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 - Appeltshauser, Luise A1 - Brunder, Anna-Michelle A1 - Heinius, Annika A1 - Körtvélyessy, Peter A1 - Wandinger, Klaus-Peter A1 - Junker, Ralf A1 - Villmann, Carmen A1 - Sommer, Claudia A1 - Leypoldt, Frank A1 - Doppler, Kathrin T1 - Antiparanodal antibodies and IgG subclasses in acute autoimmune neuropathy JF - Neurology: Neuroimmunology & Neuroinflammation N2 - Objective To determine whether IgG subclasses of antiparanodal autoantibodies are related to disease course and treatment response in acute- to subacute-onset neuropathies, we retrospectively screened 161 baseline serum/CSF samples and 66 follow-up serum/CSF samples. Methods We used ELISA and immunofluorescence assays to detect antiparanodal IgG and their subclasses and titers in serum/CSF of patients with Guillain-Barre syndrome (GBS), recurrent GBS (R-GBS), Miller-Fisher syndrome, and acute- to subacute-onset chronic inflammatory demyelinating polyradiculoneuropathy (A-CIDP). We evaluated clinical data retrospectively. Results We detected antiparanodal autoantibodies with a prevalence of 4.3% (7/161), more often in A-CIDP (4/23, 17.4%) compared with GBS (3/114, 2.6%). Longitudinal subclass analysis in the patients with GBS revealed IgG2/3 autoantibodies against Caspr-1 and against anti-contactin-1/Caspr-1, which disappeared at remission. At disease onset, patients with A-CIDP had IgG2/3 anti-Caspr-1 and anti-contactin-1/Caspr-1 or IgG4 anti-contactin-1 antibodies, IgG3 being associated with good response to IV immunoglobulins (IVIg). In the chronic phase of disease, IgG subclass of one patient with A-CIDP switched from IgG3 to IgG4. Conclusion Our data (1) confirm and extend previous observations that antiparanodal IgG2/3 but not IgG4 antibodies can occur in acute-onset neuropathies manifesting as monophasic GBS, (2) suggest association of IgG3 to a favorable response to IVIg, and (3) lend support to the hypothesis that in some patients, an IgG subclass switch from IgG3 to IgG4 may be the correlate of a secondary progressive or relapsing course following a GBS-like onset. KW - Guillain-Barre-Syndrome KW - inflammatory demyelinating polyradiculoneuropathy KW - musk myasthenia gravis KW - periperal nerve KW - neurofascin KW - autoantibodies KW - ontactin 1 KW - biopsies KW - binding KW - switch Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230079 VL - 7 IS - 5 ER - TY - JOUR A1 - Hecker, Katharina A1 - Grüner, Julia A1 - Hartmannsberger, Beate A1 - Appeltshauser, Luise A1 - Villmann, Carmen A1 - Sommer, Claudia A1 - Doppler, Kathrin T1 - Different binding and pathogenic effect of neurofascin and contactin–1 autoantibodies in autoimmune nodopathies JF - Frontiers in Immunology N2 - Introduction IgG4 autoantibodies against paranodal proteins are known to induce acute-onset and often severe sensorimotor autoimmune neuropathies. How autoantibodies reach their antigens at the paranode in spite of the myelin barrier is still unclear. Methods We performed in vitro incubation experiments with patient sera on unfixed and unpermeabilized nerve fibers and in vivo intraneural and intrathecal passive transfer of patient IgG to rats, to explore the access of IgG autoantibodies directed against neurofascin-155 and contactin-1 to the paranodes and their pathogenic effect. Results We found that in vitro incubation resulted in weak paranodal binding of anti-contactin-1 autoantibodies whereas anti-neurofascin-155 autoantibodies bound to the nodes more than to the paranodes. After short-term intraneural injection, no nodal or paranodal binding was detectable when using anti-neurofascin-155 antibodies. After repeated intrathecal injections, nodal more than paranodal binding could be detected in animals treated with anti-neurofascin-155, accompanied by sensorimotor neuropathy. In contrast, no paranodal binding was visible in rats intrathecally injected with anti-contactin-1 antibodies, and animals remained unaffected. Conclusion These data support the notion of different pathogenic mechanisms of anti-neurofascin-155 and anti-contactin-1 autoantibodies and different accessibility of paranodal and nodal structures. KW - autoimmune nodopathy KW - IgG4 KW - neurofascin KW - contactin KW - node of ranvier KW - inflammatory neuropathy KW - passive transfer Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-320395 VL - 14 ER -