IgM responses to NF155 or NF186 were detected in 5 of 59 (8%) patients with autoimmune neuropathy: 2 with CIDP (cases 1 and 5), 1 with acute inflammatory demyelinating polyneuropathy (case 6), 1 with acute motor axonal neuropathy (case 7), and 1 with features of CIDP and GBS (case 8). This evidence concerns the gene CD40LG and chronic inflammatory demyelinating polyradiculoneuropathy.