Expression of P‐selectin and intercellular adhesion molecule‐1 in human brain after focal infarction or cardiac arrest

Data from experimental studies indicate that acute inflammation contributes to ischaemic brain damage. Tethering of neutrophils to brain endothelium is mediated by selectins, and subsequent adhesion and migration by endothelial intercellular adhesion molecule-1 (ICAM-1) and neutrophil CD18. In experimental studies of ischaemia-reperfusion injury, brain damage has been ameliorated by administration of antibodies to these adhesion molecules. We studied the expression of P-selectin and ICAM-1 in sections of brain from patients who had experienced cardiac arrest or focal brain infarction, and who died 3.5 h to 9 days later. Endothelial immunopositivity for both adhesion molecules was maximal at about 2-3 days then declined. Between 1 day and 3 days, P-selectin was also detected on platelets in blood vessels within infarcted tissue. Within infarcts, but not sections of brain from cardiac arrest patients, P-selectin and ICAM-1 were again detectable at 1 week, when hyperplastic endothelial cells were labelled in capillaries in and immediately adjacent to the infarcted tissue. The finding that P-selectin and ICAM-1 are upregulated within focally infarcted brain tissue supports the concept that blocking neutrophil adhesion may be of benefit in treating atherothrombotic strokes in man.