Hepatitis C virus and autoimmunity.
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Autoimmunity↗
Biomedical subjects
F B Bianchi
Publications and source records attributed to F B Bianchi.
Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane.
BACKGROUND: Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack. METHODS: The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confocal laser microscopy of isolated rat hepatocytes probed with 10 LKM1 positive sera (five from patients with AIH and five from patients with chronic HCV infection) and a rabbit polyclonal anti-CYP2D6 serum. RESULTS: Serum from both types of patient stained the plasma membrane of non-permeabilised cells, where the fluorescent signal could be visualised as discrete clumps. Conversely, permeabilised hepatocytes showed diffuse submembranous/cytoplasmic staining. Adsorption with recombinant CYP2D6 substantially reduced plasma membrane staining and LKM1 immunoblot reactivity. Plasma membrane staining of LKM1 colocalised with that of anti-CYP2D6. Immunoprecipitation experiments showed that a single 50 kDa protein recognised by anti-CYP2D6 can be isolated from the plasma membrane of intact hepatocytes. CONCLUSIONS: AIH and HCV related LKM1 recognise CYP2D6 exposed on the plasma membrane of isolated hepatocytes. This observation supports the notion that anti-CYP2D6 autoreactivity may be involved in the pathogenesis of liver damage.
Adult↗
Testing for antineutrophil cytoplasmic antibodies.
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Antibodies, Antineutrophil Cytoplasmic↗
A novel assay for detecting antibodies to cytochrome P4502D6, the molecular target of liver kidney microsomal antibody type 1.
Liver Kidney Microsomal type 1 (LKM1) antibody, the diagnostic marker of autoimmune hepatitis type 2, is also found in a proportion of patients with hepatitis C virus infection (HCV). It is detected conventionally by the subjective immunofluorescence technique. Our aim was to establish a simple and objective enzyme-linked immunosorbent assay (ELISA) that measures antibodies to cytochrome P4502D6 (CYP2D6), the target of LKM1. An indirect ELISA using eukaryotically expressed CYP2D6 was designed. Absorbance values obtained against a reference microsomal preparation were subtracted from those obtained against a microsomal preparation over-expressing CYP2D6, thus removing the non-CYP2D6-specific reaction. Sera from 51 LKM1 positive patients (21 autoimmune hepatitis and 30 with HCV infection), 111 LKM1 negative patients with chronic liver disease (including 20 with HCV infection) and 43 healthy controls were tested. Of 51 patients positive by immunofluorescence, 48 were also positive by ELISA while all the 154 LKM1 negative subjects were also negative by ELISA. There was a high degree of association between IFL and ELISA as demonstrated by a kappa reliability value of 0.96. The absorbance values by ELISA correlated with immunofluorescence LKM1 titres both in autoimmune hepatitis (r = 0.74, p < 0.001) and HCV infection (r = 0.67, p < 0.001). The simple, objective ELISA described has the potential to replace the standard immunofluorescence technique.
Adolescent↗
International Autoimmune Hepatitis Group Report: review of criteria for diagnosis of autoimmune hepatitis.
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Diagnostic Techniques, Digestive System↗
Auto-antibodies in hepatitis C.
Hepatitis C virus (HCV) has been implicated in the development of a variety of autoimmune phenomena, some of which are well documented and include a panel of auto-antibodies shared with autoimmune hepatitis (AIH). Anti-nuclear (ANA) and smooth muscle (SMA) antibodies (markers of AIH type 1 [AIH-1]), have been demonstrated in 9-38% and 5-91% of cases respectively, whereas anti-liver/kidney microsomal type 1 (anti-LKM-1) and anti-liver cytosol type 1 antibodies (anti-LC1) (markers of AIH type 2 [AIH-2]), are definitely rarer, especially in adults. The presence of these auto-reactivities in chronic hepatitis C generates clinical overlaps and dilemmas in the correct classification and treatment of such patients. The immunopathological characterization of the auto-antibodies, anti-nuclear and smooth muscle antibodies in particular, combined with internationally defined criteria for the diagnosis of AIH is helpful in this clinical process. Thyroid auto-antibodies and cryoprecitable rheumatoid factors are also commonly detected in hepatitis C, while the occurrence of other auto-antibodies still awaits confirmation.
