Fas-mediated T-cell apoptosis is impaired in patients with chronic inflammatory demyelinating polyneuropathy.

The Fas death receptor is expressed by activated lymphocytes and is involved in switching-off the immune response. Its inherited defects cause auto-immune lymphoproliferative syndrome. Impaired Fas function may also play a role in other auto-immune diseases, such as multiple sclerosis and type 1 diabetes mellitus. The aim of this work was to evaluate Fas function in T cells from patients with chronic inflammatory demyelinating polyneuropathy (CIDP). We evaluated Fas-induced apoptosis in T-cell lines from 27 patients with CIDP, 12 patients with acute inflammatory demyelinating polyneuropathy (AIDP), and 110 controls. CIDP patients displayed lower Fas function than both AIDP patients and controls, whereas no statistically significant difference was found between AIDP patients and controls. Moreover, Fas function was lower in CIDP patients with progressive course than in those with relapsing-remitting course and lower in CIDP patients with axonal damage than in those with pure demyelination. These data suggest that defective Fas function favours CIDP development and aggressive evolution.