Limbic-predominant age-related TDP-43 encephalopathy in black and white decedents

Objective: The association of limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) with cognition and dementia was assessed in community-dwelling black elders, and racial differences in these associations were tested.

Methods: Black (n = 76) and white decedents (n = 152) from 4 longitudinal clinical pathologic studies of aging were matched two-to-one by age at death, gender, years of education, dementia status and follow-up time. LATE-NC detected by immunohistochemistry was dichotomized into none/mild and moderate/severe groups. Distribution, clinical and pathologic characteristics of LATE-NC and its association with cognitive profiles and odds of dementia were determined in blacks and racial differences in these associations were also assessed.

Results: The overall frequency of LATE-NC in blacks and whites was similar (40.8% vs 45.4%). Blacks with moderate/severe LATE-NC, were older, had significantly lower global cognition scores particularly in memory domains and had higher frequency of Alzheimer's disease, hippocampal sclerosis and cerebral amyloid angiopathy than the LATE-NC none/mild group. LATE-NC in blacks was independently associated with impaired global cognition, episodic and semantic memory and visuospatial abilities. There were no racial differences in clinical features or pathologic distribution of LATE-NC except for a significant increase in the mean cytoplasmic inclusions in the entorhinal and midtemporal cortices in white as compared to black decedents. Also, no racial differences in the cognitive profiles or the odds of dementia were observed in black vs white decedents.

Conclusions: Consistent with findings in whites, LATE-NC in blacks is associated with impaired cognition, including memory domains.