MKT/BF/328

Transcription

1 MKT/BF/328 BIO-FLASH posters presented at ECCMID, 23rd Congress of Clinical Microbiology and Infectious Diseases Evaluation of HBV/HCV/HIV 1+2 Evaluation of TORC panel As you know this year was the first time Biokit was exhibiting at the ECCMID 23rd Congress of Clinical Microbiology and Infectious Diseases, in Berlin in April ECCMID was a great opportunity to display our BIO-FLASH system in this forum which specializes in microbiology and infectious diseases. Moreover, the organizing committee also approved the publication of two posters that demonstrate the high quality of performance of our chemiluminescent reagents in the BIO-FLASH (see BKNEWS MKT/ 321, including the abstracts presented to submission). Please find attached the complete version of these posters which were published and exhibited at this International Congress. We consider these posters as an excellent summary of the performance of the BIO-FLASH infectious disease reagents. BIOKIT S.A. Can Malé, s/n Lliçà d Amunt Barcelona, Spain Tel Fax Joaquín Ortiz Group Product Manager Rapid Tests, ELISA & Western Blot Blood Bank Support jortiz@biokit.com Carlos Fernández Product Manager Instrumentation cfernandez.cepeda@biokit.com Joan Vilà Key Account Manager Werfen Products MKTG & Sales Support (Western Europe & NOA) jvila@biokit.com Montse Armengol Marketing Assistant montse.armengol@biokit.com Biokit Marketing Team Ricard Forns Marketing and Technical Service Director rforns@biokit.com Biokit Phone: Biokit Mktg Fax: Sandra Roselló Product Manager Turbidimetry MKTG & Sales Support (EEMEIA) sandra.rosello@biokit.com Fran Sánchez Product Manager Instrumentation fran.sanchez@biokit.com Jordi Gómez Key Account Manager OEM & Raw Materials jordi.gomez@biokit.com Jesús Balta Marketing Support jesus.balta@biokit.com

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3 Evaluation of TORC assays on Biokit s analyser M. Rodriguez, T. Bori-Sanz, M. Martos, M. Bernadó, and D. Giles* Biokit SA, Lliçà d Amunt, Spain Introduction The TORC panel consists of tests for antibodies to three organisms that cause congenital infections transmitted from mother to fetus. The name is an acronym for the organisms detected by this panel: Toxoplasma gondii (toxoplasmosis), rubella (German measles) and cytomegalovirus (CMV). Although the three diseases are not particularly serious for adults who are ex posed and treated, women who become affected with any of these diseases during pregnancy are at risk for miscarriage, still birth, or for a child with serious birth defects and/or illness. Thus, this test is performed before or as soon as pregnancy is diagnosed to determine the mother's history of exposure to these organisms. The test is also performed on neonatal serum when the newborn presents sy mptoms consistent with a congenitally acquired infection by one of the organisms above. Toxoplasmosis and cytomegalovirus can also cause acute infections in immunocompromised patients. The TORC assays (Toxo IgG & IgM, Rubella IgG & IgM and CMV IgG & IgM) comprise 6 chemiluminiscent immunoassays on the analyser for the detection of anti-torc IgG and IgM type antibodies in human serum or plasma as an aid in the serodiagnosis of TORC in pregnant women as well as in immunocompromised patients. Aim of the Study To evaluate the performance of these markers on the analyser when compared to other commercially available TORC assays. Materials and methods The TORC assays consist of paramagnetic particles coated with either antigens or monoclonals, a reaction buffer and isoluminol labeled antigens or monoclonals as tracer (schemes vary from assay to assay, Fig. 1 and 2). The paramagnetic particles allow for a high surface binding and for a very efficient wash of the unbound material. Specific antibodies that are present in the sample will bind to the coated microparticles. A magnetic separation followed by a wash step is done to remove residual sample. Immediately after, the tracer is added and may bind to the specific antibodies captured by the microparticles. After a second incubation, a magnetic separation and a wash step, reagents that trigger the chemiluminescent reaction are added. The emitted light is measured as relative light units (RLU) by the BIO-FLASH luminometer. The RLUs are automatically converted into an antibody titer or concentration by the instrument s working calibration curve. ABEI Triggers Triggers ABEI Ag ABEI RLU Figure 1: Reaction scheme for an indirect assay: Toxo IgG, Toxo IgM, Rubella IgG, CMV IgG & CMV IgM RLU Figure 2: Reaction scheme for a µ-capture assay: Rubella IgM The assay calibrators and controls contain antibodies IgG or IgM type specific against the organism. Page 3 of 9

