Long-term effects of intravenous immunoglobulin in CIDP.

ABSTRACT

OBJECTIVE: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired demyelinating disease of the peripheral nervous system characterized by muscle weakness, areflexia or hyporeflexia, and sensory disturbances. Although short-term efficacy of intravenous immunoglobulin (IVIg) has been demonstrated in randomized-controlled trials, the data pertaining to long-term outcome in CIDP are limited. Consequently, the aim of the present study was to assess the long-term effects of IVIg on neurophysiological parameters in CIDP. METHODS: Neurophysiological records from 11 CIDP patients, treated with IVIg for 12 months, were reviewed. Nerve conduction studies were assessed at baseline, 1-year, and last follow-up. RESULTS: There was a significant reduction in the frequency of conduction blocks (pre-treatment nerve segments affected 61%; last follow-up 39%, P<0.01) and a reduction in ongoing axonal loss (pre-treatment regions with spontaneous activity, 47%; post-treatment 29%, P<0.01) with IVIg treatment. Further, there was significant improvement in sensory nerve conduction studies with IVIg treatment (sensory amplitudes reduced pre-treatment, 90% nerves tested; post-treatment, 62%, P<0.01). CONCLUSIONS: The present study suggests that long-term IVIg maintenance therapy improves neurophysiological parameters in CIDP. However, CIDP patients remain IVIg dependent and new conduction blocks may develop. SIGNIFICANCE: The present study suggests that long-term IVIg maintenance therapy improves neurophysiological parameters in CIDP, possibly by reducing the immune response and thereby fostering nerve healing.