Syria Laperche

Institut National de la Transfusion Sanguine, Paris, Lutetia Parisorum, Île-de-France, France

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Publications (152)447.09 Total impact

  • Source
    The Journal of infectious diseases. 09/2014;
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    ABSTRACT: The risk assessment for blood transfusion is an essential step that must precede any screening strategy of a pathogen transmitted by transfusion. After several cases of HEV transmission by transfusion in France, a risk assessment for this virus was performed.
    Transfusion clinique et biologique : journal de la Societe francaise de transfusion sanguine. 09/2014;
  • S Laperche, J Pillonel
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    ABSTRACT: In high-income countries, the safety of blood transfusion related to viruses has reached a very high level, especially thanks to the implementation of multiple measures aimed at reducing the transfusion risk. The cost-effectiveness of these preventive measures is frequently discussed due to global financial resources, which are more and more limited. Hence, the revision of safety strategies is a key issue, especially when these strategies are redundant, as those implemented to avoid Human T-cell Lymphotropic Virus (HTLV) transmission, which are based on both antibodies screening and leucoreduction of blood products. The residual risk of the transmission of HTLV by transfusion has been recently estimated at 1 in 20 million donations (2010-2012) in France (excluding overseas territories). This estimation did not take into account the leucoreduction, which appears to be a very efficient preventive measure as the virus is strictly intra-cellular. To help decision-making, we have evaluated some parameters related to HTLV blood transmission. Firstly, the probability that an incident occurring during the leucoreduction process affects a HTLV-positive blood donation has been estimated at 1 in 178 million. Estimation of clinical consequences of HTLV-positive transfusions would affect 1 to 2 transfused-patients without leucoreduction, and one recipient every 192 years in case of 10% failures of the filtration method. Obviously, despite a risk, which appears to be controlled, HTLV screening will be disputed as soon as the efficiency of leucoreduction to totally prevent virus blood transmission will be proven and when pathogen inactivation methods are generalized to all blood cellular products.
    Transfusion clinique et biologique : journal de la Societe francaise de transfusion sanguine. 09/2014;
  • Transfusion 08/2014; 54(8). · 3.53 Impact Factor
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    ABSTRACT: Hepatitis B virus (HBV) basal core promoter (BCP) and precore (PC) mutations, HBV viral load and HBV surface antigen (HBsAg) quantitation were screened to assess correlations between these HBV markers in asymptomatic chronic hepatitis B carriers in France. From January 2006 to July 2007, 200 sera were collected from patients who were discovered to be HBsAg-positive when they volunteered to give blood. Direct sequencing of precore/core gene was used to detect A1762T/G1764A mutations in the BCP and G1896A in the PC region. HBV viral load and HBsAg were quantified with two commercials assays. The prevalence of the BCP and PC mixed/mutants were 37% and 60% respectively (P = 0.0001). HBV DNA level and HBsAg titer were significantly lower in subjects harboring the mixed/mutant PC virus compared to those infected by the wild phenotype. No significant difference was observed in HBV viral loads of blood donors infected by wild or mixed/mutant BCP viruses. Mutant or mixed PC virus was associated with male gender, HBeAb-positive status and HBV/D and HBV/E genotypes. BCP mutations were associated with age, and both HBV/A-HBV/E genotypes.The genetic properties of HBV in this cohort showed that most of the blood donors had a negative HBeAg serological status and harbored the PC mutant phenotype in combination with low levels of both HBV DNA and HBsAg. As the study was conducted in healthy subjects who could be considered as asmptomatic carriers, these results suggest a possible protective effect of the G1896A mutation against severe liver lesions. J. Med. Virol. © 2014 Wiley Periodicals, Inc.
