Alzheimer's-fighting peptide found naturally in human blood, levels halved in patients

Discovery of endogenous HAEE could lead to new diagnostic biomarker and treatment for the disease

By LineZotpaper

Published23 October 2026

Read Time2 min

Researchers who developed a synthetic peptide to block Alzheimer's-related protein clumps have discovered that the same molecule is already present in human blood, with levels roughly halved in people diagnosed with the disease. The finding, published in PNAS Nexus, suggests HAEE could serve both as a biomarker for early detection and as a basis for therapy.

The peptide, called HAEE (Ac-His-Ala-Glu-Glu-NH2), was originally designed by researchers from the startup Lifemission and the Russian Academy of Sciences to stop amyloid-beta plaques from forming by blocking zinc ions thought to act as biological 'glue'. In mouse tests, the peptide reduced plaque counts.

When the team developed a method to measure HAEE in human blood to prepare for clinical trials, they found the peptide in every sample from 150 healthy volunteers. Blood samples from people with Alzheimer's averaged roughly half the HAEE level of healthy controls, suggesting the molecule might be used as a disease biomarker.

"We discovered that the human blood contains an endogenous replica of this peptide, and that its concentration is sharply reduced in patients with a clinical diagnosis of Alzheimer's disease," the researchers wrote. "Our findings uncover a new molecule of the human body and suggest that endogenous HAEE deficiency plays a significant role in the pathogenesis of Alzheimer's disease."

The study has limitations. Alzheimer's diagnoses were based on clinical assessments alone, without brain imaging or biomarker tests, so some patients may have had other forms of dementia. Age varied between groups, and HAEE levels did not differ significantly by disease severity. The work was funded by Lifemission, which holds patents on HAEE as a blood test, and two of the study researchers are connected to the company.

The researchers say HAEE deficiency may result from reduced production or increased consumption during the disease. Further studies are needed to clarify the relationship and whether synthetic HAEE could be used as a drug.

Analysis

Why This Matters

Alzheimer's disease affects tens of millions worldwide, with no cure and limited early diagnostic tools. A blood-based biomarker like HAEE could enable cheaper, earlier detection.
If synthetic HAEE proves safe and effective, it could become a disease-modifying therapy, not just a diagnostic.
The finding that the body already makes a version of the peptide may accelerate drug development by providing a natural template.

Background

Alzheimer's disease is characterized by build-up of amyloid-beta plaques between neurons. For years, researchers have sought ways to clear or prevent these clumps. The HAEE peptide was designed to interfere with zinc ions that help plaques form. The discovery that humans naturally produce the same peptide was unexpected and may reshape understanding of the disease's mechanisms.

Key Perspectives

Researchers (Lifemission/Russian Academy of Sciences): They view HAEE deficiency as a significant factor in Alzheimer's and see potential for both a diagnostic test and a therapeutic. They acknowledge the need for validation in larger, more rigorous studies. Critics/Skeptics: The study's reliance on clinical diagnoses without imaging or biomarker confirmation, plus funding and patent ties to Lifemission, raise questions about bias and generalizability. Age differences between groups could also affect results.

What to Watch

Large-scale validation studies using biomarker-confirmed Alzheimer's cases and cognitively normal controls.
Clinical trials of synthetic HAEE as a potential drug, likely starting with safety and dosing.
Independent replication by other laboratories to confirm the biomarker finding.

Sources

Researchers Developed a Molecule to Fight Alzheimer's – Then Found It's Already in Our Blood · ScienceAlert

Checked

12 claims in this story checked against 1 source: 11 supported.

Show each claim

SupportedThe peptide HAEE is naturally present in human blood.ScienceAlert: “they found the peptide was already present – in every sample from 150 healthy volunteers.”
SupportedPeople with Alzheimer’s had roughly half the HAEE level of healthy controls, on average.ScienceAlert: “the blood samples taken from people with Alzheimer's had around half the level of HAEE on average as healthy controls”
Partly supportedHAEE could enable early detection as a biomarker and provide a basis for treatment.ScienceAlert: “Deficiency of endogenous HAEE may be considered as a potential blood-based biomarker in the diagnosis of Alzheimer's disease, while exogenous synthetic HAEE may serve as a drug in Alzheimer's disease-modifying therapy”
SupportedThe researchers wrote: “We discovered that the human blood contains an endogenous replica of this peptide, and that its concentration is sharply reduced in patients with a clinical diagnosis of Alzheimer's disease.”ScienceAlert: “We discovered that the human blood contains an endogenous replica of this peptide, and that its concentration is sharply reduced in patients with a clinical diagnosis of Alzheimer's disease,”
SupportedThe researchers wrote that their findings uncover a new molecule and suggest endogenous HAEE deficiency plays a significant role in Alzheimer’s pathogenesis.ScienceAlert: “Our findings uncover a new molecule of the human body and suggest that endogenous HAEE deficiency plays a significant role in the pathogenesis of Alzheimer's disease.”
SupportedResearchers from Lifemission and the Russian Academy of Sciences developed HAEE.ScienceAlert: “researchers from the startup Lifemission and the Russian Academy of Sciences previously developed a peptide called HAEE”
SupportedHAEE was designed to block zinc ions thought to act as biological glue and stop amyloid-beta clumps from forming.ScienceAlert: “to stop these clumps from forming by blocking zinc ions that are thought to act as a kind of biological 'glue'.”
SupportedIn mouse tests, HAEE reduced amyloid-beta plaque counts in the brain.ScienceAlert: “In tests on mice, the peptide has already been shown to reduce the number of amyloid-beta plaques in the brain.”
SupportedResearchers found HAEE in every blood sample from 150 healthy volunteers.ScienceAlert: “they found the peptide was already present – in every sample from 150 healthy volunteers.”
SupportedThe study was published in PNAS Nexus.ScienceAlert: “The findings have been published in PNAS Nexus.”
SupportedAlzheimer’s diagnoses relied on clinical assessments alone, without brain imaging or biomarker tests, so some patients may have had other forms of dementia.ScienceAlert: “Alzheimer's diagnoses were based on clinical assessments alone, without brain imaging or biomarker tests, so some patients may have had other forms of dementia.”
SupportedLifemission funded the study and holds patents relating to HAEE as an Alzheimer’s blood test.ScienceAlert: “the study was funded by the startup Lifemission, which holds patents relating to HAEE as an Alzheimer's blood test.”