S.D. Pas
Erasmus University Medical Center
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Featured researches published by S.D. Pas.
Neurology | 2014
J.J.J. van Eijk; R.G. Madden; A. A. van der Eijk; J.G. Hunter; Johan Reimerink; Richard Bendall; S.D. Pas; Vic Ellis; N. van Alfen; L. Beynon; L. Southwell; Brendan McLean; B. C. Jacobs; B.G.M. van Engelen; Harry R. Dalton
Objective: To determine whether there is an association between an acute preceding hepatitis E virus (HEV) infection and neuralgic amyotrophy (NA), and if so, whether patients with HEV-related NA differ from patients without an associated HEV infection. Methods: HEV testing was conducted in a retrospective cohort of 28 Cornish patients with NA (2011–2013) and a prospective cohort of 38 consecutive Dutch patients with NA (2004–2007). Acute-phase serum samples were analyzed for the presence of anti-HEV immunoglobulin (Ig) M and IgG and HEV RNA (quantitative real-time PCR). Results: Five cases (10.6%) of acute hepatitis E infection were identified in a total group of 47 patients with NA of whom serum samples were available. In 4 patients, HEV RNA was detected in serum samples taken at presentation. All patients with HEV-associated NA had clinical and electrophysiologic evidence of bilateral brachial plexus involvement. Anti-HEV IgM positivity was not related to age, sex, disease severity, disease course, or outcome. Conclusions: Acute hepatitis E is found in 10% of patients with NA from the United Kingdom and the Netherlands. Further research is required to investigate the role of HEV in NA in other geographical locations and to determine pathophysiologic mechanisms.
Hepatology | 2015
Thomas Vanwolleghem; Jun Hou; Gertine van Oord; Arno C. Andeweg; Albert D. M. E. Osterhaus; S.D. Pas; Harry L.A. Janssen; A. Boonstra
To identify immunological mechanisms that govern distinct clinical phases of a chronic hepatitis B virus (HBV) infection—immune tolerant (IT), immune active (IA), inactive carrier (IC), and hepatitis B e antigen (HBeAg)‐negative (ENEG) hepatitis phases—we performed a systems biology study. Serum samples from untreated chronic HBV patients (nu2009=u200971) were used for multiplex cytokine measurements, quantitative hepatitis B surface antigen (HBsAg), HBeAg levels, HBV genotype, and mutant analysis. Leukocytes were phenotyped using multicolor flow cytometry, and whole‐blood transcriptome profiles were generated. The latter were compared with liver biopsy transcriptomes from IA (nu2009=u200916) and IT (nu2009=u20093) patients. HBV viral load as well as HBeAg and HBsAg levels (Pu2009<u20090.001), but not leukocyte composition, differed significantly between distinct phases. Serum macrophage chemotactic protein 1, interleukin‐12p40, interferon (IFN)‐gamma‐inducible protein 10, and macrophage inflammatory protein 1 beta levels were different between two or more clinical phases (Pu2009<u20090.05). Comparison of blood transcriptomes identified 64 differentially expressed genes. The gene signature distinguishing IA from IT and IC patients was predominantly composed of highly up‐regulated immunoglobulin‐encoding genes. Modular repertoire analysis using gene sets clustered according to similar expression patterns corroborated the abundant expression of B‐cell function‐related genes in IA patients and pointed toward increased (ISG) transcript levels in IT patients, compared to subsequent phases. Natural killer cell activities were clustered in clinical phases with biochemical liver damage (IA and ENEG phases), whereas T‐cell activities were higher in all phases, compared to IT patients. B‐cell‐related transcripts proved to be higher in biopsies from IA versus IT patients. Conclusion: HBV clinical phases are characterized by distinct blood gene signatures. Innate IFN and B‐cell responses are highly active during the IT and IA phases, respectively. This suggests that the presumed immune tolerance in chronic HBV infections needs to be redefined. (Hepatology 2015;62:87‐100)
Journal of Clinical Microbiology | 2013
S.D. Pas; Richard Molenkamp; Janke Schinkel; Sjoerd Rebers; C. Copra; S. Seven-Deniz; D. Thamke; R. J. de Knegt; Bart L. Haagmans; Martin Schutten
ABSTRACT To evaluate the analytical performance and explore the clinical applicability of the new Roche cobas AmpliPrep/cobas TaqMan HCV test, v2.0 (CAP/CTM v2.0), a platform comparison was performed on panels and diagnostic samples with the Roche cobas AmpliPrep/cobas TaqMan HCV test (CAP/CTM v1.0), the Siemens Versant HCV RNA 3.0 branched DNA (bDNA) test, the Abbott m2000 RealTime HCV assay (Realtime assay), and the Siemens Versant HCV transcription-mediated amplification (TMA) test (TMA assay). The analytical performance of the CAP/CTM v2.0 on WHO and Acrometrix panels and clinical specimens of patients infected with HCV genotype 1, 2, 3, 4, 5, or 6 relative to that of the CAP/CTM v1.0 was significantly improved. In a qualitative comparison of the CAP/CTM v2.0 relative to the TMA assay on genotype 1 to 4 samples, the two tests proved to be almost equally sensitive. Response-guided therapy in one of five HCV genotype 4-infected patients previously tested with the CAP/CTM v1.0 would have significantly changed if tested with the CAP/CTM v2.0. In conclusion, the Roche CAP/CTM v2.0 has significantly better performance characteristics than the former CAP/CTM HCV v1.0 and the bDNA assay and performance characteristics comparable to those of the Realtime assay.
