Subcutaneous Immunoglobulin in De-novo CIDP (SIDEC)

Inclusion Criteria: * Fulfilling EFNS/PNS criteria for definite, probable or pure motor CIDP. * No previous treatment with IVIG or SCIG. * Age ≥ 18. * ODSS ≥ 2 - either (arm/leg): 1/1, 2/0 or 0/2 at the time of inclusion. Clinical criteria for typical CIDP * Chronically progressive, stepwise, or recurrent symmetric proximal and distal weakness and sensory dysfunction of all extremities, developing over at least 2 months; cranial nerves may be affected. * Absent or reduced tendon reflexes in all extremities. Criteria for pure motor CIDP • Pure motor affection; otherwise as for typical CIDP. Electrophysiological criteria for CIDP 1. Motor distal latency prolongation ≥50% above ULN in two nerves (excluding median neuropathy at the wrist from carpal tunnel syndrome), or 2. Reduction of motor conduction velocity ≥30% below LLN in two nerves, or 3. Prolongation of F-wave latency ≥30% above ULN in two nerves (≥50% if amplitude of distal negative peak CMAP ≤80% of LLN values), or 4. Absence of F-waves in two nerves of these nerves have distal negative peak CMAP amplitudes ≥20% of LLN + ≥1 other demyelinating parameter in ≥1 other nerve, or 5. Partial motor conduction block: ≥50% amplitude reduction of the proximal negative peak CMAP relative to distal, if distal negative peak CMAP \>20% of LLN, in two nerves, or in one nerve + ≥1 other demyelinating parameter in ≥1 other nerve, or 6. Abnormal dispersion (≥30% duration increase between the proximal and distal negative peak CMAP) in ≥2 nerves, or 7. Distal CMAP duration (interval between onset of the first negative peak an return to baseline of the last negative peak) increase in ≥1 nerve (median ≥6.6 ms, ulnar ≥6.7 ms, peroneal ≥7.6 ms, tibial ≥8.8 ms) + ≥1 other demyelinating parameter in ≥1 other nerve Electrophysiological criteria for probable CIDP (a) ≥30% amplitude reduction of the proximal negative peak CMAP relative to distal, excluding the posterior tibial nerve, if distal negative peak CMAP ≥20% of LLN, in two nerves, or in one nerve + ≥1 other demyelinating parameter in ≥1 other nerve Exclusion Criteria: * Other causes of neuropathy * Increased risk of thromboembolism * Pregnancy (Plasma HCG is tested at inclusion in all fertile women) * Breast feeding * Malignancy * Severe medical disease * Other immune modulating treatment than low dose steroid (prednisolon \< 25 mg daily) within the last 6 months prior to inclusion * Hepatitis B or C or HIV infection (screening at inclusion) * Known IgA deficiency * Known allergy to consents in PRIVIGEN or HIZENTRA * Body weight \> 120 kg After treatment initiation: * Pregnancy * Serious medical disease that affects treatment or examinations * Non-compliance to treatment * Initiation of other immune modulating therapy * Unacceptable side effects * Withdrawal of consent to participate (drop-out)