rologie i - European Congress of Virology

5 th European Congress of Virology6,HSV 1,HSV 2,VZV,EBV and CMV DNA. HHV 6 chromosomal integration(CIHHV 6) was determined by virus DNA amplification in hairfollicles. Cutaneous swab and skin biopsy as well as serum and wholeblood resulted positive for HHV 6 DNA (3.2 × 102,2.7 × 103,1.5 × 102and 4.5 × 106copies/ml,respectively) whereas were negative for the otherviruses. Since the presence of high viral copy number in whole blood togetherwith lower level in serum is suggestive of CIHHV 6, hair follicles wereinvestigated for HHV 6 DNA and CIHHV 6 was established. Histologywas consistent with a small vessel neutrophilic/leukocytoclastic vasculitis.The skin rash spontaneously disappeared within 4 weeks. Six monthslater the persistence of HHV 6 DNA was confirmed by RT PCR in bothserum and whole blood. No clinical recurrence was observed in the following12 months.According to the most recent data, our finding supportsthat the expression of HHV 6 genes after viral chromosomal integrationmight contribute to explain, at least in part, the development of immunemediated diseases, such as leukocytoclastic vasculitis.REF 465Comparison of Viral Load Assays for the Quantification of HCVGenotypes 14intheSetting of Low Viremic SamplesPatrick BRAUN 1 , Frank WIESMANN 1 , Annemarie BERGER 3 , RolfKAISER 2 , Gudrun NAETH 1 , Robert EHRET 4 , Heribert KNECHTEN 11 PZB Aachen, Aachen, GERMANY; 2 Institute of Virology, Cologne,GERMANY; 3 Institute of Frankfurt, Frankfurt, GERMANY; 4 MedicalLaboratory Berg, Berlin, GERMANYBackground: The aim of this study was to assess the variation between5 quantitative HCV RNA assays in the range of clinical decision points,recently established i.e. for treatment with protease inhibitors.Methods: Serial dilutions from the 3rd WHO and PEI standards [nominal:1000, 500, 200, 100, 25, 10 & 5 IU/mL] were tested with 5 HCV viral load[VL] assays (artus HCV QS RGQ [Qiagen], COBAS Ampliprep/COBASTaqMan (CTM) HCV v1 and v2 [Roche], RealTime HCV [Abbott] andVersant HCV RNA 1.0 [Siemens]) in triplicate in a single run. Interassaycoefficients of variation (CV) were determined for serial dilutions of 1000,100 & 25 IU/ml [gt1:N=6/gt2,3,4: N=1 each). 20 clinical gt1 samples weremeasured in triplicates to determine the differences in VL between theassays.Results: From 100 1000 IU/ml, the max. difference from nominal valuesranged from CTM v2 results of 0.51 log [PEI] and 0.91 log [WHO] toartus results of +0.25 log [PEI] and 0.07 [WHO]. Within the dilution of 525 IU/mL for both standards, artus “detected” 9/18, CTM v1 14/18, CTMv2 7/18, RealTime 16/18 and Versant 10/18, respectively. The mean CV%for clinical gt1 samples at 1000/100/25 IU/mL was 27%/35%/81% (artus),21%/30%/54% (CTM v1), 30%/32%/65% (CTM v2), 15%/18%/26%(RealTime) and 28%/31%/46% (Versant), respectively. The widest discrepancybetween two assays was observed between artus and RealTime[0.68 0.75 log].Conclusion: High sensitivity and accuracy of HCV quantification assaysare crucial for reliability of clinical decisions concerning treatment continuation.REF 466Performance Evaluation of Toxoplasma IgG and IgM assays fromBioPlex ® 2200 ToRC Multiplexed Panels (Bio Rad)Ermanno CANDOLFI, Elodie HAAR, Denis FILISETTI, OdileVILLARDInstitut de Parasitologie et de Pathologie Tropicale, Centre National deRéférence pour la Toxoplasmose, laboratoire associé, Un, Strasbourg,FRANCEObjectives: BioPlex ® 2200 multiplexed ToRC assays offer the ability toreport Toxoplasma, Rubella and CMV results in a single test. The aimof this study is to evaluate the performances of the BioPlex ® 2200 ToxoplasmaIgG and IgM immunoassays by comparing with our routine method(Architect, Abbott). Moreover very specific retrospective samples werealso assessed using BioPlex ® 2200 kits. Methods: 200 routine sampleswere submitted to BioPlex ® 2200 assays and compared to Architect’sresults (142 IgG/IgM, 3 IgG/IgM+, 33 IgG+/IgM, 22 IgG+/IgM+). Moreover41 sera with low titers of IgG (and IgM negative) and 27 seroconversionpanels were also assessed. Finally 44 samples from chronic infection(IgG positive) with persistent IgM, and 53 possibly interfering sampleswere also tested. Discrepant results were arbitrated on Western Blot IgGII(LDBIO) and ISAGA IgM test (bioMérieux). Results: Relative sensitivityand specificity of BioPlex ® 2200 Toxoplasma assays compared to Architectare respectively of 96.4% and 99.3% for IgG, and 86.4% and 92.3%for IgM. All 41 samples with IgG low titer were confirmed positive onBioPlex ® 2200. However, Toxoplasma IgG titers were overestimated inlatent toxoplasmosis. In acute toxoplasmosis, for 5 seroconversion casesout of 27, a delay is observed for the detection of IgG but the concordancefor IgM is perfect. Finally the IgM assay is fortunately less sensitive toresidual IgM.Conclusion: BioPlex ® 2200 Toxoplasmosis assays demonstrate satisfactoryperformances with a good overall concordance with our routinemethod.REF 468Anti HCV Signal to Cut off ratios for prediction of HCV infectionRoselyne FALCOU BRIATTE 4 , Guillaume DAUSSANGE 1,2,3 , PascaleTRIMOULET 1,2,3 , Christine MASSON 4 , Christophe HILLAIRET 5 ,Hervé FLEURY 1,2,31 Laboratoire de Virologie, CHU de Bordeaux, Bordeaux, France; 2 CNRS,Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux,France; 3 Univ. Bordeaux Segalen, Microbiologie Fondamentale et Pathogénicité,UMR 5234, Bordeaux, France; 4 Bio Rad, Marnes la Coquette,France; 5 Beckman Coulter Inc., Villepinte, FRANCEObjectives: the screening and diagnosis of hepatitis C virus (HCV) infectioninvolve the detection of specific antibodies (anti HCV) and of HCVRNA. Positive result of anti HCV must be confirmed by another immunoassayand/or by HCV RNA quantification to detect viremia. The aim ofthis study is to determine specific Signal to Cut off (S/Co) ratios with thecommercial kit that is used routinely in our laboratory for the prediction ofanti HCV or HCV RNA positivity. Methods: A chemiluminescence immunoassay(CIA) system with random access (UniCel ® DxI 800, BeckmanCoulter) was used to detect anti HCV status (Access ® HCV Ab PLUS,Bio Rad) between January and September 2012. Positive results of antiHCV were followed by an enzyme immunoassay (EIA) (MONOLISA ®Anti HCV PLUS version2, Bio Rad) used on the ETI MAX 3000 system(DiaSorin) to confirm anti HCV positivity and/or HCV RNA quantification.The Statistical Analyse it ® 2.30 software was used for data analysis.ROC curves were analyzed to ascertain the optimal S/Co ratios to predictHCV infection. Results: With the CIA method, the S/Co ratios weredetermined on 15,552 patient samples. 4.7% of patients had positive testresults. A S/Co ratio