Journal of Virology | 2016
Martijn D. B. van de Garde; S.D. Pas; Guido G. Van Der Net; Robert A. de Man; Albert D. M. E. Osterhaus; Bart L. Haagmans; Andre Boonstra; Thomas Vanwolleghem
ABSTRACT Genotype 3 (gt3) hepatitis E virus (HEV) infections are emerging in Western countries. Immunosuppressed patients are at risk of chronic HEV infection and progressive liver damage, but no adequate model system currently mimics this disease course. Here we explore the possibilities of in vivo HEV studies in a human liver chimeric mouse model (uPA+/+Nod-SCID-IL2Rγ−/−) next to the A549 cell culture system, using HEV RNA-positive EDTA-plasma, feces, or liver biopsy specimens from 8 immunocompromised patients with chronic gt3 HEV. HEV from feces- or liver-derived inocula showed clear virus propagation within 2 weeks after inoculation onto A549 cells, compared to slow or no HEV propagation of HEV RNA-positive, EDTA-plasma samples. These in vitro HEV infectivity differences were mirrored in human-liver chimeric mice after intravenous (i.v.) inoculation of selected samples. HEV RNA levels of up to 8 log IU HEV RNA/gram were consistently present in 100% of chimeric mouse livers from week 2 to week 14 after inoculation with human feces- or liver-derived HEV. Feces and bile of infected mice contained moderate to large amounts of HEV RNA, while HEV viremia was low and inconsistently detected. Mouse-passaged HEV could subsequently be propagated for up to 100 days in vitro. In contrast, cell culture-derived or seronegative EDTA-plasma-derived HEV was not infectious in inoculated animals. In conclusion, the infectivity of feces-derived human HEV is higher than that of EDTA-plasma-derived HEV both in vitro and in vivo. Persistent HEV gt3 infections in chimeric mice show preferential viral shedding toward mouse bile and feces, paralleling the course of infection in humans. IMPORTANCE Hepatitis E virus (HEV) genotype 3 infections are emerging in Western countries and are of great concern for immunosuppressed patients at risk for developing chronic HEV infection. Lack of adequate model systems for chronic HEV infection hampers studies on HEV infectivity and transmission and antiviral drugs. We compared the in vivo infectivity of clinical samples from chronic HEV patients in human liver chimeric mice to an in vitro virus culture system. Efficient in vivo HEV infection is observed after inoculation with feces- and liver-derived HEV but not with HEV RNA-containing plasma or cell culture supernatant. HEV in chimeric mice is preferentially shed toward bile and feces, mimicking the HEV infection course in humans. The observed in vivo infectivity differences may be relevant for the epidemiology of HEV in humans. This novel small-animal model therefore offers new avenues to unravel HEVs pathobiology.
