Response to therapy in patients with chronic inflammatory demyelinating polyradiculoneuropathy: An observational study

Abstract

Background & Objective: The existing practice in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is to initiate therapy with steroids, intravenous immune globulin (IVIg), or plasma exchange (PLEX) followed by period of immunosuppression. The objective of this study is to assess disability outcomes at 6 months after starting therapy. Methods: Patients who were diagnosed as having CIDP from the Army Hospital of Research and Referral, Delhi; who were initiated and maintained on therapy by treating neurologists with a six month follow up were included in this study. They were retrospectively divided into three groups based on initial therapy received. The primary outcome was comparison of the Inflammatory Neuropathy Cause and Treatment (INCAT) group overall disability sum score (INCAT-ODSS) at 6 months. Secondary outcomes were difference in score at 1 and 3 months, proportion with at least 20% response at 3 and 6 months (“responders”) and proportion who needed “rescue” therapy during the 6 months. Results: Sixty patients (26 retrospective, 34 prospective) were included in this study. They were treated with IVIg (33), steroid (19) and PLEX (8). Baseline INCAT-ODSS score (±SD) was 7.2(2.2), 7.2(1.5) and 7.5(1.9) respectively. All received some form of oral immune suppression during follow up. Twenty one (35%) needed additional rescue therapy. There was an overall significant reduction in the mean INCAT-ODSS disability score from 7.2 to 3.1 (Mean difference 4.2; CI 3.6-4.8); p<0.01). Nearly 88% of patients (51/58) showed at least 20% improvement from baseline. Two were lost to follow up (1 IVIg, 1 steroid). There was no difference in the ODSS at 6 months [2.9(2.4), 3.5(2.7) and 2.7(1.3)] respectively. No difference in ODSS at 1 and 3 months. Proportion of responders at 6 months and proportion who needed rescue therapy were also similar. Conclusion: Irrespective of initial therapy and maintenance oral immunosuppression used, the overall disability reduction in treatment with IVIg, steroid or PLEX is significant; however the three modalities are comparable in terms of disability reduction at 6 months. At least a third may need additional rescue therapy.