Animals↗
Prevalence of non-organ-specific autoantibodies and chronic liver disease in the general population: a nested case-control study of the Dionysos cohort.
BACKGROUND: Several retrospective and prospective studies report an increased prevalence of non-organ-specific autoantibodies (NOSAs) in patients with hepatitis C virus (HCV) related chronic liver disease (CLD). Some of the data so far available are controversial and the true prevalence of NOSAs in the general population is still not known. AIM: To explore the prevalence of NOSAs, their relation to different HCV genotypes, and the presence and severity of CLD in the general population of Northern Italy. PATIENTS: All 226 anti-HCV positive and 87 hepatitis B surface antigen (HBsAg) positive patients of the Dionysos cohort study were analysed and compared with sex and age matched cases (226) negative for both anti-HCV antibody and HBsAg selected from the same cohort. METHODS: Sera tested for the presence of NOSAs (anti-nuclear antibody (ANA), anti-smooth muscle antibody (SMA), and anti-liver/kidney microsomes type 1 antibody (LKM1)) were screened by indirect immunofluorescence at a 1:40 serum dilution. HCV RNA and HCV genotypes were also determined by nested polymerase chain reaction (PCR) of the 5' non-coding region and by PCR amplification of the core region with type specific primers. RESULTS: The overall prevalence of NOSA reactivity was significantly higher in anti-HCV positive subjects than in both normal and pathological controls (25% v 6% and 7% respectively, p<0.05). ANA, SMA, and LKM1 occurred in 16, 10, and 1. 3% of cases respectively. No specific association between NOSAs and a specific HCV genotype was found. NOSAs were found more often associated with more than one genotype (35.7%) and with untypable genotypes (34.6%), although the association was not statistically significant. NOSAs were associated with HCV RNA and CLD but not with the presence of cirrhosis and/or hepatocellular carcinoma. On univariate analysis, NOSA reactivity was independently associated with abnormal alanine aminotransferase (p<0.01) and gamma-glutamyltranspeptidase levels (p<0.05). The risk for the presence of NOSAs was 5.1 times higher in anti-HCV subjects than in controls. CONCLUSIONS: In the general population the prevalence of NOSAs is higher in anti-HCV positive subjects than in normal or disease controls. Moreover NOSAs are associated with CLD and with a more active disease in terms of alanine aminotransferase activity.
Adolescent↗
Coeliac disease hidden by cryptogenic hypertransaminasaemia.
BACKGROUND: Hypertransaminasaemia of unknown, cryptogenic, origin occasionally has been found to be the only sign of coeliac disease. Raised concentrations of transaminases, or aminotransferases, have been retrospectively observed in about a half of patients with coeliac disease who are on a gluten-containing diet. We aimed to establish the overall prevalence of coeliac disease among patients with cryptogenic hypertransaminasaemia. METHODS: Of the 600 consecutive patients referred to our outpatient clinic for liver disease due to raised serum transaminases from September, 1995, to June, 1997, 55 were classified as having cryptogenic hypertransaminasaemia after the exclusion of every known cause of liver disease. These patients were tested by indirect immunofluorescence for IgA to endomysium and for IgA and IgG to gliadin. FINDINGS: Five patients were positive for both IgA to endomysium and IgG to gliadin, whereas IgA to gliadin was only found in four patients. IgG to gliadin was also present in another patient who was not positive for antibodies to endomysium. The six antibody-positive patients had duodenal biopsy that showed a subtotal villous atrophy consistent with coeliac disease in the five patients with antibodies to endomysium. The patient with only IgG to gliadin had a normal small-intestine mucosa. None of the five patients with coeliac disease had gastrointestinal symptoms. Liver biopsy samples were taken from three of the five patients with flat mucosa and showed a histological picture of nonspecific reactive hepatitis. Transaminase concentrations reverted to normal within 6 months in four patients with coeliac disease who followed a strict gluten-free diet. INTERPRETATION: Our results show that about 9% of patients with cryptogenic hypertransaminasaemia are affected by symptom-free coeliac disease. Gluten-sensitive enteropathy and antibody screening for coeliac disease by means of antibodies to endomysium and gliadin should be considered in these patients.
