This study is designed as an explorative study aiming at exploring safety and efficacy of immunoadsorption (IA) in patients with Chronic Inflammatory Demyelinating Poly-neuropathy (CIDP) compared to intravenous immunoglobulins (IVIg) and methyl-prednisolone (MP). For this purpose, approximately 140 patients with CIDP will be included within the framework of the German multicenter network Kompetenznetz Peripherer Nerv (KKPNS). The study will be purely observational. IA will be performed as an escalation therapy, i.e., in patients who did not respond to IVIg and/or MP treatment. Patients will be included in the study during ongoing IVIg or MP treatment and switched to IA during the 18-month observation period in case of an insufficient response. IA will be performed according to the therapeutic scheme of each participating center. A non-mandatory recommendation for number of sessions, treatment volumes, and frequency will be given (see below). Six-month follow-up visits including collection of standardized clini-cal data will be performed.