the outcome of antiviral therapy in patients with HCV infection.

METHODS

Baseline samples from patients with hepatitis C treated with interferon and ribavirin were tested for ANA positivity by indirect immunofluorescence.

RESULTS

The mean age was 48.3+/-11.1 years and 56% were men. Among 234 included patients, 22 patients (9.4%) were positive for ANA. These patients showed significantly higher median alanine aminotransferase level (3.52 vs. 2.39 x upper limit of normal, P=0.009) when compared with ANA-negative patients. Fibrosis stage and necroinflammatory grading were not influenced by ANA positivity. Sustained virological response (SVR) rates were similar between ANA-positive and ANA-negative patients (27 vs. 29%, P=0.882). Alanine aminotransferase flares (> or = 1.5-fold the baseline) during treatment were observed in 28 patients (12%), irrespective of the presence of ANA and without any clinical significance.

CONCLUSION

Among HCV patients, ANA positivity seems to represent an immunological epiphenomenon. It neither influences clinical, biochemical, and histological features of chronic hepatitis C nor predicts response to antiviral treatment.

[Hemoptysis and acute renal failure in a 29-year-old patient with chronic hepatitis C infection]

A 29-year-old male patient with chronic hepatitis C infection and interferon alpha therapy in his medical history was admitted to the hospital because of the clinical manifestation of a pulmonary renal syndrome. High titers of proteinase-3-ANCA were detected, while an infectious agent was ruled out. After diagnosis of Wegener's granulomatosis the patient received prednisolone and cyclophosphamide pulse therapy and remission developed rapidly. Chronic hepatitis C infection as well as interferon therapy are frequently associated with autoimmune disorders. We assume that the interferon therapy itself has triggered autoimmune processes resulting in Wegener's granulomatosis in our patient. Thus we recommend to search specifically for autoimmune disorders in the past medical history and if necessary to consider a screening for autoantibodies before starting an interferon therapy. An autoimmune disease should also be taken into account if new symptoms develop under an ongoing interferon alpha therapy.