Association between progranulin and beta-amyloid in dementia with Lewy bodies.

Recent studies demonstrated that progranulin plays an integral role in the pathogenesis of frontotemporal dementia. To begin to explore the role of progranulin in dementia with Lewy bodies, we investigate its association with pathologic proteins that characterize this disease. We assessed immunoreactivity for progranulin in medial temporal lobe structures of 12 cases of dementia with Lewy bodies. Similar data were collected for beta-amyloid burden, and alpha-synuclein pathology. Blinded investigators used a 0-3-point scale to quantify progranulin burden. Double labeling for progranulin and beta-amyloid was also performed. We were able to demonstrate progranulin immunoreactivity throughout the medial temporal lobe in all dementia with Lewy body cases. We identified a significant positive correlation (r = 0.606; P = .037) between beta-amyloid burden and progranulin. There was no significant correlation between alpha-synuclein pathology or Braak stage and progranulin. Progranulin and beta-amyloid colocalized in plaques in dementia with Lewy bodies, suggesting that there is likely a biological association between these 2 aggregated proteins.