Table 1.
Cohort characteristicsa
| Characteristic | Braak Stages 1-3 | Braak Stages 4 and 5 | Statistical analysis |
|---|---|---|---|
| N | 18 | 18 | — |
| Men, % | 27 | 27 | C; Pearson test, χ2 = 0; p = 1.0 |
| Mean age at death (yr) | 86.0 (4.7) | 84.4 (5.7) | Mann–Whitney test, p = 0.29 |
| Mean education (yr) | 18.3 (3.5) | 18.4 (2.8) | Mann–Whitney test, p = 0.81 |
| Mean MMSE | 25.2 (7.0) | 21.8 (7.6) | Mann–Whitney test, p = 0.076 |
| Global cognition score | −0.61 (0.96) | −0.94 (0.94) | Mann–Whitney test, p = 0.15 |
| apoE ε4 allele carriage (%) | 17 | 56† | C; Pearson test, χ2 = 5.90; p = 0.015 |
| Reagan score 3/2/1 (n) | 10/8/0 | 4/7/7 | — |
| CERAD score 4/3/2/1 (n) | 5/4/7/2 | 4/0/5/9 | — |
| ABC diagnosis Ctrl/AD (n) | 8/10 | 3/15 | — |
| Clinical diagnosis NCI/MCI/AD (n) | 8/5/5 | 4/7/7 | — |
| Cerebellar pH | 6.42 (0.31) | 6.45 (0.29) | Mann–Whitney test, p = 0.68 |
| Postmortem delay (h) | 5.26 (3.27) | 7.86 (5.82) | Mann–Whitney test, p = 0.24 |
| Neuron diffuse plaque counts | 7.44 (9.7) | 20.6 (19.7)* | Mann–Whitney test, p = 0.011 |
| Neuron plaque counts | 5.4 (6.9) | 15.2 (15.9)* | Mann–Whitney test, p = 0.024 |
| Soluble Aβ40 concentration (fg/μg protein) | 132.7 (59.8) | 689.2 (855.1) | Mann–Whitney test, p = 0.088 |
| Soluble Aβ42 concentration (fg/μg protein) | 1497.2 (1536.3) | 2772.2 (2312.7)* | Mann–Whitney test, p = 0.010 |
| Insoluble Aβ40 concentration (pg/mg tissue) | 4.70 (7.22) | 66.5 (113.7) | Mann–Whitney test, p = 0.33 |
| Insoluble Aβ42 concentration (pg/mg tissue) | 581.3 (652.9) | 1507.5 (1169.7) | Mann–Whitney test, p = 0.084 |
| Neurofibrillary tangle counts | 0.17 (0.51) | 4.50 (11.44) | Mann–Whitney test, p = 0.082 |
| Total insoluble tau | 660.7 (268.2) | 2164.2 (1633.2)* | Mann–Whitney test, p = 0.0042 |
| Insoluble phospho-tau (S396/404) | 24.0 (58.1) | 1406.0 (2075.6)*** | Mann–Whitney test, p = 0.0008 |
aSubjects were grouped based on Braak neuropathological assessment as controls (Braak Stages 1-3) or AD (Braak Stages 4 and 5). All neuropathology and biochemistry were performed in the parietal cortex. Soluble Aβ peptide concentrations were determined by ELISA. Tau concentrations were measured using WBs in formic acid extracts with antibodies Tau 13 and PHF1 to assess total tau and insoluble phospho-tau (S396/404), respectively. Brain pH was measured in cerebellum extracts. Values are mean (SD) unless specified otherwise. C, Contingency; CERAD, Consortium to Establish a Registry for Alzheimer's Disease; MCI, mild cognitive impairment; NCI, healthy controls with no cognitive impairment.
Statistical analysis (comparing Braak Stages 4 and 5 to Braak Stages 1-3): Mann–Whitney test,
*p < 0.05,
***p < 0.001; Pearson's χ2 contingency test,
†p < 0.05.