Journal of Hepatology | 2002
A.A. van der Eijk; H G M Niesters; S.D. Pas; R.A. de Man
To the Editor: Lamivudine is a registered nucleoside analogue which has been found to suppress hepatitis B virus (HBV) replication. In chronic HBV carriers the decrease in serum HBV DNA levels is followed by improvement in liver histology [1]. The emergence of viral resistance however may compromise this. A 54-year-old woman with treatment naive chronic HBV infection (biopsy stage cirrhose, HBeAg negative, HBV DNA 1.53 E7 geq/ml (Digene Hybrid Capture II assay), ALT 48 IU/l (normal ,31 IU/l) was treated with Lamivudine therapy for 95 weeks. Six weeks before therapy no variant viruses could be found. After 77 weeks of treatment HBV DNA-level levels increased 1.48 E7 geq/ml. Ten weeks later the ALT level increased to 106 IU/l. DNA sequence analyses were performed (Inno Lipa HBVDR, Innogenetics Ghent Belgium) starting from week 89. Analyses of the YMDD motif of the HBV polymerase gene showed a methionine-toisoleucine substitution; rtM204I (YIDD variant). After 95 weeks of treatment with Lamivudine treatment was ceased. HBV DNA level at that time was 2.85 E8 geq/ml and ALT level 44 IU/l. Patient was closely monitored and HBV DNA, ALT and DNA sequence analyses were repeated (Fig. 1). Although Lamivudine was withdrawn, while at week 18 post-dosing a mixture of wild type virus and YIDD variants were detected, at week 41 post-dosing a mixture of wild type-virus, YIDD and YVDD (rtM204V), was still detectable. Mutant detection dropped below the 5% range of the assay detection limit at week 54 post-dosing. Viral resistance to Lamivudine with the emergence of YMDD variants during long-term Lamivudine therapy is well described and considered to be a problem for future optimal therapy [2–4]. Also described is replacement of variant viruses by wild type virus 3–6 months after cessation of Lamivudine therapy [2,3]. This is however the first report of persistence of YMDD variants for at least 41 weeks. Our Letters to the Editor 304
BMC Infectious Diseases | 2015
Ludi Koning; Michael R. Charlton; S.D. Pas; Julie K. Heimbach; Albert D. M. E. Osterhaus; Kymberly D. Watt; Harry L.A. Janssen; Robert J. de Knegt; Annemiek A. van der Eijk
BackgroundInfection with hepatitis E virus (HEV) in immunocompromised patients can lead to severe liver disease. Treatment options for HEV include peginterferon or ribavirin, routinely also used for the treatment of hepatitis C virus (HCV) infection.We determined the prevalence and clinical consequences of HEV in United States (US) based patients who underwent liver transplantation (LT) for chronic HCV.MethodsSeroprevalence of HEV in 145 US LT recipients with a history of chronic HCV was determined pre-LT, 1, 3 and 5xa0years post-LT. All last available samples and all samples in IgM positive patients and post-LT IgG seroconverters were tested for HEV RNA.ResultsOverall anti-HEV seroprevalence was 42xa0%. Five patients were HEV IgM positive pre-LT, one patient had IgM seroconversion post-LT and eight patients had IgG seroconversion post-LT. None of the tested samples were positive for HEV RNA. Eight out of nine of the post-LT seroconverters had been treated for HCV recurrence before or at the moment of seroconversion.ConclusionsLT recipients in the US are at risk of acquiring HEV. Post-LT HCV treatment with interferons and/or ribavirin may have protected patients against chronic HEV. With the arrival of new direct antiviral agents for the treatment of HCV and the elimination of peginterferon and ribavirin from HCV treatment regimens, the prevalence of chronic HEV in this population may rise again.
Journal of Clinical Virology | 2017
Maurits P.A. van Meer; Ramona Mögling; Janienne Klaasse; Felicity D. Chandler; S.D. Pas; Annemiek A. van der Eijk; Marion P.G. Koopmans; Chantal B.E.M. Reusken; Corine H. GeurtsvanKessel
BACKGROUNDnDiagnostic requests for both Zika virus (ZIKV) and dengue virus (DENV) infections in returning travelers have significantly increased during the recent ZIKV outbreak in the Americás. These flaviviruses have overlapping clinical syndromes and geographical distribution, but diagnostic differentiation is important because of different clinical consequences. As flaviviruses are known to have a short viremic period, diagnostics often rely on serological methods, which are challenging due to extensive cross-reactive antibodies.nnnOBJECTIVEnTo re-evaluate the performance of DENV serological assays in laboratory confirmed ZIKV-infected travelers.nnnSTUDY DESIGNnThe extent of cross-reactivity of the DENV NS1 antigen, IgM and IgG ELISA was analyzed in 152 clinical blood samples collected from 69 qRT-PCR and 24 virus neutralization titer (VNT) confirmed ZIKV-infected travelers.nnnRESULTSnThe majority of travelers in the presented cohort returned to the Netherlands from Suriname and presented with symptoms of fever and rash. Twenty-three percent of the female travelers were pregnant. None of the 39 ZIKV RNA positive blood samples were cross-reactive in the DENV NS1 antigen ELISA. The rates of cross-reactivity of the DENV IgM and IgG ELISÁs were 31% and 54%, respectively, after excluding travelers with (potential) previous DENV exposure.nnnCONCLUSIONSnAlthough the DENV NS1 antigen assay was highly specific in this cohort of laboratory confirmed ZIKV-infected travelers, we demonstrate high percentages of cross-reactivity of DENV IgM and IgG ELISÁs of which diagnostic laboratories should be aware. In addition, the high rate of DENV IgG background of >25% complicates a proper serological diagnosis in this group.
