Autoimmune serology of primary sclerosing cholangitis.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to L Muratori.
Explore the source record for details and available documents.
Antilactoferrin antibodies have been reported in patients with several autoimmune disorders, including primary biliary cirrhosis, autoimmune hepatitis and autoimmune cholangitis. We investigated the prevalence and the clinical significance of such autoreactivity in patients with autoimmune and viral chronic liver disease. Sera from 39 patients with autoimmune hepatitis, 51 with primary biliary cirrhosis, 17 with autoimmune cholangitis, 24 with primary sclerosing cholangitis and 28 with HCV-related chronic hepatitis were studied. Positivity for antilactoferrin antibodies was evaluated by Western immunoblotting with purified human lactoferrin. Antilactoferrin antibodies were detected more often in autoimmune liver disorders (25% autoimmune hepatitis, 25% primary biliary cirrhosis, 35% autoimmune cholangitis, 29% primary sclerosing cholangitis) than in HCV-related chronic hepatitis (3.5%, P < 0.02 versus all). Positivity for antilactoferrin antibodies was not associated with a particular clinical or biochemical profile of the underlying liver disease. No correlation was observed between antilactoferrin reactivity and perinuclear antineutrophil cytoplasmic antibodies. Antilactoferrin antibodies are present significantly more often in autoimmune than in viral liver disorders, but they cannot be considered the serological marker of a specific autoimmune liver disease.
Liver cytosol antibody type 1 (LC1) is regarded as a serologic marker of type 2 autoimmune hepatitis, in addition to liver kidney microsomal antibody type 1. Among 38 patients with type 2 autoimmune hepatitis, 23 were positive for LC1 antibodies. The antigen recognized by LC1 has been identified as a liver-specific 58-kd metabolic enzyme named formiminotransferase cyclodeaminase (FTCD). All 23 LC1-positive sera immunoprecipitated rat FTCD, and 22 gave an identity reaction with rat FTCD by immunodiffusion. No reaction was observed with sera from 10 patients with type 1 autoimmune hepatitis, 10 with primary biliary cirrhosis, 10 with chronic hepatitis C, and 10 healthy controls. By Western immunoblotting all 23 LC1-positive sera and all the controls tested negative, suggesting that all the antigenic epitopes were destroyed by denaturation. FTCD is a bifunctional protein composed of distinct globular FT and CD domains connected by a short linker. To identify epitopes that trigger the LC1 autoimmune response, we tested LC1 antibodies against FTCD constructs encoding the N-terminal FT domain (amino acids 1-339), or the C-terminal CD domain (amino acids 332-541). Of 20 sera positive against full-length FTCD, 8 (40%) recognized the FT domain and the CD domain, 7 (35%) recognized only the FT domain, and 5 (25%) did not recognize either construct. No sera reacted with only the CD domain. These data indicate that multiple regions of FTCD trigger the LC1 autoimmune response, and that LC1 reactivity is mainly directed to conformation-sensitive epitopes located in the FT region of FTCD.
Explore the source record for details and available documents.
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.
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.
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.
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.
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.
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.
In situ reverse transcriptase-polymerase chain reaction is a novel and exciting technique which couples the extremely high sensitivity of DNA amplification with the advantages of in situ hybridisation, allowing the preservation of cell morphology and the localisation of the positive signal within intact cells. In this brief report, we analyse and discuss the application of such a technique to the study of hepatitis C virus (HCV) infection, the most common cause of chronic liver disease worldwide. Moreover, given the lymphotropism of this virus, we describe here our own approach to detect and localise HCV RNA within intact peripheral blood mononuclear cells and to quantify the relative number of infected cells.
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.
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.
BACKGROUND/AIMS: Liver kidney microsomal type 1 antibody (LKM1) is the diagnostic marker of autoimmune hepatitis (AIH) type 2 and is also found in patients with hepatitis C virus (HCV) infection. Cytochrome P4502D6 (CYP2D6) is the documented target antigen of LKM1 in AIH, but not in HCV infection. To compare the reactivity in the two conditions, we established a radioligand assay using eukaryotically expressed CYP2D6 as target. METHODS: A 1.2-kb human CYP2D6 cDNA was isolated from a human liver cDNA library and subcloned into an in vitro transcription vector pSP64 Poly(A). Recombinant CYP2D6 was then produced by in vitro transcription/translation, metabolically labelled with 35S methionine and used in the immunoprecipitation assay. Antibodies that bound radiolabelled CYP2D6 were immunoprecipitated and their levels assessed as cpm. Sera from 50 LKM1-positive patients (26 with AIH; 24 with HCV infection), 128 LKM1-negative patients and 57 normal controls were tested. RESULTS: Reactivity to 35S labelled CYP2D6 was observed in all LKM1-positive sera from patients with AIH and HCV infection, but in none of the controls. The cpm in both conditions were significantly higher than in normal controls (p<0.0001), and were correlated with the immunofluorescence titres of LKM1 (r 0.87, p<0.001 and r=0.64, p<0.001 for AIH and HCV infection, respectively). Reactivity to 35S labelled CYP2D6 was inhibited by addition of an excess of eukaryotically expressed CYP2D6. CONCLUSIONS: CYP2D6 is a major target antigen of both AIH and HCV infection. The novel radioligand assay is highly sensitive and specific.
Explore the source record for details and available documents.
