Inclusion Criteria:  Diagnosis of Guillain-Barré Syndrome according to the diagnostic criteria proposed by Doorn et al. (Clinical features, pathogenesis, and treatment of Guillain-Barré syndrome, Lancet neurology 2008) age 18 years or above  Exclusion Criteria:  Clinical or laboratory (C-reactive protein 20 mg/l or above, or evidence of nitrite-positive urinary tract infection) evidence of manifest systemic infection Intake of angiotensin converting enzyme inhibitor within1 weeks before first treatment Other contraindications against immunoadsorption or plasma exchange