Autopsy of a multiple lobar hemorrhage case with amyloid-β-related angiitis

A 92-year-old man died of multiple lobar hemorrhage with amyloid-β protein (Aβ)-related angiitis (ABRA) with an unusual pathological appearance. Although he had shown relatively rapid progressive dementia, starting 1 year before death, there was no detailed clinical investigation, and no immunosuppressive or anticoagulant therapy, because of his advanced age. The autopsy showed two lobar hemorrhagic lesions in the right parietal lobe and temporal lobes. Microscopically, almost all the brain's blood vessels showed cerebral amyloid angiopathy with many foci of transmural vasculitis. Infiltrating cells were predominantly CD8-positive T-lymphocytes, but we observed no granulomatous inflammation with appearance of multinucleated giant cells. We found fibrinoid necrosis in some blood vessels and disruption of these blood vessels in the arachnoid space–cerebral cortex junction in the hemorrhagic lesion at the temporal lobe. We also observed an unusual, neutrophil-predominant, abscess-like vasculitis in the subarachnoid space; almost all such unusual vasculitides were located at a short distance from the two lobar hemorrhagic lesions. Serum anti-neutrophil cytoplasmic myeloperoxidase and proteinase-3 antibodies were negative, and the genotype of the apolipoprotein E (ApoE) gene (ApoE) was ε2/ε3. Although we did not observe some of ABRA's typical histopathological findings, transmural and vascular destructive inflammation with Aβ deposition was consistent with ABRA. Vulnerability of blood vessels to fibrinoid necrosis might be associated with disruption of the relevant blood vessels, leading to lobar hemorrhage. ABRA exhibits various clinical and histopathological findings, depending on the patient's age, immune function status, treatment, and ApoE genotype. This is the first case and the oldest (92 years old) autopsy of ABRA associated with ApoE-ε2/ε3 genotype.