Diagnostic Accuracy of ELISA and xMAP Technology for Analysis of Amyloid β42 and Tau Proteins

Abstract

ELISA were observed for each biomarker, indicating that a constant correction factor cannot be applied to recalculate xMAP results into ELISA results. When a combination of CSF markers was used, the sensitivity, specificity, and area under the ROC curves for xMAP assays and ELISAs were not significantly different in differentiating AD patients from vascular dementia patients and controls. Conclusions: A constant conversion factor cannot be used successfully to recalculate results obtained with xMAP assays to those from the ELISAs. With the use of analysis of a combination of A␤ 42 , t-tau, and p-tau in CSF, however, differentiation of clinical groups is equivalent when either xMAP technology or conventional ELISA is used.

β-Amyloid in CSF

“…All analyses were performed in the RUNMC with an ELISA as described previously (all from Innogenetics NV, Gent, Belgium). 18 We performed standard CSF analysis, including leukocyte count, erythrocyte count, total protein, and glucose. A leucocyte count #4/mL, red blood cells ,1,500/mL, total protein ,700 mg/L, and glucose ,4.3 mmol/L were considered normal.…”

Evaluation of a Multianalyte Profiling Assay and an Enzyme-Linked Immunosorbent Assay for Serological Examination of Epstein-Barr Virus-Specific Antibody Responses in Diagnosis of Nasopharyngeal Carcinoma

“…The discrepancies between the xMAP and ELISA methods could be attributed to differences in antigen coating, reaction principles, and procedure (29). Our results showed that ELISA was better for anti-EBV IgA and that the xMAP assay was better for IgG-EA-D for distinguishing NPC patients from healthy populations, although the reasons remain unclear.…”

“…Furthermore, more than 100 distinct reactions can be carried out simultaneously on the various beads in one tube, in which the individual bead is identified by a Luminex 100 or 200 instrument (11,12,21). Obviously, the xMAP assay requires a smaller sample volume, fewer procedure steps, and less total reaction time than tradi-tional ELISA (27,29). Moreover, the xMAP technology is highly reproducible because each result is the mean for ϳ100 readings (28).…”

Quantitative detection of amyloid-β peptides by mass spectrometry: state of the art and clinical applications

“…This quantification is based the recognition of the epitopes corresponding to the C-terminus amino acids of Aβ 1-40 and Aβ 1-42 using, respectively, the 2G3 and 21F12 antibodies. Recently, new multiplex immunoassays detecting multiples isoforms of Aβ peptides (1-38, 1-40 and 1-42) have been developed using Meso Scale Discovery (MSD) and Luminex platforms [15][16][17][18][19].…”