Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Autoantibodies to soluble liver antigen (SLA) are considered a specific marker of autoimmune hepatitis. We have performed immunoscreening of a human liver gene expression library with an anti-SLA-positive serum. A reactive clone with a 35-kd open reading frame (ORF) and a 563 base pair (bp) 3' untranslated region (UTR) was isolated (soluble liver antigen [SLA]-p35), showing strong homology to an independently isolated putative SLA/liver-pancreas antigen (LP) sequence (Acc. No. AF146396), and a UGA serine tRNA-protein complex (tRNP)((Ser) Sec) related protein (AJ238617), as well as different expression sequence tag (EST)-clones from lymphatic and oncofetal tissues. Expressed in Escherichia coli, SLA-p35 showed dose-dependent and complete blocking of reactivity to native SLA antigen after preabsorption with the 35-kd recombinant protein. It recognized 67/85 (78.8%) precharacterized anti-SLA-positive sera in dilutions up to 1:40,000 in immunoblot, without detectable cross reactivity in the controls. The commercially available SLA/LP enzymelinked immunosorbent assay (ELISA), by comparison, recognized 63/85 samples (74.1%). Of the negative samples, 18% showed strong inhibition rates (80% and above) in the polyclonal inhibition ELISA. We conlude that the complementary DNA now isolated by 3 independent approaches encodes for the major but not sole antigenic component of soluble liver antigen. Although its truncated form presented here may serve to improve diagnostics based on the new recombinant polypeptide, it currently cannot fully replace the polyclonal inhibition ELISA.
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PMID:Soluble liver antigen: isolation of a 35-kd recombinant protein (SLA-p35) specifically recognizing sera from patients with autoimmune hepatitis. 1123 Jul 39

Antibodies to a soluble liver antigen/liver pancreas (SLA/LP) appear to be highly specific for the diagnosis of autoimmune hepatitis. The SLA/LP target antigen was recently identified as a hitherto unknown gene encoding 474 amino acid residues. The function of this antigen remains unclear, because it does not share sequence homology with proteins of known function stored in any of the publicly accessible databases. Therefore we used a new theoretical method called fold recognition and could show that the SLA/LP sequence is compatible with the architecture of the superfamily of pyridoxal phosphate (PLP; vitamin B6)-dependent transferases. Its function is likely to be that of a serine hydroxymethyltransferase and may be an important enzyme in the thus far poorly understood selenocysteine pathway.
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PMID:A bioinformatical approach suggests the function of the autoimmune hepatitis target antigen soluble liver antigen/liver pancreas. 1148 5

Prevalence and clinical relevance of antibodies to soluble liver antigen (tRNP((Ser)Sec)/SLA) in autoimmune hepatitis (AIH) have been investigated using partially purified or prokaryotically expressed antigen. The aim of this study was to improve the detection of anti-tRNP((Ser)Sec)/SLA by establishing an immunoassay that was able to identify antibodies directed to conformational epitopes and to investigate the clinical implication of this autoantibody in autoimmune liver disease. By using eukaryotically expressed tRNP((Ser)Sec)/SLA as target in a radioligand assay (RLA), 81 patients with autoimmune liver disease (AILD) (33 type 1 AIH, 31 type 2 AIH, and 17 autoimmune sclerosing cholantitis [ASC]), 147 pathologic, and 56 healthy controls were investigated. RLA results were compared with those obtained using a commercial enzyme-linked immunosorbent assay (ELISA) and immunoblot. Reactivity to tRNP((Ser)Sec)/SLA was present in 58% of patients with type 1 and type 2 AIH, 41% with ASC, but in only 3 pathologic controls. RLA was similarly disease-specific but remarkably more sensitive than ELISA and immunoblot. A prospective study showed that anti-tRNP((Ser)Sec)/SLA-positive patients run a severe clinical course, having worse histology, needing longer to achieve remission, relapsing and requiring liver transplantation or dying more frequently than anti-tRNP((Ser)Sec)/SLA negative patients. Anti-tRNP((Ser)Sec)/SLA production was favored by the possession of DR3 and A1-B8-DR3 in AIH type 1 and ASC, and prevented by the possession of A2 in all 3 types of AILD, particularly in type 2 AIH. In conclusion, anticonformational tRNP((Ser)Sec)/SLA reactivity is frequent in type 1 and type 2 AIH and ASC, defining patients with a worse prognosis.
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PMID:Antibodies to conformational epitopes of soluble liver antigen define a severe form of autoimmune liver disease. 1219 75

