Clinical Information

Neurofascin-155 IgG4 antibodies are present in approximately 4% to 18% of patients with chronic inflammatory demyelinating neuropathy (CIDP) and, more rarely, in those with more acute forms of demyelinating neuropathy. This biomarker aids in the identification of a subset of these patients who are more likely to present with distal weakness, gait disturbance, tremor, and dysarthria as compared to classic CIDP. Most patients who are seropositive for neurofascin-155 IgG4 have been reported to be refractory to intravenous immune globulin (IVIG) therapy and often require second line treatment that includes B-cell depleting therapies such as rituximab. Studies in animal models, as well as the disease pathology indicate neurofascin-155 IgG4 antibodies directly disrupt the paranodal structure ultimately leading to demyelination. The presence of these antibodies, when detected, using flow cytometry is highly specific to CIDP and has not been reported in other disease mimics such as hereditary neuropathies, distal acquired demyelinating symmetric neuropathy, and motor neuron disease. This is test is useful in diagnostic work up of patients being evaluated for CIDP and related demyelinating peripheral neuropathies. This test should only be utilized in the appropriate clinical context.