CIDP is considered a treatable form of autoimmune neuropathy, and therefore a variety of immunomodulatory and immunosuppressive agents have been studied for its treatment.
Several controlled and retrospective studies as well as a few randomized trials have confirmed the efficacy of current first-line treatments: corticosteroids, IVIG, and PLEX [131-133]. Approximately, 50-70% of patients with CIDP respond to one of these treatments, with another 50% of the remainder responding to one of the other therapies [78, 134].
Steroids are the oldest treatment used for CIDP. The mechanism of action of steroids is multimodal and includes decrease in circulating lymphocytes, inflammatory cytokines, macrophage activation, and lymphocyte transmigration. A 3-month, randomized, placebo-controlled trial showed the efficacy of high-dose prednisone (120 mg) on alternate days in 28 CIDP patients . A clinical response to steroid treatment occurs between 2 weeks and several months with an average of about 8 weeks [91, 121]. Although oral steroids are effective, daily dosing is commonly poorly tolerated due to multiple side effects (osteoporosis, weight gain, glycemic control, stomach irritation). As a result, pulse treatments with intravenous methyl- prednisolone or oral dexamethasone have been investigated as an alternative approach. When the efficacy of dexamethasone 40 mg daily for 4 days a month was compared to prednisolone at 60 mg in a double-blind, randomized, controlled trial, remission occurred in about 40% of patients at both arms at 12 months . The median time to remission was however shorter in the dexamethasone (20 weeks) versus prednisone group (39 weeks). Another retrospective study evaluated intravenous methylprednisolone, loading dose of 1 g/day for 3-5 days followed 1 g/week for 4-8 weeks, and then a slow taper over a period of 2 months to 2 years . There was favorable response as assessed by remission rate and improved disability score, in 13 out of 16 patients at 6-month follow-up, and IV methylprednisolone regimen was equal in efficacy to IVIG and oral prednisolone arms in that study. There were fewer steroid-related side effects in the IV methylprednisolone than the prednisone arm.