Tear Liquid for Predictive Diagnosis of Alzheimer’s Disease

Abstract

The common approach of the diagnosis of Alzheimer’s Disease (AD) is made with an analysis of the cerebrospinal fluid or the study of retinal fundus and the plaques formation through optical corneal tomography (OCT), or more simply with a fundus camera. Tears analysis is widely discussed in literature as an essential method to describe molecular and biochemical alterations in different diseases. The aim of our study was the identification with immunocytochemistry of Amyloid Beta-42 in tears from patients with or without familiarity for Alzheimer Disease, in order to make the diagnosis earlier and more accessible compared to other invasive methods. Our study was performed on tears from three phenotypically healthy subjects: two of them were Caucasian with Alzheimer familiarity (48 and 55 years old) and the other one was Asian without Alzheimer familiarity (45 years old) and affected by an adenoviral keratoconjunctivitis at the moment of withdrawal. Tear samples were collected from eye fornix and were examinated by immunocytochemistry (ICC) assay using anti-Amyloid Beta X-42 antibody. Two out of three tears samples showed positive Amyloid Beta-42. Considering that our patients were phenotypically healthy, the identification of Amyloid Beta-42 by ICC could be a candidable method to make the diagnosis of the disease earlier and more accessible and available then other current and invasive methods and it could be a candidate for a screening method too.