Evidence map›Paper›PMID 41449469›Full record

ArticleTranslational neurodegeneration2025

Pretargeted brain PET imaging reveals amyloid-β pathology using a TCO-modified antibody and a fluorine-18-labeled tetrazine.

Sara Lopes van den Broek, Jonas Eriksson, Qiaojun Yang, Nadja M Bucher, Eva Schlein, Lorenzo J I Balestri, Luke R Odell, Dag Sehlin, Stina Syvänen

Abstract read
In one paragraph

Article in Translational neurodegeneration, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Sara Lopes van den BroekDepartment of Public Health and Caring Sciences, Uppsala University, 751 85, Uppsala, Sweden.
Jonas ErikssonDepartment of Medicinal Chemistry, Uppsala University, 751 85, Uppsala, Sweden.
Qiaojun YangDepartment of Public Health and Caring Sciences, Uppsala University, 751 85, Uppsala, Sweden.
Nadja M BucherDepartment of Public Health and Caring Sciences, Uppsala University, 751 85, Uppsala, Sweden.
Eva SchleinDepartment of Public Health and Caring Sciences, Uppsala University, 751 85, Uppsala, Sweden.
Lorenzo J I BalestriDepartment of Medicinal Chemistry, Uppsala University, 751 85, Uppsala, Sweden.
Luke R OdellDepartment of Medicinal Chemistry, Uppsala University, 751 85, Uppsala, Sweden.
Dag SehlinDepartment of Public Health and Caring Sciences, Uppsala University, 751 85, Uppsala, Sweden.
Stina SyvänenDepartment of Public Health and Caring Sciences, Uppsala University, 751 85, Uppsala, Sweden. stina.syvanen@uu.se.ORCID http://orcid.org/0000-0002-8196-4041

Funding

Vetenskapsrådet 2021-01083Vetenskapsrådet 2021-03524
6 · The paper itself

Abstract

backgroundAntibody-based positron emission tomography (PET) imaging holds great promise for visualizing disease-related proteins in the brain. However, its clinical utility is limited by poor antibody penetration across the blood-brain barrier (BBB) and the requirement for long-lived radionuclides due to slow antibody pharmacokinetics. Pretargeted imaging strategies, in which antibody administration and radioligand injection are separated in time, enable the use of short-lived, high-resolution PET-compatible radionuclides such as fluorine-18.

methodsA bispecific antibody, Bapi-Fab8D3, which targets both amyloid beta (Aβ) and the transferrin receptor (TfR) for TfR-mediated transport across the BBB, was conjugated with trans-cyclooctene (TCO) to enable in vivo click chemistry. Following antibody administration to Alzheimer's disease (AD) model mice and sufficient time for accumulation at intrabrain Aβ deposits, a fluorine-18-labeled tetrazine was injected to react in vivo with the TCO handles on the antibody. PET imaging, autoradiography, ex vivo quantification, and histological analyses were performed to evaluate the specificity and distribution of the imaging signal.

resultsBapi-Fab8D3 retained its binding affinity for both Aβ and TfR after TCO-conjugation. In brain sections, reactive TCOs were detected up to three days after antibody injection, indicating successful transcytosis across the BBB and stable target engagement. Pretargeted PET imaging after fluorine-18-labeled tetrazine injection revealed significantly higher signals in AD mice that received TCO-Bapi-Fab8D3 compared to wild-type controls or AD mice that received the unmodified antibody. The uptake pattern corresponded to Aβ plaque distribution, and quantitative analysis showed increased signal in AD-relevant brain regions including the hippocampus and thalamus.

conclusionsThis study demonstrates successful pretargeted PET imaging of brain Aβ pathology using a systemically administered bispecific antibody capable of BBB penetration and a fluorine-18-labeled tetrazine. These findings establish a generalizable strategy for high-contrast in vivo imaging of brain protein targets using pretargeted PET, with the potential to expand molecular imaging to protein targets in the brain that are currently inaccessible.

Indexed as

Alzheimer DiseaseAmyloid beta-PeptidesAntibodies, BispecificBrainFluorine RadioisotopesPositron-Emission TomographyAnimalsBlood-Brain BarrierCyclooctanesMiceMice, TransgenicRadiopharmaceuticalsReceptors, TransferrinAmyloid beta-PeptidesAntibodies, BispecificCyclooctanesFluorine-18Fluorine RadioisotopesRadiopharmaceuticalsReceptors, TransferrinAmyloid-βBispecific antibodyBlood–brain barrierFluorine-18 tetrazinePretargeted PET imaging

Identifiers

PMID41449469
PMCPMC12742193

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.