Prevalence and Characteristic Features of Anti-Human Neurofascin 155 Antibody-Associated Chronic Inflammatory Demyelinating Polyradiculoneuropathy (P7.081)

OBJECTIVE: To develop anti-human neurofascin 155 (NF155) antibody assays, and clarify prevalence and features of anti-NF155 antibody-associated chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). BACKGROUND: We reported that patients with combined central and peripheral demyelination had antibodies against rat NF155, which acts as an adhesion molecule between axons and myelin-forming cells, while other reported occurrence of the antibody in a fraction of multiple sclerosis (MS) and CIDP patients. DESIGN/METHODS: Sera from 43 consecutive patients diagnosed by the European Federation of Neurological Societies/Peripheral Nerve Society task force CIDP diagnostic criteria at Kyushu University Hospital between 2004 and 2014 were enrolled together with 17 MS patients, and 10 healthy controls (HCs). Anti-human NF155-antibodies were measured by ELISA using a human recombinant NF155 protein and a cell-based assay (CBA) using HEK293 cells expressing human recombinant NF155 protein. Additional two anti-NF155 antibody-positive CIDP cases diagnosed in other clinics were also included for clinical analyses. RESULTS: Positivity rates for anti-human NF155 antibodies by both ELISA and CBA in patients with CIDP and MS, and HCs were 20.9[percnt] (9/43), 0[percnt] (0/17) and 0[percnt] (0/10), respectively. All eleven patients with anti-NF155 antibodies had predominantly distal sensorimotor polyneuropathy with distal muscle atrophy in 9/11, while the age of onset was 24.3±10.9 (mean±SD) (range; 13 to 50) years. The nerve conduction study revealed severe demyelinating patterns affecting both sensory and motor nerves with some axonal damages in all. CSF protein levels were 266±119 mg/dl while 7/7 showed marked spinal root hypertrophy on MRI. CNS involvement in MRI and/or evoked potentials was seen in 4 while kinetic tremor was present in 5. Plasma exchange was effective in 3/4. CONCLUSIONS: About 20[percnt] of CIDP patients harbor anti-NF155 antibodies and have characteristic features, such as younger ages at onset, distal muscle atrophy, severe sensory and motor nerve demyelination, root hypertrophy and CNS involvement. Disclosure: Dr. Ogata has nothing to disclose. Dr. Matsuse has nothing to disclose. Dr. Yamasaki has received research support from Bayer Schering Pharma, Biogen Idec, Novartis, and Mitsubishi Tanabe Pharma. Dr. Kawamura has nothing to disclose. Dr. Matsushita has received personal compensation for activities with Bayer Schering Pharma, Pfizer Inc., and Mitsubishi Tanabe Pharma Corporation as a speaker. Dr. Kira has received personal compensation for activities with Biogen Idec.