Fungal infection in patients with Alzheimer's disease.

Alzheimer's disease is a progressive neurodegenerative disorder that leads to dementia mainly among the elderly. This disease is characterized by the presence in the brain of amyloid plaques and neurofibrillary tangles that provoke neuronal cell death, vascular dysfunction, and inflammatory processes. In the present work, we have analyzed the existence of fungal infection in Alzheimer's disease patients. A proteomic analysis provides compelling evidence for the existence of fungal proteins in brain samples from Alzheimer's disease patients. Furthermore, PCR analysis reveals a variety of fungal species in these samples, dependent on the patient and the tissue tested. DNA sequencing demonstrated that several fungal species can be found in brain samples. Together, these results show that fungal macromolecules can be detected in brain from Alzheimer's disease patients. To our knowledge these findings represent the first evidence that fungal infection is detectable in brain samples from Alzheimer's disease patients. The possibility that this may represent a risk factor or may contribute to the etiological cause of Alzheimer's disease is discussed.