4 Precision was assessed with the assay controls and with a sample at the assays cut-off level. An evaluation was performed for the 6 markers by analysing retrospective and prospective samples including both negative and positive specimens assayed with its corresponding TORC assay on the and also with other commercially available TORC assays as shown in the results section. Results Precision, method comparisons, and other characteristics were evaluated for each of the 6 BIO- FLASH TORC assays and the results were as follows: Precision Within run and total (run to run and day to day) precision were assessed (following CLSI EP05-A Guidelines) over multiple runs. Results are summarized in the following table: Level Mean Within-run CV Total %CV Negative Control 2.8 IU/mL Positive Control 50.4 IU/mL Toxo IgG High Positive Control IU/mL Cut-off level 9.1 IU/mL Toxo IgM Rubella IgG Rubella IgM CMV IgG CMV IgM Negative Control 0.23 S/CO (expressed in SD) (expressed in SD) Positive Control 2.53 S/CO Cut-off level 0.82 S/CO Negative Control 2.8 IU/mL Positive Control 25.1 IU/mL High Positive Control 81.0 IU/mL Cut-off level 8.6 IU/mL Negative Control 0.21 S/CO (expressed in SD) (expressed in SD) Positive Control 2.32 S/CO Cut-off level 0.80 S/CO Negative Control 5.1 AU/mL Positive Control AU/mL Cut-off level 12.2 AU/mL Negative Control 0.25 S/CO (expressed in SD) (expressed in SD) Positive Control 2.65 S/CO Cut-off level 0.77 S/CO Method comparison An evaluation was performed for the 6 markers by analysing retrospective and prospective samples including both negative and positive specimens assayed with its corresponding TORC assay on the and also with other commercially available TORC assays. The relative sensitivity, relative specificity and concordance were calculated using the consensus results of the reference methods. Toxo IgG Toxo IgG ( ) ( ) ( ) VIDAS, Access The Toxo IgG is a quantitative assay referenced to the WHO International Standard Anti- Toxoplasma Serum Ig (NISBC code: TOXM) and results are expressed in IU/mL Toxo IgM Toxo IgM ( ) 92.9 ( ) 92.3 ( ) VIDAS, AxSYM Page 4 of 9

5 Rubella IgG Rubella IgG ( ) 99.2 ( ) 99.4 ( ) VIDAS, Access, AxSYM and bioelisa The Rubella IgG is a quantitative assay referenced to the WHO International Standard Anti Rubella Immunoglobulin, Human (NIBSC code: RUBI-1-94) and results are expressed in IU/mL Rubella IgM Rubella IgM ( ) 97.6% ( ) 97.8 ( ) VIDAS, Access, AxSYM and bioelisa CMV IgG CMV IgG ( ) 99.5 ( ) 99.3 ( ) VIDAS, AxSYM CMV IgM CMV IgM ( ) 96.9 ( ) 96.3 ( ) VIDAS, AxSYM Other characteristics Other characteristics where evaluated such as Limit of Detection (LoD), Limit of Quantitation (LoQ), assay range, on-board stabilities of the reagent pack, and throughput of the assay on the. Results are summarized in the following table: LoD LoQ range On-board stability Throughput Toxo IgG 0.9 IU/mL 0.9 IU/mL IU/mL 11 weeks 60 test/hour Toxo IgM n/a n/a n/a 8 weeks 60 test/hour Rubella IgG 0.3 IU/mL 0.4 IU/mL IU/mL 5 weeks 60 test/hour Rubella IgM n/a n/a n/a 11 weeks 30 test/hour CMV IgG 0.3 AU/mL 0.7 AU/mL AU/mL 5 weeks 60 test/hour CMV IgM n/a n/a n/a 14 weeks 60 test/hour n/a = not applicable because assays are qualitative Conclusions The six TORC assays used on the analyser are an excellent choice for routine use in a laboratory showing a good clinical performance when compared to other commercial TORC assays and features such as robustness, long on-board stability, random-access sample load capability, throughput, and easiness of use. Page 5 of 9