Adult↗
Haplotype HLA-B8-DR3 confers susceptibility to hepatitis C virus-related mixed cryoglobulinemia.
Our aim was to investigate whether host genetic factors are involved in the onset of hepatitis C virus (HCV)-related mixed cryoglobulinemia (MC). We studied 25 consecutive patients presenting with a full-blown clinical picture of MC by physical examination, blood chemistry, assessment of cryoglobulins and their composition, nonorgan-specific autoantibodies, antibodies to HCV, serum HCV RNA, and HLA polymorphism. Biopsies of liver, bone marrow, and minor salivary glands were also performed in a number of patients. HLA results were compared with those of normal controls and patients with chronic HCV infection without MC and negative for autoimmune phenomena (pathological controls). Type II MC was found in 14 of 25 patients (56%), and type III MC was found in the remaining 11 (44%). All patients were positive for antibodies to HCV and/or serum HCV RNA. HLA-B8 was found in 40% (10 of 25) of patients compared with 10. 1% (38 of 377) of normal controls (P = .00003, Pcorrected = .0005, relative risk [RR] 5.9) and 6.7% (2 of 30) of pathological controls (P = .007, Pcorrected = not significant). As for class II HLA molecules, only DR3 was significantly more frequent in MC patients (40%, 10 of 25) than in normal controls (15.1%, 57 of 377; P = .003, Pcorrected = .03, RR 3.7). Odds ratio (OR) for the risk of developing MC was calculated in patients positive for B8 and/or DR3, and the highest OR (8.2) was observed in individuals possessing both. The results suggest that the development of HCV-related MC is associated with HLA-B8 and DR3 markers.
Adult↗
Expression of co-stimulatory molecules by Kupffer cells in chronic hepatitis of hepatitis C virus etiology.
In this paper we show that in viral hepatitis most Kupffer cells (KCs) are activated and express high levels of CD80, CD40, and class-II MHC molecules, thus acquiring the phenotype of professional antigen presenting cells (APCs). Activated KCs display a close contact with CD4+ T lymphocytes and form KCs-T lymphocyte clusters. Clusters are found within the sinusoids, across the sinusoid wall, and within the liver parenchyma as well, as a consequence of transendothelial migration (TEM). The positivity of activated KCs for hepatitis C virus (HCV) antigens, which likely reflects phagocytosis of infected hepatocytes, suggests that KCs-T cell clusters represent the morphological expression of the functional interaction between KCs acting as professional APCs and antigen-experienced CD4+ T lymphocytes within the liver. These phenotypic and morphological changes are distinct features of livers in chronic hepatitis patients compared with controls.
Adult↗
Frequency and significance of anti-gliadin and anti-endomysial antibodies in autoimmune hepatitis.
Celiac disease has been associated with autoimmune disorders, but its frequency in autoimmune hepatitis is unknown. Sera from 157 patients with type 1 autoimmune hepatitis, 24 patients with type 2 autoimmune hepatitis, 62 patients with primary biliary cirrhosis, 30 patients with chronic hepatitis B, and 80 patients with chronic hepatitis C were tested for immunoglobulin A anti-endomysial antibodies by indirect immunofluorescence and immunoglobulin A and G antibodies to gliadin by enzyme immunoassay. Duodenal biopsy evaluation was recommended in patients seropositive for immunoglobulin A anti-endomysial antibodies. Immunoglobulin A anti-endomysial antibodies were present in eight of the 181 patients with autoimmune hepatitis (4%), including six with type 1 disease (4%) and two with type 2 disease (8%). Immunoglobulin A antibodies to gliadin were found in six of these eight patients, but they were also present in two others, including one patient with chronic hepatitis C. Five of the eight patients with immunoglobulin A antiendomysial antibodies, including three patients with no gastrointestinal symptoms, had duodenal biopsies and subtotal villous atrophy was present in all of them. No patient with primary biliary cirrhosis or chronic viral hepatitis had antiendomysial antibodies. The presence of celiac disease in autoimmune hepatitis is high (at least one in 36 patients) and it is predominantly asymptomatic. Screening with anti-endomysial and anti-gliadin antibodies should be performed and results confirmed with intestinal biopsy.
