Correlations of CSF tau and amyloid levels with Alzheimer pathology in neuropathologically verified dementia with Lewy bodies.

OBJECTIVE

The presence of concomitant Alzheimer pathology has been linked to earlier death in cases with dementia with Lewy bodies (DLB). Recently, elevated cerebrospinal fluid (CSF) tau protein levels have been reported to be associated with shorter survival in clinically diagnosed DLB. Correlations between CSF biomarkers and neuropathological findings in DLB are missing. The aim of this study was to investigate correlations between CSF biomarker levels and histopathological findings, with a focus on concomitant Alzheimer pathology, in neuropathologically verified DLB cases.

METHODS

The extent of neurofibrillary pathology (Braak stage), neuritic plaques (CERAD stage), Alzheimer pathology (PPAD9 stage) and cerebral amyloid angiopathy was assessed in 16 cases with DLB in whom total tau (T-tau), hyperphosphorylated tau and amyloid beta 1-42 (Aβ42) protein levels in CSF had been analyzed in vivo. Demographic and clinical data were collected.

RESULTS

Both Braak and PPAD9 stages were inversely correlated with Aβ42 levels, whereas CERAD stage showed no significant correlations. Cerebral amyloid angiopathy correlated positively with T-tau and T-tau/Aβ42 ratio, and inversely with Aβ42 levels, but the group showed a very heterogeneous extent of cerebral amyloid angiopathy.

CONCLUSIONS

The burden of concomitant Alzheimer pathology correlates with CSF Aβ42 but not with T-tau levels in cases with neuropathologically defined DLB.