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15283 New Sensitive and Specific Rapid HSV-2 Antibody Test Objective To describe the performance and uses of a new HSV-2 specific serological rapid test, HerpeSelect® Express™, which received FDA clearance for use in moderately complex point of care sites, and has been submitted for CLIA waived status. Methods A total of 976 (575 from sexually active adults, 401 from pregnant women) samples were tested with the HerpeSelect® Express™ IgG test. Results were compared to the HerpeSelect® 2 ELISA IgG and HerpeSelect®1 and 2 Immunoblot IgG. In addition, sera positive for other viruses were used to determine cross-reactivity. The HerpeSelect Express IgG test was performed by adding sample and a buffer to the device per the package insert. The test and control lines form within 15 minutes and the device is read. The test is considered valid if a control line appears. Results The sensitivity of HerpeSelect Express IgG test compared with the HerpeSelect 2 ELISA was 97.5% (237/243) and the specificity was 98.5% (322/327) among the sexually active adult population with capillary whole blood samples. The sensitivity of HerpeSelect Express IgG test compared with the HerpeSelect 2 ELISA was 94.2% (114/121) and the specificity was 96.4% (266/276) among the pregnant women population with capillary whole blood samples. Cross-reactivity was not observed with HSV-1 IgG positive serum samples. Concordance of results between whole blood and serum was 99%. Reproducibility between lots, operators, and sites was excellent. Overall cross-reactivity was 4.2% (9/213). Conclusion The HerpeSelect Express IgG test demonstrates excellent sensitivity, specificity and concordance compared to HerpeSelect 2 ELISA IgG and HerpeSelect 1 and 2 Immunoblot IgG. Implications This HerpeSelect Express IgG test is a FDA-cleared point-of-care test that performs comparably to HerpeSelect 2 ELISA Herpes simplex virus type 2 (HSV-2) is a common human pathogen that causes a variety of clinical manifestations, and is the most common cause of genital herpes. Identification of HSV-2 antibodies can be important for patient counseling and education. HerpeSelect Express is a glycoprotein-G2 based test and measures HSV-2 specific antibodies. HerpeSelect Express IgG test is FDA cleared, it is currently CLIA moderately complex, and CLIA waiver is being sought. Abstract A total of 575 sexually active adults and 401 pregnant women were prospectively tested for HSV-2 using capillary whole blood, venous blood and serum samples. To evaluate the HerpeSelect Express IgG test’s cross-reactivity, 213 specimens that were HSV-2 negative by HerpeSelect ELISA, and IgG positive for at least one virus (HSV-1, rubella, varicella zoster virus, Epstein Barr virus, or cytomegalovirus) OR positive for rheumatoid factor or anti-nuclear antibody. Focus Diagnostics tested a CDC panel composed of 100 samples (65 HSV-2 positive and 35 negative samples). Five clinical sites (Focus, a clinical laboratory, a public health clinic, a university student health clinic, and a STD clinic) assessed inter/intra-operator reproducibility and inter/intra-site reproducibility. Each site tested ten samples in singlicate on three different days. HerpeSelect Express device is run as follows: After addition of sample and buffer, the antibody-gold conjugate and sample migrate across the test strip. HSV-2 antibodies (if present) and gold conjugate sequentially contact the test and controls lines and cause specific colored lines to form within 15 minutes. Materials and Methods Figure 2: Assay cartridge. Cross-sectional view of the test cartridge. Figure 1: Diagram of the mechanism of the assay. Figure 3: A. Finger Stick, B. Sample Being Added to Device, C. Buffer Being Added to Device, D. HSV-2 Negative Result. E. HSV-2 Positive Result. ABCDE HerpeSelect® Express™ Performance vs. HerpeSelect® 2 ELISA IgG HerpeSelect® Express™ Performance vs. HerpeSelect® 2 Immunoblot IgG PopulationSample TypeSensitivitySpecificitySensitivitySpecificity Sexually Active Adults (n = 575) 1 Capillary Whole Blood 97.5%98.5%93.8%91.8% Venous Whole Blood 97.1%98.8%93.4%92.4% Serum97.1%98.8%92.9%91.8% Pregnant Women (n = 401) 2 Capillary Whole Blood 94.2%96.4%94.9%95.4% Venous Whole Blood 92.6%97.8%93.2%97.2% Serum91.7%96.7%92.3%96.1% Table 1: Summary of the sensitivity and specificity for the HerpeSelect Express with capillary whole blood, venous blood and serum samples versus HSV-2 ELISA and HSV-1/2 Immunoblot. CDC HSV-2n HerpeSelect® Express™ % Agreement PositiveNegativeInvalid Positive35 00100% Negative651 098.5% Table 2: Agreement with CDC Panel (n=100) Cross-Reactantn HerpeSelect® Express™ PositiveNegativeInvalid% Cross-Reactivity HSV-1 IgG+250 00.0% Rubella +2512404.0% VZV IgG +4243809.5% EBV IgG +2512404.0% CMV IgG +3213103.1% RF +3313203.0% ANA +3113003.2% Combined Cross-Reactants213920404.2% Table 4: Cross-reactivity Testing (n=213) Inter-Lot Reproducibility< 10% Inter-Operator and Inter-Site Reproducibility≤ 65.0% Intra-Operator Reproducibility≤ 35.1% Intra-Site Reproducibility≤ 23.0% Table 3: Reproducibility Conclusions HerpeSelect Express IgG rapid test demonstrated excellent sensitivity (97.5%) and specificity (98.5%) compared with HerpeSelect 2 ELISA IgG and HerpeSelect 1 and 2 Immunoblot IgG. Overall cross-reactivity was 4.2% HerpeSelect Express is a point-of-care test with performance comparable to HerpeSelect 2 ELISA IgG Background Andrew Hudak 1, Jay M. Lieberman, M.D. 1, and Gary A. Richwald, M.D., MPH 2 Focus Diagnostics, Inc., Cypress, CA 1 / HSV & HPV Support Groups Los Angeles, CA 2 Materials and Methods (cont) Results Andrew Hudak, Scientist Research and Development Focus Diagnostics, Inc. 5785 Corporate Avenue Cypress, CA 90630 Tel 714-220-1900 x2728 Fax 714-484-1296 Ahudak@focusdx.com Results (cont) 1 5 samples were not tested, 1 sample was equivocal on the Immunoblot and was excluded. 2 1 ELISA sample was not tested, 3 samples were equivocal on ELISA. 2 Immunoblot samples were not tested. Note: Sensitivity and Specificity calculations include samples that tested invalid on HerpeSelect Express Acknowledgement: Erik Zendejas, MD, MPH, Biostatistician, Focus Diagnostics, Inc. Constance Bridges, MBA, RAC, ASQ-CBA, Director of Regulatory Affairs, Focus Diagnostics, Inc. The results are presented as a means to convey further information on the performance of this assay with a masked characterized serum panel and do not imply endorsement by CDC.
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