    Journal of Medical Virology 08/2014; · 2.37 Impact Factor
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    ABSTRACT: Droplet digital PCR (ddPCR), which has been recently developed to provide an absolute quantitation of target molecules without relying on the use of standard curves (1), might be an interesting alternative to conventional real-time PCR assays used for viral load (VL) determination (2, 3).…
    Journal of clinical microbiology. 07/2014;
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    ABSTRACT: Background and Objectives Serologic screening for the major transfusion transmissible viruses (TTV) is critical to blood safety and has been widely implemented. However, actual performance as measured by proficiency testing has not been well studied in sub-Saharan Africa. Therefore, we conducted an external quality assessment of laboratories engaged in transfusion screening in the region.Materials and Methods Blinded test panels, each comprising 25 serum samples that were pedigreed for HIV, HBsAg, HCV and negative status, were sent to participating laboratories. The panels were tested using the laboratories' routine donor screening methods and conditions. Sensitivity and specificity were calculated, and multivariable analysis was used to compare performance against mode of testing, country and infrastructure.ResultsA total of 12 African countries and 44 laboratories participated in the study. The mean (range) sensitivities for HIV, HBsAg and HCV were 91·9% (14·3–100), 86·7% (42·9–100) and 90·1% (50–100), respectively. Mean specificities for HIV, HBsAg and HCV were 97·7%, 97% and 99·5%, respectively. After adjusting for country and infrastructure, rapid tests had significantly lower sensitivity than enzyme immunoassays for both HBsAg (P < 0·0001) and HCV (P < 0·05). Sensitivity also varied by country and selected infrastructure variables.Conclusion While specificity was high, sensitivity was more variable and deficient in a substantial number of testing laboratories. These findings underscore the importance of proficiency testing and quality control, particularly in Africa where TTV prevalence is high.
    Vox Sanguinis 07/2014; · 2.85 Impact Factor
  • Transfusion 03/2014; 54(3):744-5. · 3.53 Impact Factor
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    ABSTRACT: A French national quality control for serological and molecular diagnosis of hepatitis Delta virus (HDV) was organized. All participants detected total HDV antibodies; 8/14 failed to detect low titers of IgM; 6/11 laboratories failed to quantify and/or underestimated RNA viral load in several samples. These discrepancies are likely related to HDV molecular diversity.
    Journal of clinical microbiology 02/2014; · 4.16 Impact Factor
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    ABSTRACT: In low-income-countries, screening for hepatitis C virus (HCV) infection is often based on rapid tests (RT). Their lower sensitivity compared to enzyme immunoassay (EIA) suggests that newer HCV Antigen/Antibody (Ag/Ab) combination assays might have a role in such countries. To test this idea, 1998 blood donors were tested at the University Teaching Hospital blood bank in Yaoundé, Cameroon simultaneously with a RT (HCV rapid test, Human Diagnostics, Berlin, Germany) according to standard practice (S1) and with an Ag/Ab assay (Monolisa HCV Ag/Ab Ultra, Biorad, France) (S2). All discordant, borderline and reactive samples were submitted to confirmatory testing by immunoblot and/or HCV-RNA. Of the 86 (4.3%) samples positive with one or both strategies, 29 were confirmed negative, 37 positive and 20 were false positive or resolved infection. There was a significant difference in test sensitivity (p=0.01) between S1 (70.3%) and S2 (91.9%) but not in test specificity (99.4% and 98.6%, respectively). The benefit of the Ag/Ab assay in the detection of recent HCV seronegative infections could not be evaluated since no Antigen-only donations were identified. However, better Ag/Ab test sensitivity compared to RT supports the implementation of these newer immunoassays for HCV screening in the African blood bank setting.
