Dimitra Bon
Goethe University Frankfurt
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Featured researches published by Dimitra Bon.
JAMA | 2013
Anuoluwapo Osinusi; Eric G. Meissner; Yu Jin Lee; Dimitra Bon; Laura Heytens; Amy Nelson; Michael C. Sneller; Anita Kohli; Michael A. Proschan; Eva Herrmann; Bhavana Shivakumar; Wenjuan Gu; Richard Kwan; Geb Teferi; Rohit Talwani; Rachel Silk; Colleen Kotb; Susan Wroblewski; Dawn Fishbein; Robin L. Dewar; Helene Highbarger; Xiao Zhang; David E. Kleiner; Brad J. Wood; Jose Chavez; William T. Symonds; M. Subramanian; John G. McHutchison; Michael A. Polis; Anthony S. Fauci
IMPORTANCE The efficacy of directly acting antiviral agents in interferon-free regimens for the treatment of chronic hepatitis C infections needs to be evaluated in different populations. OBJECTIVE To determine the efficacy and safety of sofosbuvir with weight-based or low-dose ribavirin among a population with unfavorable treatment characteristics. DESIGN, SETTING, AND PATIENTS Single-center, randomized, 2-part, open-label phase 2 study involving 60 treatment-naive patients with hepatitis C virus (HCV) genotype 1 enrolled at the National Institutes of Health (October 2011-April 2012). INTERVENTIONS In the studys first part, 10 participants with early to moderate liver fibrosis were treated with 400 mg/d of sofosbuvir and weight-based ribavirin for 24 weeks. In the second part, 50 participants with all stages of liver fibrosis were randomized 1:1 to receive 400 mg of sofosbuvir with either weight-based or low-dose 600 mg/d of ribavirin for 24 weeks. MAIN OUTCOMES AND MEASURES The primary study end point was the proportion of participants with undetectable HCV viral load 24 weeks after treatment completion (sustained virologic response of 24 weeks [SVR24]). RESULTS In the first part of the study, 9 participants (90%; 95% CI, 55%-100%) achieved SVR24. In the second part, 7 participants (28%) in the weight-based group and 10 (40%) in the low-dose group relapsed after treatment completion leading to SVR24 rates of 68% (95% CI, 46%-85%) in the weight-based group and 48% (95% CI, 28%-69%; P = .20) in the low-dose group. Twenty individuals participated in a pharmacokinetic-viral kinetic substudy, which demonstrated a slower loss rate of infectious virus in relapsers than in participants who achieved SVR (clearance, 3.57/d vs 5.60/d; P = .009). The most frequent adverse events were headache, anemia, fatigue, and nausea. There were 7 grade 3 events including anemia, neutropenia, nausea, hypophosphatemia, and cholelithiasis or pancreatitis. No one discontinued treatment due to adverse events. CONCLUSION AND RELEVANCE In a population of patients with a high prevalence of unfavorable traditional predictors of treatment response, a 24-week regimen of sofosbuvir and weight-based or low-dose ribavirin resulted in SVR24 rates of 68% and 48%, respectively. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01441180.
