Saliva levels of Abeta1-42 as potential biomarker of Alzheimer's disease: a pilot study

Abstract

BackgroundSimple, non-invasive tests for early detection of degenerative dementia by use of biomarkers are urgently required. However, up to the present, no validated extracerebral diagnostic markers for the early diagnosis of Alzheimer disease (AD) are available. The clinical diagnosis of probable AD is made with around 90% accuracy using modern clinical, neuropsychological and imaging methods. A biochemical marker that would support the clinical diagnosis and distinguish AD from other causes of dementia would therefore be of great value as a screening test. A total of 126 samples were obtained from subjects with AD, and age-sex-matched controls. Additionally, 51 Parkinson's disease (PD) patients were used as an example of another neurodegenerative disorder. We analyzed saliva and plasma levels of β amyloid (Aβ) using a highly sensitive ELISA kit.ResultsWe found a small but statistically significant increase in saliva Aβ42 levels in mild AD patients. In addition, there were not differences in saliva concentration of Aβ42 between patients with PD and healthy controls. Saliva Aβ40 expression was unchanged within all the studied sample. The association between saliva Aβ42 levels and AD was independent of established risk factors, including age or Apo E, but was dependent on sex and functional capacity.ConclusionsWe suggest that saliva Aβ42 levels could be considered a potential peripheral marker of AD and help discrimination from other types of neurodegenerative disorders. We propose a new and promising biomarker for early AD.

Early diagnosis of mild cognitive impairment and Alzheimer's disease based on salivary lactoferrin

“…Unstimulated whole saliva was collected into sterile plastic containers precoated with 2% sodium azide solution, as described previously [7]. Collected samples were immediately placed on ice and precleared by a low spin at 600× g for 10 minutes at 4°C.…”

Aluminium-Maltolate-induced Impairment of Learning, Memory and Hippocampal Long-term Potentiation in Rats

“…AD is a progressive form of dementia in the elderly and is the most prevalent neurodegenerative disease in the world 13) . It is well established that exposure to Al represents a risk for the development of AD 20) .…”

“…Al has also been proposed to be one of the critical environmental factors related to several serious neurodegenerative diseases, such as Alzheimer's disease (AD) 3,[9][10][11][12] . AD is the most common form of dementia, and with increasing life expectancy across the world, AD is a rapidly growing socioeconomic and medical problem 13) . AD is clinically characterised by progressive learning impairment and memory loss followed by cognitive decline.…”

Alzheimer’s Diseases: Towards Biomarkers for an Early Diagnosis

“…Among these biological fluids, a special attention is accorded to saliva and urine. The study of Bermejo and colleagues (Bermejo-Pareja et al, 2010) found that saliva A 42 is, in comparison with control subjects, significantly elevated in early stage AD patients while   levels remain unchanged within all the samples analyzed. Curiously the elevated saliva A 42 levels were not observed in severe stages of the disease.…”