Long-Term Disability of Chronic Demyelinating Polyradiculoneuropathy Lessened With Early Treatment Initiation

Yusuf Rajabally, MD

A recently published retrospective study using multiple different cohorts of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) showed that initiation of the first treatment within 1 year from disease onset was associated with milder post-treatment disability as well as greater amplitude of treatment responses. All told, time to treatment, disabling comorbidities, and pre-treatment disability were identified as key prognostic factors.

Published in the European Journal of Neurology, the analysis comprised of 144 patients with CIDP from 3 cohorts: a UK cohort, Korean cohort, and combined cohort. For the UK cohort, pre- and post-treatment disability was assessed using the Overall Neuropathy Limitation Scale (ONLS, 0-12), while the Korean cohort used the Inflammatory Neuropathy Cause and Treatment (INCAT, 0-10) score. Post-treatment Inflammatory Rasch-built Overall Disability Scale (I-RODS, 0-100) was available for most patients in both cohorts, allowing I-RODS to be used as a unified outcome measure to analyzed prognostic factors across cohorts.

Led by Yusuf Rajabally, MD, a professor of neurology at the Aston Medical School in France, the study was intended to assess the impact of clinical and therapeutic factors on long-term disability in CIDP. At baseline, main differences between the cohorts were the absence of distal CIDP in the UK cohort (P = .007), a longer delay to the first treatment in the Korean cohort (P = .04), and predominant use of IVIG in the UK and of corticosteroids in Korea as first-line treatment (P <.001).

Regarding treatment timing, those in the UK cohort who received their first treatment within 1 year of onset demonstrated better ONLS at follow-up than those who were treated after 1 year (P = .0018). In both Korean and UK patients, initiating treatment within 1 year was associated with improved outcomes, including better follow-up INCAT scores (P = .0026 in Korean patients), enhanced I-RODS scores (P = .00064), and greater improvements in ONLS and INCAT scores (P = 4.3 x 10^-5 and P = .012, respectively).

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"Our study provides insights into optimizing routine care to improve outcomes in CIDP. A timely intervention has been emphasized in various neuroimmunological disorders," Rajabelly et al wrote. "From a pathological perspective, in CIDP patients with active disease, once macrophages strip the myelin sheath, risk of secondary axonal degeneration follows. Axonal damage can have a greater impact on disability than demyelination itself. Early treatment, in this context, may help control neural inflammation before irreversible axonal damage accumulates. Additionally, it may halt the propagation of autoimmune responses by preventing epitope spreading."

The timing of treatment significantly influenced response rates and muscle strength outcomes. While no differences were observed between patients treated within or after 1 year using the 1-point MCID cut-off for INCAT and ONLS scales (Korean cohort: P = 0.079; UK cohort: P = 0.081), an at least 2-point improvement defined significantly more responders in both cohorts when treated within 1 year (Korean: P = 0.005; UK: P < 0.001). Similarly, patients treated within 1 year showed better grip strength at follow-up (48 Korean and 22 UK subjects, P = 0.014) and greater improvement in MRCSS (63 UK subjects, P = 0.019). Although the association between follow-up MRCSS and treatment timing was not statistically significant (P = 0.12), a clear difference emerged among 49 subjects with typical CIDP (P = 0.0092).

All told, shorter time to treatment, absence of comorbidities, younger age, and IVIG as first-line therapy were linked to better prognosis in univariate analysis, but only time to treatment and comorbidities remained significant in multiple regression (P = 0.004 and P = 0.020, respectively). In subgroup analyses, results showed that the association between early treatment initiation and better I-RODS outcomes was significant in those aged 60 years or older (P = .002), but not in those who were younger (P = .26), those with variant forms (P = .138), and those with a chronic mode of onset (P = .233).

The study authors wrote, “our subgroup analyses provide additional valuable insights into which patients are most likely to benefit from early treatment initiation. The effect was particularly evident in older subjects, possibly due to reduced capacity for axonal regeneration and reinnervation, or a lower density of myelinated fibers at baseline. The lack of a significant impact of treatment timing in CIDP variants could be due to heterogenous pathophysiology among subtypes, or a type 2 error resulting from the smaller sample size in this group."

REFERENCE
1. Min YG, Jeon J, Kim SM, et al. Determinants of long-term disability in chronic inflammatory demyelinating polyradiculoneuropathy: a multicenter Korea/UK study of 144 patients. European Journal of Neurol. 2025;32(1):e16575. doi:10.1111/ene.16575