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Featured researches published by George N. Dalekos.


Hepatology | 2008

Simplified criteria for the diagnosis of autoimmune hepatitis

E. M. Hennes; Mikio Zeniya; Albert J. Czaja; Albert Parés; George N. Dalekos; Edward L. Krawitt; Paulo Lisboa Bittencourt; Gilda Porta; Kirsten Muri Boberg; Harald Hofer; Francesco B. Bianchi; Minoru Shibata; Christoph Schramm; Barbara Eisenmann de Torres; Peter R. Galle; Ian G. McFarlane; H. P. Dienes; Aw Lohse

Diagnosis of autoimmune hepatitis (AIH) may be challenging. However, early diagnosis is important because immunosuppression is life‐saving. Diagnostic criteria of the International Autoimmune Hepatitis Group (IAIHG) were complex and purely meant for scientific purposes. This study of the IAIHG aims to define simplified diagnostic criteria for routine clinical practice. Candidate criteria included sex, age, autoantibodies, immunoglobulins, absence of viral hepatitis, and histology. The training set included 250 AIH patients and 193 controls from 11 centers worldwide. Scores were built from variables showing predictive ability in univariate analysis. Diagnostic value of each score was assessed by the area under the receiver operating characteristic (ROC) curve. The best score was validated using data of an additional 109 AIH patients and 284 controls. This score included autoantibodies, immunoglobulin G, histology, and exclusion of viral hepatitis. The area under the curve for prediction of AIH was 0.946 in the training set and 0.91 in the validation set. Based on the ROC curves, two cutoff points were chosen. The score was found to have 88% sensitivity and 97% specificity (cutoff ≥6) and 81% sensitivity and 99% specificity (cutoff ≥7) in the validation set. Conclusion: A reliable diagnosis of AIH can be made using a very simple diagnostic score. We propose the diagnosis of probable AIH at a cutoff point greater than 6 points and definite AIH 7 points or higher. (HEPATOLOGY 2008.)


The New England Journal of Medicine | 2011

Peginterferon plus Adefovir versus Either Drug Alone for Hepatitis Delta

Heiner Wedemeyer; Cihan Yurdaydin; George N. Dalekos; A. Erhardt; Yilmaz Cakaloglu; Halil Degertekin; Selim Gurel; Stefan Zeuzem; Kalliopi Zachou; Hakan Bozkaya; Armin Koch; Thomas Bock; Hans Peter Dienes; Michael P. Manns

BACKGROUND Chronic infection with hepatitis B virus and hepatitis delta virus (HDV) results in the most severe form of viral hepatitis. There is no currently approved treatment. We investigated the safety and efficacy of 48 weeks of treatment with peginterferon alfa-2a plus adefovir dipivoxil, peginterferon alfa-2a alone, and adefovir dipivoxil alone. METHODS We conducted a randomized trial in which 31 patients with HDV infection received treatment with 180 μg of peginterferon alfa-2a weekly plus 10 mg of adefovir daily, 29 received 180 μg of peginterferon alfa-2a weekly plus placebo, and 30 received 10 mg of adefovir alone weekly for 48 weeks. Follow-up was conducted for an additional 24 weeks. Efficacy end points included clearance of HDV RNA, normalization of alanine aminotransferase levels, and a decline in levels of hepatitis B surface antigen (HBsAg). RESULTS The primary end point--normalization of alanine aminotransferase levels and clearance of HDV RNA at week 48--was achieved in two patients in the group receiving peginterferon alfa-2a plus adefovir and two patients in the group receiving peginterferon alfa-2a plus placebo but in none of the patients in the group receiving adefovir alone. At week 48, the test for HDV RNA was negative in 23% of patients in the first group, 24% of patients in the second, and none of those in the third (P = 0.006 for the comparison of the first and third groups; P = 0.004 for the comparison of the second and third). The efficacy of peginterferon alfa-2a was sustained for 24 weeks after treatment, with 28% of the patients receiving peginterferon alfa-2a plus adefovir or peginterferon alfa-2a alone having negative results on HDV-RNA tests; none of the patients receiving adefovir alone had negative results. A decline in HBsAg levels of more than 1 log(10) IU per milliliter from baseline to week 48 was observed in 10 patients in the first group, 2 in the second, and none in the third (P<0.001 for the comparison of the first and third groups and P = 0.01 for the comparison of the first and second). CONCLUSIONS Treatment with peginterferon alfa-2a for 48 weeks, with or without adefovir, resulted in sustained HDV RNA clearance in about one quarter of patients with HDV infection. (Current Controlled Trials number, ISRCTN83587695.).


