Microscopic aspects of macrophage system cells in hemorrhagic stroke in humans

Stroke is an important public health issue because it has high morbidity and mortality rates. In addition, it has one of the highest rates of disability in adults. Recent data show that macrophage system cells, especially microglial cells, are involved both in neuroprotective processes and in the neurotoxicity, depending on the type and extent of the brain damage. In our study, using histology and immunohistochemistry techniques, we evaluated the macrophage-type cell reaction in cerebral hemorrhage. We found that the number of CD68-positive cells increased 7-8 folds per square millimeter of cortical surface in the cerebral parenchyma adjacent to the hemorrhage. We identified a large number of perivascular-activated macrophages, in areas distant to the hemorrhage, showing that individuals with hemorrhagic stroke have profound and extensive alterations of the blood-brain barrier.