Hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D): II--A review of histopathological aspects.

[hereditary cerebral hemorrhage with amyloidosis]

Cerebral amyloid-beta (A beta ) angiopathy is the histopathological hallmark of hereditary cerebral hemorrhage with amyloidosis (Dutch ) (HCHWA-D ). A beta deposits are found mainly in the cerebral and cerebellar meningocortical blood vessels and as plaques throughout the cerebrocortical gray matter . A beta deposition in arteries and arterioles starts at the junction of media and adventitia and proceeds to involve the media causing degeneration of the vascular smooth muscle cells . Cerebrocortical arterioles often show one or two layers of radial A beta around a layer of homogenous A beta that replaces the media . Degenerating neurites , reactive astrocytes and microglial cells may surround cerebrocortical angiopathic arterioles and capillaries , probably in reaction to invasion of the perivascular neuropil by A beta fibrils . Furthermore , clusters of coarse extracellular matrix deposits may be found near A beta -laden cerebrocortical arterioles . The amyloid-associated proteins , cystatin C , and beta PP colocalize diffusely with Dutch vascular A beta , whereas HLA-DR immunoreactivity is found only in the periphery of the diseased vessel wall . The latter phenomenon may be related to the presence of perivascular cells . Angiopathic blood vessels frequently show structural changes . The relation of the described pathology to the development of hemorrhage , infarction and leukoencephalopathy needs further elucidation .