Anti-GLDN antibody–associated CIDP (nodopathy): transient IVIg response and B-cell depletion remission

BACKGROUND: The classification of chronic inflammatory demyelinating polyneuropathy (CIDP) is evolving with the discovery of autoantibodies against nodal and paranodal proteins, leading to the recognition of "autoimmune nodopathies." While anti-neurofascin-155 (NF155) and anti-contactin-1 (CNTN1) antibodies are well-characterized, the phenotype of anti-gliomedin (GLDN) antibodies remains poorly defined. We present a comprehensive case to delineate its clinical and serological profile. CASE PRESENTATION: We report a detailed longitudinal case of a patient with anti-GLDN antibody-positive CIDP, including clinical presentation, electrophysiological and imaging studies, serological testing, treatment response, and follow-up. RESULTS: A 48-year-old woman presented with an 11-month history of relapsing-remitting, symmetric sensorimotor polyneuropathy, triggered by immune-activating events. Electrodiagnostic studies confirmed a demyelinating polyneuropathy meeting definitive European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) criteria. Cerebrospinal fluid (CSF) analysis showed marked albuminocytological dissociation (protein 1631 mg/L). Serology was positive for anti-GLDN IgG (cell-based assay titer 1:32). The patient exhibited an excellent but transient response to intravenous immunoglobulin (IVIg), leading to multiple relapses. Subsequent B-cell targeted therapy with rituximab resulted in sustained clinical stabilization, effective B-cell depletion, and negative conversion of anti-GLDN IgG antibody. CONCLUSIONS: This case suggests that anti-GLDN antibody-associated CIDP may be associated with a recognizable phenotype within the autoimmune nodopathy spectrum. Potential key features include a relapsing course following immune stimulation, markedly elevated cerebrospinal fluid protein, a unique pattern of robust but unsustained response to intravenous immunoglobulin (IVIg), and a favorable response to B-cell depletion therapy as evidenced by clinical remission and seroconversion.