Test Guide - Quest Test Directory

Autoimmune Nodopathy (CIDP-like) Evaluation

This test is used to diagnose chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)-like autoimmune nodopathy and identify patients who would benefit from alternative therapies to first-line intravenous immunoglobulin (IVIg).

Test Summary

Autoimmune Nodopathy (CIDP-like) Evaluation

Test code:18702

Clinical use

Diagnose chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)-like autoimmune nodopathy
Identify patients who would benefit from alternative therapies to first-line intravenous immunoglobulin (IVIg)

Clinical background

Autoimmune nodopathy is a disease that was previously considered a type of CIDP (an immune-mediated peripheral neuropathy with a pooled population prevalence of about 3 in 100,000).1 However, autoimmune nodopathy has since been reclassified due to distinct clinical features and differences in pathogenesis.2 Muscle weakness and/or sensory loss are characteristic of both diseases, but patients with autoimmune nodopathy often present with special features (eg, ataxia and tremor, Table) that are not included in the clinical criteria for CIDP.2 Autoimmune nodopathy is thus considered a separate disease from CIDP and has been described as CIDP-like.2

Table. Autoimmune Nodopathy: Clinical Features and Associated Antibodies

Clinical features2	Antibody2
Predominantly motor (vs sensory), predominantly distal (vs proximal), ataxia, tremor; mainly occurring in young adults	Anti-NF155
Motor and sensory, cranial nerve and bulbar involvement; may lead to quadriplegia and respiratory failure	Anti-NF186
Predominantly motor, predominantly distal, ataxia, tremor, nephrotic syndrome	Anti-CNTN1
Predominantly motor, predominantly distal, neuropathic pain, occasional cranial nerve involvement and respiratory failure	Anti-CASPR1

Features of autoimmune nodopathy pathogenesis are also considered in the reclassification of the disease. The absence of significant inflammatory infiltrate in autoimmune nodopathy suggests that antibodies have a direct effect in disease pathogenesis; this feature is seen in antibodies that directly target cell-adhesion molecules (CAMs) at myelinated nerve nodes or paranodes in contrast to macrophage-mediated demyelination that is characteristic of CIDP.2,3

Neurofascin 155 (NF155) is a paranodal CAM found on the surface of the myelin sheath and is a common target in autoimmune nodopathy. NF155 binds to the axon surface via a complex of CAMs consisting of contactin 1 (CNTN1) and contactin associated protein 1 (CASPR1). In autoimmune nodopathy, antibodies to NF155, or less commonly to CNTN1 and/or CASPR1, disrupt such binding.3 Rarely, patients may produce antibodies to the nodal CAM NF186. Patients with NF186 or with antibodies to both NF186 and NF155—so-called pan-neurofascin autoimmune nodopathy—may have risk of associated glomerulosclerosis.⁴

Testing for NF155, NF186, CNTN1, and CASPR1 antibodies can help distinguish autoimmune nodopathy from CIDP and should be prompted by the presence of guideline-indicated clinical features, some of which are associated with specific antibodies (Table).² Antibody testing is recommended to support the diagnosis of autoimmune nodopathy and inform treatment, which differs from that given for CIDP because patients with autoimmune nodopathy show poor response to IVIg.²

The Quest Autoimmune Nodopathy (CIDP-like) Evaluation test helps diagnose autoimmune nodopathy and distinguish it from CIDP. It is appropriate as an initial assessment to help identify patients who would benefit from alternative therapies to IVIg, such as rituximab.²

Individuals suitable for testing

Patients with clinical suspicion of autoimmune nodopathy (CIDP-like) or CIDP

Method

Cell-based immunofluorescence assay (IFA)
Positive IFA results after exposure to serum specimens based on patterns of antibody staining in recombinant cell substrates transfected with antigen targets

Interpretive information

Positive results indicate the presence of NF155, NF186, CNTN1, and/or CASPR1 antibodies. Reactivity to the CNTN1/CASPR1 complex in the absence of antibody to CNTN1 indicates that antibodies to CASPR1 may be present. The prevalence of these antibodies in autoimmune nodopathy is not well-established, so a negative result may not exclude the presence of disease.

References

Broers MC, Bunschoten C, Nieboer D, et al. Incidence and prevalence of chronic inflammatory demyelinating polyradiculoneuropathy: a systematic review and meta-analysis. Neuroepidemiology. 2019;52(3-4):161-172. doi:10.1159/000494291
Van den Bergh P, van Doorn PA, Hadden RDM, et al. European Academy of Neurology/Peripheral Nerve Society guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: report of a joint task force—second revision. Eur J Neurol. 2021;28(11):3556-3583. doi:10.1111/ene.14959
Quinot V, Rostasy K, Höftberger R. Antibody-mediated nodo- and paranodopathies. J Clin Med. 2024;13(19):5721. doi:10.3390/jcm13195721
Zhang S, Yang S, Lu J, et al. CIDP-like autoimmune nodopathy complicated with focal segmental glomerulosclerosis: a case study and literature review. J Neurol. 2023;270(1):493-502. doi:10.1007/s00415-022-11369-4

Content reviewed 8/2026

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Related tests (1)

18702 - Autoimmune Nodopathy (CIDP-like) Evaluation

Chronic autoimmune peripheral neuropathies include a variety of disorders. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) defines a syndrome with chronic symmetrical proximal and distal muscle weakness and areflexia. Several subtypes have been recognized, depending on whether there is localization and/or predominance of motor or sensory symptoms. Previously considered a type of CIDP, patients in whom autoantibodies to components of the myelinated nerve node or paranode are present have been characterized as having a separate syndrome. It differs from CIDP in presentation (patients often have ataxia and tremor), pathogenesis (absence of significant inflammatory infiltrate suggest that antibodies have a direct effect), and response to treatment (unlike patients with CIDP, it is unlikely to respond to IVIg and may need alternative therapy, such as rituximab). The separate syndrome has been termed autoimmune nodopathy. Testing for the associated autoantibodies can help distinguish it for CIDP.

Related guides (1)

Immune-Mediated Peripheral Neuropathies: Laboratory Support of Diagnosis

This clinical focus provides information on laboratory testing that supports evaluation and diagnosis of immune-mediated causes of primary peripheral neuropathy, including Guillain-Barre syndrome (GBS) or acute inflammatory demyelinating polyradiculoneuropathy (AIDP), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and autoimmune nodopathy.

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Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.

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