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1.
Digestion ; 83(4): 275-82, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21282952

RESUMO

BACKGROUND AND AIM: Sorafenib has become the treatment standard for patients with advanced hepatocellular carcinoma (HCC). It is not clear whether patients with advanced liver function impairment (Child B) and patients undergoing additional locoregional therapy may tolerate treatment with sorafenib and benefit. We aimed to evaluate the tolerability and efficiency of sorafenib in patients with advanced HCC and different stages of liver cirrhosis, and in combination with locoregional therapy. METHODS: In 50 patients with advanced HCC treated with sorafenib tolerability and efficiency of the therapy with respect to stage of liver cirrhosis, existence of extrahepatic tumor spread, and additional locoregional therapy were evaluated. RESULTS: Fifty patients with advanced HCC were treated with sorafenib, and 13 received additional locoregional therapy. Tolerability of the systemic treatment was moderate in all patients, with no significant differences between the subgroups, while the median survival was better in patients with Child A than Child B cirrhosis. CONCLUSION: Tolerability and toxicity of a systemic treatment with sorafenib are moderate in patients with liver cirrhosis in Child A or B. Prospective randomized studies are required to evaluate the efficacy and tolerability of combined systemic and locoregional treatment approaches in patients with advanced HCC.


Assuntos
Antineoplásicos/uso terapêutico , Benzenossulfonatos/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Cirrose Hepática/complicações , Neoplasias Hepáticas/tratamento farmacológico , Piridinas/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Benzenossulfonatos/efeitos adversos , Carcinoma Hepatocelular/etiologia , Estudos de Coortes , Feminino , Humanos , Neoplasias Hepáticas/etiologia , Masculino , Pessoa de Meia-Idade , Niacinamida/análogos & derivados , Compostos de Fenilureia , Piridinas/efeitos adversos , Sorafenibe , Resultado do Tratamento , Adulto Jovem
2.
J Hepatol ; 53(3): 484-91, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20605050

RESUMO

BACKGROUND & AIMS: Mannose-binding lectin (MBL) is a serum lectin synthesized by the liver and involved in innate host defense. MBL deficiency increases the risk of various infectious diseases mostly in immune-deficient conditions. Bacterial infections are a significant cause of morbidity and mortality in liver cirrhosis due to the relative immuncompromised state. METHODS: Sera of 929 patients with various chronic liver diseases [autoimmune liver diseases (ALD), 406; viral hepatitis C (HCV), 185; and liver cirrhosis (LC) with various etiologies, 338] and 296 healthy controls (HC) were assayed for MBL concentration. Furthermore, a follow-up, observational study was conducted to assess MBL level as a risk factor for clinically significant bacterial infections in cirrhotic patients. RESULTS: MBL level and the prevalence of absolute MBL deficiency (<100 ng/ml) was not significantly different between patients and controls (ALD: 14.5%, HCV: 11.9%, LC: 10.7%, HC: 15.6%). In cirrhotic patients, the risk for infection was significantly higher among MBL deficient subjects as compared to non-deficient ones (50.0% vs. 31.8%, p=0.039). In a logistic regression analysis, MBL deficiency was an independent risk factor for infections (OR: 2.14 95% CI: 1.03-4.45, p=0.04) after adjusting for Child-Pugh score, co-morbidities, gender, and age. In a Kaplan-Meier analysis, MBL deficiency was associated with a shorter time to develop the first infectious complication (median days: 579 vs. 944, pBreslow=0.016, pLogRank=0.027) and was identified as an independent predictor in a multivariate Cox-regression analysis (p=0.003, OR: 2.33, 95% CI: 1.34-4.03). CONCLUSIONS: MBL deficiency is associated with a higher probability and shorter time of developing infections in liver cirrhosis, further supporting the impact of the MBL molecule on the host defense.


