Nodes, paranodes and neuropathies Fehmi, Janev; Scherer, Steven S; Willison, Hugh J ...
Journal of neurology, neurosurgery and psychiatry,
01/2018, Letnik:
89, Številka:
1
Journal Article
Recenzirano
Odprti dostop
This review summarises recent evidence supporting the involvement of the specialised nodal and perinodal domains (the paranode and juxtaparanode) of myelinated axons in the pathology of acquired, ...inflammatory, peripheral neuropathies.The identification of new target antigens in the inflammatory neuropathies heralds a revolution in diagnosis, and has already begun to inform increasingly targeted and individualised therapies. Rapid progress in our basic understanding of the highly specialised nodal regions of peripheral nerves serves to strengthen the links between their unique microstructural identities, functions and pathologies. In this context, the detection of autoantibodies directed against nodal and perinodal targets is likely to be of increasing clinical importance. Antiganglioside antibodies have long been used in clinical practice as diagnostic serum biomarkers, and associate with specific clinical variants but not to the common forms of either acute or chronic demyelinating autoimmune neuropathy. It is now apparent that antibodies directed against several region-specific cell adhesion molecules, including neurofascin, contactin and contactin-associated protein, can be linked to phenotypically distinct peripheral neuropathies. Importantly, the immunological characteristics of these antibodies facilitate the prediction of treatment responsiveness.
ObjectivesWe aimed to define the clinical and serological characteristics of pan-neurofascin antibody-positive patients.MethodsWe tested serum from patients with suspected immune-mediated ...neuropathies for antibodies directed against nodal/paranodal protein antigens using a live cell-based assay and solid-phase platform. The clinical and serological characteristics of antibody-positive and seronegative patients were then compared. Sera positive for pan-neurofascin were also tested against live myelinated human stem cell-derived sensory neurons for antibody binding.ResultsEight patients with IgG1-subclass antibodies directed against both isoforms of the nodal/paranodal cell adhesion molecule neurofascin were identified. All developed rapidly progressive tetraplegia. Cranial nerve deficits (100% vs 26%), autonomic dysfunction (75% vs 13%) and respiratory involvement (88% vs 14%) were more common than in seronegative patients. Four patients died despite treatment with one or more modalities of standard immunotherapy (intravenous immunoglobulin, steroids and/or plasmapheresis), whereas the four patients who later went on to receive the B cell-depleting therapy rituximab then began to show progressive functional improvements within weeks, became seronegative and ultimately became functionally independent.ConclusionsIgG1 pan-neurofascin antibodies define a very severe autoimmune neuropathy. We urgently recommend trials of targeted immunotherapy for this serologically classified patient group.
Treatment of CIDP Fehmi, Janev; Bellanti, Roberto; Misbah, Siraj A ...
Practical neurology,
02/2023, Letnik:
23, Številka:
1
Journal Article
Recenzirano
Chronic inflammatory demyelinating polyneuropathy is a disabling but treatable disorder. However, misdiagnosis is common, and it can be difficult to optimise its treatment. Various agents are used ...both for first and second line. First-line options are intravenous immunoglobulin, corticosteroids and plasma exchange. Second-line therapies may be introduced as steroid-sparing agents or as more potent escalation therapy. It is also important to consider symptomatic treatment of neuropathic pain and non-pharmacological interventions. We discuss the evidence for the various treatments and explain the practicalities of the different approaches. We also outline strategies for monitoring response and assessing the ongoing need for therapy.
