Relação entre a Doença de Alzheimer e os níveis séricos de leptina e interleucinas: um estudo caso-controle

Abstract

Introduction: Aging is a natural process in which biological changes favoring the onset of dementia; which are characterized as syndromes that impair memory, thinking, behavior and alteration of daily activities. Alzheimer's disease (AD) is characterized as a disease of progressive, degenerative and irreversible damage that affects areas of the cortex and hippocampus. The β-amyloid cascade (Aβ) and post-translational modification of tau protein are considered the most important hypotheses of the causes of AD. In response to Aβ deposition, microglia and astrocytes release inflammatory cytokines (IL-1, IL-6, IL-10, TNF-α, IF-ɣ) in order to regulate the intensity and duration of neuroinflammation. Leptin is related to a decrease in Aβ levels by attenuating its production and increasing its clearance as well as attenuating tau protein phosphorylation. Objective: The aim of this study was to verify the serum inflammatory process in AD patients and non-demented elderly. Methodology: This is a case-control study composed of elderly with AD without dementia. For IL-1, IL-6, IL-10, TNFα, IF-γ dosing, a commercial Proteintech® ELISA kit was used and for serum leptin dosing a Raybio® commercial ELISA kit was used. Nutrition Mini-Assessment (NMA) and Body Mass Index (BMI) were used to assess nutritional status in both groups. Results: The results showed that elderly with AD had worse nutritional status (p <0.001) and mental status (p <0.001) when compared to participants in the control group. In addition, serum IL-1, IL-6, TNF-α and INF-ɣ levels were statistically higher in the AD patient groups, while serum IL-10 and Leptin levels were statistically lower in the AD patient groups. A negative correlation was observed between BMI and leptin (R2: 0.6425; p <0.05) in the AD group. Conclusion: Given the results obtained, it is suggested that an systemic inflammatory response may occur in elderly with AD, by increasing the levels of proinflammatory cytokines IL-1, IL-6, TNF-α and IFN-γ; in addition to changes in body composition and leptin levels.