SERUM AND CSF LEVELS OF SOLUBLE INTERCELLULAR-ADHESION MOLECULE-1 (ICAM-1) IN INFLAMMATORY NEUROLOGIC DISEASES

Intercellular adhesion molecule-1 (ICAM-1), a cell surface receptor im portant for cellular interactions in immune responses, especially leuk ocyte trafficking into inflamed tissue, is released in a soluble form (sICAM-1) into.the extracellular space. In this study, we measured sIC AM-1 in paired serum and CSF samples from patients with inflammatory d iseases of the nervous system (IND) and calculated a sICAM-1 index as a measure of the intrathecal release of ICAM-1. In comparison with non inflammatory neurologic disease (NIND) controls, we found increased sI CAM-1 index levels in viral meningoencephalitis, bacterial meningitis and, to a lesser degree, multiple sclerosis but not in Guillain-Barre syndrome. Serial examination of viral meningoencephalitis patients in most cases showed a decrease of sICAM-1 index in parallel with falling cell counts and clinical improvement. Except for those in bacterial m eningitis, sICAM-1 serum levels of IND patients were not significantly different from those of NIND controls. The increased intrathecal rele ase of sICAM-1 in viral meningoencephalitis and bacterial meningitis m ost likely reflects activation of macrophages and lymphocytes and prov ides evidence for a strong local immune response that itself, in addit ion to the infectious agent, may damage nervous tissue.