Journal of Autoimmune Diseases | 2004

Autoantibodies and autoantigens in autoimmune hepatitis: important tools in clinical practice and to study pathogenesis of the disease

Kalliopi Zachou; Eirini I. Rigopoulou; George N. Dalekos

Autoimmune hepatitis (AIH) is a chronic necroinflammatory disease of the liver characterized by hypergammaglobulinemia, characteristic autoantibodies, association with HLA DR3 or DR4 and a favorable response to immunosuppressive treatment. The etiology is unknown. The detection of non-organ and liver-related autoantibodies remains the hallmark for the diagnosis of the disease in the absence of viral, metabolic, genetic, and toxic etiology of chronic hepatitis or hepatic injury. The current classification of AIH and the several autoantibodies/target-autoantigens found in this disease are reported. Current aspects on the significance of these markers in the differential diagnosis and the study of pathogenesis of AIH are also stated. AIH is subdivided into two major types; AIH type 1 (AIH-1) and type 2 (AIH-2). AIH-1 is characterized by the detection of smooth muscle autoantibodies (SMA) and/or antinuclear antibodies (ANA). Determination of antineutrophil cytoplasmic autoantibodies (ANCA), antibodies against the asialoglycoprotein receptor (anti-ASGP-R) and antibodies against to soluble liver antigens or liver-pancreas (anti-SLA/LP) may be useful for the identification of patients who are seronegative for ANA/SMA. AIH-2 is characterized by the presence of specific autoantibodies against liver and kidney microsomal antigens (anti-LKM type 1 or infrequently anti-LKM type 3) and/or autoantibodies against liver cytosol 1 antigen (anti-LC1). Anti-LKM-1 and anti-LKM-3 autoantibodies are also detected in some patients with chronic hepatitis C (HCV) and chronic hepatitis D (HDV). Cytochrome P450 2D6 (CYP2D6) has been documented as the major target-autoantigen of anti-LKM-1 autoantibodies in both AIH-2 and HCV infection. Recent convincing data demonstrated the expression of CYP2D6 on the surface of hepatocytes suggesting a pathogenetic role of anti-LKM-1 autoantibodies for the liver damage. Family 1 of UDP-glycuronosyltransferases has been identified as the target-autoantigen of anti-LKM-3. For these reasons the distinction between AIH and chronic viral hepatitis (especially of HCV) is of particular importance. Recently, the molecular target of anti-SLA/LP and anti-LC1 autoantibodies were identified as a 50 kDa UGA-suppressor tRNA-associated protein and a liver specific enzyme, the formiminotransferase cyclodeaminase, respectively. Anti-ASGP-R and anti-LC1 autoantibodies appear to correlate closely with disease severity and response to treatment suggesting a pathogenetic role of these autoantibodies for the hepatocellular injury. In general however, autoantibodies should not be used to monitor treatment, predict AIH activity or outcome. Finally, the current aspects on a specific form of AIH that may develop in some patients with a rare genetic syndrome, the autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED) are also given. Autoantibodies against liver microsomes (anti-LM) are the specific autoantibodies detected in AIH as a disease component of APECED but also in cases of dihydralazine-induced hepatitis. Cytochrome P450 1A2 has been identified as the target-autoantigen of anti-LM autoantibodies in both APECED-related AIH and dihydralazine-induced hepatitis. The latter may indicate that similar autoimmune pathogenetic mechanisms can lead to liver injury in susceptible individuals irrespective of the primary defect. Characterization of the autoantigen-autoantibody repertoire continues to be an attractive and important tool to get access to the correct diagnosis and to gain insight into the as yet unresolved mystery of how hepatic tolerance is given up and AIH ensues.


Gut | 2005

Prevalence and clinical significance of isotype specific antinuclear antibodies in primary biliary cirrhosis.