JAMA | 2015
Anu Osinusi; Kerry Townsend; Anita Kohli; Amy Nelson; Cassie Seamon; Eric G. Meissner; Dimitra Bon; Rachel Silk; Chloe Gross; Angie Price; Mohammad M. Sajadi; Sreetha Sidharthan; Zayani Sims; Eva Herrmann; John F. Hogan; Gebeyehu Teferi; Rohit Talwani; Michael A. Proschan; Veronica Jenkins; David E. Kleiner; Brad J. Wood; G. Mani Subramanian; Phillip S. Pang; John G. McHutchison; Michael A. Polis; Anthony S. Fauci; Henry Masur; Shyam Kottilil
IMPORTANCE There is an unmet need for interferon- and ribavirin-free treatment for chronic hepatitis C virus (HCV) infection in patients co-infected with human immunodeficiency virus (HIV). OBJECTIVE To evaluate the rates of sustained virologic response (SVR) and adverse events in previously untreated patients with HCV genotype 1 and HIV co-infection following a 12-week treatment of the fixed-dose combination of ledipasvir and sofosbuvir. DESIGN, SETTING, AND PARTICIPANTS Open-label, single-center, phase 2b pilot study of previously untreated, noncirrhotic patients with HCV genotype 1 and HIV co-infection conducted at the Clinical Research Center of the National Institutes of Health, Bethesda, Maryland, from June 2013 to September 2014. Patients included those receiving antiretroviral therapy with HIV RNA values of 50 copies/mL or fewer and a CD4 T-lymphocyte count of 100 cells/mL or greater or patients with untreated HIV infection with a CD4 T-lymphocyte count of 500 cells/mL or greater. Serial measurements of safety parameters, virologic and host immune correlates, and adherence were performed. INTERVENTIONS Fifty patients with HCV genotype 1 never before treated for HCV were prescribed a fixed-dose combination of ledipasvir (90 mg) and sofosbuvir (400 mg) once daily for 12 weeks. MAIN OUTCOMES AND MEASURES The primary study outcome was the proportion of patients with sustained viral response (plasma HCV RNA level <12 IU/mL) 12 weeks after end of treatment. RESULTS Forty-nine of 50 participants (98% [95% CI, 89% to 100%]) achieved SVR 12 weeks after end of treatment, whereas 1 patient experienced relapse at week 4 following treatment. In the patient with relapse, deep sequencing revealed a resistance associated mutation in the NS5A region conferring resistance to NS5A inhibitors, such as ledipasvir. The most common adverse events were nasal congestion (16% of patients) and myalgia (14%). There were no discontinuations or serious adverse events attributable to study drug. CONCLUSIONS AND RELEVANCE In this open-label, uncontrolled, pilot study enrolling patients co-infected with HCV genotype 1 and HIV, administration of an oral combination of ledipasvir and sofosbuvir for 12 weeks was associated with high rates of SVR after treatment completion. Larger studies that also include patients with cirrhosis and lower CD4 T-cell counts are required to understand if the results of this study generalize to all patients co-infected with HCV and HIV. TRIAL REGISTRATION clinicaltrials.gov Identifier:NCT01878799.
The Lancet | 2015
Anita Kohli; Anuoluwapo Osinusi; Zayani Sims; Amy Nelson; Eric G. Meissner; Dimitra Bon; Miriam M. Marti; Rachel Silk; Colleen Kotb; Chloe Gross; Tim A. Jolley; Sreetha Sidharthan; Tess Petersen; Kerry Townsend; D'Andrea Egerson; Rama Kapoor; Emily Spurlin; Michael C. Sneller; Michael A. Proschan; Eva Herrmann; Richard Kwan; Gebeyehu Teferi; Rohit Talwani; Gabbie Diaz; David E. Kleiner; Brad J. Wood; Jose Chavez; Stephen Abbott; William T. Symonds; G. Mani Subramanian
BACKGROUND Direct-acting antiviral drugs have a high cure rate and favourable tolerability for patients with hepatitis C virus (HCV). Shorter courses could improve affordability and adherence. Sofosbuvir and ledipasvir with ribavirin have high efficacy when taken for 8 weeks but not for 6 weeks. We assessed whether the addition of a third direct-acting antiviral drug to sofosbuvir and ledipasvir would allow a shorter treatment duration. METHODS In this single-centre, open-label, phase 2A trial, we sequentially enrolled treatment-naive patients with HCV genotype 1 infection into three treatment groups: 12 weeks of sofosbuvir and ledipasvir; 6 weeks of sofosbuvir, ledipasvir, and GS-9669; or 6 weeks of sofosbuvir, ledipasvir, and GS-9451. Patients and investigators were not masked to treatment assignment. The primary endpoint was the propotion of patients with sustained viral response at 12 weeks after treatment completion (SVR12), assessed by serum HCV RNA concentrations lower than 43 IU/mL (the lower limit of quantification). We did an intention-to-treat analysis for the primary endpoint and adverse events. This study is registered with ClinicalTrials.gov, number NCT01805882. FINDINGS Between Jan 11, 2013, and Dec 17, 2013, we enrolled 60 patients, and sequentially assigned them into three groups of 20. We noted an SVR12 in all 20 patients (100%, 95% CI 83-100) allocated to sofosbuvir and ledipasvir for 12 weeks; in 19 (95%, 75-100) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9669 for 6 weeks (one patient relapsed 2 weeks after completion of treatment); and in 19 (95%, 75-100%) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9451 for 6 weeks (one patient was lost to follow-up after reaching sustained viral response at 4 weeks). Most adverse events were mild and no patients discontinued treatment. Two serious adverse events occurred (pain after a post-treatment liver biopsy and vertigo), both unrelated to study drugs. INTERPRETATION In this small proof-of-concept study, two different three-drug regimens that were given for 6 weeks resulted in high cure rates for HCV infection with excellent tolerability. Addition of a third potent direct-acting antiviral drug can reduce the duration of treatment required to achieve sustained viral response in patients with chronic HCV genotype 1 infection without cirrhosis. FUNDING National Institute of Allergy and Infectious Diseases (NIAID), National Cancer Institute and Clinical Center Intramural Program, German Research Foundation, National Institutes of Health, Gilead Sciences.
