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Featured researches published by Sander van Assen.


Arthritis & Rheumatism | 2010

Humoral responses after influenza vaccination are severely reduced in patients with rheumatoid arthritis treated with rituximab

Sander van Assen; Albert Holvast; Cornelis A. Benne; Marcel D. Posthumus; Miek A. van Leeuwen; Alexandre E. Voskuyl; Marlies Blom; Anke P. Risselada; Aalzen de Haan; Johanna Westra; Cees G. M. Kallenberg; Marc Bijl

OBJECTIVE For patients with rheumatoid arthritis (RA), yearly influenza vaccination is recommended. However, its efficacy in patients treated with rituximab is unknown. The objectives of this study were to investigate the efficacy of influenza vaccination in RA patients treated with rituximab and to investigate the duration of the possible suppression of the humoral immune response following rituximab treatment. We also undertook to assess the safety of influenza vaccination and the effects of previous influenza vaccination. METHODS Trivalent influenza subunit vaccine was administered to 23 RA patients who had received rituximab (4-8 weeks after rituximab for 11 patients [the early rituximab subgroup] and 6-10 months after rituximab for 12 patients [the late rituximab subgroup]), 20 RA patients receiving methotrexate (MTX), and 29 healthy controls. Levels of antibodies against the 3 vaccine strains were measured before and 28 days after vaccination using hemagglutination inhibition assay. The Disease Activity Score in 28 joints (DAS28) was used to assess RA activity. RESULTS Following vaccination, geometric mean titers (GMTs) of antiinfluenza antibodies significantly increased for all influenza strains in the MTX-treated group and in healthy controls, but for no strains in the rituximab-treated group. However, in the late rituximab subgroup, a rise in GMT for the A/H3N2 and A/H1N1 strains was demonstrated, in the absence of a repopulation of CD19+ cells at the time of vaccination. Seroconversion and seroprotection occurred less often in the rituximab-treated group than in the MTX-treated group for the A/H3N2 and A/H1N1 strains, while seroprotection occurred less often in the rituximab-treated group than in the healthy controls for the A/H1N1 strain. Compared with unvaccinated patients in the rituximab-treated group, previously vaccinated patients in the rituximab-treated group had higher pre- and postvaccination GMTs for the A/H1N1 strain. The DAS28 did not change after vaccination. CONCLUSION Rituximab reduces humoral responses following influenza vaccination in RA patients, with a modestly restored response 6-10 months after rituximab administration. Previous influenza vaccination in rituximab-treated patients increases pre- and postvaccination titers. RA activity was not influenced.


Arthritis & Rheumatism | 2009

Studies of Cell-Mediated Immune Responses to Influenza Vaccination in Systemic Lupus Erythematosus

Albert Holvast; Sander van Assen; Aalzen de Haan; Anke Huckriede; Cornelis A. Benne; Johanna Westra; Abraham Palache; Jan Wilschut; Cees G. M. Kallenberg; Marc Bijl

OBJECTIVE Both antibody and cell-mediated responses are involved in the defense against influenza. In patients with systemic lupus erythematosus (SLE), a decreased antibody response to subunit influenza vaccine has been demonstrated, but cell-mediated responses have not yet been assessed. This study was therefore undertaken to assess cell-mediated responses to influenza vaccination in patients with SLE. METHODS Fifty-four patients with SLE and 54 healthy control subjects received subunit influenza vaccine. Peripheral blood mononuclear cells and sera were obtained before and 1 month after vaccination. Cell-mediated responses to A/H1N1 and A/H3N2 vaccines were evaluated using an interferon-gamma (IFNgamma) enzyme-linked immunospot assay and flow cytometry. Antibody responses were measured using a hemagglutination inhibition test. RESULTS Prior to vaccination, patients with SLE had fewer IFNgamma spot-forming cells against A/H1N1 compared with control subjects and a lower frequency of IFNgamma-positive CD8+ T cells. After vaccination, the number of IFNgamma spot-forming cells increased in both patients and control subjects, although the number remained lower in patients. In addition, the frequencies of CD4+ T cells producing tumor necrosis factor and interleukin-2 were lower in patients after vaccination compared with healthy control subjects. As expected for a subunit vaccine, vaccination did not induce a CD8+ T cell response. For A/H3N2-specific responses, results were comparable. Diminished cell-mediated responses to influenza vaccination were associated with the use of prednisone and/or azathioprine. The increase in A/H1N1-specific and A/H3N2-specific antibody titers after vaccination was lower in patients compared with control subjects. CONCLUSION In addition to a decreased antibody response, cell-mediated responses to influenza vaccination are diminished in patients with SLE, which may reflect the effects of the concomitant use of immunosuppressive drugs. This may render these patients more susceptible to (complicated) influenza infections.