Eirini I. Rigopoulou; E T Davies; Albert Parés; Kalliopi Zachou; Christos Liaskos; D.P. Bogdanos; Juan Rodés; George N. Dalekos; Diego Vergani

Background: Antinuclear antibodies (ANA) giving a rim-like/membranous (RL/M) or a multiple nuclear dot (MND) pattern are highly specific for primary biliary cirrhosis (PBC). Aim and subjects: To assess the prevalence of PBC specific ANAs, their Ig isotype, and their clinical significance in 90 PBC patients from Greece and Spain. Twenty eight patients with chronic hepatitis C, 23 patients with systemic lupus erythematosus, and 17 healthy subjects were studied as controls. Methods: PBC specific ANA reactivity was tested by indirect immunofluorescence using HEp2 cells as substrate and individual Ig class (IgG, IgA, IgM) and IgG subclass (IgG1, IgG2, IgG3, IgG4) specific antisera as revealing reagents. Results: Fourteen of 90 (15.6%) PBC patients had PBC specific ANA reactivity when an anti-IgG (total) antiserum was used as the revealing reagent while 58 (64.4%) were positive when specific antisera to each of the four IgG isotypes were used. The prevailing isotype was IgG3 for MND and IgG1 for RL/M. PBC patients with specific ANA, in particular of the IgG3 isotype, had significantly more severe biochemical and histological disease compared with those who were seronegative. None of the controls was positive. Conclusions: Disease specific ANA are present in the majority of patients with PBC when investigated at the level of immunoglobulin isotype. PBC specific ANA, in particular of the IgG3 isotype, are associated with a more severe disease course, possibly reflecting the peculiar ability of this isotype to engage mediators of damage.


Journal of Hepatology | 2011

Mycophenolate for the treatment of autoimmune hepatitis: prospective assessment of its efficacy and safety for induction and maintenance of remission in a large cohort of treatment-naïve patients.

Kalliopi Zachou; Nikolaos K. Gatselis; Georgia Papadamou; Eirini I. Rigopoulou; George N. Dalekos

BACKGROUND & AIMS Standard therapy for autoimmune hepatitis (AIH) is corticosteroids with or without azathioprine. However, 20% of patients do not respond or are intolerant to conventional treatment. Therefore, we evaluated prospectively the efficacy and safety of mycophenolate mofetil (MMF) in inducing and/or maintaining remission in treatment-naïve AIH patients. METHODS Fifty-nine treatment-naïve patients with well defined AIH were treated with prednisolone plus 1.5-2g/d of MMF. Patients were candidates for MMF withdrawal after at least 4 years. Treatment outcomes were defined according to the International Autoimmune Hepatitis Group report. RESULTS Treatment duration with MMF was 26months (range 3-92). Eighty-eight percent (52/59) of patients responded initially clinically and biochemically (normalization of transaminases and γ-globulins) most of them within 3months. The remaining 7 patients (12%) had partial response. In total, 59.3% (35/59) of patients had complete response (CR) with 37% (22/59) of them having achieved CR off prednisolone, while 28.8% (17/59) had initial CR with relapses. No patient was non-responder. Prednisolone withdrew in 57.6% (34/59) of patients in 8months. The only independent predictor of treatment outcome, was γ-GT (baseline γ-GT, p=0.008 and γ-GT on month 24, p<0.05). Severe side effects leading to MMF discontinuation occurred in only 3.4% (2/59) of patients. Six patients (2 according to protocol and 4 for personal reasons), stopped treatment with MMF, but 3 relapsed. CONCLUSIONS MMF seems safe and effective as first-line therapy in inducing and maintaining remission in treatment-naive patients with AIH, having a significant and rapid steroid sparing effect as attested by the fact that so far, 37% (22/59) of AIH patients achieved CR off prednisolone.