Adolescent↗
Liver/kidney microsomal antibody type 1 and liver cytosol antibody type 1 concentrations in type 2 autoimmune hepatitis.
BACKGROUND: Liver/kidney microsomal antibody type 1 (LKM1) and liver cytosol antibody type 1 (LC1) are the serological markers of type 2 autoimmune hepatitis (AIH). AIMS: Since LKM1 and LC1 react against two distinct liver specific autoantigens (cytochrome P450IID6 (CYP2D6) and a 58 kDa cytosolic polypeptide respectively), the aim was to see whether LKM1 and LC1 concentrations correlate with liver disease activity. PATIENTS: Twenty one patients with type 2 AIH were studied. METHODS: All sera were tested by indirect immunofluorescence, counterimmunoelectrophoresis, and immunoblotting visualised by enhanced chemiluminescence. To evaluate LKM1 and LC1 levels, the 50 kDa microsomal reactivity (corresponding to CYP2D6) and the 58 kDa cytosolic reactivity were quantified by densitometric analysis. RESULTS: Seven patients were positive for LKM1, nine for LC1, and five for both. Serial serum samples at onset and during immunosuppressive treatment were analysed in 13 patients (four positive for LKM1, six positive for LC1 and three positive for both). During remission, LKM1 concentration remained essentially unchanged in six of seven patients, and decreased in only one. Conversely, in two of nine patients, LC1 was completely lost, and, in the remaining seven, LC1 concentration was reduced by more than 50%. After immunosuppression tapering or withdrawal, flare ups of liver necrosis ensued with increasing LC1 concentration, but not LKM1. CONCLUSIONS: LC1 concentration, at variance with that of LKM1, parallels liver disease activity, and its participation in the pathogenic mechanisms of liver injury can be hypothesised.
Adolescent↗
Anti-neutrophil cytoplasmic antibodies in type 1 and 2 autoimmune hepatitis.
Perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) have been recently defined as the most sensitive autoantibody of type 1 autoimmune hepatitis (AIH-1). Their prevalence in type 2 autoimmune hepatitis (AIH-2) has not yet been evaluated. The aim of the present study was to verify the association of pANCA with AIH-1 in an Italian series and to investigate the prevalence of the antibodies in AIH-2 and in proper control groups represented by cases of chronic hepatitis C (CH-C) with similar autoimmune features. pANCA were found in 30 of 46 (65%) AIH-1 and in 4 of 30 (13%) ANA/smooth muscle antibody (SMA) positive CH-C (P = .0000006). Nineteen AIH-2, 29 liver kidney microsomal antibody type 1/liver cytosol antibody type 1 (LKM1/LC1) positive CH-C cases and 50 healthy controls were all negative. In AIH-1, pANCA were significantly (P = .009) more frequent in males (8 of 9, 89%) than in females (22 of 37, 59%). All pANCA positive sera showed SMA of the antiactin type. The present data confirm that pANCA, although less prevalent in our series than in other reports, do associate with AIH-1 also in the Mediterranean area and show that it can identify a small subgroup (13%) of ANA/SMA positive chronic hepatitis C, in which autoimmune reactions might play a more relevant role than viral infection. They also show the antibodies are absent in AIH-2. In conclusion, pANCA appear to be mutually exclusive of LKM1 positivity, either hepatitis C virus-related or not, thus representing a further valuable tool to differentiate the two types of autoimmune hepatitis.
Adolescent↗
Serum autoantibodies in chronic hepatitis C: comparison with autoimmune hepatitis and impact on the disease profile.
