Immunoadsorption Versus Immunoglobulins for Treatment of Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

• Immunoadsorption (Device): see arm/group description
• Immunoglobulins (Biological): see arm/group description

Primary outcomes

• CIDP Score [15 weeks]: The CIDP Score is a combined score of Inflammatory Cause and Treatment (INCAT) Disability Score, Oxford Muscle Strength Score, and Vibration Score, with each subscore equally weighted.
• Inflammatory Neuropathy Cause and Treatment (INCAT) Disability Score [15 weeks]: Standard clinical score for CIDP, quantifying disability.
• Oxford Muscle Strength Score (Medical Research Council, MRC) [15 weeks]: Standard clinical score for evaluation of muscle strength / paresis. Muscle strength is evaluated on a scale between 0/5 (no movement) and 5/5 (full strength) at 8 pre-defined muscles (one proximal and one distal muscle at each extremity).
• Vibration Score [15 weeks]: Standard clinical score for evaluation of pallesthesia, using a 256 Hz tuning fork. The individual perception threshold for vibration sensations on a scale between 0/8 (no perception) and 8/8 (normal perception) will be determined at 4 predefined spots (processus styloideus radii and malleolus lateralis on each side).

Secondary outcomes

• CIDP Score [1, 7, and 13 weeks]: The CIDP Score is a combined score of Inflammatory Cause and Treatment (INCAT) Disability Score, Oxford Muscle Strength Score, and Vibration Score, with each subscore equally weighted.
• Inflammatory Neuropathy Cause and Treatment (INCAT) Disability Score [1, 7, and 13 weeks]: Standard clinical score for CIDP, quantifying disability.
• Oxford Muscle Strength Score (Medical Research Council, MRC) [16 weeks]: Standard clinical score for evaluation of muscle strength / paresis. Muscle strength is evaluated on a scale between 0/5 (no movement) and 5/5 (full strength) at 8 pre-defined muscles (one proximal and one distal muscle at each extremity).
• Vibration Score [16 weeks]: Standard clinical score for evaluation of pallesthesia, using a 256 Hz tuning fork. The individual perception threshold for vibration sensations on a scale between 0/8 (no perception) and 8/8 (normal perception) will be determined at 4 predefined spots (processus styloideus radii and malleolus lateralis on each side).
• Pain [1, 7, 13, and 15 weeks]: Quantifying pain on a Visual Analog Scale between 0 (no pain) and 10 (maximum pain).
• N20 Latency [15 weeks]: N20 latency of Nervus medianus (both sides) in somatosensory evoked potentials (SEPs).
• P40 Latency [15 weeks]: P40 latency of Nervus tibialis (both sides) in somatosensory evoked potentials (SEPs).
• Nerve Conduction Velocity [15 weeks]: Nerve conduction velocities of clinically affected nerves as measured by electroneurography (ENG).
• Euro Quality of Life 5 Dimension 5 Levels (EQ-5D-5L) [1, 7, 13, and 15 weeks]: Quality of Life Scale
• Immunoglobulin A [1, 7, 13, and 15 weeks]: Immunoglobulin A serum levels
• Immunoglobulin G [1, 7, 13, and 15 weeks]: Immunoglobulin G serum levels
• Immunoglobulin M [1, 7, 13, and 15 weeks]: Immunoglobulin M serum levels
• Interleukin-1 [1, 7, 13, and 15 weeks]: Interleukin-1 serum levels
• Interleukin-6 [1, 7, 13, and 15 weeks]: Interleukin-6 serum levels
• Anti-contactin-1 [1, 7, 13, and 15 weeks]: Anti-contactin-1 serum levels
• Anti-neurofascin155 [1, 7, 13, and 15 weeks]: Anti-neurofascin155 serum levels
• Anti-contactin-associated-protein1 [1, 7, 13, and 15 weeks]: Anti-contactin-associated-protein1 serum levels
• Anti-neurofascin186 [1, 7, 13, and 15 weeks]: Anti-neurofascin186 serum levels
• Anti-neurofascin140 [1, 7, 13, and 15 weeks]: Anti-neurofascin140 serum levels
• Neurofilament Light Chain (NfL) [1, 7, 13, and 15 weeks]: Neurofilament light chain (NfL) serum levels
• Therapeutic Response [15 weeks]: Share of patients with at least 10% improvement in CIDP score compared to baseline.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Diagnosis of possible, probable, or definite CIDP (typical or atypical) according to European Federation of Neurological Societies (EFNS) guidelines
* Disease duration of 3 years or less
* Age 18 years or above
* Previous treatment with methyl-prednisolone and insufficient therapeutic response as judged by the treating physician, or contraindications against methyl-prednisolone, or clinically significant side effects under methyl-prednisolone therapy as judged by the treating physician

Exclusion Criteria:

* Clinical or laboratory evidence of manifest systemic infection, i.e., C-reactive protein (CRP) above 20 mg/l, or evidence of nitrite-positive urinary tract infection
* Intake of angiotensin converting enzyme inhibitor within 1 week before first treatment
* immunoglobulin A deficiency
* Other contraindications against immunoadsorption or intravenous immunoglobulins

• Johannes Dorst, Prof, Principal investigator, University of Ulm