Journal of Autoimmunity | 2010

PBC Screen: An IgG/IgA dual isotype ELISA detecting multiple mitochondrial and nuclear autoantibodies specific for primary biliary cirrhosis

Haiying Liu; Gary L. Norman; Zakera Shums; Howard J. Worman; Edward L. Krawitt; Nicola Bizzaro; Diego Vergani; Dimitrios P. Bogdanos; George N. Dalekos; Piotr Milkiewicz; Albert J. Czaja; E. Jenny Heathcote; Gideon M. Hirschfield; Eng M. Tan; Kiyomitsu Miyachi; Monica Bignotto; Pier Maria Battezzati; Ana Lleo; Patrick S.C. Leung; Mauro Podda; M. Eric Gershwin; Pietro Invernizzi

A dual isotype (IgG, IgA) enzyme-linked immunosorbent assay (ELISA) designed to provide enhanced detection of primary biliary cirrhosis (PBC)-specific autoantibodies against both major mitochondrial and nuclear antigens has been developed and recently become commercially available. The assay (PBC Screen) simultaneously detects IgG and IgA autoantibodies to the immunodominant portions of the 3 major mitochondrial (MIT3) and nuclear (gp210, and sp100) antigens. The aim of this study was to compare the performance of the PBC Screen to the combined performance obtained with individual IgG ELISAs to MIT3, gp210, and sp100 on a large group of selected patients from multiple centers. A total of 1175 patients with PBC and 1232 subjects without PBC were evaluated. Non-PBC groups included healthy controls (624) as well as individuals with autoimmune hepatitis (281), primary sclerosing cholangitis (77), viral hepatitis (91 hepatitis B and 98 hepatitis C), other liver diseases (31), and other infectious or autoimmune diseases (30). The PBC Screen at the receiver operator characteristic optimized cutoff of 27.8 units, had an overall sensitivity of 83.8%, specificity of 94.7% and area under curve of 0.9212. This was similar to the specificity of 96.1% obtained by the combined results of individual MIT3, sp100, and gp210 IgG ELISAs (kappa index at 0.898). Of the 253 PBC patients without AMA detectable by immunofluorescence, 113 (44.7%) were interpreted as positive for PBC-specific autoantibodies. In conclusion, the PBC Screen is an appropriate first-line test for the diagnosis of PBC, including for patients negative for markers assessed using conventional methods.


Hepatology | 2014

Late HDV RNA relapse after peginterferon alpha-based therapy of chronic hepatitis delta

B. Heidrich; Cihan Yurdaydin; Gökhan Kabaçam; Boris A. Ratsch; Kalliopi Zachou; B. Bremer; George N. Dalekos; A. Erhardt; Fehmi Tabak; Kendal Yalçin; Selim Gurel; Stefan Zeuzem; Markus Cornberg; C.-Thomas Bock; Michael P. Manns; Heiner Wedemeyer

Interferon alpha is the only treatment option for hepatitis delta virus (HDV). Trials investigating the efficacy of pegylated interferon alpha (PEG‐IFNa) showed HDV RNA negativity rates of 25‐30% 24 weeks after therapy. However, the clinical and virological long‐term outcome of HDV‐infected patients treated with PEG‐IFNa is unknown. We performed a retrospective‐prospective follow‐up of 77 patients treated for 48 weeks with either PEG‐alfa‐2a and adefovir (ADV) or either drug alone in the Hep‐Net‐International‐Delta‐Hepatitis‐Intervention‐Study 1 (HIDIT‐1) trial. Long‐term follow‐up data were available for 58 out of 77 patients (75%) with a median time of follow‐up of 4.5 (0.5‐5.5) years and a median 3 visits per patient. Patients treated with ADV alone received retreatment with PEG‐IFNa (48% versus 19%; P = 0.02) more often. Hepatitis B virus surface antigen (HBsAg) became negative in six PEG‐IFNa‐treated patients until the end of long‐term follow‐up (10%). Sixteen patients tested HDV RNA‐negative 6 months after PEG‐IFNa treatment who were entered in the long‐term follow‐up study. Out of these, nine individuals tested HDV RNA‐positive at least once during further long‐term follow‐up, with seven patients being HDV RNA‐positive at the most recent visit. Clinical endpoints (liver‐related death, liver transplantation, hepatic decompensation, hepatocellular carcinoma) were observed in three PEG‐IFNa‐treated (8%) and three ADV‐treated (14%) patients during posttreatment long‐term follow‐up with an overall annual event rate of 2.5% (4.9% in cirrhosis). Sequencing confirmed the reappearance of pretreatment virus strains in all cases. Conclusion: Late HDV RNA relapses may occur after PEG‐IFNa therapy of hepatitis delta and thus the term sustained virological response should be avoided in HDV infection. The annual posttreatment rate of clinical events in hepatitis delta patients eligible for PEG‐IFNa therapy is about 2.5% and 4.9% in patients with cirrhosis. (Hepatology 2014;60:87‐97)


