IgG4 anti-neurofascin155 antibodies in chronic inflammatory demyelinating polyradiculoneuropathy: Clinical significance and diagnostic utility of a conventional assay

- Anti-Neurofascin155 antibody was measured in CIDP patients by multiple methods.
- The diagnostic utility of human NF155-based ELISA for screening is validated.
- Western blot and CBA are useful for confirmation of positive results in ELISA.
- Development of the optimal treatment will require gathering of more information.

We aimed to validate the diagnostic utility of enzyme-linked immunosorbent assay (ELISA) for the detection of anti-neurofascin (NF) 155 antibody in 191 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Human NF155-based ELISA clearly distinguished between anti-NF155 antibody-positive and -negative sera. Fifteen CIDP patients (8%) were IgG4 anti-human NF155 antibody-positive, which were confirmed by western blot, cell-based assay and immunohistochemical study. None of disease controls or healthy subjects had positive results. Clinical presentation of IgG4 anti-NF155 antibody-positive patients was consistent with those in previous reports. This ELISA combined with determination of the IgG4 subclass is useful in screening for anti-NF155 antibodies.

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