Giant multinucleated macrophages occur in acute spinal cord injury

Using a cell-isolation and -culture procedure specific for macrophages, we report the existence of giant (more than 50 mum diameter), multinucleated m acrophages within an acute, 5-day-old adult rat spinal cord injury. The siz e and multinuclearity of these isolated giant cells was confirmed using tra nsmission electron microscopy. Giant macrophages are markers for longterm i nfection, disease, and chronic injury in other soft tissues and are unexpec ted in the acute inflammatory stage of central nervous system injury. To ou r knowledge, this descriptive report is the first confirming the existence of giant macrophages in any injured nervous tissue, with additional data su ggesting some of these cells to be multinucleated.