Journal of Clinical Investigation | 2014
Eric G. Meissner; David Wu; Anu Osinusi; Dimitra Bon; Kimmo Virtaneva; Dan E. Sturdevant; Steve Porcella; Honghui Wang; Eva Herrmann; John G. McHutchison; Michael A. Polis; Stephen M. Hewitt; Ludmila Prokunina-Olsson; Henry Masur; Anthony S. Fauci; Shyamasundaran Kottilil
BACKGROUND. Hepatitis C virus (HCV) infects approximately 170 million people worldwide and may lead to cirrhosis and hepatocellular carcinoma in chronically infected individuals. Treatment is rapidly evolving from IFN-α-based therapies to IFN-α-free regimens that consist of directly acting antiviral agents (DAAs), which demonstrate improved efficacy and tolerability in clinical trials. Virologic relapse after DAA therapy is a common cause of treatment failure; however, it is not clear why relapse occurs or whether certain individuals are more prone to recurrent viremia. METHODS. We conducted a clinical trial using the DAA sofosbuvir plus ribavirin (SOF/RBV) and performed detailed mRNA expression analysis in liver and peripheral blood from patients who achieved either a sustained virologic response (SVR) or relapsed. RESULTS. On-treatment viral clearance was accompanied by rapid downregulation of IFN-stimulated genes (ISGs) in liver and blood, regardless of treatment outcome. Analysis of paired pretreatment and end of treatment (EOT) liver biopsies from SVR patients showed that viral clearance was accompanied by decreased expression of type II and III IFNs, but unexpectedly increased expression of the type I IFN IFNA2. mRNA expression of ISGs was higher in EOT liver biopsies of patients who achieved SVR than in patients who later relapsed. CONCLUSION. These results suggest that restoration of type I intrahepatic IFN signaling by EOT may facilitate HCV eradication and prevention of relapse upon withdrawal of SOF/RBV. TRIAL REGISTRATION. ClinicalTrials.gov NCT01441180.
The Journal of Infectious Diseases | 2014
Eric G. Meissner; Dimitra Bon; Ludmila Prokunina-Olsson; Wei Tang; Henry Masur; Thomas R. O'Brien; Eva Herrmann; Shyamasundaran Kottilil; Anuoluwapo Osinusi
Response to pegylated interferon-alpha and ribavirin (IFN-α/RBV) treatment for chronic hepatitis C virus (HCV) infection is influenced by host genetic factors, but their role for IFN-α-free, direct-acting antiviral (DAA) regimens is unclear. An exonic deletion allele (IFNL4-ΔG) bolsters the established association with IFN-α/RBV therapy treatment outcome of another IFNL4 variant, rs12979860, which is located upstream of IFNL3 (IL28B). We report that in patients treated with the DAA sofosbuvir along with RBV, IFNL4-ΔG is associated with slower early viral decay, due to slower loss of free virus (P = .039) and decreased drug efficacy (P = .048), suggesting functional relevance of IFN-λ4 in IFN-α-free DAA therapies.
