Measuring disease activity and predicting response to intravenous immunoglobulin in chronic inflammatory demyelinating polyneuropathy

Table 2 Emerging biomarkers in CIDP

Investigation		Comments
Serum biomarkers
Paranodal antibodies	anti-NF155 IgM	Can be seen in GBS, CMT and CIDP
	anti-NF155 IgG4	Highly specific for CIDP, often characterised by younger age of disease onset, sensory ataxia and poor response to IVIg
	anti-NF186 IgG4
	anti-NF140 IgG4
	anti-CNTN1 IgG4
Serologic response to IVIg	Change in total IgG level
	IgG dimer index
	Level of sialylated IgG
Electrophysiology
Resolution of conduction block		Correlate well with longitudinal disease activity unlike most other nerve conduction studies
Averaged CMAP amplitude
Accumulation of demyelinating features		Predictor of relapse following treatment withdrawal
Imaging
High resolution ultrasound	Cross sectional nerve area
	Nerve echogenicity	Role still unclear
	Nerve vascularization	Role still unclear
Magnetic resonance neurography	Cross sectional nerve area
Magnetic resonance neurography	Nerve signal change
Functional MRI (Diffusion tensor imaging)	Fractional anisotropy	Correlate well with electrophysiological markers of demyelination
	Radial diffusivity	Role still unclear
	Axial diffusivity	Role still unclear

Abbreviations: NF Neurofascin, GBS Guillain Barre Syndrome, CIDP Chronic inflammatory demyelinating polyneuropathy, IVIg intravenous immunoglobulin, CMAP compound motor action potential, MRI: magnetic resonance imaging

ISSN: 2050-7771