Science News: Clinical Relevance of Distinguishing Autoimmune Nodopathies From CIDP: Longitudinal Assessment in a Large Cohort

Submitted by: Pritikanta Paul, MD
Edited by: Miliva Pleitez, MD

Citation: Broers MC, Wieske L, Erdag E, et al. Clinical relevance of distinguishing autoimmune nodopathies from CIDP: longitudinal assessment in a large cohort. Journal of Neurology, Neurosurgery & Psychiatry 2024;95:52-60.

Summary: Patients with autoimmune nodopathy (AN) typically have specific clinical features and may not respond well to initial treatment with intravenous immunoglobulin (IVIg). However, there is limited documentation on investigating serial antibody titers in correlation with treatment response over the disease course.

This prospective study aimed to assess the treatment response in patients with AN initially diagnosed as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Antibody titers for neurofascin-155 (NF155), contactin-1 (CNTN1), and contactin-associated protein 1 (CASPR1) were measured in CIDP patients. Among 401 patients, 21 were identified with AN. The study's findings align with previously reported prevalence rates for anti-NF155 (3% vs 1–25%), anti-CNTN1 (2% vs 0.7–7%), and anti-CASPR1 (2% vs 0.2–3%) antibodies.

The study observed stable or increased antibody titers in most patients treated with IVIg. Patients undergoing plasmapheresis, corticosteroids, rituximab^®, or a combination tended to experience a decrease in antibody titers. Notably, stopping immunomodulatory therapy led to clinical deterioration in four patients, accompanied by the reappearance of antibodies or an increased antibody titer in three cases supporting their pathogenic role. All four patients demonstrated clinical improvement upon resuming treatment. The authors concluded that monitoring disease activity using antibodies against paranodal proteins can be beneficial, particularly when contemplating treatment withdrawal. Limitations of the study include diverse treatment regimens among patients, complicating the assessment of treatment efficacy.

Comments: This study shows that patients with AN treated with plasma exchange, corticosteroids, or rituximab^® often reduce antibody levels, but stopping therapy may cause clinical decline and antibody reappearance. This highlights the potential of using antibodies against nodal/paranodal proteins to monitor disease activity during treatment withdrawal. Further research is needed to compare rituximab's effects with non-B-cell depleting agents. A vast majority of AANEM audience are care providers for patients with CIDP and autoimmune nodopathy and this study provides updated knowledge as well as directions for future research.