The diagnosis of autoimmune hepatitis (AIH) relies on the exclusion of viral, metabolic, genetic, and toxic etiologies of chronic hepatitis or hepatic injury. There are few parameters that positively predict the presence of AIH. Autoantibodies have been intensively evaluated in this respect and have led to the classification of AIH into three serological subgroups: antinuclear and smooth muscle antibody-positive (ANA/SMA, type 1), liver-kidney microsomal antibody-positive (LKM-1, type 2), and soluble liver antigen/liver-pancreas antigen antibody-positive (SLA/LP, type 3) AIH. Although there are few clinical implications resulting from this classification, autoantibody profiles indicate that AIH is a heterogenous group of entities. The molecular characterization of B cell autoimmunity has led to the identification of major phase I and phase II metabolic enzymes as well as structural and functional components of the cell nucleus as immunologic targets. Autoantibodies and their corresponding autoantigens are intensively studied to provide clues to the understanding of disease initiation, tissue specificity, and propagation of hepatic autoimmune diseases.
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PMID:Autoantibodies and autoantigens in autoimmune hepatitis. 1244 6

Antibodies against soluble liver antigen/liver-pancreas (SLA/LP) have been associated with severe autoimmune hepatitis (AIH) and poor outcome, but most of these reports have focused on adult patients. The aim of this study was to assess the prevalence and clinical significance of anti-SLA/LP antibodies in a pediatric population with AIH. We developed a quantitative enzyme-linked immunoassay (ELISA), a Western blot (WB) and an immunoprecipitation assay (IPA) based on recombinant cDNA from activated Jurkat cells. The specificity of these tests was validated by testing 200 serum samples from healthy subjects, and from patients with liver and non-liver diseases. Anti-SLA/LP antibodies were found in patients with type 1 and type 2 AIH. The prevalence of these antibodies in patients with type 1 AIH was: 42% when tested by ELISA, 15% by WB and 50% by IPA. In patients with type 2 AIH, the prevalence rates were 42% by ELISA, 18% by WB and 44% by IPA. The mean titer values for anti-SLA/LP antibodies was significantly higher in type 2 AIH (1:1,300 +/- 339) than in type 1 AIH (1:600 +/- 71; p < 0.0001) and closely associated with higher titers of anti-liver kidney microsome type 1 (LKM1) and anti-liver cytosol type 1 (LC1) antibodies in sera. The presence of anti-SLA/LP showed a significant female preponderance in type 1 and 2 AIH patients (p = 0.0003 and p = 0.003, respectively), and was significantly correlated with a lower age at diagnosis (p = 0.05) in type 1 AIH patients. In conclusion, anti-SLA/LP antibodies in pediatric patients are associated with both type 1 and 2 AIH.
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PMID:Anti-soluble liver antigen/liver-pancreas (SLA/LP) antibodies in pediatric patients with autoimmune hepatitis. 1276 73

