CIDP: Mimics and Chameleons
Four recent Cochrane reviews have evaluated the efficacy of treatments in CIDP, which include the three standard therapies. The evidence for the efficacy of corticosteroids is based on two randomised controlled trials, with patients treated with corticosteroids having improved neuropathy impairment scores after 12 weeks compared to patients randomised to no treatment. There was no statistical difference in remission rates at 1 year in people treated with standard dose oral prednisolone compared to monthly high-dose oral dexamethasone. Nevertheless, oral corticosteroids are typically employed as first-line treatment in cases of newly diagnosed CIDP. The quality of the evidence for the efficacy for intravenous immunoglobulin and plasma exchange is moderate to high, with plasma exchange providing significant short-term improvements in disability, clinical impairment and motor nerve conduction velocities, although there may be rapid deterioration postexchange. The evidence for intravenous immunoglobulin from the eight published randomised controlled trials confirms that intravenous immunoglobulin improves disability for at least 2–6 weeks compared to placebo, with comparable efficacy to plasma exchange and oral corticosteroids. Only one study (the ICE trial) had long-term follow-up and reported that the benefit of intravenous immunoglobulin on disability persisted for 24, and possibly 48 weeks, compared to placebo. There was no significant difference in the mean disability scores in people treated with intravenous immunoglobulin or plasma exchange at 6 weeks. Similarly, there was no difference in improvement in disability between people treated with prednisolone and intravenous immunoglobulin at 6 weeks. There was no significant difference in the frequency of side effects between the three treatment modalities although a more recent randomised controlled trial found that people treated with a 6-month course of intravenous immunoglobulin were less likely to stop treatment because of inefficacy, intolerance or adverse effects compared to treatment with intravenous methylprednisolone. Intravenous methylprednisolone, however, produced a more sustained remission when stopped, if it were tolerated for the full course.
The Efficacy of Immune-modulatory Therapies in CIDP
Four recent Cochrane reviews have evaluated the efficacy of treatments in CIDP, which include the three standard therapies. The evidence for the efficacy of corticosteroids is based on two randomised controlled trials, with patients treated with corticosteroids having improved neuropathy impairment scores after 12 weeks compared to patients randomised to no treatment. There was no statistical difference in remission rates at 1 year in people treated with standard dose oral prednisolone compared to monthly high-dose oral dexamethasone. Nevertheless, oral corticosteroids are typically employed as first-line treatment in cases of newly diagnosed CIDP. The quality of the evidence for the efficacy for intravenous immunoglobulin and plasma exchange is moderate to high, with plasma exchange providing significant short-term improvements in disability, clinical impairment and motor nerve conduction velocities, although there may be rapid deterioration postexchange. The evidence for intravenous immunoglobulin from the eight published randomised controlled trials confirms that intravenous immunoglobulin improves disability for at least 2–6 weeks compared to placebo, with comparable efficacy to plasma exchange and oral corticosteroids. Only one study (the ICE trial) had long-term follow-up and reported that the benefit of intravenous immunoglobulin on disability persisted for 24, and possibly 48 weeks, compared to placebo. There was no significant difference in the mean disability scores in people treated with intravenous immunoglobulin or plasma exchange at 6 weeks. Similarly, there was no difference in improvement in disability between people treated with prednisolone and intravenous immunoglobulin at 6 weeks. There was no significant difference in the frequency of side effects between the three treatment modalities although a more recent randomised controlled trial found that people treated with a 6-month course of intravenous immunoglobulin were less likely to stop treatment because of inefficacy, intolerance or adverse effects compared to treatment with intravenous methylprednisolone. Intravenous methylprednisolone, however, produced a more sustained remission when stopped, if it were tolerated for the full course.