The US National Institutes of Health (NIH) recently proposed the first guidance to recognise a brain disorder that mimics Alzheimer’s disease (AD), known as limbic-predominant age-related TDP-43 encephalopathy (LATE).
Alzheimer’s disease LATE
The proposal includes detailed notes on disease definition and diagnostic criteria, which were agreed upon by an international working group, to advance research and promote awareness of the disorder.
While LATE shares certain clinical features with AD, autopsies reveal that LATE affects brain tissue differently than AD does, and includes a high presence of misfolded TDP-43 proteins. Normal TDP-43 proteins control various functions, including an individual’s memory and thought process. Although this is not a newly discovered disorder, formally differentiating LATE from AD will likely have a significant public health impact.
According to the NIH study by Nelson and colleagues published in 2019, almost 25% of clinically diagnosed AD patients of advanced age (80 years and older) actually have LATE. To demonstrate the magnitude of this potential reclassification, GlobalData epidemiologists present the total prevalent cases (undiagnosed and diagnosed) of AD in patients of advanced age in the seven major pharmaceutical markets (7MM: The US, France, Germany, Italy, Spain, the UK and Japan), alongside the potentially reclassified cases (as shown in Figure 1).
Distinguishing LATE from AD will likely result in a major reduction in total prevalent cases of AD, reclassifying up to 100,000 cases in the UK and up to 800,000 cases in Japan. GlobalData epidemiologists believe that this new guidance may result in a shift in the epidemiology of AD, especially with the inevitable changes in patient diagnosis and treatment.
Figure 1: 7MM, total prevalent cases of AD and potentially reclassified AD attributable to LATE, 2019, both sexes, ages greater than or equal to 80 years (N).