The role of soluble intercellular adhesion molecules in neurodegenerative disorders

Immunological disturbances have been implicated in the pathogenesis of some neurodegenerative disorders like Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS). Adhesion molecules are markers of activated endothelial cells upregulated by action of cytokines.

To investigate the activation or not of the vascular cells in AD and ALS, serum soluble intercellular adhesion molecule-1 (ICAM-1) and soluble E-selectin were evaluated (enzyme-like immunosorbent assay, ELISA) in 22 patients with Alzheimer's disease (AD), 20 patients with amyotrophic lateral sclerosis (ALS), 34 patients with non-inflammatory neurological diseases (NIND) and 15 control subjects.

Patients with AD had higher s-ICAM-1 levels compared to NIND patients and control subjects (p<0.0027 and p<0.04, respectively). Patients with ALS had not higher s-ICAM-1 levels compared to NIND patients and control subjects (p<0.21 and p<0.31, respectively). Soluble-E-selectin levels in AD and ALS patients were not statistically different compared to NIND patients and controls (p<0.4, p<0.9 and p<0.3, p<0.19, respectively).

The presence of high s-ICAM values may be related to immunological processes involved in pathogenetic mechanisms of AD. The not statistically significant values of s-E selectin, a glycoprotein considered an exclusive marker of endothelial activation, seem to suggest the neural rather than the endothelial s-ICAM origin in patients with AD. The low values of s-ICAM-1 and sE-selectin in the serum of ALS patients do not exclude the presence of an unconventional immunological abnormality in this disorder.