In the study, researchers detected a new association with the HLA (human leukocyte antigen) region, which contains a large number of genes related to immune system function in humans. With the new findings, and link to HLA, researchers will now be encouraged to take a fresh look at the possible role of infections, inflammation and autoimmunity in Parkinson's disease.
HLA genes are essential for recognizing foreign invaders from the body's own tissues. Similarly, HLA molecules are supposed to recognize a body's own tissue as itself and prevent immune reactions against them. But the system doesn't always work perfectly. HLA genes are highly variable from individual to individual. Certain variants of the genes are associated with increased risk or protection against infectious disease, while other variants can induce autoimmune disorders in which the immune system attacks the body's own tissues. Multiple sclerosis, a neurological disease caused by autoimmunity, is also associated with HLA-DR. The genetic variant that is associated with Parkinson's disease is in the same region as the one associated with multiple sclerosis.