    Journal of virological methods 01/2014; · 2.13 Impact Factor
  • S. Laperche, J. Pillonel
    [Show abstract] [Hide abstract]
    ABSTRACT: In high-income countries, the safety of blood transfusion related to viruses has reached a very high level, especially thanks to the implementation of multiple measures aimed at reducing the transfusion risk. The cost-effectiveness of these preventive measures is frequently discussed due to global financial resources, which are more and more limited. Hence, the revision of safety strategies is a key issue, especially when these strategies are redundant, as those implemented to avoid Human T-cell Lymphotropic Virus (HTLV) transmission, which are based on both antibodies screening and leucoreduction of blood products. The residual risk of the transmission of HTLV by transfusion has been recently estimated at 1 in 20 million donations (2010–2012) in France (excluding overseas territories). This estimation did not take into account the leucoreduction, which appears to be a very efficient preventive measure as the virus is strictly intra-cellular. To help decision-making, we have evaluated some parameters related to HTLV blood transmission. Firstly, the probability that an incident occurring during the leucoreduction process affects a HTLV-positive blood donation has been estimated at 1 in 178 million. Estimation of clinical consequences of HTLV-positive transfusions would affect 1 to 2 transfused-patients without leucoreduction, and one recipient every 192 years in case of 10% failures of the filtration method. Obviously, despite a risk, which appears to be controlled, HTLV screening will be disputed as soon as the efficiency of leucoreduction to totally prevent virus blood transmission will be proven and when pathogen inactivation methods are generalized to all blood cellular products.
    Transfusion Clinique et Biologique 01/2014; · 0.64 Impact Factor
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    ABSTRACT: Background The risk assessment for blood transfusion is an essential step that must precede any screening strategy of a pathogen transmitted by transfusion. After several cases of HEV transmission by transfusion in France, a risk assessment for this virus was performed. Methods We used a method based on the prevalence of HEV-RNA in plasmas collected for the preparation of SD-plasma. To estimate the rate of HEV-RNA positive among all blood donations, data on SD-plasma were adjusted on the following HEV risk factors: gender, age group and region of residence. We assumed that HEV risk factors were the same in plasma donors and whole blood donors. Results Among 57,101 plasma donations tested for HEV-RNA in 2013, 24 were positive (crude rate of 4.2 per 10,000 donations). After adjustment, the total number of HEV-RNA positive blood donations was estimated at 788, accounting for a rate of 2.65 per 10,000 donations (95% CI: 1.6–3.7) or 1 in 3800 donations (1 in 6,200–1 in 2,700). This rate was 12 times higher in men than in women, increased with age, and varied according to region of residence. Conclusion The risk of blood donation contamination by HEV has been estimated to be 1 in 3800 donations in 2013. An essential input is still missing to assess now the risk in recipients: the minimum infectious dose. Furthermore, the risk in recipients has to be analyzed according to characteristics of transfused patients: presence of anti-HEV immunity, existence of chronic liver disease or immunodeficiency.
    Transfusion Clinique et Biologique 01/2014; · 0.64 Impact Factor
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    ABSTRACT: In France, there are no consistent data estimating hepatitis delta virus (HDV) prevalence in the general population. To better characterize HDV/HBV infection and its trends over a 15-years period from 1997 to 2011, we used data retrieved from the National Epidemiological Donors database including viral and demographic characteristics of all French HBV infected blood donors. Of the 39,911,011 donations collected over the 15 year-study-period, 6214 (1.56 in 10(4) donations) were confirmed positive for HBV from which 72.3% were tested for HDV antibodies (Ab). HDV viral load was performed using a real-time PCR assay on positive HDV Ab samples and HDV genotype determined for each positive viremic sample. Among the 4492 HBV donations, 89 (1.98%) were HDV Ab positive. After being stable around 1.1% from 1997 to 2005, this rate has continuously increased to reach 6.5% in 2010, before declining to 0.85% in 2011. Of the 61 investigated HDV Ab positive individuals, 22.9% were viremic with a viral load ranging from 10(4) to 9.8×10(7)copiesmL(-1). Genotyping revealed 12 HDV-1, 1 HDV-6 and 1 HDV-7 in accordance with the geographical origin of individuals. Such a study gives unexpected features of HBV-HDV infection in the population of blood donors which is a priori, a healthy population. The increase of HDV prevalence mainly linked to migration of population from endemic countries, demonstrates that there is still no complete control of HBV infection and must encourage HBV vaccination campaigns and systematic screening for HDV in HBV-infected.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 12/2013; · 3.12 Impact Factor