09.24 Phone a friend? Minton, Thomas; Fuller, Geraint; Rinaldi, Simon ...
Journal of neurology, neurosurgery and psychiatry,
12/2019, Letnik:
90, Številka:
12
Journal Article
Recenzirano
A 72-year-old man with type 2 diabetes mellitus was admitted under nephrology with malaise. He was diagnosed with acute kidney injury secondary to urinary retention and hydronephrosis. Over 10 days ...during this admission he developed progressive symmetrical limb paraesthesia and weakness with areflexia.Neurophysiological studies demonstrated a severe demyelinating polyneuropathy with widespread motor slowing and prolonged distal motor latencies. CSF was acellular with a protein of 5.9 g/L. He was treated with IV immunoglobulins and stabilised for 2 weeks. He then deteriorated over the next four weeks despite IV methylprednisolone, oral corticosteroids and 5 cycles of plasma exchange. He had profound limb weakness (0/5) and required ventilation. He had hypoalbuminaemia, with 1.5 g proteinuria consistent with a nephrotic syndrome.We phoned a friend.IgG4 anti–contactin-1 (CNTN1) antibodies were identified in serum with a CNTN1 at 1:1600.He received 4 cycles of Rituximab. After 6 weeks he was off ventilation with grade 4 power in both arms.Recently autoantibodies against node of Ranvier proteins have emerged in a subset of patients with CIDP. These patients have a homogenous clinical phenotype with an aggressive polyneuropathy, proteinuria and poor response to conventional therapy, but seem to respond to other agents, including Rituximab and Cyclophosphamide.
ImportanceDisease modifying treatments in Guillain-Barré syndrome (GBS) are not tailored to the different pathological subtypes. Strategies to prospectively identify sub-sets of patients with ...specific disease mecha- nisms and inform the use of non-standard therapies may lead to improved outcomes. We present a case series of seven patients with IgG1 subclass pan-neurofascin antibodies.ResultsAll seven patients presented with a severe, acute or sub-acute onset, predominantly motor, autoimmune neuropathy. In all but one case the neuropathy was severe enough to warrant mechanical ventilation and intensive care support. Cranial nerve deficits were universally present and autonomic dysfunction was common. Although clinically resembling GBS, the response to standard GBS therapies was poor. Four patients received the B-cell depleting therapy rituximab and showed significant and sustained functional improvement within weeks of treatment. The three remaining patients who did not receive rituximab died.Conclusions and RelevanceThese observations should lead to a re-evaluation of the benefit of nodal/paranodal antibody testing in neuropathies with acute onset, GBS-like presentations. We believe that such testing should form part of the routine diagnostic work up of such patients, and that the identifica- tion of a distinct, serologically-defined disease sub-type should prompt consideration of more targeted immunotherapy. The apparent benefit of rituximab reported here should be evaluated in a well-conduc- ted clinical trial, the design of which must consider the potentially grave outcome in pan-neurofascin antibody-positive patients receiving only standard therapies.simon.rinaldi@nhs.net
Pain is a under‐recognized association of leucine‐rich glioma‐inactivated 1 (LGI1) and contactin‐associated protein‐like 2 (CASPR2) antibodies. Of 147 patients with these autoantibodies, pain was ...experienced by 17 of 33 (52%) with CASPR2‐ versus 20 of 108 (19%) with LGI1 antibodies (p = 0.0005), and identified as neuropathic in 89% versus 58% of these, respectively. Typically, in both cohorts, normal nerve conduction studies and reduced intraepidermal nerve fiber densities were observed in the sampled patient subsets. In LGI1 antibody patients, pain responded to immunotherapy (p = 0.008), often rapidly, with greater residual patient‐rated impairment observed in CASPR2 antibody patients (p = 0.019). Serum CASPR2 antibodies, but not LGI1 antibodies, bound in vitro to unmyelinated human sensory neurons and rodent dorsal root ganglia, suggesting pathophysiological differences that may underlie our clinical observations. ANN NEUROL 2021;90:683–690
Membranous glomerulonephritis (MGN) is a common cause of nephrotic syndrome in adults, mediated by glomerular antibody deposition to an increasing number of newly recognised antigens. Previous case ...reports have suggested an association between patients with anti-contactin-1 (CNTN1)-mediated neuropathies and MGN. In an observational study we investigated the pathobiology and extent of this potential cause of MGN by examining the association of antibodies against CNTN1 with the clinical features of a cohort of 468 patients with suspected immune-mediated neuropathies, 295 with idiopathic MGN, and 256 controls. Neuronal and glomerular binding of patient IgG, serum CNTN1 antibody and protein levels, as well as immune-complex deposition were determined. We identified 15 patients with immune-mediated neuropathy and concurrent nephrotic syndrome (biopsy proven MGN in 12/12), and 4 patients with isolated MGN from an idiopathic MGN cohort, all seropositive for IgG4 CNTN1 antibodies. CNTN1-containing immune complexes were found in the renal glomeruli of patients with CNTN1 antibodies, but not in control kidneys. CNTN1 peptides were identified in glomeruli by mass spectroscopy. CNTN1 seropositive patients were largely resistant to first-line neuropathy treatments but achieved a good outcome with escalation therapies. Neurological and renal function improved in parallel with suppressed antibody titres. The reason for isolated MGN without clinical neuropathy is unclear. We show that CNTN1, found in peripheral nerves and kidney glomeruli, is a common target for autoantibody-mediated pathology and may account for between 1 and 2% of idiopathic MGN cases. Greater awareness of this cross-system syndrome should facilitate earlier diagnosis and more timely use of effective treatment.