Assuntos
Infecções Bacterianas/sangue , Infecções Bacterianas/etiologia , Cirrose Hepática/sangue , Cirrose Hepática/complicações , Lectina de Ligação a Manose/deficiência , Adulto , Idoso , Infecções Bacterianas/imunologia , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Humanos , Hungria , Imunidade Inata , Cirrose Hepática/imunologia , Hepatopatias/sangue , Hepatopatias/complicações , Hepatopatias/imunologia , Masculino , Lectina de Ligação a Manose/sangue , Lectina de Ligação a Manose/imunologia , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Risco , Fatores de Tempo
3.
BMC Cancer ; 10: 317, 2010 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-20569442

RESUMO

BACKGROUND: The product of CDKN2A, p16 is an essential regulator of the cell cycle controlling the entry into the S-phase. Herein, we evaluated CDKN2A promoter methylation and p16 protein expression for the differentiation of hepatocellular carcinoma (HCC) from other liver tumors. METHODS: Tumor and corresponding non-tumor liver tissue samples were obtained from 85 patients with liver tumors. CDKN2A promoter methylation was studied using MethyLight technique and methylation-specific PCR (MSP). In the MethyLight analysis, samples with > or = 4% of PMR (percentage of methylated reference) were regarded as hypermethylated. p16 expression was evaluated by immunohistochemistry in tissue sections (n = 148) obtained from 81 patients using an immunoreactivity score (IRS) ranging from 0 (no expression) to 6 (strong expression). RESULTS: Hypermethylation of the CDKN2A promoter was found in 23 HCCs (69.7%; mean PMR = 42.34 +/- 27.8%), six (20.7%; mean PMR = 31.85 +/- 18%) liver metastases and in the extralesional tissue of only one patient. Using MSP, 32% of the non-tumor (n = 85), 70% of the HCCs, 40% of the CCCs and 24% of the liver metastases were hypermethylated. Correspondingly, nuclear p16 expression was found immunohistochemically in five (10.9%, mean IRS = 0.5) HCCs, 23 (92%; mean IRS = 4.9) metastases and only occasionally in hepatocytes of non-lesional liver tissues (mean IRS = 1.2). The difference of CDKN2A-methylation and p16 protein expression between HCCs and liver metastases was statistically significant (p < 0.01, respectively). CONCLUSION: Promoter methylation of CDKN2A gene and lack of p16 expression characterize patients with HCC.


Assuntos
Biomarcadores Tumorais , Carcinoma Hepatocelular/química , Carcinoma Hepatocelular/genética , Inibidor p16 de Quinase Dependente de Ciclina , Metilação de DNA , Neoplasias Hepáticas/química , Neoplasias Hepáticas/genética , Regiões Promotoras Genéticas , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/patologia , Inibidor p16 de Quinase Dependente de Ciclina/análise , Inibidor p16 de Quinase Dependente de Ciclina/genética , Epigênese Genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase
5.
J Cancer Res Clin Oncol ; 134(5): 579-89, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-17973119

RESUMO

PURPOSE: We investigated the impact of promoter methylation on APC protein expression in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: 50 patients [HCC (n=19), liver metastasis (n=19), cholangiocellular cancer (n=7), and benign liver tumors (n=5)] were studied for methylation using Methylight analysis. APC mutation was investigated by protein truncation test and direct sequencing of genomic DNA. The protein expression was evaluated by immunohistochemistry and Western blot analysis. RESULTS: The APC promoter was hypermethylated in 81.8% of non-cancerous liver tissue samples. All HCC samples and ten patients with liver metastasis (52.6%) exhibited APC promoter methylation. The degree of methylation was significantly higher in samples from HCC compared to the non-cancerous liver tissue samples (63.1% vs. 24.98%; p=0.001). The level of APC protein expression was significantly reduced in HCC samples compared to that of the corresponding non-tumor liver tissue (p<0.05). CONCLUSIONS: Promoter methylation of the APC gene seems to be of significance in hepatocarcinogenesis and results in reduced protein expression in HCC. Interestingly, APC promoter methylation is also present in the vast majority of non-cancerous liver tissue whose (patho)physiological function remains unresolved.