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    ABSTRACT: Rapid diagnostic tests (RDT) have been developed for the detection of hepatitis B surface antigen (HBsAg). They represent a promising alternative to enzyme immunoassays and a powerful tool for large-scale screening and diagnosis of HBV infection, especially in regions without easy access to serological and molecular testing. The aims of the present study were to evaluate the characteristics and clinical performance of a new CE-marked HBsAg RDT, DRW-HBsAg v2.0 assay (Diagnostics for the Real World™, Ltd., USA), in various patient populations, including those chronically infected with HBV, patients with severe acute hepatitis of unknown origin and pregnant women with unknown HBV serological status at delivery. The lower limit of detection of the assay, evaluated in 21 clinical samples, ranged from 0.30±0.07 to 0.97±0.26 international units/mL (using Abbott Architect as a reference), depending on the HBV genotype. The assay tested positive in 100% of patients with chronic hepatitis B, 96.3% of HBsAg-positive acute hepatitis patients, and 95.2% of HBsAg-positive pregnant women. Its specificity was 98.8% in HBsAg-negative patients, 98.7% in HBsAg-negative patients with acute hepatitis of unknown origin and 97.8% in HBsAg-negative pregnant women. Amino acid substitutions in the HBsAg major hydrophilic region did not affect HBsAg detection by DRW-HBsAg v2.0. The new DRW-HBsAg v2.0 assay is a simple, rapid, easy-to-run and highly sensitive assay that can be used in both high- and low-risk populations for the diagnosis of HBsAg carriage. It appears to be a promising new tool for large-scale screening and diagnosis of HBV infection.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 12/2013; · 3.12 Impact Factor
  • Transfusion Clinique et Biologique 06/2013; 20(3):208-209. · 0.64 Impact Factor
  • Transfusion Clinique et Biologique 06/2013; 20(3):262. · 0.64 Impact Factor
  • Source
    S. Laperche
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    ABSTRACT: Enzyme Immunoassays (EIAs) detecting antibodies (Ab) or antigen (Ag) used to avoid viral transmissions by transfusion, are the most suitable methods for blood screening because they are economical and adaptable to high-throughput testing. The continuing need to improve screening for HIV and HCV, led to develop Ag/Ab combination assays. The benefit of such assays has been widely demonstrated, since they are able to detect infected individuals in viremic pre-seroconversion phase, making them particularly attractive for ensuring blood safety when nucleic acid testing (NAT) cannot be implemented. In resource-limited countries, especially in remote-areas, blood safety is often based upon rapid tests (RT) which are easy to handle and can be used with whole blood. Nevertheless, the poor sensitivity of RT compared to EIAs could significantly impair blood safety. Because NAT could efficiently detect serologically negative donors, many developed countries have implemented this method in blood screening. NAT yields vary depending on epidemiological situations. NAT is subjected to false-negative results due to viral diversity or to extremely low viral loads, but also to false-positive due to sample cross-contamination. A repeatedly NAT reactive sample with multiplexed NAT is submitted to a virus-specific amplification testing to discriminate between the viruses, creating some problematic situations consisting of samples reactive with the screening assay but non-reactive with the discriminatory assay. Although the primary purpose of viral screening testing is to prevent pathogen transmission to recipients, confirmatory testing intends to manage donors with adverse test results and to guarantee an optimal blood supply. As EIAs show a low positive predictive value in low-prevalence countries due to frequent non-specific reactions, the use of confirmatory assays is justified. Nevertheless confirmatory tests are known to be less sensitive than EIAs in the early phase of infection and show also nonspecific reactivity leading to indeterminate results which create difficulties in managing donors. As in limited-resource countries, specific confirmatory assay cannot be used, alternate strategies for confirmatory testing have been proposed, as to simultaneously test blood with two assays and to exclude donors reactive with both, or to use screening test signal values to support confirmation. Although the direct detection of the virus through its genome might be considered as the best solution to ensure blood safety, the choice of blood screening strategy should be adapted to local epidemiology and organization constraints.
