Early therapy initiation is crucial in chronic inflammatory demyelinating polyneuropathy: prospective multimodal data...

Diagnosing chronic inflammatory demyelinating polyneuropathy (CIDP) can be challenging, leading to delays in initiating therapy. As disability in CIDP is mainly dependent on axonal damage, the impact of delayed immunotherapy remains unclear. We multimodally investigated the clinical outcomes of patients with early CIDP regarding different treatment strategies and time points.

Patients with CIDP diagnosis within 1 year before study inclusion were systematically selected from the prospective Immune-mediated Neuropathies Biobank (INHIBIT) registry. Clinical and therapeutic data, and findings from nerve conduction study (NCS), and nerve and muscle ultrasound were correlated at inclusion and 12 months later. The patient outcomes were compared between immunotherapies. The effect of timing immunotherapy on clinical outcomes was determined using regression analysis.

In total, 30 patients were included (time from diagnosis to inclusion 22 ± 19 weeks). Low amplitudes of compound muscle potential were significantly associated with pathological spontaneous activity (PSA, r = 0.467) and correlated with the Heckmatt scale (r_Sp = 0.391). All three parameters were significantly associated with higher overall disability sum scores (NCS score r_Sp = 0.581, PSA r = 0.385, Heckmatt scale r_Sp = 0.472). The delays in initiating therapy resulted in progression of axonal damage (r_Sp = 0.467) and disability (R² = 0.200). The combination of first-line therapies led to reduced disability progression (r = 0.773), while second-line therapies resulted in improved overall axonal damage (r = 0.467).

Axonal damage occurs early and is the main cause of clinical disabilities. Prompt initiation of therapy is crucial to prevent axonal damage and thereby disability progression. A comprehensive therapeutic approach, including a combination of first- or second-line therapies, may improve long-term outcomes.