PT  - JOURNAL ARTICLE
AU  - Luise Appeltshauser
AU  - Anna-Michelle Brunder
AU  - Annika Heinius
AU  - Peter Körtvélyessy
AU  - Klaus-Peter Wandinger
AU  - Ralf Junker
AU  - Carmen Villmann
AU  - Claudia Sommer
AU  - Frank Leypoldt
AU  - Kathrin Doppler
TI  - Antiparanodal antibodies and IgG subclasses in acute autoimmune neuropathy
AID  - 10.1212/NXI.0000000000000817
DP  - 2020 Sep 01
TA  - Neurology - Neuroimmunology Neuroinflammation
PG  - e817
VI  - 7
IP  - 5
4099  - http://nn.neurology.org/content/7/5/e817.short
4100  - http://nn.neurology.org/content/7/5/e817.full
SO  - Neurol Neuroimmunol Neuroinflamm2020 Sep 01; 7
AB  - 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-Barré 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.A-CIDP=acute-onset chronic inflammatory demyelinating polyradiculoneuropathy; Caspr-1=contactin-1-associated protein-1; CBA=cell-based assay; CIDP=chronic inflammatory demyelinating polyradiculoneuropathy; GBS=Guillain-Barré syndrome; HEK=human embryonic kidney; HLA=human leukocyte antigen; ICU=intensive care unit; IVIg=IV immunoglobulin; MFS=Miller-Fisher syndrome; NF=neurofascin; OD=optical density; R-GBS=recurrent GBS