Journal of Hepatology | 2015

Incidence and predictors of hepatocellular carcinoma in Caucasian chronic hepatitis B patients receiving entecavir or tenofovir

George V. Papatheodoridis; George N. Dalekos; Cihan Yurdaydin; Maria Buti; John Goulis; Pauline Arends; Vana Sypsa; Spilios Manolakopoulos; G. Mangia; Nikolaos K. Gatselis; Onur Keskin; Savvoula Savvidou; Bettina E. Hansen; Christos Papaioannou; Kostantinos Galanis; Ramazan Idilman; Massimo Colombo; Rafael Esteban; Harry L.A. Janssen; P. Lampertico

BACKGROUND & AIMS The risk of hepatocellular carcinoma (HCC) in Caucasian patients with chronic hepatitis B (CHB), treated with entecavir (ETV) or tenofovir (TDF), is unclear. We evaluated the incidence and predictors of HCC and the accuracy of existing HCC risk scores in Caucasian CHB patients receiving ETV/TDF. METHODS This large, multicentre, retrospective cohort study included 1666 adult Caucasian CHB patients under ETV/TDF for 39 months. CHB without cirrhosis, compensated and decompensated cirrhosis were present in 67%, 39%, and 3% of patients, respectively. The predictability of baseline parameters and three risk scores (GAG-HCC, CU-HCC, and REACH-B), developed in Asian patients, was assessed. RESULTS The cumulative probability of HCC was 1.3%, 3.4%, and 8.7% at year-1, year-3, and year-5 after ETV/TDF onset. Older age and lower platelets were strong independent HCC predictors in the total population and in the subgroups of cirrhotic and non-cirrhotic patients, while liver disease severity was an independent HCC predictor in the total population and in the cirrhotics. GAG-HCC, CU-HCC, and REACH-B risk scores were associated with HCC development only in the univariable but not in the multivariable analyses and offered poor to modest predictability. CONCLUSIONS HCC can still develop in Caucasian CHB patients treated with ETV/TDF. Besides the well-known predictors of HCC, such as older age, male gender and more advanced liver disease, lower platelets represent an independent factor of higher HCC risk. The applicability and predictability of HCC risk scores developed in Asian patients are poor or modest in Caucasian CHB patients, for whom different risk scores are required.


Atherosclerosis | 2013

Adipokines as mediators of endothelial function and atherosclerosis

George Ntaios; Nikolaos K. Gatselis; Konstantinos Makaritsis; George N. Dalekos

For many decades, adipose tissue was considered as an inactive body compartment that was only used as an energy store. During the recent years, an increasing amount of data has revealed that adipose tissue is a major endocrine and paracrine organ producing numerous enzymes, hormones and growth factors which are collectively termed as adipokines. Several experimental and clinical studies showed that adipokines modulate insulin sensitivity and have an influence on glucose/fat metabolism and obesity. Apart from these properties, recent research revealed several direct actions of adipokines on endothelial function, vascular homeostasis and atherogenesis which are independent of their effects on glucose and fat metabolism. The present review focuses on the direct effects of adipokines on vascular/endothelial function and atherosclerosis and summarizes the experimental and clinical data which suggest a role for these molecules as potential diagnostic and prognostic cardiovascular markers as well as potential therapeutic target to reduce cardiovascular risk.


Liver International | 2010

Quantitative HBsAg and HDV-RNA levels in chronic delta hepatitis.

Kalliopi Zachou; Cihan Yurdaydin; Uta Drebber; George N. Dalekos; A. Erhardt; Yilmaz Cakaloglu; Halil Degertekin; Selim Gurel; Stefan Zeuzem; Hakan Bozkaya; Verena Schlaphoff; Hans Peter Dienes; Thomas Bock; Michael P. Manns; Heiner Wedemeyer

Background: Hepatitis delta virus (HDV) causes severe liver disease.

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Bettina E. Hansen

Erasmus University Rotterdam

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