TY - JOUR A1 - Hartmannsberger, Beate A1 - Doppler, Kathrin A1 - Stauber, Julia A1 - Schlotter-Weigel, Beate A1 - Young, Peter A1 - Sereda, Michael W. A1 - Sommer, Claudia T1 - Intraepidermal nerve fiber density as biomarker in Charcot-Marie-Tooth disease 1A JF - Brain Communications N2 - Charcot–Marie–Tooth disease type 1A, caused by a duplication of the gene peripheral myelin protein 22 kDa, is the most frequent subtype of hereditary peripheral neuropathy with an estimated prevalence of 1:5000. Patients suffer from sensory deficits, muscle weakness and foot deformities. There is no treatment approved for this disease. Outcome measures in clinical trials were based mainly on clinical features but did not evaluate the actual nerve damage. In our case–control study, we aimed to provide objective and reproducible outcome measures for future clinical trials. We collected skin samples from 48 patients with Charcot–Marie–Tooth type 1A, 7 patients with chronic inflammatory demyelinating polyneuropathy, 16 patients with small fibre neuropathy and 45 healthy controls. To analyse skin innervation, 40-µm cryosections of glabrous skin taken from the lateral index finger were double-labelled by immunofluorescence. The disease severity of patients with Charcot–Marie–Tooth type 1A was assessed by the Charcot–Marie–Tooth neuropathy version 2 score, which ranged from 3 (mild) to 27 (severe) and correlated with age (P < 0.01, R = 0.4). Intraepidermal nerve fibre density was reduced in patients with Charcot–Marie–Tooth type 1A compared with the healthy control group (P < 0.01) and negatively correlated with disease severity (P < 0.05, R = −0.293). Meissner corpuscle (MC) density correlated negatively with age in patients with Charcot–Marie–Tooth type 1A (P < 0.01, R = −0.45) but not in healthy controls (P = 0.07, R = 0.28). The density of Merkel cells was reduced in patients with Charcot–Marie–Tooth type 1A compared with healthy controls (P < 0.05). Furthermore, in patients with Charcot–Marie–Tooth type 1A, the fraction of denervated Merkel cells was highly increased and correlated with age (P < 0.05, R = 0.37). Analysis of nodes of Ranvier revealed shortened paranodes and a reduced fraction of long nodes in patients compared with healthy controls (both P < 0.001). Langerhans cell density was increased in chronic inflammatory demyelinating polyneuropathy, but not different in Charcot–Marie–Tooth type 1A compared with healthy controls. Our data suggest that intraepidermal nerve fibre density might be used as an outcome measure in Charcot–Marie–Tooth type 1A disease, as it correlates with disease severity. The densities of Meissner corpuscles and Merkel cells might be an additional tool for the evaluation of the disease progression. Analysis of follow-up biopsies will clarify the effects of Charcot–Marie–Tooth type 1A disease progression on cutaneous innervation. KW - Charcot–Marie–Tooth disease type 1A KW - skin punch biopsy KW - intraepidermal nerve fibre density KW - Merkel cell density KW - reproducible outcome measure Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229538 VL - 2 IS - 1 ER - TY - JOUR A1 - Stengel, Helena A1 - Vural, Atay A1 - Brunder, Anna-Michelle A1 - Heinius, Annika A1 - Appeltshauser, Luise A1 - Fiebig, Bianca A1 - Giese, Florian A1 - Dresel, Christian A1 - Papagianni, Aikaterini A1 - Birklein, Frank A1 - Weis, Joachim A1 - Huchtemann, Tessa A1 - Schmidt, Christian A1 - Körtvelyessy, Peter A1 - Villmann, Carmen A1 - Meinl, Edgar A1 - Sommer, Claudia A1 - Leypoldt, Frank A1 - Doppler, Kathrin T1 - Anti–pan-neurofascin IgG3 as a marker of fulminant autoimmune neuropathy JF - Neurology: Neuroimmunology & Neuroinflammation N2 - Objective To identify and characterize patients with autoantibodies against different neurofascin (NF) isoforms. Methods Screening of a large cohort of patient sera for anti-NF autoantibodies by ELISA and further characterization by cell-based assays, epitope mapping, and complement binding assays. Results Two different clinical phenotypes became apparent in this study: The well-known clinical picture of subacute-onset severe sensorimotor neuropathy with tremor that is known to be associated with IgG4 autoantibodies against the paranodal isoform NF-155 was found in 2 patients. The second phenotype with a dramatic course of disease with tetraplegia and almost locked-in syndrome was associated with IgG3 autoantibodies against nodal and paranodal isoforms of NF in 3 patients. The epitope against which these autoantibodies were directed in this second phenotype was the common Ig domain found in all 3 NF isoforms. In contrast, anti–NF-155 IgG4 were directed against the NF-155–specific Fn3Fn4 domain. The description of a second phenotype of anti–NF-associated neuropathy is in line with some case reports of similar patients that were published in the last year. Conclusions Our results indicate that anti–pan-NF-associated neuropathy differs from anti–NF-155-associated neuropathy, and epitope and subclass play a major role