This study aims analyze the transcriptome to identify predictive biomarkers of IVIG in CIDP patients. 25 patients with a diagnosis of CIDP according to European criteria, naïve of treatment, will be included and followed for 1 year. Clinical assessment (RT-MRC ; Martin vigorimeter, RT-mISS,R-ODS,TW25, 9hole-peg test) will be performed at baseline and at 3, 6 and 12 months after the first IVIG course. Responder/No responder status will be defined at 3 month and confirmed at 12 months. Blood samples will be collected before the IVIG course at baseline, and at 2months and 6 months. At the end of the first IVIG course a blood sample will be collected to assess early changes of transcriptome. The CIDP diagnosis and responder/no responder status will be confirmed by an independent committee. The transcriptome of the patients will be individually analyzed and compared regarding Responder/Non responder status to a control groups of 20 healthy subjects

Inclusion Criteria:

• chronic inflammatory demyelinating polyradiculoneuropathy (according to european criterions)
• first line of treatment
• treatment with intravenous immunoglobulin required
• healthy subjects matched for age and gender

Exclusion Criteria:

For CIDP patients

• uncontrolled diabetes, monoclonal spike with anti-ganglioside activity, anti myelin-associated glycoprotein antibodies, HIV infection, HBV infection, HCV infection, connective tissue disease, hemopathy, evolutive disease)

For healthy subjects:

any chronic or autoimmune disease

For all subjets viral or bacterial infection in the last 30 days chemotherapy in the last 5 years immunosuppressive therapy

patients with chronic inflammatory demyelinating polyradiculoneuropathy. Transcriptome, metabolome and proteome analysis compared with those of healthy subjects