Welcome to the WCN 2023 Interactive Program

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Treatment status of CIDP

Liying Cui

Department of Neurology

Peking Union Medical College Hospital

Chronic inflammatory demyelinating multiple neuropathy (CIDP) is a heterogeneous immune-mediated polyneuropathy involving the myelin of motor and sensory nerves, characterized by a relapsing or progressive course, and electrophysiological or pathological evidence of peripheral demyelination. The etiology and pathogenesis of CIDP are not fully understood. However, animal studies have found that it is related to both humoral immunity and cellular immunity. It is a rear neurological disease, with a worldwide prevalence of 0.7-10.3/100,000, incidence of 0.7-1.6/100,000. Average age of diagnosis is 50 years old. Male to female ratio is 2:1.

CIDP is a treatable disease. Established treatments include intravenous immunoglobulin (IVIg), corticosteroids and plasma exchange. While these options deliver meaningful clinical improvements in approximately two-thirds of patients Data from US/UK (HCP and patient marked research study): IVIg 90%, steroids 0-5%, IVIg+steroids 5-10%, PE about 10%. About 1/3 of patients will not respond to standard of care. More than 10% of patients with CIDP remain severely disabled despite treatment.

In my report, I briefly reviewed the history of CIDP treatment and some RCT studies, introduced 2021-EAN/PNS, treatment recommendations, first-line treatment and second-line treatment, and the status of CIDP treatment in China, etc., and answered several practical problems encountered in clinical practice: What is the best choice for corticosteroids therapy regimen: oral prednisone? pulsed IVMP/Dex? Efficacy of IVIg? Whether the efficacy of IVIG+ corticosteroids combined is better than single drug, Can SCIg replace IVIg? The course of the treatment.

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Charcot Marie Tooth disease (CMT) has traditionally been classified into demyelinating CMT (CMT1) with upper limb motor conduction velocities (MCVs) below 38 m/s and axonal CMT (CMT2) with MCVs above 38 m/s. This remains very useful especially at differentiating the commonest form of CMT, CMT1A secondary to a duplication of PMP22 from other forms of CMT. CMT1A is pathologically characterised by de- and re-myelination accompanied by onion bulbs and is the classic form of CMT1.

Increasingly forms of CMT are described with intermediate MCVs ranging from 25-45 m/s where the pathology does not show classical de-and re-myelination including x-linked CMT due to GJB1 variants. Other CMT genes have been described with MCVs less than 38 m/s where the pathology shows loss of large axons e.g. CMT due to NEFL variants.

It is therefore clear that MCVs can be less than 38 m/s in different forms of CMT for a variety of reasons and not just due to pathological demyelination. It is important to recognise this as slow conduction does not necessarily mean a demyelinating neuropathy pathologically and both CMT1 and CMT2 genes may be in the differential for an individual patient.

In acquired neuropathies it can be misleading to equate slow conduction with demyelination as this can lead to erroneous diagnosis.

This talk will explore slow conduction in inherited neuropathies and argue that in both genetic and acquired neuropathies the term demyelination should be confined to pathological descriptions and the term slow conduction should be adopted for neurophysiological descriptions.

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The discovery of autoantibodies targeting critical structural proteins of the node and paranode of Ranvier has had important clinical implications. Patients harbouring these antibodies are frequently initially diagnosed with Guillain-Barré syndrome (GBS) or chronic inflammatory demyelinising polyneuropathy (CIDP). However, they are now considered to have a distinct group of disorders Crucially, these disorders, now termed autoimmune nodopathies, have different ultrastructural pathology and fail to respond to usual first line therapies used in GBS/CIDP.

The most established and well-studied associations are for antibodies targeting the paranodal cell-adhesion molecules contactin-1 (CNTN1), Caspr or neurofascin(NF)-155, and the nodal NF186. NF155 antibodies are associated with prominent tremor and sensory ataxia. Patients with CNTN1 antibodies frequently have co-existent nephrotic syndrome due to glomerular nephritis. Those with pan-neurofascin antibodies (targeting both NF155 and NF186) typically present with a fulminant GBS-like neuropathy with profound tetraplegia, autonomic dysfunction, cranial nerve involvement and neuromuscular respiratory failure.

Accumulating evidence supports these antibodies having a direct pathogenic effect. In many cases IgG4 subclass antibodies are predominant, and appear to disrupt paranodal structure and function without activating immune effector functions. In others, Ig1/3 subclass antibodies target the nodal axolemma and activate complement, which unchecked leads to early axonal degeneration.

In contrast to seronegative CIDP, few patients with autoimmune nodopathies have any meaningful response to intravenous immunoglobulin. However, some appear to achieve long-term remission following steroids, and case reports and small series suggest treatment with the B-cell depleting anti-CD20 agent rituximab is even more effective.