Antibodies to nuclei (ANA), smooth muscle (SMA), and liver/kidney microsomes type 1 (anti-LKM1) may occur in chronic hepatitis C. Distinct subspecificities, including ANA with the homogeneous pattern (ANA-H) and SMA with antiactin specificity (SMA-AA), are found in autoimmune hepatitis (AIH). This study was performed to characterize the hepatitis C virus (HCV)-associated autoantibodies and to evaluate their influence on the profile of the disease. Two hundred ninety consecutive patients with chronic hepatitis C and 35 control cases with AIH were screened for autoantibodies by indirect immunofluorescence (IFL) at 1:40 serum dilution. The ANA pattern was defined by IFL on HEp-2 cells and the SMA-AA identified by the presence of at least two of the following elements: 1) SMA(T) or SMA(G) pattern by IFL on kidney sections; 2) XR1 precipitating system by counterimmunoelectrophoresis; or 3) typical pattern by IFL on liver sections from phalloidin-intoxicated rats. ANA, SMA, and anti-LKM1 occurred in 9%, 20%, and 6% of chronic hepatitis C cases, respectively. The overall prevalence of autoantibodies was 30% (87 of 290). Compared with AIH, HCV-associated ANA and SMA exhibited ANA-H and SMA-AA at a lower prevalence (38% vs. 71%, P = .04 and 8% vs. 87%, P < .000001, respectively) and had a lower median titer (1:80 vs. 1:320, P < .001 and 1:40 vs. 1:320, P < .000001, respectively). The concomitant positivity for ANA-H and SMA-AA was detected in none of the HCV cases, but in 46% of AIH sera (P < .000001). Two parameters were independently associated with the autoantibodies in chronic hepatitis C: high alanine transaminase (ALT) serum levels (F = 14.04) and female gender (F = 5.03). At the univariate analysis, patients with autoantibodies had a more severe portal-periportal necroinflammation (median Scheuer's score: 2.05 vs. 1.64, P = .003). The presence of autoantibodies did not influence the response to interferon (IFN). In chronic hepatitis C, serum autoantibodies are common, but their subspecificities are distinct from those occurring in AIH. Whereas the absence of ANA-H and/or SMA-AA does not exclude AIH, the characterization of ANA and SMA may help to discriminate between the two conditions. As compared with the seronegative counterpart, autoantibody-positive chronic hepatitis C is more common in females and exhibits a more severe biochemical and histological activity. The response to IFN therapy, however, is similar.
Analysis of Variance↗
Quantitative analysis of hepatitis C virus activity in vivo in different groups of untreated patients.
Highly sensitive competitive PCR (cPCR) and competitive reverse transcription PCR (cRT-PCR) methodologies were recently developed and applied for quantifying viral DNA and RNA species (including HCV RNA) present in clinical samples at low concentration. In this study, we used cRT-PCR to compare the viral load of 118 untreated patients with HCV infection and different clinical conditions (80 patients with chronic hepatitis, 18 infected subjects with persistently normal ALT levels and various degrees of liver injury, 10 HCV infected subjects that tested positive for anti-LKM1 antibodies, and 10 patients with HCV infection and cryoglobulinemia). The results indicate that while great individual variability of HCV viremia is detectable even among patients with similar clinical conditions, the mean HCV RNA copy number in samples from patients with different clinical conditions was similar in all groups with the single exception of patients that tested positive for anti-liver-kidney microsomal auto-antibodies type 1 (anti-LKM1); interestingly, lower HCV viremia levels were revealed in these anti-LKM1-positive cases with liver disease of uncertain pathogenesis.
Gene Dosage↗
Quantitative liver parameters of HCV infection: relation to HCV genotypes, viremia and response to interferon treatment.
BACKGROUND/AIMS: This study aimed to evaluate the relation between the number of hepatocytes positive for HCV antigens and the amount of HCV RNA in the liver and to evaluate the relationship between the above parameters and viremia levels, HCV genotype and response to interferon treatment. METHODS: This was a retrospective study on 31 consecutive patients with chronic HCV-related liver disease, selected on the basis of the availability of frozen liver tissue for both liver HCV antigens detection and liver HCV RNA quantitation. HCV antigens (immunohistochemistry), liver and plasma HCV RNA (competitive RT-PCR), and HCV genotype (commercial kit) were studied. RESULTS: A significant correlation (p=0.0005) was found between the amount of liver HCV RNA (log 10 copy/microg of extracted RNA) and the number of HCV-infected hepatocytes (scored from 0 to 3). These parameters were not significantly correlated with viremia levels. The highest liver HCV RNA levels and HCV antigen scores were found in patients infected with genotype 1b. Liver HCV RNA (median 541 x 10(3) vs 118 x 10(3) copy number/microg, p=0.031) and liver HCV antigens (mean score 2.3 vs 1.3, p=0.018) but not plasma HCV RNA (median 14956 x 10(3) vs 2885 [correction of 2.885] x 10(3) copy number/ml, ns) were significantly higher in patients not responding to interferon treatment compared to responders. CONCLUSIONS: The tissue parameters tested in this study were significantly correlated, shared the same clinical implications and predicted short-term response to interferon treatment better than viremia levels. We suggest that these tests should be included in the study protocol of patients under evaluation for interferon treatment, basing the choice on local facilities.