Anti-soluble liver antigen/liver pancreas (SLA/LP) autoantibody has been proposed to be one of the autoantibodies characterizing autoimmune hepatitis (AIH). Recently, one of the autoantigens to anti-SLA/LP was identified as a UGA suppressor tRNA-associated protein. Although the function of this protein remains unknown, the recombinant protein has been prokaryotically expressed. Using this protein as an antigen, a recombinant immunoassay for anti-SLA/LP autoantibody has been established and the frequency and significance of this autoantibody have been discussed in European countries. So, in the present study, we investigated anti-SLA/LP autoantibodies in Japanese patients with autoimmune liver diseases using the recombinant antigen ELISA and Western blot assay. Seventy-five patients with AIH type 1, 5 with AIH type 2, 46 with primary biliary cirrhosis, 10 with primary sclerosing cholangitis, 47 with chronic hepatitis C, 48 with systemic lupus erythematosus, 3 with cryptogenic hepatitis, and 40 normal controls were the subjects of the present study. Anti-SLA/LP autoantibodies were detected in only 5 of 75 (6.7%) patients with AIH type 1, but in none of the other 159 patients or 40 normal controls. The clinicopathologic features of anti-SLA/LP-positive AIH type 1, including carriers of HLA DR locus variations, were not significantly different from anti-SLA/LP-negative patients except for the mortality rate. Anti-SLA/LP autoantibody was detected at a low frequency in Japanese patients with AIH type 1 and did not significantly influence clinical features. However, since it has high disease-specificity to AIH type 1, further analysis of SLA/LP may contribute to help clarify the pathogenesis of AIH type 1.
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PMID:Low frequency of anti-SLA/LP autoantibody in Japanese adult patients with autoimmune liver diseases: analysis with recombinant antigen assay. 1289 38

Autoimmune hepatitis is an unresolving, hepatocellular inflammation of unknown cause that is characterized by the presence of periportal hepatitis on histologic examination, tissue autoantibodies in serum, and hypergammaglobulinemia. By international consensus, the designation autoimmune hepatitis has replaced alternative terms for the condition. Three types of autoimmune hepatitis have been proposed based on immunoserologic findings. Type 1 autoimmune hepatitis is characterized by the presence of antinuclear antibodies (ANA) or smooth muscle antibodies (SMA) (or both) in serum. Seventy percent of patients with type 1 of autoimmune hepatitis are women. This type is the most common form and accounts for at least 80% of cases. Type 2 is characterized by the presence of antibodies to liver-kidney microsome type 1 (anti-LKM1) in serum. Patients with this type of autoimmune hepatitis are predominantly children. Type 3 autoimmune hepatitis is characterized by the presence of antibodies to soluble liver antigen (anti-SLA) in serum. There are no individual features that are pathognomonic of autoimmune hepatitis, and its diagnosis requires the confident exclusion of other conditions. The large majority of patients show satisfactory response to corticosteroid (usually prednisone or prednisolone) therapy. For the past 30 years it has been customary to add azathioprine as a "steroid sparing" agent to allow lower doses of steroids to be used and remission, once achieved, can be sustained in many patients with azathioprine alone after steroid withdrawal. Patients with autoimmune hepatitis who have decompensated during or after corticosteroid therapy are candidates for liver transplantation.
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PMID:[Autoimmune hepatitis]. 1458 66

Autoimmune hepatitis (AIH) is an inflammatory disease of unknown cause characterized by periportal hepatitis, increased serum globulins and the presence of certain antibodies. The disorder can be classified in three types. Type 1 AIH is characterized by the presence of antinuclear antibodies (ANA) and smooth muscle autoantibodies (SMA) in up to 70-80% of patients. ANA and SMA can be the only antibodies present in 13 and 33% of cases respectively. Type 2 AIH is defined by the presence of liver and kidney antimicrosomal antibodies (LKM1). Type 2 AIH is the only form of the disease in which the autoantigen has been identified: cytochrome mono-oxygenase (P-450 IID6) CYP2D6. In type 3 AIH the presence of anti-SLA/LP (soluble liver antigen/liver pancreas) targets a cytosolic protein involved in the incorporation of selenocysteine into peptidic chains. The pathophysiology of AIH is complex and involves genetic predisposition, previous exposure to antigens (autoantigens), presence of triggering factors and defects in immunoregulation. In spite of the advances in the understanding of AIH, the role of autoantibodies in the pathophysiology of this disease has not been fully established and their presence does not clearly distinguish any prognostic groups. Further investigations will help in the diagnosis of this disorder, the comprehension of its origins and the establishment of new forms of treatment.
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PMID:[Antibodies and physiopathogeny of autoimmune hepatitis]. 1496 79

