Amyloid β peptides in plasma in early diagnosis of Alzheimer's disease: A multicenter study with multiplexing

Serum concentration of beta amyloid peptide and the activity of angiotensin converting enzyme in alzheimers disease patients: search for a potential biomarker

“…Our results does not affirm those studies that show an increase in Aβ 42 and/or Aβ 40 in plasma of AD patients [26][27] and is in line with those that report decreases in Aβ 42 and Aβ 40 in plasma of AD patients compared with non-AD demented individuals and controls. [28][29][30][31] Data in Figure 3, about the concentration ratios of Aβ 42 to Aβ 40 , shows that the ratio does not change significantly when compared to control samples (Figure 3a), and also the differences are not significant when the effect of aging was studied in either males (Figure 3b) or females (Figure 3c). Generally, it seems that Aβ 42 /Aβ 40 could not be considered as either a diagnostic or prognostic indicator.…”

“…26,27 Decrease in Aβ 42 and/or the ratio of Aβ 42 /Aβ 40 in plasma of AD patients compared with non-AD demented individuals and controls has also been reported. [28][29][30][31] According to some studies it seems that a low level of Aβ42/Aβ40 ratio is associated with AD and generally with dementias. 26 On the other hand, most prospective studies indicate that elevation in plasma Aβ 42 level is present before or just at the onset of a clinically diagnosed disease.…”

Stability of amyloid‐β peptides in plasma and serum

“…Blood-based biomarkers for diagnosing and tracking the course of dementias are currently under intensive investigation, and promising results for detecting incipient AD by specific Ab peptide derangements have been reported over the past 5 years [3,[8][9][10]. Otherwise, the measurement of plasma Ab peptides failed to serve as a reliable AD diagnostic test in cross-sectional studies [5][6][7].…”

“…In summary, various publications suggested that low or decreasing plasma Ab42 is associated with a high risk of conversion to dementia in the further course. [3,[8][9][10]. Thus, serial measurement of plasma Ab1-42 may be of relevance for the detection of the subjects who are at risk of cognitive and tracking the course of disease.…”

Blood-based biomarkers in Alzheimer’s disease: an overview on proteomic and lipidomic approaches

“…Research projects that studied AD and mild cognitive impairment of AD type (MCI-AD) patients show that they had significantly lower Aβ1-42 plasma concentrations and lower Aβ1-42/1-40 ratios as compared to patients with other types of MCI or dementias (25)(26)(27). What is more there have been found correlations between Aβ plasma levels and the rate of cognitive decline independent of baseline psychological scores, age or treatment intake, but dependent on history of stroke and myocardial infarction (28).…”