Assuntos
Proteína da Polipose Adenomatosa do Colo/biossíntese , Proteína da Polipose Adenomatosa do Colo/genética , Carcinoma Hepatocelular/genética , Metilação de DNA , Neoplasias Hepáticas/genética , Regiões Promotoras Genéticas/genética , Sequência de Bases , Western Blotting , Carcinoma Hepatocelular/metabolismo , Análise Mutacional de DNA , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/metabolismo , Dados de Sequência Molecular , Mutação
7.
Gastroenterology ; 131(5): 1418-30, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17101318

RESUMO

BACKGROUND & AIMS: The identification of novel genetic and epigenetic markers indicative of changes in the pathogenesis of colon cancer, along with easier-to-use, more sensitive assay methods, may improve the detection, treatment, and overall prognosis of this malignancy. METHODS: Using methylation-specific arbitrarily primed polymerase chain reaction, a fragment of the Aristaless-like homeobox-4 (ALX4) gene that was highly methylated in colon adenomas and cancer was identified. Methylation of ALX4 was analyzed in colorectal adenomas and cancers, in the liver metastases of patients with colorectal cancer, and in 61 other neoplasias, including gastric, esophageal, and hepatocellular cancer and cholangiocarcinoma. ALX4 methylation was also analyzed in the serum of 30 patients with colon cancer. RESULTS: ALX4 gene methylation was confirmed in colon adenomas (11/13) and more frequently present in primary colorectal cancers (30/47) compared with the normal colon mucosa (0/21) (P < .0001). In addition, ALX4 methylation was frequently observed in adenocarcinomas of the esophagus (12/14), stomach (11/15), and bile ducts (4/5) compared with all other cancers (P < .001). ALX4 gene methylation was also more frequently found in sera of patients with colon cancer compared with noncancer controls (P < .0001). Using a cutoff of 41.4 pg/mL, sensitivity and specificity were 83.3% and 70%, respectively. CONCLUSIONS: Apart from colon adenomas and primary and metastatic colorectal cancers, ALX4 is frequently methylated in adenocarcinomas of the gastrointestinal tract. ALX4 gene methylation in sera of patients with cancer may thus serve as a methylation-specific test for colon and other gastrointestinal cancers.


Assuntos
Adenocarcinoma/genética , Neoplasias Colorretais/genética , Proteínas de Ligação a DNA/genética , Fatores de Transcrição/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , Pólipos do Colo/genética , Metilação de DNA , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Metástase Neoplásica , Lesões Pré-Cancerosas/genética
9.
Scand J Gastroenterol ; 41(7): 838-43, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16785198

RESUMO

OBJECTIVE: Transabdominal ultrasound (US) is the most frequently used imaging method for the diagnosis of choledocholithiasis. The aim of this prospective study was to evaluate the diagnostic accuracy of high-resolution US in the diagnosis of common bile duct stones depending on the operator's experience and in comparison with endoscopic retrograde cholangiography (ERC) as the gold standard. MATERIAL AND METHODS: From April 2003 through November 2004, 126 patients referred because of clinically and biochemically suspected common bile duct stones were included in the study. Two patients were excluded because they refused to undergo ERC. Consequently, the study comprised 124 patients (86 F, 38 M, mean age 63.2 years, range 21-91 years). High-resolution US was performed (2-5 MHz sector scanner; Siemens Elegra, Erlangen, Germany) by operators who were unaware of the results of other imaging procedures. The definitive diagnosis was established by means of ERC. RESULTS: Thirty-five out of 124 patients were investigated by experienced examiners. Twenty-seven of 35 patients (77%) were found to have stones at ERC. Bile duct stones were correctly found by US in 22 out of 27 patients (sensitivity 82%, 95% CI: 63-92). Of the 8 patients without stones at ERC, one false-positive diagnosis was made with US (specificity 88%, 95% CI: 53-98). Correct diagnoses were made in 29 out of 35 (accuracy 83%, 95% CI: 67-92) patients investigated by experienced examiners. Eighty-nine out of 124 patients were investigated by less-experienced examiners. Fifty-four of 89 patients (61%) were found to have stones at ERC. Choledocholithiasis was found correctly in only 25 out of 54 patients (sensitivity 46%, 95% CI: 34-59). Of the 35 patients without stones at ERC, three false-positive diagnoses were made with US (specificity 91%, 95% CI: 78-97). In conclusion, correct diagnoses were observed in 57 of 89 patients (accuracy 64%, 95% CI: 54-73) investigated by less-experienced examiners (p<0.05 in comparison with the results of experienced examiners). CONCLUSIONS: High-resolution US carried out by experienced examiners has a high diagnostic accuracy in the diagnosis of choledocholithiasis. Therefore, good training and continued experience are prerequisites for successful sonographic detection of bile duct stones using US. Under these conditions, further expensive and invasive methods such as ERC, magnetic resonance cholangiopancreatography and endoscopic ultrasonography may not be necessary in cases with a clear sonographic diagnosis.


