A large number of immunosuppressants (azathioprine, cyclophosphamide, methotrexate, cyclosporine A, mycophenolate mofetil, rituximab) and immunomodulatory drugs (alpha and beta interferon) have been tried for CIDP. Although some of the aforementioned medications are commonly used in CIDP patients as steroid-sparing drugs, none have been shown to be effective in CIDP in randomized, controlled trials . When azathioprine was added to a regimen of alternate-day steroid treatment, the outcome was not different ; on the other hand, azathioprine has been used in the treatment of CIDP patients who also had diabetes in small case series [151, 152]. A double-blinded randomized study did not show efficacy of a weekly dose of oral methotrexate in patients in CIDP who were also on IVIG and prednisone . Interferon B1a was shown not to be effective in a cohort of ten patients with treatment-resistant CIDP in a randomized, double-blind, placebo-controlled study . High-dose cyclophosphamide (200 mg/kg over 4 days) infusion was reported to be effective in a cohort of four CIDP patients who had failed other treatments, with remissions that could last more than 3 years . Cyclosporine has been reported to be effective to sustain remission in a child with CIDP and to reduce the required dose of prednisolone in another . In a retrospective study on eight CIDP patients, neuropathy disability score improved in all eight, and in six of eight, the concomitant medications could be stopped or dose reduced by >50% . On the other hand, another study on 21 CIDP patients suggested efficacy of mycophenolate in only one third of patients . Autologous hematopoietic stem cell transplantation (AHSCT) has been successfully used for treatment-resistant CIDP . In a prospective study, 11 patients with therapy-refractory CIDP underwent AHSCT with a median follow-up time of 28 months. Eight had a drug-free remission at their last followup .
Other treatment modalities are being investigated, including agents affecting B cells, T cells, transmigration molecules, and signal transduction pathways.
Rituximab, which is a monoclonal antibody against CD20 and acts by depleting the precursors of antibody-producing B cells, was used in 13 patients with refractory CIDP, eight of whom had concurrent hematological disease (B cell lymphoma, Waldenstrom macroglobulinemia, and IgM monoclonal gammopathy of unknown significance) . Nine of 13 (7 of 8 with hematological disease) showed improved in that study, with median duration of 2 months from rituximab infusion to a response and mean duration of response of 1 year. In another study, rituximab was used in four patients with anti-CNTN1/NF155-positive, WIG-resistant, CIDP patients . The autoantibody titer diminished in all the patients and three of the four improved clinically.
Alemtuzumab is a monoclonal antibody directed against the CD52, therefore resulting in lymphocytic depletion via apoptosis. In a cohort of seven patients with treatment-resistant CIDP who underwent treatment with alemtuzumab, two had remissions and another two needed a lower dose of IVIG . Fingolimod, a sphingosine-1-phosphate receptor modulator approved for relapsing-remitting multiple sclerosis, is currently under investigation for the treatment of CIDP in a randomized, double-blind, placebo-controlled trial.
Physical therapy and supportive equipment such as canes, walking sticks, walkers, braces, and ankle-foot orthotics may be helpful in assisting CIDP patients in walking and other activities of daily living. Physical therapy may help maintain range of motion and prevent joint contractures. Neuropathic pain, anxiety, depression, and fatigue may need to be treated with symptomatic medications. Exercise can be helpful in combatting fatigue and encouraging endurance.