Premium
P1‐278: Aβ42 MEASUREMENT IN FRESH VERSUS STORED CEREBROSPINAL FLUID USING AN AUTOMATED CHEMILUMINESCENT ENZYME IMMUNOASSAY SYSTEM (LUMIPULSE ® G600 II)
Author(s) -
Sepe Federica Nicoletta,
Paciotti Silvia,
Eusebi Paolo,
Parnetti Lucilla
Publication year - 2018
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2018.06.284
Subject(s) - chemiluminescence , immunoassay , cerebrospinal fluid , chromatography , chemiluminescent immunoassay , chemistry , linear correlation , zoology , andrology , medicine , biology , immunology , mathematics , pathology , statistics , antibody
Background:Automated immunoassays can reduce the variability in the analysis of cerebrospinal fluid (CSF) biomarkers and are being implemented widely. However, most of the clinical centers that use CSF biomarkers for diagnosis have determined their cut-off values using non-automated ELISA assays. The aim of this study was to assess the correlation between the INNOTEST ELISA (Fujirebio Europe, Belgium) and the fully automated LUMIPULSE G platform (Fujirebio, Japan) for b-amyloid 1-42 (Ab1-42) and total Tau (tTau) and to verify how this affects our local cut-off values, in addition to a change in collection and storage tubes. Methods: A set of 109 CSF samples from participants of the Sant Pau Initiative on Neurodegeneration cohort (77 controls, 19 subjective cognitive decline, 13 mild cognitive impairment) were analyzed using the INNOTEST b-AMYLOID(1-42) and hTau Ag assays and the Lumipulse G b-Amyloid 1-42 and Total Tau assays on the fully automated LUMIPULSE G platform. All participants underwent a CSF collection according to two different protocols, B and E, using different collection and storage tubes. Samples collected according to protocol B were analyzed on INNOTEST while samples collected according to protocol E were analyzed on LUMIPULSE. To evaluate the effect of the two protocols on the overall correlation between the two platforms, a subset of samples (n1⁄430; protocol B) was analyzed with the two platforms. Results:The mean within-lab variation for Ab1-42 and tTau was 1.63% and 0.93% for Lumipulse, and 9.35% and 13.2% for INNOTEST, respectively. In samples that have been processed using the same protocol, the correlation between Lumipulse and INNOTEST was high for both Ab1-42 (R1⁄40.91; p<0.05) and tTau (R1⁄40.95; p<0.05). The regression analysis comparing both immunoassays resulted in a slope of 1.74 (intercept -102pg/ml) for Ab1-42 and 1.01 (intercept 67pg/ml) for tTau. The analysis between different protocols showed that the tube influenced the slopes and intercepts in the method comparison. Conclusions:The use of an automated platform reduces analytical variability. Although there is a good correlation between non-automated ELISA and the automated Lumipulse assays, it is advisable to recalculate and validate the clinical cut-off values for both Ab1-42 and tTau. P1-278 Ab42 MEASUREMENT IN FRESH VERSUS STORED CEREBROSPINAL FLUID USING AN AUTOMATED CHEMILUMINESCENT ENZYME IMMUNOASSAY SYSTEM (LUMIPULSE G600 II) Federica Nicoletta Sepe, Silvia Paciotti, Paolo Eusebi, Lucilla Parnetti, Universit a di Perugia, Perugia, Italy; Laboratory of Clinical Neurochemistry, Department of Medicine, University of Perugia, Perugia, Italy; University of Perugia, Perugia, Italy; Lab of Clinical Neurochemistry, University of Perugia, Perugia, Italy. Contact e-mail: fede8919@live.it