Sylvie Pillet

Dr. Sylvie Pillet

Faculty of Medicine-University of Saint-Etienne
+1
orcid

Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 November 2011 in American Journal of Gastroenterology
Verified
Journal Article
Closed access
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Xavier RoblinXavier Roblin
Xavier Roblin
Sylvie PilletSylvie Pillet
Sylvie Pillet
AOAbderrahim Oussalah
Abderrahim Oussalah
PBPhilippe Berthelot
Philippe Berthelot
ETEmilie Del Tedesco
Emilie Del Tedesco
BPBruno Pozzetto
Bruno Pozzetto
Previous studies have suggested an association between cytomegalovirus (CMV) infection and steroid-refractory inflammatory bowel disease. In this study, the use of CMV DNA load during acute flare-ups of ulcerative colitis (UC) to predict resistance to immunosuppressive therapy was evaluated in intestinal tissue. Forty-two consecutive patients (sex ratio M/F: 0.9, mean age: 43.6 years) hospitalized for moderate to severe UC and treated with IV steroids were included prospectively. A colonoscopy was performed for each patient at inclusion; colonic biopsy samples of the pathological tissue, and if possible, of the healthy mucosa, were tested for histological analysis and determination of CMV DNA load by real-time polymerase chain reaction assay. Patients were treated as recommended by the current guidelines. Sixteen patients were found positive for CMV DNA in inflamed intestinal tissue but negative in endoscopically healthy tissue; all of these patients were positive for anti-CMV IgG, three exhibited CMV DNA in blood, and none was positive for intestinal CMV antigen by immunohistochemistry detection. In the 26 remaining patients, no stigmata of recent CMV infection were recorded by any technique. By multivariate analysis, the only factor associated with CMV DNA in inflammatory tissue was the resistance to steroids or to three lines of treatment (risk ratio: 4.7; 95% confidence interval: 1.2–22.5). A CMV DNA load above 250 copies/mg in tissue was predictive of resistance to three successive regimens (likelihood ratio+=4.33; area under the receiver-operating characteristic curve=0.85). Eight UC patients with CMV DNA in inflamed tissue and therapeutic failure received ganciclovir; a clinical remission was observed in seven cases, with a sustained response in five of them. The CMV DNA load determined in inflamed intestinal tissue predicts resistance to steroid treatment and to three drug regimens in UC. Initiation of an early antiviral treatment in these patients might delay the occurrence of resistance to current treatments.

20 October 2010 in Journal of Antimicrobial Chemotherapy
Verified
Journal Article
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SHSébastien Hantz
Sébastien Hantz
FGFrançoise Garnier-Geoffroy
Françoise Garnier-Geoffroy
IGI. Garrigue
I. Garrigue
PMP. Merville
P. Merville
CMC. Mengelle
C. Mengelle
PRPatricia Ribaud
Patricia Ribaud
Cytomegalovirus (CMV) drug resistance is a therapeutic challenge in the transplant setting. No longitudinal cohort studies of CMV resistance in a real-life setting have been published in the valganciclovir era. We report findings for a French multicentre prospective cohort of 346 patients enrolled at initial diagnosis of CMV infection (clinical trial registered at clinicaltrials.gov: NCT01008540). Patients were monitored for detection of CMV infection for ≥2 years. Real-time detection of resistance by UL97 and UL54 gene sequencing and antiviral phenotyping was performed if viral replication persisted for >21 days of appropriate antiviral treatment. Plasma ganciclovir assays were performed when resistance was suspected. Resistance was suspected in 37 (10.7%) patients; 18/37 (5.2% of the cohort) had virological resistance, associated with poorer outcome. Most cases involved single UL97 mutations, but four cases of multidrug resistance were due to UL54 mutations. In solid organ transplant recipients, resistance occurred mainly during primary CMV infection (odds ratio 8.78), but also in two CMV-seropositive kidney recipients. Neither CMV prophylaxis nor antilymphocyte antibody administration was associated with virological resistance. These data show the feasibility of surveying resistance. Virological resistance was frequent in patients failing antiviral therapy. More than 1/5 resistant isolates harboured UL54 mutations alone or combined with UL97 mutations, which conferred a high level of resistance and sometimes were responsible for cross-resistance, leading to therapeutic failure.

