Lab Matters Summer 2018 - Page 68

APHL 2018 Annual Meeting Poster Abstracts Background: Routine detection of Measles, Mumps, Rubella and Varicella Zoster (MMRV) IgG is used to determine antibody status where infection history or previous immunization is unknown. Novel ELISA Based on Antigens from Strongyloides papillosus Instead of Strongyloides ratti Exhibits Increased Serological Specificity Materials/Methods: This MMRV assay was developed using the Dynex Technologies Multiplier system and coated bead technology. Antigen coated beads representing each MMRV specificity were embedded into the base of carrier 96 well assay plate. Each assay well contains the 4 MMRV targets for the test sample IgG detection. The final chemiluminescent reaction is imaged with the on-board camera and results output as index values referenced against the assay specific calibrator. Precision was measured by assaying a range of 14 samples 3 times across an assay plate on three instruments over three days. A ROC analysis was run in order to set the cut-off for each of MMV and confirm it for Rubella where the cut- off was ultimately defined by the International reference RUBI-1-94. Based on the resulting cut-off values, concordance was assessed on up to 929 samples collected for MMRV screening; results were compared to 510k cleared ELISA assays. B. Menge 1 , O. Klemens 1 , A. Streit 2 , O. Sendscheid 3 , J. Klemens 1 , K. Steinhagen 1 ; 1 EUROIMMUN, Lubeck, Germany, 2 Max Planck Institute for Developmental Biology, Tubingen, Germany, 3 EUROIMMUN US, Inc., Mountain Lakes, NJ Results: Percentage coefficient of variation (%CV) for each MMRV specificity was calculated and is summarized below: Precision test Within run Between run Between day Between instrument Measles (%CV) 4.54 4.51 3.56 1.41 Mumps (%CV) 5.35 5.66 4.01 3.19 Rubella (%CV) 3.69 4.64 4.76 2.24 VZV (%CV) 4.08 4.06 3.15 1.37 ROC analysis: Area under the curve (AUC) and 95% confidence interval (CI) results were: • Measles 0.995 AUC (0.991-0.998 CI) • Mumps 0.987 AUC (0.977-0.997CI) • Rubella 0.998 (0.997-0.999 CI) • VZV 0.999 (0.997-1.000 CI). • Percent positive agreement (PPA) and percent negative agreement (PNA) with 95% confidence intervals (Cl) were calculated in two ways: • Equivocal samples scored as positive PPA: Measles - 95.3% (93.5-96.6%), Mumps: 90.2 (87.8-92.2%), Rubella: 93.9 (91.9-95.4%), VZV: 98.1 (96.8-98.8%). PNA: Measles – 94.2 (90.7-97.0%), Mumps: 93.3 (88.5-96.2%), Rubella 99.5% (97.4- 99.9%), VZV 97.5 (96.3-99.2%). • Equivocal samples scored as negative PPA: Measles – 93.3% (91.2-95.0%) Mumps: 93.3 (91.1-95.0%), Rubella: 93.0 (90.9- 94.7%), VZV: 97.7 (96.3-98.5%). PNA: Measles – 95.4 (92.0- 97.4%), Mumps: 94.6 (90.8-96.9%), Rubella: 100.0 (98.4- 100.00%), VZV: 99.2 (95.6-99.9%). Conclusion: This multiplexed fully automated assay gives reproducible semi-quantitative results for MMRV IgG. It is ideal for batch testing as can handle up to ninety two test samples in a single plate to produce 368 results in <3 hours. When two plates are run together 736 results are generated in five hours. Presenter: Robert Wolfert, PhD, Dynex Technologies, Inc., Chantilly, VA, Phone: 703.803.1254, Email: rwolfert@dynex.com 66 LAB MATTERS Summer ) ɽչMɽ屽ͥ́́ѥ͕͔͕́)ѡѽMɽ屽̸!յѥMɽ屽)ѕɍɅ́ЁݥѠɵѽѕѥ)ձѽ́ɕՕѱͥѼɽ͕͔)1܁Ʌͥѥ͍́ѥս́مɕѥ)ȁͥ́䁍ɽ͍丁MɽѕЁѕ́ɔɔ)͕ͥѥٔѼѕЁѡѥم͕ɽѕ́ɔ)䁉͕ѥٔѥ́ɽLɅѤم)丁]ٕمՅѕѡЁ1%M͕L)́Ѽɕ͔丁5ѡمՅѥѡ1%M)͕Ĺ݅́əɵͥѡݥѡɕ)ɽltAѥѥѕɹՅ䁅͕͵)͍9ELU,ͥͥͥѥٔٔѥٔ)ͅltɕѥՑݥѠѡɍ ɑȁ1%M(Mɽ屽́1%MЁ͕LɅѤѥ ɑȁ)AɽՍ̰MݥɱՑ͕ɄɔɅѕɥ镐́ѡ)ͥѥٔ䤁ȁѥٔ䁵́ ɑȁ1%Mlt) ɥͽݥѠ͔1%M͕LɅѤ䁑ѕɵ)ݥѠɕЁѼɽ̵ɕѥ٥̰ͅ)ɽѥ́ݥѠѡȁɅͥѥȁѕɥѥ̤)ɽఁ́ͅɽѡ䁉̰(ɕЁݽɕ)IձltIձ́хݥѠѡѤMɽ屽́1%M)ݕɔɕЁݥѠ9ELхɝЁمՕ̹lt%Ё(̸̀ͅĔѡɕձЁѡٕ1%MɕѕݥѠ)ѡ ɑȁ1%MMٕ͍ɕЁ͕̰ݡݕɔͥѥٔ) ɑȁ1%MЁѥٔѡٕ1%Mݕɔѡ)ᅵMɽ͕́ѕѡɕ͕ѥ)ЁѡȁɅͥѕ̀A͵մMѽͽ)́ͥѡ͔͕̹ltQLɅѤ͕)1%M݅́ɕѥ̸ٔ䔁ѡ͕Ʉѡɽ̵ɕѥ٥)ؔѡ́ͅɽѡ䁥٥Յ̰奕)䁽؀%ɥͽɕѥ٥ѥ́ظȔ(ɽ̵ɕѥ٥̸Ԕѡ䁥٥Յ̤ݕɔѕѕ)ݥѠѡٕѤMɽ屽́1%Mɕձѥ)䁽Ը䔸)͍ͥQٕѤMɽ屽́1%Mɕٕ́)ѥɅ䁥ѡ͕ɽͥ́Mɽ屽̸ͥ)Q͔ѥٔѥ́ɽĹѕLɅѤ)ɕ͕́ͅ䁉ܸ̔)Aɕ͕ѕ=ٕȁM͍AUI=%55U8UL%)5չх1̰9(A̸ظ)ٕȹ͕͍ɽո)ٕЁ9ٕ9Lĵ͕1%Mȁѕѥ)M%ѥ́Ё]е9Y)<-̀Ā AݥЀĀ!Ȁ(-̀Ā