Alzheimer’s: p-Tau 217, C-Reactive Protein and 24 hour urine test

  • admin
  • Comments Off on Alzheimer’s: p-Tau 217, C-Reactive Protein and 24 hour urine test

Alzheimer’s: p-Tau 217, C-Reactive Protein and 24 hour urine test

Dennis N. Crouse 8/14/25

Biomarkers for Aluminum Accumulation

There are several biomarkers indicating the amount of aluminum accumulation in the body:

  • 24-Hour Total Aluminum in Human Urine1 – Mayo Clinic’s healthy reference value for adults age 18 or over is less than 0.48mcmoles/24hr of urine
  • pTau217 Above Mean Normal Levels in Human Serum2 – above the mean normal levels adjusted for age and APOE status (see figure 1)4
  • C- Reactive Protein (a.k.a. CRP or hsCRP) in Human Serum – healthy reference value less than 1.00mg/L3

These biomarkers each indicate our body-burden of aluminum. In order to lower our aluminum, my wife, Laurie, and I have been drinking 3 to 4 cups/day of OSA rich water (73 – 146ppm OSA) since September of 2015.  After 10 years we had these three biomarkers checked and the results are in table 1 with mean normal levels for pTau217 being adjusted for both APOE-e4 status and age using plot in figure 1 based upon data taken from a recent published study4:

References

  1. Morie, T., et al.; Urinary excretion of aluminum: effects of aging and diurnal variation; Arch. Gerontology and Genetics; 22:287-95 (1996)

2. Lu, X., et al.; Cognitive disorders and tau-protein expression among retired aluminum smelting workers; JOEM; Feb.; 56(2):155-60 (2014) Significantly higher pTau181 and 231

3. Alexandrov, P.N., et al.; Nanomolar aluminum induces expression of the inflammatory systemic biomarker C-reactive protein (CRP) in human brain microvessel endothelial cells (hBMECs); J. Inorg. Biochem.;  152:210-13 (2015)

4. Saari, T.T., et al.; Cross-sectional study of plasma phosphorylated tau 217 in persons without dementia; Alzheimer’s dementia; 17:e70107 (2025) DOI: 10.1002/dad2.70107 Study population 697 people of European ancestry mean age 76.2 +4.6 without AD diagnosis or other cognitive impairing diseases, 53% women, and including 154 full twin pairs. AlzPath data taken from four box plots in figure 1:

  • In people with no APOE e4 status the mean of pTau217 increased only slightly with age (i.e., 65-69 0.23, 70-74 0.26, 75-79 0.30, 80-84 0.375pg/ml)
  • In people with APOE e4 status the mean of pTau217 increased more quickly with age (i.e., 65-69 0.28, 70-74 0.39, 75-79 0.59, 80-84 0.63pg/ml)
  • The heritability estimate for pTau217 was 56%

5. Ashton, N.J., et al.; Diagnostic accuracy of plasma phosphorylated tau 217 immunoassay for Alzheimer’s disease pathology; JAMA Neurology; 81(3):255-63 (2024) DOI: 10.1001/jamaneueol.2023.5319 Population of WARP cohort: 323 people mean age 65.3 +6.91, 97.7% without cognitive impairment, 67.2% women, 78.9% had no beta amyloid or tau by PET. A three-range reference for beta amyloid positivity (i.e., lower, intermediate, and upper) was applied to the WARP cohort’s tau217 levels taken with AlzPath pTau21 test. The lower threshold with 95% sensitivity is <0.40pg/ml and the upper threshold with 95% specificity for beta amyloid is > 0.63pg/ml. Longitudinal trajectories of plasma ptau217 over an eight-year period for people in WARP cohort with no tau and beta amyloid by PET at first visit grew from 0.35 to 0.45pg/ml.  With beta amyloid by PET at first visit,  growth of plasma ptau217 was from 0.55 to 0.90pg/ml

6. Mammel, A.E., et al.; Clinical decision points for two plasma p-tau217 laboratory developed tests in neuropathology confirmed samples;  Jan.; Alz. Dementia Diag. Assessment Dis. Mon.; 17(1)/e70070 (2025) https://doi.org/10.1002/dad2.70070 Population of 170 people all had plasma samples collected and analyzed with both AlzPath and Fujirebio pTau217 tests. Using data from the Fujirebio pTau217 test they found the upper threshold to be 0.37pg/ml that had 93.0% specificity and 93.0% positive predictive values based upon neuropathology.  Using data from AlzPath pTau217 test they found the upper threshold to be 0.63pg/ml that had 90.0% specificity, 93.4% Sensitivity, and 92.4% accuracy based upon amyloid pathology.