Assuntos
Colangiopancreatografia Retrógrada Endoscópica , Coledocolitíase/diagnóstico por imagem , Coledocolitíase/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Coledocolitíase/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Estudos Prospectivos , Ultrassonografia
10.
World J Gastroenterol ; 12(9): 1362-6, 2006 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-16552802

RESUMO

AIM: Prednisone and azathioprine represent the standard treatment for autoimmune hepatitis (AIH). However, only 65% of the patients enter complete histological remission. Recently, budesonide (BUD) was reported to be a promising alternative. In this study we assessed the efficacy and safety of BUD in AIH. METHODS: Eighteen patients (12 women, 6 men; mean age 45.4+/-21 years)with AIH were treated with BUD (Budenofalk) 3 mg thrice daily and followed up for at least 24 wk. Seven patients also had features of primary biliary cirrhosis (n=5) or primary sclerosing cholangitis (n=2). Advanced liver fibrosis or cirrhosis was present in 6 patients. RESULTS: Fifteen (83%) patients had a complete clinical and biochemical remission. Ten patients, including five with acute hepatitis,were given BUD as first-line therapy, of which seven enter remission. Three patients, two with liver cirrhosis, did not improve.All patients with second-line therapy experienced long-term remission. A histological remission was also seen in three patients. Clinically relevant BUD-induced side effects were recorded only in patients with liver cirrhosis (n=4). CONCLUSION: BUD is effective in remission induction in the majority of our patients with AIH. Side effects and treatment failure was mainly observed in patients with liver cirrhosis.


Assuntos
Anti-Inflamatórios/uso terapêutico , Budesonida/uso terapêutico , Hepatite Autoimune/tratamento farmacológico , Adulto , Idoso , Anti-Inflamatórios/efeitos adversos , Budesonida/efeitos adversos , Feminino , Hepatite Autoimune/patologia , Humanos , Fígado/patologia , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Terapia de Salvação
11.
World J Gastroenterol ; 11(26): 4114-6, 2005 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-15996042

RESUMO

We report on a 26-year-old man who presented with severe jaundice and elevated serum liver enzyme activities after having received a dose of Twinrix. In his past medical history, jaundice or abnormal liver function tests were never recorded. Following admission, an elevated immunoglobulin G level and antinuclear antibodies at a titer of 320 with a homogenous pattern were found. Histology of a liver biopsy showed marked bridging liver fibrosis and a chronic inflammation, compatible with autoimmune hepatitis. Treatment was started with budesonide and ursodeoxycholic acid, and led to complete normalization of the pathological liver function tests. We believe that Twinrix led to an acute exacerbation of an unrecognized autoimmune hepatitis in our patient. The pathogenesis remains to be clarified. It is tempting to speculate that inactivated hepatitis A virus and/or recombinant surface antigen of the hepatitis B virus -as seen in patients with chronic hepatitis C and unrecognized autoimmune hepatitis who were treated with interferon alpha-might have been responsible for disease exacerbation.


Assuntos
Hepatite Autoimune/etiologia , Hepatite Autoimune/patologia , Vacinas Combinadas/efeitos adversos , Adulto , Biópsia , Hepatite Autoimune/tratamento farmacológico , Humanos , Imunossupressores/uso terapêutico , Fígado/patologia , Testes de Função Hepática , Masculino
12.
Dig Dis ; 23(1): 6-10, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15920320

