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Table 3 Reference intervals for plasma biomarkers of Alzheimer’s disease across age groups

From: Reference intervals for plasma amyloid-β, total tau, and phosphorylated tau181 in healthy elderly Chinese individuals without cognitive impairment

Plasma biomarkers

Age groups (years)

50–59 (n = 56)

60–69 (n = 61)

70–79 (n = 49)

80–89 (n = 27)

Total (n = 193)

Aβ42 (pg/mL)

2.53–10.31

3.17–9.82

2.31–12.4

4.16–11.93

2.72–11.09

Aβ40 (pg/mL)

56.5–280.8

61.5–260.9

74.6–319.5

122.8–349.4

61.4–303.9

Aβ42/Aβ40 ratio

0.019–0.064

0.023–0.065

0.020–0.062

0.024–0.045

0.022–0.064

t-tau (pg/mL)

0.19–4.68

0.15–3.95

0.24–2.72

0.20–2.65

0.20–3.12

p-tau181 (pg/mL)

0.39–2.67

0.55–3.15

0.59–3.26

0.57–4.29

0.49–3.29

p-tau181/t-tau ratio

0.32–4.93

0.56–6.16

0.36–6.57

0.31–8.63

0.38–6.34

p-tau181/Aβ42 ratio

0.05–0.52

0.07–0.63

0.06–0.70

0.07–0.61

0.05–0.55

  1. Reference intervals are established on the log-transformed variables and transforming back by taking antilogarithms
  2. Abbreviations: Aβ Amyloid-beta protein, t-tau Total tau, p-tau181 Tau phosphorylated at threonine 181
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Alzheimer's Research & Therapy

ISSN: 1758-9193