in the pathogenesis and severity of anti–NF-associated neuropathy and should be determined to correctly classify patients, also in respect to possible differences in therapeutic response. KW - neurology Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202462 VL - 6 IS - 5 ER - TY - JOUR A1 - Doppler, Kathrin A1 - Schuster, Yasmin A1 - Appeltshauser, Luise A1 - Biko, Lydia A1 - Villmann, Carmen A1 - Weishaupt, Andreas A1 - Werner, Christian A1 - Sommer, Claudia T1 - Anti-CNTN1 IgG3 induces acute conduction block and motor deficits in a passive transfer rat model JF - Journal of Neuroinflammation N2 - Background: Autoantibodies against the paranodal protein contactin-1 have recently been described in patients with severe acute-onset autoimmune neuropathies and mainly belong to the IgG4 subclass that does not activate complement. IgG3 anti-contactin-1 autoantibodies are rare, but have been detected during the acute onset of disease in some cases. There is evidence that anti-contactin-1 prevents adhesive interaction, and chronic exposure to anti-contactin-1 IgG4 leads to structural changes at the nodes accompanied by neuropathic symptoms. However, the pathomechanism of acute onset of disease and the pathogenic role of IgG3 anti-contactin-1 is largely unknown. Methods: In the present study, we aimed to model acute autoantibody exposure by intraneural injection of IgG of patients with anti-contacin-1 autoantibodies to Lewis rats. Patient IgG obtained during acute onset of disease (IgG3 predominant) and IgG from the chronic phase of disease (IgG4 predominant) were studied in comparison. Results: Conduction blocks were measured in rats injected with the “acute” IgG more often than after injection of “chronic” IgG (83.3% versus 35%) and proved to be reversible within a week after injection. Impaired nerve conduction was accompanied by motor deficits in rats after injection of the “acute” IgG but only minor structural changes of the nodes. Paranodal complement deposition was detected after injection of the “acute IgG”. We did not detect any inflammatory infiltrates, arguing against an inflammatory cascade as cause of damage to the nerve. We also did not observe dispersion of paranodal proteins or sodium channels to the juxtaparanodes as seen in patients after chronic exposure to anti-contactin-1. Conclusions: Our data suggest that anti-contactin-1 IgG3 induces an acute conduction block that is most probably mediated by autoantibody binding and subsequent complement deposition and may account for acute onset of disease in these patients. This supports the notion of anti-contactin-1-associated neuropathy as a paranodopathy with the nodes of Ranvier as the site of pathogenesis. KW - complement deposition KW - paranodopathy KW - anti-contactin-1 KW - CIDP KW - passive transfer KW - autoantibody Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200476 VL - 16 IS - 73 ER - TY - JOUR A1 - Doppler, Kathrin A1 - Appeltshauser, Luise A1 - Krämer, Heidrun H. A1 - King Man Ng, Judy A1 - Meinl, Edgar A1 - Villmann, Carmen A1 - Brophy, Peter A1 - Dib-Hajj, Sulayman D. A1 - Waxman, Stephen G. A1 - Weishaupt, Andreas A1 - Sommer, Claudia T1 - Contactin-1 and Neurofascin-155/-186 Are Not Targets of Auto-Antibodies in Multifocal Motor Neuropathy JF - PLoS One N2 - Multifocal motor neuropathy is an immune mediated disease presenting with multifocal muscle weakness and conduction block. IgM auto-antibodies against the ganglioside GM1 are detectable in about 50% of the patients. Auto-antibodies against the paranodal proteins contactin-1 and neurofascin-155 and the nodal protein neurofascin-186 have been detected in subgroups of patients with chronic inflammatory demyelinating polyneuropathy. Recently, auto-antibodies against neurofascin-186 and gliomedin were described in more than 60% of patients with multifocal motor neuropathy. In the current study, we aimed to validate this finding, using a combination of different assays for auto-antibody detection. In addition we intended to detect further auto-antibodies against paranodal proteins, specifically contactin-1 and neurofascin-155 in multifocal motor neuropathy patients’ sera. We analyzed sera of 33 patients with well-characterized multifocal motor neuropathy for IgM or IgG anti-contactin-1, anti-neurofascin-155 or -186 antibodies using enzyme-linked immunosorbent assay, binding assays with transfected human embryonic kidney 293 cells and murine teased fibers. We did not detect any IgM or IgG auto-antibodies against contactin-1, neurofascin-155 or -186 in any of our multifocal motor neuropathy patients. We conclude that auto-antibodies against contactin-1, neurofascin-155 and -186 do not play a relevant role in the pathogenesis in this cohort with multifocal motor neuropathy. KW - motor proteins KW - enzyme-linked immunoassays KW - binding analysis KW - neuropathy KW - nerve fibers KW - cell binding assay KW - antibodies KW - enzyme assays Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126156 VL - 10 IS - 7 ER -