Hepatology | 2015
Georgios Grammatikos; Nerea Ferreirós; Dimitra Bon; Stephanie Schwalm; J. Dietz; Caterina Berkowski; Daniel Fitting; Eva Herrmann; Stefan Zeuzem; Christoph Sarrazin; Josef Pfeilschifter
Ablation of very‐long‐chain ceramides (Cers) with consecutive elevations in sphinganine levels has been shown to cause a severe hepatopathy in a knockout mouse model. We have recently shown that serum sphingolipids (SLs) are deregulated in patients with chronic liver disease. However, their role as possible biomarkers in liver fibrosis remains to date unexplored. We assessed, using liquid chromatography/tandem mass spectrometry, serum concentrations of various SL metabolites in 406 patients with chronic viral hepatitis, 203 infected with genotype 1 hepatitis C virus (HCV) and 203 with hepatitis B virus (HBV), respectively. We observed significant variations of serum SLs, with sphingosine and sphinganine being, both in univariate (P < 0.05) as well as in multivariate analysis, significantly associated to severity of liver fibrosis in HCV‐infected patients (odds ratio [OR]: 1.111; confidence interval [CI]: 1.028‐1.202; P = 0.007 and OR, 0.634; CI, 0.435‐0.925; P = 0.018, respectively). Serum SLs correlated significantly with serum triglyceride and cholesterol levels as well as with insulin resistance, defined by the homeostatic model assessment index, in HCV patients. Sustained viral response rates in HCV patients were independently predicted by serum C24Cer (OR, 0.998; CI, 0.997‐0.999; P = 0.001), its unsaturated derivative C24:1Cer (OR, 1.001; CI, 1.000‐1.002; P = 0.059), and C18:1Cer (OR, 0.973; CI, 0.947‐0.999; P = 0.048), together with ferritin (OR, 1.006; CI, 1.003‐1.010; P < 0.001), alkaline phosphatase (OR, 1.020; CI, 1.001‐1.039; P = 0.032), and interleukin‐28B genotype (OR, 9.483; CI, 3.139‐28.643; P < 0.001). Conclusion: Our study demonstrates a tight interaction between variations in serum SL levels and progression of liver fibrosis as well as responsiveness to antiviral therapy. Particularly, sphingosine, sphinganine, and C24Cer appear as promising novel biomarkers in chronic HCV infection and should be further evaluated within the noninvasive prediction of liver fibrosis. (Hepatology 2015;61:812–822)
Oncotarget | 2016
Georgios Grammatikos; Niklas Schoell; Nerea Ferreirós; Dimitra Bon; Eva Herrmann; Harald Farnik; Verena Köberle; Albrecht Piiper; Stefan Zeuzem; Bernd Kronenberger; Oliver Waidmann; Josef Pfeilschifter
We have recently shown that major alterations of serum sphingolipid metabolites in chronic liver disease associate significantly with the stage of liver fibrosis in corresponding patients. In the current study we assessed via mass spectrometry serum concentrations of sphingolipid metabolites in a series of 122 patients with hepatocellular carcinoma (HCC) compared to an age- and sex-matched series of 127 patients with cirrhosis. We observed a highly significant upregulation of long and very long chain ceramides (C16-C24) in the serum of patients with HCC as compared to patients with cirrhosis (P < 0.001). Accordingly, dihydro-ceramides, synthetic precursors of ceramides and notably sphingosine, sphingosine-1-phosphate (S1P) and sphinganine-1-phosphate (SA1P) were upregulated in patients with HCC (P < 0.001). Especially the diagnostic accuracy of C16-ceramide and S1P, assessed by receiver operating curve (ROC) analysis, showed a higher area under the curve (AUC) value as compared to alpha fetoprotein (AFP) (0.999 and 0.985 versus 0.823, P < 0.001 respectively). In conclusion, serum levels of sphingolipid metabolites show a significant upregulation in patients with HCC as compared to patients with cirrhosis. Particularly C16-ceramide and S1P may serve as novel diagnostic markers for the identification of HCC in patients with liver diseases. Our data justify further investigations on the role of sphingolipids in HCC.
PLOS ONE | 2015
Georgios Grammatikos; Nerea Ferreirós; Oliver Waidmann; Dimitra Bon; Sirkka Schroeter; Alexander Koch; Eva Herrmann; Stefan Zeuzem; Bernd Kronenberger; Josef Pfeilschifter
Background Sphingolipids constitute bioactive molecules with functional implications in liver homeostasis. Particularly, ablation of very long chain ceramides in a knockout mouse model has been shown to cause a severe hepatopathy. Methods We aimed to evaluate the serum sphingolipid profile of 244 patients with cirrhosis prospectively followed for a median period of 228±217 days via mass spectrometry. Results We thereby observed a significant decrease of long and very long chain ceramides, particularly of C24ceramide, in patients with increasing severity of cirrhosis (p<0.001). Additionally, hydropic decompensation, defined by clinical presentation of ascites formation, was significantly correlated to low C24ceramide levels (p<0.001) while a significant association to hepatic decompensation and poor overall survival was observed for low serum concentrations of C24ceramide (p<0.001) as well. Multivariate analysis further identified low serum C24ceramide to be independently associated to overall survival (standard beta = -0.001, p = 0.022). Conclusions In our current analysis serum levels of very long chain ceramides show a significant reciprocal correlation to disease severity and hepatic decompensation and are independently associated with overall survival in patients with cirrhosis. Serum sphingolipid metabolites and particularly C24ceramide may constitute novel molecular targets of disease severity, hepatic decompensation and overall prognosis in cirrhosis and should be further evaluated in basic research studies.