1 May 2012 in Journal of Clinical Microbiology
Verified
Journal Article
Closed access
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MBMaël Bessaud
Maël Bessaud
Sylvie PilletSylvie Pillet
Sylvie Pillet
WIWafa Ibrahim
Wafa Ibrahim
MJMarie-Line JOFFRET
Marie-Line JOFFRET
BPBruno Pozzetto
Bruno Pozzetto
IGIonela Gouandjika-Vasilache
Ionela Gouandjika-Vasilache
Human enteroviruses (HEV) are among the most common viruses infecting humans. Their circulation has been widely studied in most parts of the world but not in sub-Saharan Africa, where poliomyelitis remains prevalent. We report here the molecular characterization of 98 nonpoliovirus (non-PV) HEV strains isolated from 93 randomly selected cell culture-positive supernatants from stool samples collected from 1997 through 2006 from children with acute flaccid paralysis living in the Central African Republic (CAR). The isolates were typed by sequencing the VP1 coding region and sequenced further in the VP2 coding region, and phylogenetic studies were carried out. Among the 98 VP1 sequences, 3, 74, 18, and 3 were found to belong to the HEV-A, -B, -C, and -D species, respectively. Overall, 42 types were detected. In most cases, the VP2 type was correlated with that of the VP1 region. Some of the isolates belonged to lineages that also contain viruses isolated in distant countries, while others belonged to lineages containing viruses isolated only in Africa. In particular, one isolate (type EV-A71) did not fall into any of the genogroups already described, indicating the existence of a previously unknown genogroup for this type. These results illustrate the considerable diversity of HEV isolates from the stools of paralyzed children in the CAR. The presence of diverse HEV-C types makes recombination between poliovirus and other HEV-C species possible and could promote the emergence of recombinant vaccine-derived polioviruses similar to those that have been implicated in repeated poliomyelitis outbreaks in several developing countries.

1 July 2007 in Expert Review of Molecular Diagnostics
Verified
Journal Article
Closed access
DNDorsaf Nasri
Dorsaf Nasri
LBLamjed Bouslama
Lamjed Bouslama
Sylvie PilletSylvie Pillet
Sylvie Pillet
TBThomas Bourlet
Thomas Bourlet
MAMahjoub Aouni
Mahjoub Aouni
BPBruno Pozzetto
Bruno Pozzetto
(2007). Basic rationale, current methods and future directions for molecular typing of human enterovirus. Expert Review of Molecular Diagnostics: Vol. 7, No. 4, pp. 419-434.

1 January 2016 in World Journal of Gastroenterology
Verified
Journal Article
Open access
Sylvie PilletSylvie Pillet
Sylvie Pillet
BPBruno Pozzetto
Bruno Pozzetto
Xavier RoblinXavier Roblin
Xavier Roblin
The link between cytomegalovirus (CMV) infection and inflammatory bowel diseases remains an important subject of debate. CMV infection is frequent in ulcerative colitis (UC) and has been shown to be potentially harmful. CMV reactivation needs to be diagnosed using methods that include in situ detection of viral markers by immunohistochemistry or by nucleic acid amplification techniques. Determination of the density of infection using quantitative tools (numbers of infected cells or copies of the genome) is particularly important. Although CMV reactivation can be considered as an innocent bystander in active flare-ups of refractory UC, an increasing number of studies suggest a deleterious role of CMV in this situation. The presence of colonic CMV infection is possibly linked to a decreased response to steroids and other immunosuppressive agents. Some treatments, notably steroids and cyclosporine A, have been shown to favor CMV reactivation, which seems not to be the case for therapies using anti-tumor necrosis factor drugs. According to these findings, in flare-ups of refractory UC, it is now recommended to look for the presence of CMV reactivation by using quantitative tools in colonic biopsies and to treat them with ganciclovir in cases of high viral load or severe disease.

1 June 1999 in Journal of Virology
Verified
Journal Article
Closed access
PDF file
CEC. Elbim
C. Elbim
Sylvie PilletSylvie Pillet
Sylvie Pillet
MPM. H. Prevost
M. H. Prevost
APA. Preira
A. Preira
PGP. M. Girard
P. M. Girard
MGM. A. Gougerot-Pocidalo
M. A. Gougerot-Pocidalo
Monocytes are precursors of tissue macrophages, which are major targets of human immunodeficiency virus type 1 (HIV-1) infection. Although few blood monocytes are infected, their resulting activation could play a key role in the pathogenesis of HIV disease by modulating their transendothelial migration and inducing the production of reactive oxygen species (ROS). ROS participate in chronic inflammation, HIV replication, and the apoptosis of immune system cells seen in HIV-infected subjects. Published data on monocyte activation are controversial, possibly because most studies have involved monocytes isolated from their blood environment by various procedures that may alter cell responses. We therefore used flow cytometry to study, in whole blood, the activation and redox status of monocytes from HIV-infected patients at different stages of the disease. We studied the expression of adhesion molecules, actin polymerization, and cellular levels of H2O2, Bcl-2, and thioredoxin. Basal H2O2production correlated with viral load and was further enhanced by bacterialN-formyl peptides and endotoxin. The enhanced H2O2production by monocytes from asymptomatic untreated patients with CD4+cell counts above 500/μl was associated with a decrease in the levels of Bcl-2 and thioredoxin. In contrast, in patients with AIDS, Bcl-2 levels returned to normal and thioredoxin levels were higher than in healthy controls. Restoration of these antioxidant and antiapoptotic molecules might explain, at least in part, why monocyte numbers remain relatively stable throughout the disease. Alterations of adhesion molecule expression and increased actin polymerization could play a role in transendothelial migration of these activated monocytes.