A new biomarker in blood can diagnose Alzheimer's in its earliest stages

Alzheimer’s disease (AD) is the major cause of dementia and so far, no effective treatment can prevent, delay or stop its progression. We know that AD has an extensive prodromal stage (with initial symptoms preceding the disease) which lasts 15 to 20 years before clinical signs are evident. To envision an effective future treatment for AD, we need to be able to accurately diagnose AD at its earliest (prodromal) stages. At present, there is no biomarker that could be used for prodromal AD diagnosis on a routine clinical screening base. Amyloid-β or tau detection by positron emission tomography (PET) or in the cerebrospinal fluid (CSF) have emerged as biomarkers for the progression of AD. However, all these biomarkers have a high economical cost and are invasive, making them unsuitable for routine screening.

A recent report published by a team of researchers from the UAB Institute of Neuroscience (INc) and the Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), as well as other collaborators, and led by INc researcher Dolors Siedlecki-Wullich, identified in plasma a miRNA-based signature composed by miR-92a-3p, miR-181c-5p and miR-210-3p. The authors found a significant increase in the plasma levels of these miRNAs in mild cognitive impairment (MCI) and AD patients. Moreover, preliminary data support that this miRNAs signature could be used to predict the progression from mild cognitive impairment (MCI) to AD.

"We have identified a cost-effective blood-based biomarker which would improve participants´ recruitment in future clinical trials, boosting the therapeutic advancement in AD. Moreover, it would allow patients and their families to benefit from an earlier implementation of non-pharmacological therapies used to maintain cognitive function, improving the overall quality of life of AD patients", explains UAB's INc researcher José Rodríguez.

According to Dolors Siedlecki-Wullich, "These observations would support the future development of a molecular kit that will provide an easy, minimal invasive, effective and affordable method for prodromal AD diagnosis in routine clinical screening worldwide".

The article, published this week in Alzheimer 's Research & Therapy, included the involvement of researchers from the UAB Institute of Neuroscience; the UAB Department of Biochemistry and Molecular Biology; the Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED); the Research Center and Memory Clinic, the ACE Foundation, the Catalan Institute of Applied Neurosciences of the Universitat Internacional de Catalunya (UIC); the Department of Neurology of the Hospital Sant Pau Research Institute - IIB Sant Pau, a UAB-affiliated centre; and the Department of Neurosciences of the Albert Einstein College of Medicine, New York.

Original article:
Siedlecki-Wullich D, Catala-Solsona J, Fabregas C, Hernandez I, Clarimón J, Lleó A, Boada M, Saura CA, Rodriguez-Alvarez J and Miñano-Molina AJ. Alteration of microRNAs related to synaptic function as potential plasma Biomarkers for Alzheimer disease. Alzheimer Res & Ther 11:46 (2019)