- An international study carried out by the Institute of Biomedicine of Seville (IBiS) in collaboration with the University of Santiago de Compostela and the University of Gothenburg (Sweden) reveals new findings on the temporal evolution of a common age-related pathology called primary age-related tauopathy (PART), which shares features with Alzheimer's disease.
- The research uses an innovative neuroimaging technology to detect people with PART by means of positron emission tomography (PET), and it shows that these people have a very different, and more benign, clinical and pathological course compared to patients with Alzheimer's disease. This suggests that this highly prevalent pathology in the ageing population requires a different therapeutic approach to Alzheimer's disease and that PET technology could be useful as a diagnostic biomarker for this condition.
Seville, October 19th, 2023
Alzheimer's disease is pathologically characterised by the abnormal accumulation of two distinct proteins in brain tissue, tau protein and amyloid protein. However, some older people show an abnormal accumulation of tau protein in the absence of amyloid plaques, a condition called primary age-related tauopathy (PART). Until now, clinicians have faced several unresolved questions about this condition: will these patients eventually develop Alzheimer's disease, or is it a different pathology?.
Now, a new research study coordinated at the IBiS by Dr. Michel Grothe, principal investigator of the neuroimaging line of the IBiS Movement Disorders group, has managed to provide some answers to these questions, which could open up new therapeutic avenues for this highly prevalent neurodegenerative disease in the ageing population.
Imagen -Dr. Grothe examining PET scans of patients with cognitive impairment
The research has been made possible through an international collaboration that also involves the groups of Dr. Pablo Aguiar, from the University of Santiago de Compostela, and of Dr. Michael Schöll, from the University of Gothenburg (Sweden).
In this study, published in the prestigious journal JAMA Neurology, the scientists used an innovative neuroimaging technology, which allows imaging of tau protein accumulation in the brain using positron emission tomography (PET), to confirm that a significant number of people with cognitive impairment and suspected Alzheimer's disease actually have PART. They showed that these patients continued to accumulate pathological tau over time, but at a much slower rate than people with Alzheimer's and in a much more restricted area of the brain.
Brain atrophy, measured by analysis of magnetic resonance imaging scans, and cognitive decline in these individuals reflected the differential patterns of tau accumulation. Thus, in patients with PART, the atrophy was limited to the same restricted areas of the brain where tau accumulation was seen, whereas in Alzheimer's patients atrophy was more widespread throughout the brain. In addition, individuals with PART only suffered relatively mild cognitive decline over time, almost three times less than the impairment seen in Alzheimer's patients.
The researchers conclude that, although this accumulation of tau protein in individuals with PART cannot strictly be considered a benign process, the evolution of the patients is completely different from that of Alzheimer's patients. Based on these results, PART and Alzheimer's disease probably represent two different pathological entities, each of which will require specific treatment strategies. In this sense, tau-sensitive PET imaging, originally devised to detect tau in Alzheimer's disease, may have a new diagnostic utility in detecting patients with PART, for whom no diagnostic biomarkers currently exist.
Imagen - PET-based detection of tau protein accumulation in the brains of patients with PART (left) and Alzheimer's disease (right).
In conclusion, the results of this pioneering research suggest that PART appears to be a pathological entity distinct from Alzheimer's disease, which, despite sharing some similar features, has different clinical and pathological consequences and therefore likely requires a different therapeutic approach. In this sense, the visualisation of abnormal cerebral tau accumulation by PET may be a useful tool to detect patients with PART and to study the effect of new therapies focused on this highly prevalent pathology in the ageing population.
Reference:
DOI: 10.1001/jamaneurol.2023.2560
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About IBiS
The Institute of Biomedicine of Seville (IBiS) is a multidisciplinary center focused on carrying out fundamental research on the causes and mechanisms of the most prevalent pathologies in the population and the development of new methods to diagnose and to treat diseases.
IBiS is made up of 42 consolidated groups and 42 affiliated groups led by researchers from the University of Seville, the Spanish National Research Council (CSIC) and the Virgen del Rocío and Virgen Macarena University Hospitals and Valme, organized around five thematic areas: Infectious Diseases and Immune System, Neurosciences, Onco-hematology and Genetics, Cardiovascular Pathology, Respiratory / Other Systemic Pathologies and Liver, Digestive and Inflammatory Diseases.
IBiS depends institutionally on the Department (Consejería) of Health and Consumption of the Junta de Andalucía; the Andalusian Health Service (SAS); the Department (Consejería) of University, Research and Innovation; the University of Seville and the Spanish National Research Council (CSIC). It is managed by the Public Foundation for the Management of Health Research in Seville (FISEVI).
More information:
Angeles Escudero
Unidad de comunicación| UCC+i
InstitutodeBiomedicinadeSevilla - IBiS
Campus Hospital Universitario Virgen del Rocío
Avda. Manuel Siurot s/n
41013 Sevilla
Tel 682730351
Email: comunicacion-ibis@us.es
