What the Study Found
When we get older, the DNA in our cells picks up small changes called mutations. A new study from Boston Children’s Hospital looked at tiny brain immune cells called microglia. These cells clean up waste and protect the brain.
Scientists discovered that microglia in people with Alzheimer’s often carry mutations in five genes that are known to cause blood cancers such as lymphoma and leukemia. The same mutations were also found in the blood cells of the same patients.
Why It Matters
Normally, microglia stay inside the brain and do not travel through the bloodstream. The researchers think that as we age, the barrier that separates blood from the brain can become leaky. This allows blood‑borne immune cells that already have cancer‑linked mutations to slip into the brain and turn into microglia‑like cells.
Once inside, these mutated cells may become over‑active. They can cause more inflammation and damage than healthy microglia, hurting nearby nerve cells and speeding up Alzheimer’s disease.
New Ideas for Tests and Treatments
Because it is hard to take brain tissue from a living person, the scientists suggest using a simple blood test to look for the same mutations. Finding these changes in blood could tell doctors that a person has a higher chance of developing Alzheimer’s.
The discovery also opens the door to repurposing cancer drugs for Alzheimer’s. Many medicines that target the same mutations already exist for blood cancers, and they might help protect the brain as well.
Who Did the Research
The work was led by Dr. Christopher Walsh and his team at Boston Children’s Hospital and Harvard Medical School. They worked together with researchers from the Icahn School of Medicine at Mount Sinai and received support from the Howard Hughes Medical Institute, the National Institute on Aging, and several other foundations.