Background: Little is known about long term prognosis and course after immune treatments in chronic inflammatory demyelinating polyneuropathy (CIDP).

Objective: To study long term outcomes and prognostic factors in patients with CIDP.

Methods: Clinical and electrophysiological findings, responses to immune modulating treatments, and outcomes five years after the start of treatment were reviewed in 38 CIDP patients.

Results: Patients were treated with corticosteroids (89%), immunoglobulin infusion (45%), or plasmapheresis (34%), and 58% received combined therapy. Five years after treatment was begun, 10 (26%) of the patients had complete remission (lasting >2 years with normal nerve conduction studies), and 23 (61%) had partial remission (able to walk) with (26%) or without (34%) immune treatments. The remaining five patients (13%) still had severe disability (unable to walk) or treatment dependent relapses. Patients with complete remission more often had subacute onset, symmetrical symptoms, good response to initial corticosteroid treatment, and nerve conduction abnormalities predominant in the distal nerve terminals. In contrast, insidious onset, asymmetrical symptoms, and electrophysiological evidence of demyelination in the intermediate nerve segments were associated with refractoriness to treatment or treatment dependent relapse.

Conclusions: The long term prognosis of CIDP patients was generally favourable, but 39% of patients still required immune treatments and 13% had severe disabilities. Mode of onset, distribution of symptoms, and electrophysiological characteristics may be prognostic factors for predicting a favourable outcome.