6 Evaluation of HBV/HCV/HIV 1+2 assays on Biokit s analyser M. Costa, B. Canela, A. Martínez, M. García, M. Lopez, C. Hervás, C. Rodríguez, J. Tous, J. Puig, L. Taberner Biokit SA, Lliçà d Amunt, Spain Introduction The HBV/HCV/HIV 1+2 assays comprise 5 chemiluminiscent immunoassays on the analyser for the detection of specific antibodies or antigen in human serum or plasma as an aid in the serodiagnosis. HBV, HCV, and HIV are the primary infectious agents that can be transmitted via exposure to bodily fluids; the three viruses are mandatorily tested on blood donors worldwide due to their prolonged viraemia, carrier or latent state. Diseases caused by HBV have a global distribution. It is estimated that approximately one-third of the world population has been infected with HBV. Of these, approximately 350 million individuals are chronically infected and at risk of serious illness and death, mainly from liver cirrhosis and hepatocellular carcinoma. Chronic HBV prevalence can range from 0.2 to 15%. The main modes of HBV transmission are perinatal exposure to an infected mother, horizontal, parenteral and sexual, and the relative rates of these vary throughout the world. The HCV infects liver cells and can cause severe inflammation of the liver with long-term complications. The onset of disease is usually insidious, with anorexia, vague abdominal discomfort, nausea and vomiting, fever and fatigue, progressing to jaundice in about 25% of patients. Of those exposed to HCV, about 40% recover fully, but the remainder, whether they have symptoms or not, become chronic carriers. Of these, 20% develop cirrhosis. Of those with cirrhosis, up to 20% develop liver cancer.hcv is a major cause of acute hepatitis and chronic liver disease, including cirrhosis and liver cancer. Globally, an estimated 170 million persons are chronically infected with HCV and 3 to 4 million persons are newly infected each year. HCV is spread primarily by direct contact with human blood. The major causes of HCV infection worldwide are use of unscreened blood transfusions, and re-use of needles and syringes that have not been adequately sterilized. HIV-1 and HIV-2 attack the immune system reducing its protection and allowing the appearance of opportunistic infections, often serious and deadly infections, and tumors. The number of people living with HIV worldwide is increasing and it was estimated in 2008 in about 33 millions. However, the number of deaths due to AIDS-related illness is decreasing slowly due to the antiretroviral therapies. HIV is transmitted through direct contact of a mucous membrane or the blood stream with a body fluid containing HIV. The pattern of transmission varies in different parts of the world. In Western Europe, North America and Australia the transmission mostly occurred in high risk population such men who have sex with men and injection drug users, while in the Sub-Saharan Africa are predominant heterosexual and mother-to-child transmission. Aim of the Study The aim of this study was to evaluate the performance of these markers on the analyser when compared to other commercially available HBV/HCV/HIV 1+2 assays. Materials and methods The HBV/HCV/HIV 1+2 assays consist of paramagnetic particles coated with either antigens or antibodies, a reaction buffer and isoluminol labeled antigens or antibodies as tracer (schemes vary from assay to assay, Fig. 1 to 4). The paramagnetic particles allow for a high surface binding and for a very efficient wash of the unbound material. Specific antibodies or antigens that are present in the sample will bind to the coated microparticles. A magnetic separation followed by a wash step is done to remove residual sample. Immediately after, the tracer is added and may bind to the specific antibodies or antigen Page 6 of 9

