Volatile organic compounds (VOCs) fingerprint of Alzheimer's disease

• Volatile organic compound (VOC) as a new biomarker of neurodegenerative disease.
• Real time VOC analysis is a respiratory system physiological biomarker in Alzheimer disease.
• Real time VOC profile and fingerprint of Alzheimer disease patients are presented.

Alzheimer's disease (AD) is a profoundly life changing condition and once diagnosis occurs, this is typically at a relatively late stage into the disease process. Therefore, a shift to earlier diagnosis, which means several decades before the onset of the typical manifestation of the disease, will be an important step forward for the patient.A promising diagnostic and screening tool to answer this purpose is represented by breath and exhaled volatile organic compounds (VOCs) analysis. In fact, human exhaled breath contains several thousand of VOCs that vary in abundance and number in correlation with the physiological status. The exhaled VOCs reflect the metabolism, including the neuronal ones, in healthy and pathological conditions. A growing number of studies clearly demonstrate the effectiveness of VOCs analysis in identifying pathologies, including neurodegenerative diseases. In the present study we recorded, in real time, breath parameters and exhaled VOCs. We were able to demonstrate a significant alteration in breath parameters induced by the pathology of AD. Further, we provide the putative VOCs fingerprint of AD. These vital findings are an important step toward the early diagnosis of AD.