    ISBT Science Series 06/2013; 8(1).
  • Transfusion Clinique et Biologique 06/2013; 20(3):262–263. · 0.64 Impact Factor
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    ABSTRACT: The preparation of a VHH (nanobody(TM)) named IH4 that recognizes human glycophorin A (GPA) is described. IH4 was isolated by screening a library prepared from the lymphocytes of a dromedary immunized by human blood transfusion. Phage display and panning against GPA as the immobilized antigen, allowed isolating this VHH. IH4, representing 67% of the retrieved VHH sequences, was expressed as a soluble correctly folded protein in SHuffle(TM)E. coli cells routinely yielding ca. 100 mg/L of fermentation medium. Because IH4 recognizes GPA independently of the blood-group antigens, it recognizes red cells of all humans with the possible exception of those with some extremely rare genetic background. The targeted linear epitope comprises the GPA Y52PPE55 sequence. Based on surface plasmon resonance results the dissociation constant of the IH4-GPA equilibrium is 33 nM. IH4 is a stable protein with a transition melting temperature of 75.8°C (measured by differential scanning calorimetry). As proof of concept, we fused HIV p24 to IH4 and used the purified construct expressed in E. coli to show that IH4 was amenable to the preparation of autologous erythrocyte agglutination reagents: reconstituted blood prepared with serum from an HIV positive patient was readily agglutinated by addition of the bifunctional reagent.
    Analytical Biochemistry 03/2013; · 2.58 Impact Factor
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    ABSTRACT: Hepatitis C virus (HCV) protease inhibitor resistance-associated substitutions are selected during triple therapy breakthrough. This multicenter quality control study evaluated the expertise in HCV protease inhibitor resistance genotyping of 23 French laboratories. A panel of 12 well-defined blinded samples comprising two wild-type HCV strains, nine transcripts from synthetic NS3 mutant samples or from clinical strains, and one HCV RNA-negative sample was provided to the participating laboratories. The results showed that any laboratory with expertise in sequencing techniques should be able to provide reliable HCV protease inhibitor resistance genotyping. Only 0.7% erroneous results were reported over the amino acid sites studied. The accuracy of substitution identification ranged from 75% to 100%, depending on the laboratory. Incorrect results were mainly related to the methodology used. The results could be improved by changing the primers and modifying the process in order to avoid cross-contaminations. This study underlines the value of quality control programs for viral resistance genotyping, required prior to launching observational collaborative multicenter studies on HCV resistance to direct-acting antiviral agents.
    Journal of clinical microbiology 02/2013; · 4.16 Impact Factor

Publication Stats

2k Citations
447.09 Total Impact Points

Institutions

  • 1997–2014
    • Institut National de la Transfusion Sanguine, Paris
      Lutetia Parisorum, Île-de-France, France
  • 2011
    • Institut de France
      Lutetia Parisorum, Île-de-France, France
    • University of Yaounde I
      • Faculty of Medicine and Biomedical Sciences
      Yaoundé, Centre Province, Cameroon
  • 2010
    • University of Paris-Est
      Centre, France
  • 2008–2009
    • Université Paris-Est Créteil Val de Marne - Université Paris 12
      Créteil, Île-de-France, France
    • University of Tours
      Tours, Centre, France
  • 2002–2008
    • Institut de veille sanitaire
      • Department of Infectious Diseases
      Charenton-le-Pont, Ile-de-France, France
  • 2007
    • Université Victor Segalen Bordeaux 2
      Burdeos, Aquitaine, France
  • 2006
    • Centre Hospitalier Universitaire de Toulouse
      • Laboratoire de Virologie
      Tolosa de Llenguadoc, Midi-Pyrénées, France