Clinical Infectious Diseases | 2009

Omeprazole Significantly Reduces Posaconazole Serum Trough Level

Jan-Willem C. Alffenaar; Sander van Assen; Tjip S. van der Werf; Jos G. W. Kosterink; Donald R. A. Uges

To the Editor—Cimitidine has been shown to reduce the bioavailability of posaconazole [1], and this interactive effect has also been predicted for proton pump inhibitors [2]. In our center (University Medical Center Groningen; Groningen, The Netherlands), we monitor posaconazole serum trough levels regularly in patients who receive posaconazole as salvage treatment. Serum samples are measured by liquid chromatography tandem mass spectrometry, with a validated method of analysis. In a 58-year-old male patient who was treated for invasive aspergillosis, a significant decrease in the posaconazole serum trough level was observed (figure 1). It appeared that treatment with omeprazole (40 mg once daily) had been started routinely to prevent corticosteroid-induced gastrointestinal hemorrhage. Later, because the patient had no additional risk factors for gastrointestinal hemorrhage, treatment with omeprazole was discontinued. During continued monitoring of posaconazole concentrations, the serum trough concentration increased to baseline levels again (figure 1). Because the proton pump inhibitor was administered for only 3 days, the clinical impact in this patient was likely to be limited; posaconazole levels in tissue tend to be much higher than in serum, and therefore, adequate tissue levels may have been maintained. However, with prolonged proton pump inhibition at a higher dosage, the effect could be profound, with an inherent risk of therapeutic failure. If combination with a proton pump inhibitor can not be avoided, serum levels of posaconazole should be monitored at all times to evaluate absorption, or antifungal therapy should be switched to an alternative compound. Acknowledgments


Clinical Infectious Diseases | 2008

Recovery of Viremic Control after Superinfection with Pathogenic HIV Type 1 in a Long-Term Elite Controller of HIV Type 1 Infection

Andrea Rachinger; Marjon Navis; Sander van Assen; Paul H. P. Groeneveld; Hanneke Schuitemaker

A human immunodeficiency virus type 1 (HIV-1)-infected elite controller (defined as an untreated HIV-1-infected person with a plasma HIV-1 RNA level <50 copies/mL for at least 12 months) who experienced a viremic episode after superinfection regained natural viremic control, although the viral loads in the patients 2 partners, infected with the same viral strain, were continuously approximately 30-fold higher. Thus, host mechanisms seem to be able to repeatedly control HIV-1 replication, halting disease progression.


Annals of the Rheumatic Diseases | 2016

Points to consider for reporting, screening for and preventing selected comorbidities in chronic inflammatory rheumatic diseases in daily practice: a EULAR initiative

Athan Baillet; Laure Gossec; Loreto Carmona; Maarten de Wit; Yvonne van Eijk-Hustings; Heidi Bertheussen; Kent Alison; Mette Toft; Marios Kouloumas; Ricardo J. O. Ferreira; Susan Oliver; Andrea Rubbert-Roth; Sander van Assen; William G. Dixon; Axel Finckh; A. Zink; Joel M. Kremer; Tore K. Kvien; Michael T. Nurmohamed; Désirée van der Heijde; Maxime Dougados

In chronic inflammatory rheumatic diseases, comorbidities such as cardiovascular diseases and infections are suboptimally prevented, screened for and managed. The objective of this European League Against Rheumatism (EULAR) initiative was to propose points to consider to collect comorbidities in patients with chronic inflammatory rheumatic diseases. We also aimed to develop a pragmatic reporting form to foster the implementation of the points to consider. In accordance with the EULAR Standardised Operating Procedures, the process comprised (1) a systematic literature review of existing recommendations on reporting, screening for or preventing six selected comorbidities: ischaemic cardiovascular diseases, malignancies, infections, gastrointestinal diseases, osteoporosis and depression and (2) a consensus process involving 21 experts (ie, rheumatologists, patients, health professionals). Recommendations on how to treat the comorbidities were not included in the document as they vary across countries. The literature review retrieved 42 articles, most of which were recommendations for reporting or screening for comorbidities in the general population. The consensus process led to three overarching principles and 15 points to consider, related to the six comorbidities, with three sections: (1) reporting (ie, occurrence of the comorbidity and current treatments); (2) screening for disease (eg, mammography) or for risk factors (eg, smoking) and (3) prevention (eg, vaccination). A reporting form (93 questions) corresponding to a practical application of the points to consider was developed. Using an evidence-based approach followed by expert consensus, this EULAR initiative aims to improve the reporting and prevention of comorbidities in chronic inflammatory rheumatic diseases. Next steps include dissemination and implementation.