RESUMO

Portal hypertension is defined by an elevation in blood pressure in the portal system. Different causes are known and include a pre-, intra-, or posthepatic block. Portal hypertension is also classified according to the sinusoidal system. Portal pressure becomes elevated by either an increase in blood flow (Q), an increase in resistance (R), or both. Regulation of the vascular tone in the splanchnic system includes intrinsic and extrinsic aspects. A variety of metabolic end-products (e.g. adenosine), endothelium-derived substances (e.g. nitric oxide), and certain neurotransmitters (e.g. acetylcholine) are known to relax the tone and thus produce vasodilation. Important vasoconstrictor influences on splanchnic arterioles include circulating agents (e.g. angiotensin), endothelium-derived substances (e.g. endothelin), and again neurotransmitters (norepinephrine). Besides vascular tone, structural changes (thrombosis, fibrosis, shear stress, and cell regeneration) add to overall hepatic resistance. Further consequences of portal hypertension include an increase in blood flow which leads to a hyperdynamic state with fluid retention, leading to secondary involvement of other organs, such as cirrhotic cardiomyopathy, hepatopulmonary syndrome and hepatorenal syndrome. Finally, portal hypertension will end up in the formation of collateral vessels. Varices can involve the whole gastrointestinal tract and are a frequent source of bleeding.


Assuntos
Hipertensão Portal/metabolismo , Hipertensão Portal/fisiopatologia , Fígado/irrigação sanguínea , Humanos , Fígado/anatomia & histologia , Fluxo Sanguíneo Regional , Vasoconstrição , Vasodilatação
14.
Int Immunol ; 16(1): 51-4, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14688060

RESUMO

Previously we observed elevation of the serum concentration of two acute-phase protein (AFP) complement components (C9 and C1-inhibitor) in patients with chronic hepatitis C who responded (R) to IFN-alpha therapy, but not in non-responders (NR). In the present study we investigated the effect of high-dose IFN-alpha therapy on serum concentrations of two positive [orosomucoid (OROSO) and C-reactive protein (CRP)] and two negative [transferrin (TF) and fetuin/alpha2HS-glycoprotein (AHSG)] AFP in an outpatient setting. We investigated blood samples of 40 patients with chronic hepatitis C at the onset and at the end of a 3-month treatment with high-dose IFN-alpha2b (5 MIU/day for 6 weeks, followed by 5 MIU t.i.w.) and of 52 healthy individuals. Serum concentrations of OROSO, TF and AHSG were measured by radial immunodiffusion; CRP levels were determined by immunotubridimetry. Compared to controls, patients with chronic hepatitis C had significantly lower OROSO and CRP, and higher AHSG levels. By the end of treatment, OROSO concentration increased in R (P = 0.0054), but not in NR patients. In contrast, TF levels decreased in R (P = 0.0040), but did not change in NR patients. Similarly, in R patients, AHSG levels tended to decrease (P = 0.0942) following IFN-alpha treatment. We conclude that the acute-phase reaction is suppressed in patients with chronic hepatitis C that may be potentially related to the responsiveness to IFN-alpha therapy.


Assuntos
Proteínas de Fase Aguda/análise , Proteínas de Fase Aguda/efeitos dos fármacos , Hepatite C Crônica/sangue , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Feminino , Humanos , Interferon alfa-2 , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes
15.
Immunobiology ; 207(3): 161-8, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12777057

RESUMO

Previously we detected more than 3 times higher anti-cholesterol antibody (ACHA) levels in HIV positive patients compared to healthy individuals, however, this level significantly decreased during highly active anti-retroviral therapy (HAART). In our present study we examined whether these findings could also be detected in patients with chronic hepatitis C (CHC). We calculated the correlation between the ACHA levels and the C5b-9 complement activation product. 39 patients with CHC were treated with IFN-alpha-2b (Schering-Plough) 5 MU daily for 6 weeks, followed by 5 MU TIW. Serum levels of ACHA and complement activation products were measured with ELISA. Serum HCV RNA was measured by a highly sensitive branched DNA technique before and 3, 6 and 12 months after the beginning of IFN-alpha-2b therapy. 52 healthy persons served as controls. At the onset of treatment ACHA level was significantly (p = 0.0062) higher in patients (40 (24-69) AU/ml) (median (interquartile range)) than in control sera (26 (20-35) AU/ml). In the 26 responder patients ACHA levels decreased to the normal level during the therapy, but no change was observed in the 13 non-responders. In patients with a sustained response ACHA levels remained low till the end of the 12 months IFN treatment. ACHA levels were significantly (p = 0.0422) higher in the patients with low (< 4.0 mmol/l) than in those with normal (> or = 4.0 mmol/l) cholesterol concentrations. The ACHA level before the therapy strongly correlated (r = 0.5499, p = 0.0014) with C5b-9 serum levels. ACHA levels are elevated in CHC, but this elevation is not as high as in HIV. Decrease of viral load by IFN-alpha-2b treatment in the responders results in normalization of ACHA concentration. High ACHA levels in patients with low serum cholesterol concentration suggest that high ACHA levels may contribute to the decrease in cholesterol levels. The correlation between the ACHA and C5b-9 levels indicate, that the ACHA may play a role in the complement activation in CHC.


