Background: Hereditary cerebral hemorrhage with amyloidosis (Dutch) (HCHWA-D) and Alzheimer's disease (AD) have certain clinical and histopathologic features in common; both are characterized by cerebral amyloid beta deposits. Extracellular matrix (ECM) components have been demonstrated in plaques and in vascular amyloid of AD, suggesting a causative relation.
Experimental design: We studied the immunohistochemical expression of the ECM components collagen type I, III, and IV, heparan sulfate proteoglycan (HSPG), laminin, and fibronectin in cortical tissue of six HCHWA-D patients, two AD patients, and five controls.
Results: The vasculature of control patients and the noncongophilic vessels in HCHWA-D and AD patients stained for all ECM components, with the exception of collagen type I in part of the capillaries. The media of normal larger vessels stained for collagen type I and III and fibronectin; a similar pattern was found in the vascular amyloid in HCHWA-D and AD patients. The plaques in HCHWA-D and AD reacted for HSPG and weakly for collagen III and IV and laminin. Furthermore, with the exception of anti-collagen type I, all anti-ECM Ab decorated coarse deposits clustered in the vicinity of thick-walled, amyloid-laden vessels in HCHWA-D patients; these deposits were not spatially related to amyloid beta-positive plaques.
Conclusions: This study demonstrates the presence of ECM components in the main pathologic features of HCHWA-D and as perivascular deposits. The observed distribution of matrix molecules is partly different from AD. The ECM may well be essential for the evolvement of the pathology of HCHWA-D.