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Measurement of amyloid peptide precursor of Alzheimer disease in human blood by double antibody immunoradiometric assay
Pardridge WM, Buciak JL, Yang J, Miller BL, Vinters HV.. Alzheimer disease and associated disorders, 1991-01-01
Topic: Amyloid, tau and blood-test diagnosis
The dementia of Alzheimer disease (AD) correlates with the deposition of extracellular amyloid, and this amyloid arises from the abnormal processing of a high molecular weight amyloid peptide precursor (APP), which is a normal cellular protein that is found in both brain and in peripheral tissues in humans. Overproduction of the APP in AD could cause increased concentrations of this protein in either human blood or cerebrospinal fluid (CSF). However, thus far no direct demonstration of soluble APP in human blood has been possible, owing to poor assay sensitivity and interfering plasma proteins. These two problems were eliminated with the present development of an extracting two-site immunoradiometric assay (IRMA). Two rabbit polyclonal antisera were prepared reacting to two different sites (amino acids 161-180 and 597-624) of the APP molecule. The near N-terminal antiserum (anti-APP161-180) was covalently coupled to a solid phase support and the near C-terminal directed antiserum (anti-APP597-624) was indirectly labeled using 125I-labeled near C-terminal synthetic peptide corresponding to amino acids 597-624. The IRMA was validated by partial purification of the APP from human serum and demonstration of the protein's molecular weight (112 kDa) by Western immunoblot procedures. Results of the IRMA showed that the APP is present in human plasma (mean +/- SE concentration = 32 +/- 6 pM, n = 25), and there was no significant difference in the APP concentration in 25 controls, 19 patients with AD, and 10 individuals with Down syndrome (DS). Immunoreactive APP was generally not detectable in control or AD CSF volumes as large as 1 ml.(ABSTRACT TRUNCATED AT 250 WORDS)
Key findings
- Results of the IRMA showed that the APP is present in human plasma (mean +/- SE concentration = 32 +/- 6 pM, n = 25), and there was no significant difference in the APP concentration in 25 controls, 19 patients with AD, and 10 individuals with Down syndrome (DS).
Why it matters
This study developed a two-site immunoradiometric assay that could measure amyloid peptide precursor in human blood, finding it present in plasma at a mean concentration of 32 pM. There was no significant difference in APP concentration among 25 controls, 19 Alzheimer's disease patients, and 10 individuals with Down syndrome, so the assay did not distinguish these groups.
Study details
- Participants25
- Evidence strengthLow
How this study scored 36/100
Published in a peer-reviewed journal. Scored zero for study design, effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Alzheimer disease and associated disorders) |
| Journal's citation record | 1 / 4 | Alzheimer Disease & Associated Disorders: journal h-index 131 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 1991 — older than 20 years, still counted |
| Sample size | 1 / 4 | 25 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 2 / 7 | Cited 7 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.2 citations a year over 37 year(s) since 1991 |
| Impact for its field and year | 1 / 6 | Cited 0.5× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 2 other studies in this library |
| Still being cited | 0 / 4 | Cited 0 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Harry V. Vinters: h-index 129 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University of California, Los Angeles: institution h-index 1,923 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 2025420) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 36 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Pardridge, W. M., Buciak, J. L., Yang, J., Miller, B. L., & Vinters, H. V. (1991). Measurement of amyloid peptide precursor of Alzheimer disease in human blood by double antibody immunoradiometric assay. Alzheimer disease and associated disorders. https://doi.org/10.1097/00002093-199100510-00002
Vancouver
Pardridge WM, Buciak JL, Yang J, Miller BL, Vinters HV. Measurement of amyloid peptide precursor of Alzheimer disease in human blood by double antibody immunoradiometric assay. Alzheimer disease and associated disorders. 1991. doi:10.1097/00002093-199100510-00002. PMID: 2025420.
BibTeX
@article{pardridge1991-2025420,
author = {Pardridge, W. M. and Buciak, J. L. and Yang, J. and Miller, B. L. and Vinters, H. V.},
title = {{Measurement of amyloid peptide precursor of Alzheimer disease in human blood by double antibody immunoradiometric assay}},
journal = {Alzheimer disease and associated disorders},
year = {1991},
doi = {10.1097/00002093-199100510-00002},
pmid = {2025420},
url = {https://doi.org/10.1097/00002093-199100510-00002}
}
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