A report in the January issue of Archives of General Psychiatry, one of the JAMA/Archives journals reveals, that cerebrospinal fluid levels of Aβ42 seem to be decreased at least five to 10 years prior to some patients with mild cognitive impairment developing Alzheimer disease (AD) dementia, whilst other spinal fluid levels seem to be later markers of disease.

Background information in the study states that disease-modifying therapies like immunotherapy, have a greater chance of success when started in the early stages of the disease. According to the researchers, it is necessary to identify patients with Alzheimer disease before the neurodegeneration is not too severe.

Dr. Peder Buchhave, an affiliate of Lund University and Skane University in Sweden and his team carried out an extended follow-up of the cohort from a previous study involving 137 patients with mild cognitive impairment (MCI) at baseline for an average follow-up period of 9.2 years.

72 patients or 53.7% developed AD during the follow-up whilst 21 patients or 15.7% developed other forms of dementia. At baseline the researchers discovered that compared to patients who did not develop AD, cerebrospinal fluid Aβ42 levels were lower in patients who converted to AD during follow-up, whilst other biomarkers, i.e. T-tau and P-tau levels were higher.

The findings also showed an equal reduction in baseline CSF Aβ42 levels in patients with MCI who converted to AD within five years, i.e. the early converters, compared with those who converted later, such as between five and 10 years, whilst T-tau and P-tau levels were substantially higher in early converters compared to later ones.

The findings indicate that, “approximately 90 percent of patients with MCI and pathologic CSF biomarkers at baseline will develop AD within 9.2 years.”

The researchers conclude:

“Therefore, these markers can identify individuals at high risk for future AD least five to 10 years before conversion to dementia. Hopefully, new therapies that can retard or even halt progression of the disease will soon be available. Together with an early and accurate diagnosis, such therapies could be initiated before neuronal degeneration is too widespread and patients are already demented.”

Written by Petra Rattue