Immunologic and inflammatory mediators and cognitive decline in Alzheimer's disease

Local up-regulation of immune mediators is implicated in the development of AD; however, the systemic cell-mediated immune response in patients with AD may be impaired. Progression of AD from moderate to severe stages is accompanied by a progressive decline in cognitive function, independence, and behavioral and motor impairments and by the occurrence of recurrent infections, such as bronchitis and pneumonia. Several factors, including malnutrition, may be implicated in the reduced ability to mount an adequate immune response against invading pathogens in advanced stages of AD. The immune system has an important role in the development, progression, and potential treatment of AD and is involved in determining the subsequent sequelae and morbidity outcomes in patients with advanced-stage AD. A better understanding of the immune mediators that are involved in the local and systemic immune response in AD may assist in mediating the development of AD, halting its progression, and treating patients with anti-inflammatory drugs and immunization strategies.