Scientists have identified five different biological variants of Alzheimer’s disease. These appear to differ in how they affect the brain and, in some cases, respond to treatment.
An international team of researchers who analyzed cerebrospinal fluid proteins from 606 people found that this means drugs already tested may have been mistakenly thought to be ineffective or only marginally effective. Stated.
Their findings could lead to more personalized treatments and preventive measures for these subtypes. It also shows promise for early diagnosis and intervention to delay the onset of Alzheimer’s disease (AD) symptoms.
“Given the distinct patterns of molecular processes and the genetic risk profile of Alzheimer’s disease, subtypes of Alzheimer’s disease are likely to require specialized treatments.” write Neuroscientist Betty Times and colleagues at the Amsterdam Alzheimer Center.
Alzheimer’s disease is a neurodegenerative disease that affects millions of people worldwide and is characterized by the accumulation of amyloid and tau proteins in the brain, causing progressive memory loss and decline in cognitive function. .
In addition to the accumulation of amyloid and tau proteins that form clumps and tangles within brain tissue, other biological processes in other tissues have been implicated. Using modern technology, researchers were able to precisely measure key components of these other processes.
Tijms and her team used mass spectrometry proteomics They analyzed cerebrospinal fluid from 419 Alzheimer’s patients and 187 controls, looking for differences in protein levels. This resulted in 1,058 Alzheimer’s disease-related proteins being selected for analysis.
Researchers were able to identify five distinct biological subtypes of the disease, distinguished by mutations such as hyperplasia, immune activation, RNA dysregulation, choroid plexus dysfunction, and blood-gut barrier dysfunction. Ta. Each mutation was characterized by specific changes in a cluster of proteins associated with inflammation, nerve cell growth, and other biological processes.
“Three subtypes summarized our Three previously identified subtypes (Hyperplasia, Innate Immune Activation, Blood-Brain Barrier Dysfunction)” by Tijms and team explain.
“We also identified two additional AD subtypes, one with RNA dysregulation and one with RNA dysregulation.” choroid plexus Dysfunctional. ”
Identifying biomarkers for each mutation could help diagnose Alzheimer’s disease early, when intervention is most effective.
The researchers also examined magnetic resonance imaging (MRI) scans from a subset of 503 participants to compare the subtypes to individual volume differences in specific brain regions.
“The subtypes had different genetic risk profiles for Alzheimer’s disease,” the research team said. It is written, They added that the two “also had different clinical outcomes, survival times, and anatomical patterns of brain atrophy.”
Hyperplasia appears to involve an exaggerated cell proliferation response, leading to the accumulation of amyloid and tau proteins.
in natural immunity When activated, the immune system goes into overdrive and over-attacks healthy brain tissue.
RNA dysregulation involves changes in the transport of proteins along axons that allow nerve cells to function properly.
choroid plexus Dysfunction affects the ventricular system, which contributes to the production of cerebrospinal fluid and the delivery of nutrients to the brain.
Impairment of the blood-brain barrier weakens the barrier that protects the brain, allowing harmful molecules to enter. Unlike hyperplasia, this subtype is characterized by slow neuronal growth and low amyloid production.
This could mean that some drugs are only effective against one type of Alzheimer’s disease. For example, amyloid-focused drug therapy may treat subtypes with increased amyloid production, but may harm subtypes with decreased production.
“The side effects resulting from a particular treatment may also depend on the subtype,” the authors write. To tell. “For example, in subtype 5 antibodies may cross the blood-brain barrier more easily, but these people may be at higher risk for brain hemorrhage that can occur with antibody therapy.”
Traditionally, Alzheimer’s disease has been viewed as a single disease with some variation in symptoms and progression. Despite extensive research, there is no cure, and current treatments provide limited symptom control.
Further studies are needed to validate these new findings and investigate whether the variants respond differently to drugs.
Still, this is an exciting step forward in the ongoing fight against Alzheimer’s disease, and each discovery like this brings us closer to finding a cure.
This research natural aging.