The neurodegenerative changes of Alzheimer's disease are usually gradual, and the patient may have developed disease many years before any symptoms (such as memory loss) appear. Therefore, early diagnosis can help doctors to use drugs to slow down the patient's condition. Swedish and British scientists published a paper in the latest issue of Brain, saying that their latest research found that glial fibrillary acidic protein (GFAP) may be a biomarker of the early stage of Alzheimer's disease, which helps to reveal this serious and common disease 10 years in advance. The research results show that the biomarker GFAP in the brain that activates immune cells reflects the brain changes caused by Alzheimer's disease. This change occurs before the accumulation of tau protein and the occurrence of measurable neuronal damage. In the future, it can be used as a non-invasive biomarker to activate immune cells such as astrocytes in the central nervous system in the early stage, which is very helpful for the development of new drugs and the diagnosis of cognitive diseases. According to the data of the Swedish Brain Foundation, Alzheimer's disease will worsen unconsciously, and the biological changes of the brain will occur 20 to 25 years before memory loss and other cognitive symptoms become apparent. Therefore, the earlier accurate diagnosis is made, the earlier the patients will receive correct treatment. Scientists have also been conducting more research on accurate and easy-to-use early diagnosis methods. The joint team from the Karolinska Institute, the University of Gothenburg and University College London has been studying biomarkers in the blood to discover the early pathological changes of hereditary Alzheimer's disease. In this study, they analyzed 164 plasma samples from 33 mutation carriers and their 42 relatives who had no genetic predisposition to disease. The data were collected from 1994 to 2018, and the results revealed significant changes in the concentration of several blood proteins in mutation carriers. The researchers said: "The first change is that the concentration of GFAP began to increase about 10 years before the onset of symptoms of Alzheimer's disease, and then the concentration of P-tau181 and neurofilament light protein (NfL) increased