Plasma β-amyloid levels in cerebral amyloid angiopathy-associated hemorrhagic stroke.

BACKGROUND

Cerebral amyloid angiopathy (CAA) is one of the main causes of intracerebral hemorrhage (ICH) in the elderly.

OBJECTIVE

To analyze β-amyloid (Aβ) species in plasma in order to uncover biological markers that may contribute to improve the diagnosis of CAA in life.

METHODS

We determined the level of Aβ(1-40), Aβ(N-40), Aβ(1-42) and Aβ(N-42) in plasma of CAA-related ICH patients (n = 29) and healthy controls (n = 21) using xMAP® technology. Hemorrhages were identified and classified using a CT scan and brain MRI. Patients were clinically classified as probable or possible CAA according to the Boston criteria.

RESULTS

We found that plasma full-length Aβ(1-42) and truncated fragments Aβ(N-42) were higher in probable CAA patients than in controls (p < 0.001 and p = 0.046, respectively), and full-length Aβ(1-40) was selectively elevated in probable CAA compared to possible cases (p = 0.015) and controls (p = 0.005). In addition, plasma Aβ(N-42) levels were also higher in patients that presented multiple lobar macrohemorrhages compared to patients that had one symptomatic hemorrhagic event (p = 0.022), indicating that a certain degree of CAA severity is necessary to show increased Aβ fragments in peripheral circulation.

CONCLUSION

Our results suggest that specific Aβ fragments in plasma might be considered as potential biomarkers for the diagnosis of CAA.