Autoimmune demyelinating neuropathies include several progressive conditions — among them chronic inflammatory demyelinating polyneuropathy (CIDP), Guillain-Barre syndrome (GBS), chronic immune sensory polyradiculopathy (CISP), and distal acquired demyelinating sensory (DADS) neuropathy — that share overlapping motor and/or sensory features with other peripheral neuropathies.
Frequently misdiagnosed, CIDP in most cases is highly responsive to first-line immunotherapy treatments, such as intravenous immunoglobin (IVIG). However, a subset of individuals with specific paranodal antibodies do not respond as well to these therapies. The presence of neurofascin 155 (NF155) IgG4 and contactin-1 (CNTN1) IgG indicates a unique disease etiology with antibodies targeting the paranode. These patients have relatively poor treatment response to IVIG. We’ve developed and validated a unique assay combination available exclusively at Mayo Clinic Laboratories.
Evaluates for antibodies directed against NF155 and CNTN1, two common biomarkers associated with CIDP.
Combination assay uses a fixed cell-based assay to measure antibodies directed against CNTN1 protein and live cell flow cytometry to identify antibodies directed against NF155, which offers higher clinical specificity than conventional testing methodologies.
Divyanshu (Div) Dubey, M.B.B.S., describes Mayo Clinic Laboratories' new diagnostic test for CIDP, or chronic inflammatory demyelinating polyneuropathy. The new test detects two antibodies — NF155 and CNTN1 — to enhance diagnosis and guide treatment decisions. Often misdiagnosed, CIDP is treatable if detected early.
Sophisticated laboratory testing solved a medical riddle and finally got Jori Pearson back on his feet, doing what he loves.
The presence of myelin associated glycoprotein (MAG) antibodies is often linked to a rare demyelinating neuropathy with poor treatment response known as DADS neuropathy. In some cases, reaching correct diagnosis through clinical and electrophysiological evaluation alone can be difficult due to overlapping features, or when patient evaluation occurs later in the disease course. Incorporating MAG antibody testing into the diagnostic workup can help identify the correct diagnosis and exclude patients with treatable immune-mediated neuropathies.
John Mills, Ph.D., explains Mayo Clinic Laboratories’ approach to MAG antibody testing. The ELISA-based assay uses higher reference ranges and human MAG antigen to detect MAG antibodies, which are associated with a rare, hard-to-treat condition known as DADS neuropathy.
Distal acquired demyelinating symmetric
In patient with DADS, the body generates monoclonal immunoglobulin (IgM) antibodies that bind to and prevent MAG antibodies from properly signaling the nervous system, which causes motor and sensory issues. Despite most cases of DADS having an associated IgM M-protein, conventional testing methodologies (e.g., serum electrophoresis and immunofixation) can sometimes be negative and result in delayed diagnosis. MASS-FIX testing offers enhanced specificity and sensitivity, enabling detection of the lowest possible amount of M-proteins and providing diagnostic certainty for the rare, hard-to-treat illness.
When protein electrophoresis and free light-chain testing is performed in house; M-protein isotyping by MASS-FIX only.
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Querol L, Nogales-Gadea G, Rojas-Garcia R, et al. Neurofascin IgG4 antibodies in CIDP associate with disabling tremor and poor response to IVIg. Neurology. 2014 Mar 11;82(10):879-86. doi:10.1212/WNL.0000000000000205. Epub 2014 Feb 12. PMID: 24523485; PMCID: PMC3959751.
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Dubey D, Honorat JA, Shelly S. Contactin-1 autoimmunity: Serologic, neurologic, and pathologic correlates. Neurol Neuroimmunol Neuroinflamm. 2020 May 27;7(4):e771. doi:10.1212/NXI.0000000000000771. PMID: 32461352; PMCID: PMC7286654.
Shelly S, Klein CJ, Dyck PJB, et al. Neurofascin-155 immunoglobulin subtypes: clinicopathologic associations and neurologic outcomes. Neurology. 2021 Dec 14;97(24):e2392-e2403. doi:10.1212/WNL.0000000000012932. Epub 2021 Oct 11. PMID: 34635556; PMCID: PMC8673722.
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