Associação dos níveis de BDNF (brain derived neurotrophic factor) no comprometimento cognitivo leve e na doença de Alzheimer

Abstract

Background: It has been suggested that there is an association between brain-derived neurotrophic factor (BDNF) and the neuropathology of Alzheimer’s disease (AD). However, little is known about the role of BDNF in subjects with mild cognitive impairment (MCI). In the present study, we investigated BDNF serum levels in healthy elderly, amnestic MCI, and mild to moderate AD patients in order to identify a possible role for this neurotrophin in preclinical and early stages of AD. Methods: BDNF serum levels were measured by sandwich-ELISA in healthy elderly (n=20), amnestic MCI patients (n=15) and AD patients (n=25), 12 mild and 13 moderate. MMSE scores, level of education and age were analyzed for a possible correlation with BDNF levels. Results: BDNF serum levels were significantly different between MCI patients and healthy subjects (p=0.003); MCI and mild AD patients (p=0.023); and MCI and moderate AD patients (p=0.050). BDNF showed no correlation with MMSE scores, age or level of education. Limitations: The small sample size in the present investigation could be a limitation. However, we carried out a power calculation that showed values higher than 80% for a confidence level of 95%. Conclusion: The fact that BDNF serum levels differentiated amnestic MCI patients from healthy elderly and AD patients suggests a possible role for BDNF as a preclinical biomarker of AD.