If amyloid deposits in the pancreas causes diabetes, (theory not universally accepted) then this could be an effective therapy A new treatment could represent a significant scientific step forward towards treating the millions of people suffering with Alzheimer’s and type 2 diabetes.
The treatment, called CPHPC, is aimed at preventing and potentially reversing the abnormal deposits of amyloid proteins that are a hallmark of several rare diseases called "amyloidoses," and which are present in the more common Alzheimer’s and diabetes.
In the amyloidosis diseases, which effect approximately one of every 100,000 Americans, clumps of amyloid protein accumulate and clog up organs throughout the body, causing them to malfunction and become diseased. Areas of the body most severely effected by these deposits are the heart, kidneys, pancreas, brain and digestive tract, leading to problems such as stroke, malnutrition, and heart and kidney failure.
Amyloid clumps, or plaques, are also present in the brains of Alzheimer’s patients and the pancreases of type 2 diabetics, though it is not known if these protein deposits have a direct role in the cause of disease symptoms, or if they are simply by-products of an as yet unknown tissue destroying process.
CPHPC acts in the blood by reducing levels of a protein called serum amyloid P component, or SAP, which binds to amyloid and contributes to its build-up. Decreasing SAP may therefore prevent, or possibly even help dissolve amyloid deposits.
"If [SAP] in the blood is a strong contributor to amyloid in the brain, as it seems to be in other tissues of the body, then hopefully the new drug will help prevent the buildup of plaques in the brain," explains Diane Murphy, program director at the National Institute of Neurological Disorders and Stroke in Washington, D.C. "It still remains in question as to whether or not the plaques themselves are causative of the cognitive problems in Alzheimer’s disease
"This drug could be useful for Alzheimer’s disease if amyloid deposition is the toxic agent," concurs Dr. Myron Weiner, vice-chairman of clinical services at UT Southwestern Medical Center in Dallas.
And diabetes experts share a similar optimistic yet cautious view of the new drug report.
"There is a theory that type 2 diabetes develops when amyloid deposits in the pancreas but the field of diabetes does not universally accept this theory," says Dr. George Eisenbarth, director of childhood diseases at the University of Colorado in Denver.
A study, reported this week in the scientific journal Nature, found that the drug decreased SAP levels in the blood of 19 patients suffering from amyloidosis. Special body scanning techniques also showed that the drug actually depleted SAP from amyloid deposits within their internal organs, suggesting that the drug has a direct effect on the dangerous plaques.
So far, the drug has caused no significant side effects in the 19 patients, though doctors stress the importance of assuring human safety. Because SAP’s normal role within the body is not yet known it is difficult to predict what the long term effects of CPHPC will be.
CPHPC researchers Andrew Sleight and Roland Jakob-Rotne of Roche Pharmaceuticals in Basel, Switzerland, point out that genetically engineered mice "with no SAP in them are perfectly normal and healthy," indicating that SAP may not be critical to normal body functions. Decreased blood levels of SAP could therefore be relatively safe.
"At the present time, we have no effective treatment for either primary or secondary amyloidosis. Most of these patients die within one to two years," adds Leslie Spry, spokesperson for the National Kidney Foundation in New York City.
And while the amyloidoses may be relatively rare, CPHPC’s potential for treating the four million Americans suffering from Alzheimer’s along with the more than 15 million living with type 2 diabetes is significant.
So while researchers are understandably excited about its broad reaching and potentially life-saving preventative effects, experts agree that more studies are needed to determine if these diseases can actually be halted in their tracks, and possible even reversed. Diabet Med 2002 May;19(5):393-9