Rheumatology | 2009

Effect of a second, booster, influenza vaccination on antibody responses in quiescent systemic lupus erythematosus: an open, prospective, controlled study

Albert Holvast; Sander van Assen; Aalzen de Haan; Anke Huckriede; Cornelis A. Benne; Johanna Westra; Abraham Palache; Jan Wilschut; Cees G. M. Kallenberg; Marc Bijl

OBJECTIVE In SLE, a decreased antibody response on influenza vaccination has been reported. In this study, we assessed whether a booster vaccination could improve antibody responses, as determined by seroprotection rates, in SLE patients. METHODS SLE patients (n = 52) with quiescent disease (SLEDAI < or =4) and healthy controls (HCs) (n = 28) received subunit influenza vaccine in October-December 2007. After 4 weeks, only SLE patients received a second dose of vaccination. Sera were obtained before both vaccinations, and 4 weeks after the second vaccination. At each visit, SLE disease activity was recorded. The haemagglutination inhibition test was used to measure antibody titres. Seroprotection was defined as a titre > or =40. RESULTS Following the first vaccination, seroprotection rates and geometric mean titres (GMTs) to each vaccine strain increased in both SLE patients and controls to comparable levels. Seroprotection rates in SLE patients after the first vaccination were 86.5% to A/H1N1, 80.8% to A/H3N2 and 61.5% to the B-strain while GMTs were 92.6, 56.2 and 39.2, respectively. Overall, the booster vaccination did not lead to a further rise of seroprotection rates and GMTs in SLE patients. However, in patients not vaccinated in the previous year, GMT and seroconversion rate to A/H1N1 did rise following the booster vaccination. Both influenza vaccinations did not increase SLEDAI scores. CONCLUSIONS Additional value of a booster influenza vaccination in SLE is limited to patients who were not vaccinated in the previous year.


Lancet Infectious Diseases | 2017

Diagnostic value of imaging in infective endocarditis: a systematic review

Anna Gomes; Andor W. J. M. Glaudemans; Daan Touw; Joost P. van Melle; Tineke P. Willems; Alexander H. Maass; Ehsan Natour; Niek H. J. Prakken; Ronald Borra; Peter Paul van Geel; Riemer H. J. A. Slart; Sander van Assen; Bhanu Sinha

Sensitivity and specificity of the modified Duke criteria for native valve endocarditis are both suboptimal, at approximately 80%. Diagnostic accuracy for intracardiac prosthetic material-related infection is even lower. Non-invasive imaging modalities could potentially improve diagnosis of infective endocarditis; however, their diagnostic value is unclear. We did a systematic literature review to critically appraise the evidence for the diagnostic performance of these imaging modalities, according to PRISMA and GRADE criteria. We searched PubMed, Embase, and Cochrane databases. 31 studies were included that presented original data on the performance of electrocardiogram (ECG)-gated multidetector CT angiography (MDCTA), ECG-gated MRI, 18F-fluorodeoxyglucose (18F-FDG) PET/CT, and leucocyte scintigraphy in diagnosis of native valve endocarditis, intracardiac prosthetic material-related infection, and extracardiac foci in adults. We consistently found positive albeit weak evidence for the diagnostic benefit of 18F-FDG PET/CT and MDCTA. We conclude that additional imaging techniques should be considered if infective endocarditis is suspected. We propose an evidence-based diagnostic work-up for infective endocarditis including these non-invasive techniques.


Nature Reviews Rheumatology | 2015

Vaccination of patients with autoimmune inflammatory rheumatic diseases

Johanna Westra; Christien Rondaan; Sander van Assen; Marc Bijl

Patients with autoimmune inflammatory rheumatic diseases (AIRDs) are at increased risk of infections. This risk has been further increased by the introduction of biologic agents over the past two decades. One of the most effective strategies to prevent infection is vaccination. However, patients with an AIRD have a compromised immune system, which is further impaired by medication. Another important issue is the possibility of triggering a broad nonspecific response by vaccination, potentially resulting in increased activity of the underlying autoimmune disease. In this Review, we provide an analysis of data on vaccination of patients with an AIRD. Both the efficacy and the safety of vaccination are addressed, together with the epidemiology of vaccine-preventable infectious diseases in different subgroups of adults with AIRDs. Special attention is given to vaccination of patients who are treated with biologic agents.


Lancet Infectious Diseases | 2004

A rare case of oral leishmaniasis.

