Clinical features and treatment response of anti-Neurofascin 155 antibody-positive neuropathy in neurological Institute of Thailand.

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated neuropathy that typically responds to conventional therapy. However, a subset of patients such as anti-neurofascin-155 (NF155) Ab-positive exhibit unique clinical features and a poor response to conventional therapy.

OBJECTIVES

To characterize the clinical, electrophysiological, pathological, and therapeutic features of Thai patients with anti-NF155 Ab-positive paranodopathy and to compare them with antibody-negative CIDP patients.

METHODS

A retrospective cohort study, anti-NF155 Ab-positive paranodopathy patients were compared to CIDP patients who were negative for all nodal/paranodal antibodies. Clinical data, nerve conduction studies, cerebrospinal fluid (CSF) profiles, sural nerve biopsies, and treatment outcomes were analyzed.

RESULTS

Of 41 CIDP patients tested, 11 (26.8%) were anti-NF155 Ab-positive. These patients had a younger age of onset (median 32.8 years), a higher prevalence of tremor (54.5%) and sensory ataxia (36.4%), and more frequently exhibited a distal-predominant sensorimotor phenotype. All met the EAN/PNS 2021 diagnostic criteria. Nerve biopsies showed mild generalized fiber loss without clear demyelination. Onion bulb formations were not present in anti-NF155 Ab-positive patients. Only 20% responded to IVIg, compared to 92.9% of antibody-negative patients (p = 0.006). Rituximab led to clinical improvement in 83.3% of anti-NF155 Ab-positive patients, with the median onset of response at 102 days.

CONCLUSIONS

Anti-NF155 Ab-positive paranodopathy represents a distinct clinical subtype associated with a poor IVIg response and good rituximab efficacy. Antibody testing should be considered in patients with distal weakness, tremor, high CSF protein, or IVIg refractoriness. Early identification may allow for tailored treatment and improved outcomes.