Experimental treatment with antibodies derived from human blood donors shows improvements in thinking, mood and behaviour

An experimental treatment given to a handful of New Yorkers with Alzheimer's disease appears to have given them a reprieve from the symptoms.

Six patients who received weekly, biweekly or monthly infusions of the treatment for six months scored three points higher on a standard test for Alzheimer's than they had before the treatment began.

A seventh patient's score did not improve, but also did not decline. Normally, the disease process would have left them 1 to 2 points lower during that time.

Researchers from Weill Cornell Medical Centre in Manhattan recently presented preliminary findings at the American Academy of Neurology meeting in Florida.

Encouraging, but...
"It is extremely encouraging," said Dr Norman Relkin of Cornell Weill. But he cautioned that larger studies are needed to establish the value of the treatment.

The patients received infusions of immunoglobulin, a mix of antibodies derived from human blood donors.

It was originally developed to treat children born with damaged immune systems and is now used for diseases including lupus and multiple sclerosis.

About 100,000 patients have received these infusions, Relkin said, which cost about $3,000 (about Dh11,000) to $7,000 (about Dh25,700) a month.

Overall improvement
The human antibodies in immunoglobulin destroy the sticky brain plaque called amyloid that is a hallmark of Alzheimer's.

A healthy immune system normally makes its own antibodies against amyloid.

Last year Relkin's team discovered that Alzheimer's patients had far lower antibody levels than people without the disease.

The researchers said the patients' caretakers have also noted improvements in thinking, mood and behaviour.

"We started hearing that patients were more alert and socially engaged," said Relkin.

Three months after the treatment ended, two patients' scores had declined to their original levels, Relkin said.

Researchers also took spinal fluid samples and found changes in many markers associated with Alzheimer's.

The advantage
The benefits of the approach, called passive vaccine therapy because it administers antibodies rather than requiring the body to manufacture the antibodies, is that it can be stopped at any sign of a problem, said Dr Sam Gandy, director of the Farber Institute for Neurosciences at Thomas Jefferson University Hospital in Philadelphia.

"It's intriguing and makes a lot of sense."

Researchers said the next study would examine dosage frequency.

The idea that the brain plaque would respond to a powerful immune assault was discovered in 1999 by scientists at Elan Pharmaceuticals in South San Francisco, in experiments involving animals.

Subsequently, 300 patients with mild to moderate Alzheimer's signed on to receive the experimental approach, but midway into the study, several developed brain inflammation.

The company is now testing a passive vaccine approach.