• Saliva is a reliable diagnostic biomarker and potent stem cell provenance for Alzheimer's Disease.
  • Mahtab Mottaghi,1,*
    1. Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran


  • Introduction: Alzheimer’s disease (AD) is a neurodegenerative disease that causes progressive dementia. AD is the most prevalent type of dementia; approximately 60% - 80% of cases are over 65 years old. Currently, cerebrospinal fluid (CSF) assessment is applied for AD diagnosis, which later in the disease process has good diagnostic precision. However, recent studies proposed that human saliva could be a reliable biofluid for the early diagnosis of many diseases, including oral diseases, cancer, diabetes, and brain disorders. In addition, it potentially has prognostic and therapeutic value for patient monitoring.
  • Methods: It is necessary to develop a sensitive and noninvasive method for early diagnosis and monitoring of AD. The saliva has been introduced to be a good candidate as a circulating biological marker for AD. The saliva has specific features, including early, cost-effective, noninvasive, safe, and stable diagnostic biomarkers. Moreover, it can be considered for screening in large populations. However, neuroimaging biomarkers are expensive and cause radiation. Most compounds discovered in blood can pass into the saliva via passive diffusion, active transport, or microfiltration.
  • Results: In addition, salivary glands contain stem cells with AD biomarkers and potentially sensitive cellular biomarkers for cell-based regenerative medicine. Although stem cells derived from aged salivary glands may be decreased in number, they maintain their stemness features in comparison to the stem cells harvested from young salivary glands, proposing that the salivary glands remain as a vital source of stem cells that are applicable for combat age-related disorders. Previous studies described some valuable diagnostic biomarkers for AD, like amyloid beta 1-42 (Aβ42) and tau, but lactoferrin and selected metabolites also have potential. It seems saliva studies named saliva omics can be preferable over the other invasive methods and are still a new research area that needs more studies.
  • Conclusion: Finding a peripheral biomarker with validated detection will identify high-risk cases, facilitating early initiation of treatments that may prove more effective therapeutics approaches such as stem cell transplantation. However, some limitations must be resolved before clinical studies, including regulating the host immune response and potential tumorigenesis arising from transplantation. Since saliva is affected by many exogenous factors, some inflammatory markers may be impacted by various simultaneous disorders. This subject is critical for dentists to exclude oral diseases that may dramatically affect salivary levels.
  • Keywords: Saliva, Biomarkers, Alzheimer Disease, Stem Cells, Regenerative Medicine