Philip A. Van Damme; Monique Keuter; Sander van Assen; Peter C. M. DeWilde; Pieter Beckers

THE LANCET Infectious Diseases Vol 4 January 2004 http://infection.thelancet.com 53 multidimensional intervention on the treatment of uncomplicated acute bronchitis in adults. JAMA 1999; 281: 1512–19. 49 Perz JF, Craig AS, Coffey CS, et al. Changes in antibiotic prescribing for children after a communitywide campaign. JAMA 2002; 287: 3103–09. 50 Seppala H, Klaukka T, Lehtonen R, Neonen E, Huovinen P. Outpatient use of erythromycin: link to increased erythromycin resistance in Group A streptococci. Clin Infect Dis 1995; 21: 1378–85. 51 Granizo JJ, Aguilar L, Casal J, Garcia-Rey C, Dal-Re R, Baquero F. Streptococcus pneumoniae resistance to erythromycin and penicillin in relation to macrolide and beta-lactam consumption in Spain (1979–1997). J Antimicrob Chemother 2000; 46: 767–73. 52 Granizo JJ, Aguilar L, Casal J, Dal-Re R, Baquero F. Streptococcus pyogenes resistance to erythromycin and penicillin in relation to macrolide and beta-lactam consumption in Spain (1979–1997). J Antimicrob Chemother 2000; 46: 959–64. 53 Garcia-Rey C, Aguilar L, Baquero F, Casal J, Dal-Re R. Importance of local variations in antibiotic consumption and geographical differences of erythromycin and penicillin resistance in Streptococcus pneumoniae. J Clin Microbiol 2002; 40: 159–64. 54 Guillemot D, Henriet L, Lecoeur H, Weber P, Carbon C. Optimization of antibiotic use rapidly decreases penicillin resistant Streptococcus pneumoniae (PRSp) carriage: the AUBEPPIN Study [Abstract 1527]. In: Abstracts of the 41st Annual Interscience Conference on Antimicrobial Agents and Chemotherapy; 2001 December 16–19; Chicago, IL, USA. Washington, DC: American Society for Microbiology, 2001: 264. 55 Felmingham D, Feldman C, Hryniewicz W, et al. Surveillance of bacterial resistance in communityacquired respiratory tract infections. Clin Microbiol Infect 2002; 8 (suppl 2): 12–42. 56 Vilhelmsson SE, Tomasz A, Kristinsson KG. Molecular evolution in a multidrug-resistant lineage of Streptococcus pneumoniae: emergence of strains belonging to the serotype 6B Icelandic clone that lost antibiotic resistance traits. J Clin Microbiol 2000; 38: 1375–81. 57 Bronzwaer SL, Cars O, Buchholz U, et al. A European study on the relationship between antimicrobial use and antimicrobial resistance. Emerg Infect Dis 8: 278–82. 58 Steinke D, Davey PG. The association between antibiotic resistance and community prescribing: a critical review of bias and confounding in published studies. Clin Infect Dis 2001; 33 (suppl 3): S193–205. 59 Harbarth S, Harris AD, Carmeli Y, Samore MH. Parallel analysis of individual and aggregated data on antibiotic exposure and resistance in gram-negative bacilli. Clin Infect Dis 2001; 33: 1462–68. 60 Hall AJ. Ecological studies and debate on rotavirus vaccine and intussusception. Lancet 2001; 358: 1197–98. Personal view Education to improve antibiotic use


Arthritis & Rheumatism | 2014

Altered cellular and humoral immunity to varicella-zoster virus in patients with autoimmune diseases.

Christien Rondaan; Aalzen de Haan; Gerda Horst; J Cordelia Hempel; Coretta van Leer; Nicolaas A. Bos; Sander van Assen; Marc Bijl; Johanna Westra

Patients with autoimmune diseases such as systemic lupus erythematosus (SLE) and granulomatosis with polyangiitis (Wegeners) (GPA) have a 3–20‐fold increased risk of herpes zoster compared to the general population. The aim of this study was to evaluate if susceptibility is due to decreased levels of cellular and/or humoral immunity to the varicella‐zoster virus (VZV).

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Bhanu Sinha

University Medical Center Groningen

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Johanna Westra

University Medical Center Groningen

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Marc Bijl

University Medical Center Groningen

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Aalzen de Haan

University Medical Center Groningen

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Albert Holvast

University Medical Center Groningen

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Anna Gomes

University Medical Center Groningen

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Cornelis A. Benne

University Medical Center Groningen

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Herman G. Sprenger

University Medical Center Groningen

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Peter Paul van Geel

University Medical Center Groningen

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