Voltage-Gated Potassium Channel Antibodies in Slow-Progression Motor Neuron Disease

Background: The spectrum of autoimmune neurological diseases associated with voltage-gated potassium channel (VGKC)-complex antibodies (Abs) ranges from peripheral nerve disorders to limbic encephalitis. Recently, low titers of VGKC-complex Abs have also been reported in neurodegenerative disorders, but their clinical relevance is unknown. Objective: The aim of the study was to explore the prevalence of VGKC-complex Abs in slow-progression motor neuron disease (MND). Methods: We compared 11 patients affected by slow-progression MND with 9 patients presenting typical progression illness. Sera were tested for VGKC-complex Abs by radioimmunoassay. The distribution of VGKC-complex Abs was analyzed with the Mann-Whitney U test. Results: The statistical analysis showed a significant difference between the mean values in the study and control groups. A case with long-survival MND harboring VGKC-complex Abs and treated with intravenous immunoglobulins is described. Conclusion: Although VGKC-complex Abs are not likely to be pathogenic, these results could reflect the coexistence of an immunological activation in patients with slow disease progression.