Journal of Medical Virology | 2015
Begüm Nalça Erdin; S.D. Pas; Ismet Durak; Martin Schutten; A. Arzu Sayiner
Adenoviruses are a common cause of conjunctivitis. Genotypes are diverse and differ according to population and geographical distribution of the virus. There is limited data regarding ocular adenoviral infections and genotype distribution in Turkey. This study aimed to determine the adenovirus genotypes and their epidemiological features among patients with conjunctivitis between 2006 and 2010, in Izmir, Turkey. Adenoviral DNA was detected by PCR in 213 of 488 (44%) of the ocular samples collected from patients with viral conjunctivitis during the 5‐year study period. Of these, 101 (47%) were randomly chosen and genotyped by sequence analysis. Seven genotypes were identified, including 3, 4, 8, 11, 19, 37, and 53. Genotype 8 and 4 were the dominant types detected in 67 (66.3%) and 25 (24.7%) of the samples, respectively. Other five genotypes (3, 11, 19, 37, 53) were detected in 9 (8.9%) samples. Genotype and seasonal differences observed throughout the study. Human adenoviruse (HAdV)‐8 was the most frequent type, except 2008. The prevalence of genotype 4 increased starting from 2006, became dominant in 2008 and decreased in the following years. The peak season was mostly spring months, although it was possible to detect positive samples throughout the year. In conclusion, genotype 8 followed by genotype 4 was the most frequent adenoviral types causing conjunctivitis during the 5‐year study period. Findings suggest that there is a slow shift between genotypes throughout the years. J. Med. Virol. 87:472–477, 2015.
Scientific Reports | 2017
Martijn D. B. van de Garde; S.D. Pas; Gertine van Oord; Lucio Gama; Youkyung Choi; Robert A. de Man; A. Boonstra; Thomas Vanwolleghem M.D.
Antiviral treatment options for chronic Hepatitis E Virus (HEV) infections are limited and immunological determinants of viral persistence remain largely unexplored. We studied the antiviral potency of pegylated interferon-α (pegIFNα) against HEV infections in humanized mice and modelled intrahepatic interferon stimulated gene (ISG) responses. Human gene expression levels in humanized mouse livers were analyzed by qPCR and Nanostring. Human CXCL10 was measured in mouse serum. HEV genotype 3 (gt3) infections were cleared from liver and feces within 8 pegIFNα doses in all mice and relapsed after a single pegIFNα injection in only half of treated animals. Rapid viral clearance by pegIFNα was confirmed in HEV gt1, but not in Hepatitis B Virus infected animals. No ISG induction was observed in untreated HEV gt3 and gt1 infected humanized livers compared to control chimeric mice, irrespective of the human hepatocyte donor, viral isolate or HEV infection duration. Human specific ISG transcript levels in mouse liver increased significantly after pegIFNα treatment and induced high circulating human CXCL10 in mouse serum. In conclusion, HEV gt1 and gt3 infections do not elicit innate intrahepatic immune responses and remain highly sensitive to pegIFNα in immunocompromised humanized mice.
Journal of Gastrointestinal and Liver Diseases | 2016
N.M. van Gerven; A.A. van der Eijk; S.D. Pas; Hans L. Zaaijer; Y.S. de Boer; Birgit I. Witte; C.M.J. van Nieuwkerk; C. J. J. Mulder; Gerd Bouma; R.A. de Man; J.P.H. Drenth
BACKGROUND AND AIMSnIn recent years chronic courses of hepatitis E virus (HEV) infection have been described in immunosuppressed individuals. This may implicate a potential role for HEV in the development of autoimmune diseases, including autoimmune hepatitis (AIH). Here we investigated the prevalence of HEV-antibodies in AIH patients in an endemic Central European country.nnnMETHODSnHEV-specific immunoglobulin G (IgG) and HEV RNA were determined in 354 and 377 AIH patients, respectively. Clinical characteristics and disease outcome parameters were retrospectively collected.nnnRESULTSnNo HEV viraemic patients were identified in this cohort. A total of 106 AIH patients (29.9%) tested positive for anti-HEV IgG, and this figure was slightly higher compared to the prevalence in a reference cohort including 5,329 healthy Dutch blood donors (26.7%; P>0.05).nnnCONCLUSIONnThis is the largest study on the association between HEV infection and AIH. Apparently silent HEV infection is present in a significant proportion of AIH patients, yet appears not to have significant clinical repercussions in this immune compromised group of patients. Nevertheless, since acute hepatitis E may present with histological and biochemical features of AIH, the possibility of a (concomitant) HEV infection should be considered in this category of patients.