It is known that stress and immune systems are related with Alzheimer's disease (AD). However, the relationship of both systems in the progression of disease is not clearly demonstrated. Hair cortisol and salivary immunoglobulin A (IgA) were quantified in 49 patients with mild, moderate, and severe AD. A significant change was seen in both molecules as AD progressed from mild to moderate and severe. Low levels of cortisol were observed in mild AD patients compared with moderate and severe. However, IgA showed a contrary pattern. High levels were observed in mild AD patientes but low in moderate and severe AD subjects. The secretion of cortisol and IgA seems to be very different at the start compared with posterior development of AD suggesting that neuroinflammation can be involved. Both molecules could be used as possible therapeutical tools.
Keywords: Alzheimer’s disease; Cortisol; Immune system; Immunoglobulin A; Neuroinflammation; Progression; Stress.