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P3‐061: A comparison between different β‐amyloid assays
Author(s) -
Andreasson Ulf,
Höglund Kina,
Christiansson Monica,
Källén Åsa,
Zetterberg Henrik,
Blennow Kaj
Publication year - 2008
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.2008.05.1625
Subject(s) - biomarker , receiver operating characteristic , cerebrospinal fluid , disease , alzheimer's disease , area under curve , medicine , chemistry , biochemistry , pharmacokinetics
biological markers to differentiate both disorders are still lacking. Pathologically, most cases with pure DLB exhibit a diffuse plaque-only pathology with rare or absent neocortical neurofibrillary tangles, as opposed to the wide cortical neurofibrillary-tau involvement in AD. We analyzed CSF markers chosen as to reflect some of these underlying pathological differences. Methods: CSF samples of 33 cases with probable AD (NINCDSADRA criteria) without parkinsonism, 25 cases will all the core features of DLB (Consortium criteria) and 46 age-matched controls were analyzed. Total tau, Ab1-42 amyloid, IL-1b and IL-6 levels were measured by sandwich ELISA using commercially available kits (Innogenetics NV, Belgium and Diaclone Research, France). Results: Tau protein: AD cases had significantly higher levels (500 399 pg/ml, mean SD) than DLB cases (213 243) and controls (200 243) (p 0.0001). There were no differences between DLB and control groups. The most efficient cutoff point (250 pg/ml) provided a 76% specificity to distinguish AD and DLB cases. b-amyloid: AD (348 309 pg/ml) and DLB cases (320 233) had lower b-amyloid levels than controls (462 352) but the differences did not reach statistical significance. The combination of tau/ b-amyloid levels provided the best value to differenciate AD vs controls (cut-off point 0.5, sensitivity 82,5%, specificity 75%) but was worse than tau values alone to discriminate between AD and DLB. Interleukine 1b: IL-1b levels in the three groups were within the lowest values of the standard curve. There were no significant differences among AD (2.17 3.00 pgr/ml), DLB (2.60 2.97) cases and controls (2.02 3.28). Interleukine 6: AD (7.14 5.74 pgr/ml) and DLB (6.14 5.00) cases showed slightly higher IL-6 levels than controls (4.96 4.72) but the differences among the three groups were not significant. Conclusions: Tau levels in CSF may contribute to the clinical distinction between AD and DLB. b-amyloid CSF levels are similar in AD and DLB cases and tend to be lower than in controls. Interleukine CSF concentrations do not distinguish between both dementia disord.