Chronic inflammatory demyelinating polyneuropathy disease activity status: recommendations for clinical research standards and use in clinical practice

Abstract

Defining long-term outcomes in chronic inflammatory demyelinating polyneuropathy (CIDP) has been complicated by varying definitions of treatment response and differing scales measuring impairment or disability. An expert panel was convened to devise a CIDP Disease Activity Status (CDAS) and to classify long-term outcome by applying it to 106 patients with a consensus diagnosis of CIDP. Sixty of these cases were graded blindly by three independent reviewers to assess inter-rater reliability. The mean duration of follow-up was 6.4 years (range, 3 months-23 years). Eleven percent of patients were classified as cured (stable examination and off treatment for ≥5 years), 20% were in remission (stable and off treatment for <5 years), 44% had stable active disease but required ongoing therapy for at least 1 year, 7% were improving after recent initiation of therapy, and 18% had unstable active disease (treatment naïve or treatment refractory). Excellent inter-rater reliability was observed (kappa scores: 0.93-0.97; p < 0.0001). The CDAS is considered a simple and reproducible tool to classify patients with CIDP according to disease activity and treatment status that can be applied easily in practice and potentially to select patients for clinical trials.

Incidence and Natural History of Idiopathic Chronic Inflammatory Demyelinating Polyneuropathy: A Population-Based Study in Iceland

“…This was seen in both non-RR and RR CIDP. Thus, most of them only required brief or no treatment but around a quarter of our patients (26%) did not respond to therapy, which is similar to the findings of previous studies [5,6] .…”

“…An international study reported an average follow-up time of 6.4 years for 106 cases, with 11% cured, 20% in remission, 44% with stable active disease, 7% showing improvements and 18% with unstable active disease at the end of follow-up [5] . This compares with 21, 16, 32, 5 and 26%, respectively, in the current study.…”

“…Treatment response and disease activity at the end of the follow-up period were determined using the modified CIDP disease activity status (CDAS) [5] . The study was approved by Icelandic National Bioethics Committee and Data Protection Authority.…”

Incidence and Prevalence of Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A Systematic Review and Meta-Analysis

“…In clinical practice, it may be difficult to discriminate between patients with active disease and patients with residual nerve damage but inactive disease. The CIDP Disease Activity Status tool has been developed to define long-term outcomes in CIDP and to classify patients as cured if they have a stable neurological examination (either normal or abnormal) and are off all treatment for 5 or more years [50]. However, the concept of being cured in CIDP is questionable, because patients may relapse even years after the disease became inactive [50,51].…”

“…The CIDP Disease Activity Status tool has been developed to define long-term outcomes in CIDP and to classify patients as cured if they have a stable neurological examination (either normal or abnormal) and are off all treatment for 5 or more years [50]. However, the concept of being cured in CIDP is questionable, because patients may relapse even years after the disease became inactive [50,51]. Most studies in our meta-analysis did not define the disease activity status or whether "cured" patients were excluded and this could have influenced the reported prevalence of CIDP.…”