PLOS ONE | 2016
Svenja Deuchler; Clemens Wagner; Pankaj K. Singh; Michael Müller; Rami Al-Dwairi; Rachid Benjilali; Markus A. Schill; Hanns Ackermann; Dimitra Bon; Thomas Kohnen; Benjamin Schoene; Michael Koss; Frank Koch
Purpose To evaluate the efficacy of the virtual reality training simulator Eyesi to prepare surgeons for performing pars plana vitrectomies and its potential to predict the surgeons’ performance. Methods In a preparation phase, four participating vitreoretinal surgeons performed repeated simulator training with predefined tasks. If a surgeon was assigned to perform a vitrectomy for the management of complex retinal detachment after a surgical break of at least 60 hours it was randomly decided whether a warmup training on the simulator was required (n = 9) or not (n = 12). Performance at the simulator was measured using the built-in scoring metrics. The surgical performance was determined by two blinded observers who analyzed the video-recorded interventions. One of them repeated the analysis to check for intra-observer consistency. The surgical performance of the interventions with and without simulator training was compared. In addition, for the surgeries with simulator training, the simulator performance was compared to the performance in the operating room. Results Comparing each surgeon’s performance with and without warmup trainingshowed a significant effect of warmup training onto the final outcome in the operating room. For the surgeries that were preceeded by the warmup procedure, the performance at the simulator was compared with the operating room performance. We found that there is a significant relation. The governing factor of low scores in the simulator were iatrogenic retinal holes, bleedings and lens damage. Surgeons who caused minor damage in the simulation also performed well in the operating room. Conclusions Despite the large variation of conditions, the effect of a warmup training as well as a relation between the performance at the simulator and in the operating room was found with statistical significance. Simulator training is able to serve as a warmup to increase the average performance.
Digestive and Liver Disease | 2016
Dirk Walter; Jan Peveling-Oberhag; Falko Schulze; Dimitra Bon; Stefan Zeuzem; Mireen Friedrich-Rust; Jörg G. Albert
BACKGROUND Differentiating malignancy from benign disease in indeterminate biliary stricture by imaging modalities is limited. Definite diagnosis relies on histopathological diagnosis. AIMS To assess accuracy of histopathological diagnosis of fluoroscopy-guided vs. cholangioscopy-directed intraductal biopsies in indeterminate biliary stricture. METHODS All patients with indeterminate biliary stricture and fluoroscopically (n=68) or cholangioscopy-directed (working channel 2mm, n=38) biopsies were included. Histopathological results of biopsies were classified into inflammatory lesion (class 1), dysplasia/intraepithelial neoplasia (class 2) and malignancy (class 3) and results as well as macroscopic diagnosis were compared with final diagnosis. RESULTS Sensitivity and specificity of fluoroscopy-guided vs. cholangioscopy-directed biopsies were 22.9% and 100% vs. 25.0% and 100% for class 1+2 vs. class 3 lesions, respectively. Sensitivity for class 1 vs. class 2+3 lesions was 45.7% (p=0.044) vs. 58.3% (p=0.214) for fluoroscopy-guided vs. cholangioscopy-directed biopsies, respectively, while specificity was 100% in both. There was no difference in size of the obtained sample (p=0.992). True positive diagnosis rate increased with the number of biopsies taken (p=0.028). CONCLUSION Fluoroscopy-guided and cholangioscopy-directed intraductal biopsies are equally limited in establishing the diagnosis of malignancy in indeterminate biliary stricture. Categorizing dysplasia or intraepithelial neoplasia as malignancy increases sensitivity without decrease in specificity. By taking more biopsies, diagnostic yield is increased.