[Application of immunohistochemistry to the dead brain]

To evaluate the usefulness of immunohistochemistry for studies of brain tissues taken from patients with a clinically established diagnosis of brain death, we examined 8 brains that had been removed and fixed in formalin between 13 h and 5 days after diagnosis of brain death (Table). As a control we also examined the brain of a patient who had suffered extensive infarction with a 28-day clinical course and died of pneumonia. Routine examination of each of the brains revealed old to recent tissue necrosis associated with macrophages, capillary proliferation and/or astrocytic gliosis. The streptavidin-biotin immunoperoxidase method was applied to the materials using four monoclonal antibodies: antiglial fibrillary acidic protein (GFAP), anti-vimentin (vimentin), LN-1 and LN-3. GFAP was stained in reactive astrocytes even 5 days after diagnosis of brain death (Fig. 3, 7). Vimentin (Fig. 2, 4) was stained in reactive astrocytes until 3 days after diagnosis of brain death. LN-1 (Fig. 5) produced positive staining in resting microglias until 3 days after diagnosis of brain death. LN-3 (Fig. 1, 6, 8), which detects human leukocyte antigen-DR, stained reactive microglias and macrophages even 5 days after diagnosis of brain death. From our findings, it is considered that immunohistochemical examination is useful even in brains from patients diagnosed as brain-dead.