Clinical And Lumbosacral MRI Features Of Anti-Neurofascin 155 Antibody Positive Chronic Inflammatory Demyelinating Polyneuropathy

Background and objectiveChronic inflammatory demyelinating polyradiculoneuropathy(CIDP)is a type of immune-mediated chronic motor-sensory peripheral neuropathy.Magnetic resonance imaging(MRI)is an important supporting diagnostic evidence.CIDP patients with positive anti-neurofascin 155(NF155)antibodies are significantly heterogeneous in clinical manifestations,electrophysiology,and MRI from CIDP with negative antibodies.Researchers found that the nerve roots of antibody positive CIDP were significantly thickened in MRI.This study summarized the clinical manifestations and the characteristics of lumbosacral plexus MRI of anti-NF155 antibody positive CIDP,which may facilitate clinicians to identify anti-NF 155 antibody positive CIDP and provide guidance for its diagnosis and treatment from the view of neuroimaging.Methods8 anti-NF 155 antibody positive CIDP patients diagnosed by cell-based assay(CBA)in Qilu Hospital of Shandong University from August 2018 to December 2020 were included as antibody positive group,10 anti-NF155 antibody negative CIDP patients as antibody negative group,and 8 patients with other diseases as other disease(OD)group.The clinical manifestations,CSF protein count and electrophysiological examination of anti-NF155 antibody positive CIDP patients were collected.The severity of clinical disease was evaluated by Hughes score and MRC sum score.Three-dimensional short inversion-time inversion recovery sequence(3D STIR)was used for lumbosacral plexus magnetic resonance imaging.The cross-sectional area(CSA)of bilateral L3-S2 nerve roots in the three groups was measured.ANOVA was used to compare the CSA of three groups.The correlation between lumbosacral nerve root CSA and the course of disease,Hughes score,MRC sum score,CSF protein count,CSF IgG and electrophysiological parameters were analyzed by Pearson’s or Spearman’s correlation.The ROC curve of the CSA from the nerve roots was made.Results1.Anti-NF155 antibody positive CIDP is more likely to occur in young people and males(75.0%).It is characterized by distal motor sensory peripheral neuropathy,tremor(82.5%),ataxia(100%)and significantly elevated CSF protein.2.The sural nerve biopsy of 3 cases with anti-NF155 antibody positive CIDP showed slightly reduction of myelinated fibers,few onion bulbs and no inflammatory infiltrates.3.Anti-NF155 antibody positive CIDP has relatively poor response to intravenous immunoglobulin,but good response to corticosteroids and plasma exchange.If the above treatment all shows poor effect,rituximab can be considered.4.The CSA of lumbosacral nerve roots in the anti-NF155 antibody positive group was larger than that in the anti-NF155 antibody negative group in bilateral L3-L5.5.The motor nerve conduction velocity(MCV)of peroneal nerve and tibial nerve were negatively correlated with nerve root CSA in anti-NF155 antibody positive CIDP.The correlation is significant between MCV of peroneal and right L3,left L4,right L5,left L5,left S1,left S2.The correlation is significant between MCV of tibial and right L3,right L5,left L5,right S1,left S1.The TLI was positively correlated with nerve root CSA.The correlation is significant between TLI of peroneal and right L3,left L3,right L5,left L5,left S1,left S2.The correlation is significant between TLI of tibial and right L3 and left L5.6.There was no significant correlation between disease course,Hughes score,MRC sum score,CSF protein count,compound muscle action potentials(CMAP)and nerve root CSA in anti-NF155 antibody positive CIDP.7.Left L5 nerve root CSA 34.68mm2 could be used as the cut-off value for distinguishing CIDP from normal people.Left L3 nerve root CSA 50.89mm2 could be used as the cut-off value for distinguishing anti-NF155 antibody positive CIDP from anti-NF155 antibody negative CIDP.Conclusion1.Tremor,ataxia and significant increase of CSF protein are the characteristic manifestations of anti-NF155 antibody positive CIDP.Intravenous immunoglobulin therapy is less effective,while corticosteroids,plasma exchange and rituximab may have good response.2.Lumbosacral nerve roots in anti-NF155 positive are significantly thickened in CIDP.Lumbosacral plexus MRI may provide an evidence for distinguishing the immunological subtypes of CIDP.The cross-sectional area of nerve roots can be used as an important parameter to distinguish CIDP with roughly normal people or anti-NF155 antibody positive with anti-NF155 antibody negative CIDP.