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Three-Repeat Tau with Grain-Like Structures and Distribution in an 83-Year-Old Man
Naoki Kasahata1,2, Tomohide Sato3, Iichiroh Onishi4
1Laboratory of Structural Neuropathology, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
Journal of Alzheimer'S Disease : JAD
|April 29, 2017
Summary
This study found that 3-repeat tau deposition can form grain-like structures, similar to those typically associated with 4-repeat tau. These findings expand our understanding of tauopathies and their diverse pathological presentations.
Area of Science:
- Neuropathology
- Neurodegenerative Diseases
- Tauopathies
Background:
- Argyrophilic grains are typically associated with 4-repeat tau deposition in neurodegenerative diseases.
- Understanding the specific tau isoforms involved in different pathological structures is crucial for diagnosis and treatment.
Observation:
- An 83-year-old male presented with 3-repeat dominant grain-like tau deposition.
- Tau-positive lesions showed morphological and distributional similarities to argyrophilic grains in the ambient gyrus, amygdala, and temporal tip.
- Oligodendroglia exhibited abundant 3-repeat tau immunoreactivity, and tuft-shaped astrocytes showed partial 3-repeat tau immunoreactivity.
Findings:
- Grain-like structures, tuft-shaped astrocytes, and oligodendroglia demonstrated predominant 3-repeat tau immunoreactivity.
- This suggests that grain-like structures and their distribution are not exclusive to 4-repeat tau deposition.
- The 3-repeat tau deposits were associated with pTDP immunoreactivity, macrophage infiltration, and spongiosis.
Implications:
- These findings broaden the pathological spectrum of tauopathies, indicating that 3-repeat tau can form structures previously thought to be unique to 4-repeat tau.
- This has potential implications for the diagnostic criteria and understanding the molecular mechanisms underlying different tauopathies.
- Further research may elucidate the specific pathways driving 3-repeat tau aggregation and its clinical correlations.
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