A new UCLA study, published in the journal of Aging, has revealed that Alzheimer’s disease consists of three distinct subtypes, differentiated by immune and metabolic response and brain region. Alzheimer’s disease is expected to increase to 15 million in 2050, from nearly 6 million today. The public health cost to treat people in the U.S. with Alzheimer’s is expected to reach $226 billion in 2015.
The scientists investigated the possibility of Alzheimer disease differentiation as one specific subtype had different characteristics than the other two.
The cortical subtype affects young individuals and appears more widely distributed across the brain than the other subtypes of Alzheimer’s.
It typically does not seem to cause memory loss at first, but people with this subtype of the disease tend to lose language skills. It is often misdiagnosed, typically affects people who do not have an Alzheimer’s-related gene and is associated with a significant zinc deficiency.
“Because the presentation varies from person to person, there has been suspicion for years that Alzheimer’s represents more than one illness,” said Dr. Dale Bredesen, the founding president of the Buck Institute for Research on Aging. “When laboratory tests go beyond the usual tests, we find these three distinct subtypes.
“The important implications of this are that the optimal treatment may be different for each group, there may be different causes, and, for future clinical trials, it may be helpful to study specific groups separately.”
The subtypes are:
Inflammatory, in which markers such as C-reactive protein and serum albumin to globulin ratios are increased.
Non-inflammatory, in which these markers are not increased but other metabolic abnormalities are present.
Cortical, which is more widely distributed across the brain than the other subtypes of Alzheimer’s.