Summary: Analyzing nasal discharge could be a new tool in diagnosing and monitoring the progression of Alzheimer’s disease. Researchers found certain Alzheimer’s related proteins can be detected in nasal discharge.
The Republic of Korea, like other countries with a rapidly ageing population, is facing increasing numbers of patients with dementia, of which Alzheimer’s disease (AD) is the most representative type. Unfortunately, AD has no complete cure yet; but, some treatments have been proven to delay its progression. Of course, this means that timely diagnosis while the symptoms are still mild is essential to maximize a patient’s quality of life.
However, currently available technologies for diagnosing AD are limited because they involve expensive machinery and invasive or inconvenient procedures. Now, in a recent study published in Scientific Reports, scientists from Daegu Gyeongbuk Institute of Science and Technology, Korea, hint at a novel way of diagnosing AD in a much simpler way –collecting and analyzing specific proteins in nasal discharge samples.
Professor Cheil Moon, who led the study, explains how they came up with the idea: “In 2017, we found that olfactory dysfunction occurred in the early stages of AD in mice and suggested that the cause of the symptoms was induced by soluble species of amyloid-β (Aβ) oligomer accumulations in the peripheral olfactory system. We hypothesized that soluble Aβ oligomers could be detectable in nasal discharge and that they may be a useful parameter to monitor disease progression.” To test their hypothesis, they gathered and compared nasal discharge samples from 39 patients with AD and 21 people from an age-matched control group.
They found that the levels of two particular Aβ oligomers (the aggregated forms of Aβ implicated as characteristic of Alzheimer’s) were consistently higher in patients from the AD group. What’s more, the levels of the “soluble” form of this protein could be used to not only separate healthy subjects from patients with AD, but also predict the onset and progression of AD over a three-year period.
Although further research will be required to better understand the link between Aβ oligomers in nasal discharge and the cognitive impairments related to AD, the results are certainly promising. Prof Moon remarks, “Routine nasal discharge screenings would be a better option to screen for AD because of its various advantages, such as its relatively low cost and non-invasive nature. The results of our study introduce a novel and simple approach to assess AD progression.”
This new diagnostic technique will hopefully help in simpler and faster detection of Alzheimer’s and improving the disease outcome, thus bringing much needed relief to millions suffering from the Alzheimer’s worldwide.
About this neurology research article
Source: DGIST Contacts: Kwanghoon Choi – DGIST Image Source: The image is in the public domain.
Longitudinal profiling of oligomeric Aβ in human nasal discharge reflecting cognitive decline in probable Alzheimer’s disease
Despite clinical evidence indicating a close relationship between olfactory dysfunction and Alzheimer’s disease (AD), further investigations are warranted to determine the diagnostic potential of nasal surrogate biomarkers for AD. In this study, we first identified soluble amyloid-β (Aβ), the key biomarker of AD, in patient nasal discharge using proteomic analysis. Then, we profiled the significant differences in Aβ oligomers level between patient groups with mild or moderate cognitive decline (n = 39) and an age-matched normal control group (n = 21) by immunoblot analysis and comparing the levels of Aβ by a self-standard method with interdigitated microelectrode sensor systems. All subjects received the Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), and the Global Deterioration Scale (GDS) for grouping. We observed higher levels of Aβ oligomers in probable AD subjects with lower MMSE, higher CDR, and higher GDS compared to the normal control group. Moreover, mild and moderate subject groups could be distinguished based on the increased composition of two oligomers, 12-mer Aβ56 and 15-mer AβO, respectively. The longitudinal cohort study confirmed that the cognitive decline of mild AD patients with high nasal discharge Aβ56 levels advanced to the moderate stage within three years. Our clinical evidence strongly supports the view that the presence of oligomeric Aβ proteins in nasal discharge is a potential surrogate biomarker of AD and an indicator of cognitive decline progression.