Adult↗
Ultrasound-detected abdominal lymphadenopathy in chronic hepatitis C: high frequency and relationship with viremia.
BACKGROUND/AIMS: This study aimed to investigate the prevalence and significance of ultrasound-detected deep abdominal lymphadenopathy in chronic hepatitis due to C virus. METHODS: One hundred and thirty-four consecutive patients with various liver disorders were examined with portable real-time equipment. RESULTS: In 25 (19%), the procedure failed because of excessive meteorism. Deep nodes, mainly located in the hepato-duodenal ligament, were detected in 62 of the remaining 109 patients (57%), reaching the highest prevalences in primary biliary cirrhosis (5/7, 71%), chronic hepatitis C (44/66, 67%) and autoimmune hepatitis type 1 (2/3, 67%). For all patients, including those with liver diseases with multiple etiology, lymphadenopathy was more frequent in anti-HCV positive (51/81, 63%) than in negative cases (11/28, 39% p=0.02). In chronic hepatitis C, serum HCV RNA was detected by nested polymerase chain reaction in all 31 patients with, but in only 75% (12/16) of those without nodes (p=0.018). No other distinct clinical or laboratory feature was found in association with lymphadenopathy; in particular, its incidence was similar in cases with and without liver cirrhosis. CONCLUSIONS: Enlarged deep abdominal lymph nodes are frequently detected by ultrasound in patients with chronic hepatitis C. This feature may be of diagnostic utility, especially in early cases, when liver cirrhosis has not yet developed and therefore no other ultrasound sign of the underlying disease can be detected. Lymphadenopathy may be of biological significance, marking hepatitis C virus infection in a replicative, viremic stage. These observations support the existence of a close interaction between hepatitis C virus and the lymphatic system.
Abdomen↗
Clinical implications of GBV-C/HGV infection in patients with "HCV-related" chronic hepatitis.
BACKGROUND/AIMS: To evaluate the clinical, biochemical and histological implications of a concomitant HGV infection in "HCV-related" chronic liver disease. METHODS: Eighty-three HCV-RNA positive patients with chronic liver disease were tested for GBV-C/HGV coinfection by heminested PCR. RESULTS: Twenty-two (26.5%) patients were found to be positive for GBV-C/HGV RNA. GBV-C/HGV+ patients differed significantly from GBV-C/HGV- ones for younger age, higher frequency of history of drug addiction, which in turn might favor coinfection with interferon-sensitive HCV genotypes (3a), and increased probability of long-term response to interferon. GBV-C/HGV infection appears to have no responsibility for specific aspects of HCV infection such as biochemical or histological cholestatic features, lymphoid follicles, symptomatic cryoglobulinemia or presence of serum autoantibodies, including LKM1. It does not worsen the HCV-related disease (ALT levels and histological activity) and does not significantly interfere with HCV infection, as explored by the number of hepatocytes positive for HCV antigens. The amount of steatosis (mean score) was shown to be higher in GBV-C/HGV+ patients. A virological follow up was performed in 17 interferon-treated GBV-C/HGV+ patients On the whole, GBV-C/HGV seems to be as sensitive to IFN treatment as HCV, but recurrence after withdrawal is more frequent. In spite of this, ALT levels often remain normal after treatment withdrawal. CONCLUSIONS: The present data suggest that GBV-C/HGV infection, apart from more marked liver steatosis, does not modify the overall picture of chronic hepatitis due to HCV infection.
Adolescent↗