The delay phenomenon in the transverse rectus abdominis myocutaneous (TRAM) flap was studied by means of a laser-Doppler flowmeter and an echo color-flow Doppler device. Twenty-eight patients who underwent breast reconstruction with a TRAM flap in our hospitals were analyzed. Eighteen of them underwent selective delay 1 month before the major surgical procedure, and of them, 15 completed the reconstructive procedure. Ten patients were used as a control group and underwent TRAM flap breast reconstruction without selective delay. Cutaneous blood flow in the TRAM flaps was measured in 20 patients with a laser-Doppler flowmeter, and measurements were taken before, during, and after the surgical procedure, following a standardized protocol, as in Tuominen's original scheme. Variations in the cutaneous blood flow in the standard TRAM flap (10 patients) confirmed data obtained from the literature, i.e., an increase when elevating the cutaneous and subcutaneous parts of the flap and a decrease when ligating the deep inferior and superficial epigastric vessels. Compared with the standard TRAM flap, blood flow in the delayed flaps (10 patients) seemed to be more stable, without falling under the baseline. When elevating the cutaneous and subcutaneous parts of the flap (phase 3), blood flow values reached 120.2 percent (SEM 46.8 percent) on the random side and 131.6 percent (p < 0.009, SEM 9.58 percent, standard deviation 30.3 percent) on the axial side. During phase 4 (cutting the rectus muscles), blood flow values reached 115.0 percent (SEM 40.5 percent) on the random side and 102.8 percent (SEM 1.2 percent, standard deviation 3.8 percent, p < 0.049) on the axial side. In order to obtain further hemodynamic data, 10 patients who underwent selective vascular delay 1 month prior to breast reconstruction with a delayed TRAM flap in our hospitals were then studied by means of an echo color-flow Doppler device. Two of these patients also had been studied with the laser-Doppler flowmeter. Superior epigastric artery diameter (in millimeters) and resistivity (expressed as Pourcelot's index) were measured before and after selective delay of the deep and superficial inferior epigastric vessels, following a standardized protocol. Measurements were taken with 7.5- and 10-MHz linear probes at a point located after the origin of the costomarginal artery. In every patient an increase in the superior epigastric artery diameter and a decrease in the resistivity index were observed, and this was statistically significant. In the nonirradiated patients, the increase in the average diameter of the superior epigastric artery was 98.1 percent, and the average resistivity index decrease was 14.1 percent. In the irradiated patients, the increase in the average diameter of the superior epigastric artery was 35.5 percent, and the average resistivity index decrease was 29.8 percent. In conclusion, laser-Doppler flowmeter evaluations show that cutaneous blood flow in the delayed flap is more constant and undergoes fewer variations than that in the standard TRAM flap. In addition, echo color-flow Doppler indicates that the basis for the increase in the vascular territory of the superior epigastric artery caused by the delay maneuver is an increase in the superior epigastric artery diameter, always accompanied by a decrease in the resistivity index. Two different mechanisms seem to us to be related to these modifications in the blood circulation. In the nonirradiated patients, superior epigastric artery dilation prevails, whereas in the irradiated patients, a decrease in the resistivity index is the dominant mechanism of compensation. These hemodynamic findings well support the decrease in flap necrosis reported in our series (standard TRAM: 30 percent; delayed TRAM: 7.1 percent).
Hepatitis C virus (HCV) is known to infect peripheral blood mononuclear cells (PBMC) of patients with chronic hepatitis C, but the proportion of HCV-infected circulating cells is not detectable by conventional reverse transcriptase-polymerase chain reaction (RT-PCR) and the pathogenic significance of HCV lymphotropism is still unclear. Therefore, we have devised an in situ RT-PCR technique using fluorescein-labeled HCV-specific primers revealed by flow cytometry. PBMC were isolated from 28 patients with chronic HCV-related liver disease; of these, 6 had previously received an orthotopic liver transplantation (OLT) and were on immuno-suppressive treatment. Fourteen patients (50%) were found positive for HCV genome within PBMC by in situ RT-PCR, the proportion of HCV-infected cells ranging from 0.2% to 8.1%. All 6 OLT patients tested positive. The fluorescent signal, corresponding to the HCV-specific 340-bp amplicon, was confined to part of the cytoplasmic compartment of scattered PBMC. Of these 14 patients, 12 had also negativestrand HCV RNA within PBMC detected by "tagged" RT-PCR. We conclude that HCV may infect a significant proportion of PBMC in chronic hepatitis C patients, especially immunosuppressed OLT cases, and that viral replication within PBMC is a common occurrence. Over time, the persistence of HCV-infected immune system cells might interfere with normal immunologic mechanisms and play a role in the pathogenic processes leading to extrahepatic disorders such as mixed cryoglobulinemia and B-cell malignant lymphoma.
We have reclassified 110 patients with autoantibody-positive cryptogenic chronic hepatitis according tot he aggregate scoring system proposed by the International Autoimmune Hepatitis Group for signs of hepatitis C virus (HCV) infection and the newly proposed terminology of "unclassified" chronic hepatitis. Anti-HCV and HCV viremia were assessed by second-generation assays and reverse transcription-polymerase chain reaction. Immunomorphological and immunochemical characterizations of antinuclear, smooth, muscle, liver-kidney microsomal type 1, and liver cytosol type 1 autoantibodies were also performed. All 45 anti-HCV negative patients fulfilled the score criteria for the diagnosis of "definite" or "probable" autoimmune hepatitis (AIH). Eight anti-HCV-positive cases reached the score of "probable" AIH, whereas the remaining 57 cases were diagnosed as unclassified chronic hepatitis. The scoring system allows the correct identification of all autoimmune cases without HCV infection. Autoimmune hepatitis runs a more severe disease course than unclassified chronic hepatitis, whose clinical and histological features are similar to those of autoantibody-negative chronic hepatitis C.