Several phase I and phase II multi-drug metabolizing enzymes, such as CYP2D6, 3A4, and UGTA1, were reported to act as immunotargets in a subset of autoimmune hepatitis and hepatic autoimmunity. However, it is uncertain whether glutathione S-transferase (GST) A1-1, one of the phase II multi-drug metabolizing enzymes, is also an immunotarget in autoimmune hepatitis. So, in the present study, we investigated the frequency and significance of anti-GST A1-1 in sera from patients with autoimmune hepatitis. A total of 74 serum samples from patients with autoimmune hepatitis were examined in the present study. As controls, 20 serum samples from patients with primary biliary cirrhosis, 10 serum samples from patients with primary sclerosing cholangitis, 40 serum samples from patients with liver cirrhosis type B and C, 32 serum samples from patients with systemic lupus erythematosus, and 20 serum samples from normal controls were used. Anti-GST A1-1 antibody was determined by immunoblotting using the recombinant full-length GST A1-1 protein as the antigen. The immunofluorescent staining pattern of anti-GST A1-1 was investigated using rat liver and kidney sections. We compared clinicopathologic findings between anti-GST A1-1-positive and -negative autoimmune hepatitis patients. Anti-GST A1-1 was detected in 12 (16%) of 74 patients with autoimmune hepatitis, however, it was not detected in any control serum samples except for two patients with primary biliary cirrhosis. The immunofluorescence staining pattern of anti-GST A1-1 was found to be unique and different from those of anti-mitochondrial antibody or anti-liver-kidney microsome type 1 antibody. Anti-GST A1-1 coexisted with other autoantibodies such as anti-nuclear or anti-smooth muscle antibodies, but did not coexist with anti-soluble liver antigen/liver pancreas. Anti-GST A1-1-positive autoimmune hepatitis patients had severe clinical features and a poor prognosis compared with anti-GST A1-1-negative patients. These findings suggested that despite the low frequency, anti-GST A1-1 might be the marker of an early progression in autoimmune hepatitis.
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PMID:Frequency and significance of anti-glutathione S-transferase autoantibody (anti-GST A1-1) in autoimmune hepatitis. 1504 Oct 41

Hepatitis C infection is associated with autoimmune disorders, such as the production of autoantibodies. Anti-LKM1 and anti-LC1, immunomarkers of type 2 autoimmune hepatitis, have been previously associated with a HCV infection. Anti-Soluble-Liver-Antigen autoantibodies (SLA) are specifically associated with type 1 and type 2 autoimmune hepatitis and more closely related to patients who relapse after steroid therapy. The recent molecular cloning of the soluble liver antigen provides the opportunity to develop more specific tests for the detection of antibodies against it. The aim of this work is to characterize anti-soluble-liver autoantibodies in sera from patients chronically infected by HCV. A recombinant cDNA from activated Jurkat cells coding for the full length tRNP(Ser)Sec/SLA antigen was obtained. ELISA, Western Blot and immunoprecipitation tests were developed and used to search for linear and conformational epitopes recognized by anti-SLA antibodies in sera from patients chronically infected by HCV. Anti-soluble liver antigen antibodies were found in sera from 10.4% of HCV-infected patients. The prevalence was significantly increased to 27% when anti-LKM1 was also present. Most anti-SLA reactivity was directed against conformational epitopes on the antigen. The means titers by ELISA were lower than those obtained in type 2 AIH. The result of autoantibody isotyping showed a subclass restriction to IgG1 and also IgG4. This study shows the presence of anti-SLA antibodies in approximately 10% of HCV infected patients. The prevalence of SLA autoantibodies in HCV infected patients increases when LKM1 autoantibodies are also present. The relationship between the prevalence of this characteristic autoimmune hepatitis autoantibody and the implication of an autoimmune phenomenon in the liver injury of patients chronically infected by HCV needs further investigation.
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PMID:Anti-soluble liver antigen (SLA) antibodies in chronic HCV infection. 1549 55


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