With the recent development of novel, more potent cancer treatment, in particular, immune ‘checkpoint inhibitors’, cases of neurological immune-related adverse events are on the rise. Although rare, ...this includes Guillain-Barré Syndrome (GBS). We present the case of a 68-year-old male who was admitted with sudden onset of worsening neurological symptoms following immunotherapy treatment. These symptoms progressed quickly to respiratory failure requiring intubation and admission to the intensive care unit. He was thoroughly investigated and is believed to have an axonal neuropathy in the form of Miller Fisher Syndrome (MFS) variant of GBS, secondary to immunotherapy treatment. He was initially treated with intravenous immunoglobulin, and later, perhaps more effectively, with high dose steroids which significantly improved his symptoms. This case of checkpoint inhibitor-induced MFS is one of few in the literature and is an important reminder of the potential for new immunotherapeutic agents to cause significant neurotoxic effects. These should be promptly and thoroughly investigated, in particular, as the management of these patients can differ from standard treatments used in these conditions.
The inflammatory neuropathies are disabling conditions with diverse immunological mechanisms. In some, a pathogenic role for immunoglobulin G (IgG)-class autoantibodies is increasingly appreciated, ...and immunoadsorption (IA) may therefore be a useful therapeutic option. We reviewed the use of and response to IA or plasma exchange (PLEx) in a cohort of 41 patients with nodal/paranodal antibodies identified from a total of 573 individuals with suspected inflammatory neuropathies during the course of routine diagnostic testing (PNAb cohort). 20 patients had been treated with PLEx and 4 with IA. Following a global but subjective evaluation by their treating clinicians, none of these patients were judged to have had a good response to either of these treatment modalities. Sequential serology of one PNAb+ case suggests prolonged suppression of antibody levels with frequent apheresis cycles or adjuvant therapies, may be required for effective treatment. We further retrospectively evaluated the serological status of 40 patients with either Guillain-Barré syndrome (GBS) or chronic inflammatory demyelinating polyneuropathy (CIDP), and a control group of 20 patients with clinically-isolated syndrome/multiple sclerosis (CIS/MS), who had all been treated with IgG-depleting IA (IA cohort). 32 of these patients (8/20 with CIDP, 13/20 with GBS, 11/20 with MS) were judged responsive to apheresis despite none of the serum samples from this cohort testing positive for IgG antibodies against glycolipids or nodal/paranodal cell-adhesion molecules. Although negative on antigen specific assays, three patients’ pre-treatment sera and eluates were reactive against different components of myelinating co-cultures. In summary, preliminary evidence suggests that GBS/CIDP patients without detectable IgG antibodies on routine diagnostic tests may nevertheless benefit from IA, and that an unbiased screening approach using myelinating co-cultures may assist in the detection of further autoantibodies which remain to be identified in such patients.
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