Antibodies that attack the amyloid protein believed responsible for Alzheimer’s disease may offer a new way to treat the brain-destroying illness, U.S. researchers reported on Tuesday.

The infusion of antibodies seemed to be safe and may have delayed or even halted progression of the disease, the researchers said.

But the trial of immunoglobulin, or IVIg, therapy was done in just eight patients and it is too early to know much about its promise, the team at New York-Presbyterian Hospital/Weill Cornell Medical Center cautioned.

“If these results are confirmed in larger, controlled trials, we might have a safe Alzheimer’s treatment capable of clearing the amyloid protein away,” Dr. Marc Weksler, who helped lead the study, said in a statement.

In the phase I safety trial, eight Alzheimer’s patients were treated with IVIg for six months and then tested for decline in their mental function.

Cognitive function stopped worsening in seven patients tested so far and has improved in six, the researchers told a meeting of the American Academy of Neurology in Miami.

The antibodies target beta-amyloid, a protein that is a key feature of the brain-clogging plaques and tangles that characterize Alzheimer’s. It seems to kill nearby brain cells, robbing patients of memories and eventually of all ability to function and care for themselves.

Previous studies had shown that antibodies, which are immune system proteins that recognize and latch onto germs and abnormal cells, can also pull beta-amyloid out of the nervous system.

Using infusions of antibodies from blood is called passive immunization and has been used to fight diseases such as hepatitis.

“Immune therapy for Alzheimer’s disease has shown tremendous promise in the laboratory but has been difficult to translate into clinical practice,” said Dr. Norman Relkin of Weill Cornell Medical College.

Other efforts to make a vaccine against Alzheimer’s have been troubled by complications - one vaccine caused fatal encephalitis, a swelling of the brain, for instance.

But IVIg has been approved for decades for use in treating immune disorders. It turns out it contains elements specific for beta-amyloid.