Newer therapeutic options for chronic inflammatory demyelinating polyradiculoneuropathy

Abstract

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated disorder with variable symptoms and severity that can be difficult to diagnose. Intravenous immunoglobulin, plasma exchange and corticosteroids have all been proven to be beneficial in randomized controlled trials, although the proof for corticosteroids is less clear. Although these treatments are likely to be similar in efficacy, they differ in terms of their cost, availability and adverse effects. These characteristics should be taken into account when deciding which treatment to offer a patient. If there is no response to the first treatment option, one of the other treatments should be tried. Patients with a pure motor CIDP may deteriorate after corticosteroid treatment. Some patients do not respond or become refractory or intolerant to these conventional treatments. Those who become unresponsive to therapy should be checked again for the appearance of a monoclonal protein or other signs of malignancy. Over the years, small non-randomized studies have reported possible beneficial effects of various immunosuppressive agents. A Cochrane review concluded that currently there is insufficient evidence to decide whether these immunosuppressive drugs are beneficial in CIDP. When giving immunosuppressive drugs, one should be aware that some might even cause demyelinating disease. It is difficult to prove beneficial effects of these newer treatments since they have only been used in small groups of patients, who are refractory to other treatments, and often in combination with other treatments. CIDP patients can deteriorate during or after infections or improve spontaneously, making it more difficult to judge treatment efficacy. Various treatments for CIDP are described such as azathioprine, ciclosporin, cyclophosphamide, interferons, methotrexate, mycophenolate mofetil, rituximab and etanercept. An overview of these newer treatments, their mode of action, adverse effects and potential place in the spectrum of treatments for CIDP based on previous reports and their level of evidence is given.