Scientists have identified a protein that may help them better study the onset of Alzheimer’s disease.

Many scientists believe that the immune system plays a role in the progression of neurodegenerative diseases like Alzheimer’s, a type of dementia most notably marked by memory problems. The Munich researchers from the German Center for Neurodegenerative Diseases, known by its German acronym DZNE, and Ludwig Maximilian University found an “immune response in individuals with a genetic predisposition to Alzheimer's” that could appear in higher levels early on in the condition’s progression — several years before symptoms are expected to present themselves, according to a statement from the DZNE.

Those inflammatory processes they discovered were detected by the presence of a protein in the patients’ cerebrospinal fluid, “offering physicians the possibility to trace the progression of the disease.”

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Their study, in Science Translational Medicine, used information from more than 120 people who had a genetic predisposition to Alzheimer’s, and showed either no symptoms of the disease or just minor symptoms. The protein increased as early as seven years before the onset of symptoms, but after other early signs of the disease appeared in the body, like nerve damage, which can begin many years earlier.

Although there is also a significant population of people with Alzheimer’s who did not have a genetic predisposition, the scientists suggested the protein they identified, TREM2, could also be used to track the immune system’s activity as the disease progresses in those cases.

The implications go beyond dementia, the study says: The protein is involved in many neurological disorders and “may therefore not only hold a key for understanding disease progression but also be a new and unexpected therapeutic target, probably even for cases who have already progressed to overt disease.”

Source: Haass C, Ewers M, Suárez-Calvet M, et al. Early changes of CSF sTREM2 in Dominantly Inherited Alzheimer's Disease follow markers of Amyloid Deposition and Neuronal Injury. Science Translational Medicine. 2016.

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