7 captured by the microparticles. After a second incubation, a magnetic separation and a wash step, reagents that trigger the chemiluminescent reaction are added. The emitted light is measured as relative light units (RLU) by the BIO-FLASH luminometer. The RLUs are automatically converted into an antibody or antigen concentration by the instrument s working calibration curve. Figure 1: Reaction scheme for anti-hbc Figure 2: Reaction scheme for anti-hcv efigure 3 : Reaction for anti-hiv 1+2 and anti-hbc Figure 4: Reaction scheme for HBsAg The assay calibrators and controls contain antibodies specific against the corresponding viruses (BIO- FLASH anti-hbc, anti-hbs, anti-hcv and anti-hiv 1+2) or human HBsAg ( HBsAg). Precision was assessed with the assay controls and with a sample at the assays cut-off level. An evaluation was performed for the 5 markers by analyzing retrospective and prospective samples including both negative and positive specimens assayed with its corresponding HBV/HCV/HIV 1+2 assay on the and also with other commercially available assays as shown in the results section. Results Precision, method comparisons, and other characteristics were evaluated for each of the 5 HBV/HCV/HIV 1+2 assays and the results were as follows: Precision Within run and total (run to run and day to day) precision were assessed (following CLSI EP05-A Guidelines) over multiple runs. Results are summarized in the following table: Level Mean Within-run CV Total %CV anti-hbc Negative Control 0.28 AU/mL (expressed in SD) (expressed in SD) Positive Control 2.12 AU/mL Cut-off level 1.09 AU/mL anti-hcv Negative Control 0.26 S/CO Positive Control 3.16 S/CO Cut-off level 0.94 S/CO anti-hiv 1+2 Negative Control 0.27 S/CO (expressed in SD) (expressed in SD) V 1 Positive Control 3.43 S/CO V 2 Positive Control 3.42 S/CO Cut-off level 1.06 S/CO HBsAg Negative Control 0.57 S/CO (expressed in SD) (expressed in SD) Positive Control S/CO Cut-off level 0.88 S/CO anti-hbs Negative Control* 778 RLU Positive Control 44.7 miu/ml igh Positive Control 33.0 miu/ml Cut-off level 9.4 miu/ml * The negative control is close to the limit of quantitation and for this reason the mean RLU was calculated instead of the mean concentration. Page 7 of 9

8 Method comparison Specificity assessment was based upon testing unselected blood donor serum samples, including first time donors, and hos. Sensitivity was evaluated by testing specimens with verified positivity. Samples were assayed with its corresponding HBV/HCV/HIV 1+2 assay on the and also with other commercially available assays (AxSYM, Vitros, PRISM Virosnostika and bioelisa ). sensitivity and specificity were calculated against the consensus results. anti-hbc Anti-HBc ve , Prism, AxSYM anti-hcv Anti-HCV ve m, Vitros and bioelisa anti-hiv 1+2 HIV 1+2 ve sm, AxSYM osnostika, and bioelisa HBsAg HBsAg ve , Prism, AxSYM anti-hbs Anti-HBs ve s Other characteristics Other characteristics where evaluated such as Limit of Detection (LoD), Limit of Quantitation (LoQ), assay range, on-board stabilities of the reagent pack, and throughput of the assay on the. Results are summarized in the following table: LoD LoQ range -board stability Throughput IO-FLASH anti-hbc 39 AU/mL n/a 0 12 AU/mL 8 weeks 60 test/hour IO-FLASH anti-hcv.08 S/CO n/a S/CO 6 weeks 60 test/hour O-FLASH anti-hiv S/CO n/a S/CO 10 weeks 60 test/hour HBsAg.74 S/CO n/a S/CO 12 weeks 60 test/hour IO-FLASH anti-hbs 6 miu/ml 6 miu/ml 1900 AU/mL 12 weeks 60 test/hour n/a = not applicable because assays are qualitative Page 8 of 9

9 Conclusions The five HBV/HCV/HIV 1+2 assays used on the analyser showed a good concordance with other commercial assays in terms of performance. Due to their robustness, long on-board stability, random-access sample load capability, throughput, and easiness of use they are an excellent choice for routine use in a clinical or blood bank laboratory. Page 9 of 9