Assuntos
Colesterol/imunologia , Hepatite C Crônica/sangue , Hepatite C Crônica/terapia , Interferon-alfa/uso terapêutico , Adulto , Anticorpos Anti-Idiotípicos , Estudos de Casos e Controles , Colesterol/sangue , Ativação do Complemento , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Hepacivirus/genética , Humanos , Interferon alfa-2 , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , Proteínas Recombinantes , Fatores de Tempo , Triglicerídeos/sangue
16.
Clin Dev Immunol ; 10(2-4): 173-81, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14768949

RESUMO

BACKGROUND AND AIMS: Antimitochondrial antibodies (AMA) which recognize pyruvate acetyltransferase (PDC-E2) represent a highly diagnostic feature of primary biliary cirrhosis (PBC). The analysis of immunofluorescence (IF)-AMA-positive sera in PBC patients indicates a conformational epitope located within the lipoyl binding domain of bovine branched-chain acyltransferase (BCKADC-E2) alone or in combination with AMA directed against PDC-E2 the significance of which is presently unclear. In the present study, immunoreactivities and disease associations of AMA against BCKADC-E2 were analyzed. B-cell autoepitopes on BCKADC-E2 were mapped by immunoprecipitation assay. METHODS: Sera of 96 IF-AMA-positive patients with serological evidence of anti-BCKADC-E2 alone (n = 26), anti-PDC-E2 alone (n = 15), and both anti-BCKADC-E2 and anti-PDC-E2 (n = 55) were analyzed by Western blot and ELISA in addition to an analysis of B cell autoepitopes on BCKADC-E2 by immunoprecipitation using in vitro translated, unmodified human proteins. Ninety-four patients without IF-AMA [blood donors (n = 30), rheumatoid arthritis (n = 40), autoimmune hepatitis (AIH)(n = 10) and primary sclerosing cholangitis (PSC) (n = 14) served as controls. RESULTS: Eighty of 81 (99%) sera positive for BCKADC-E2 recognized the full length, mature protein, while only 2/10 AIH sera and none of the other controls showed reactivity. Of the 68 PBC sera 58 (85%) recognized the N-terminus consisting of aa 1-144 representing the lipoyl domain. Surprisingly, C-terminal sequences (aa 143-421) were recognized by 46 out of 68 sera (68%). Three PBC sera reacted with the C-terminus only. Only 1/7 serum from patients with an "overlap syndrome of PBC and AIH" was reactive with C-terminal sequences. CONCLUSIONS: Our analysis of BCKADC-E2-positive PBC sera identified a novel B cell epitope on the C-terminal part of the human protein. Our data indicate that a distinct subset of AMA recognize sequence(s) on BCKADC-E2 which located outside of the lipoyl binding domain. The absence of immunoreactivity against C-terminal sequences may serve as a marker differentiating patients with PBC and overlap syndrome of PBC with AIH.


Assuntos
Aciltransferases/imunologia , Autoanticorpos/imunologia , Autoantígenos/imunologia , Linfócitos B/imunologia , Epitopos de Linfócito B/imunologia , Hepatite Autoimune/imunologia , Cirrose Hepática Biliar/imunologia , Aciltransferases/química , Aciltransferases/genética , Aciltransferases/metabolismo , DNA Complementar/genética , Mapeamento de Epitopos , Hepatite Autoimune/sangue , Hepatite Autoimune/complicações , Hepatite Autoimune/enzimologia , Humanos , Cirrose Hepática Biliar/sangue , Cirrose Hepática Biliar/complicações , Cirrose Hepática Biliar/enzimologia , Ensaio Radioligante , Sensibilidade e Especificidade
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