ObjectiveTo assess the prevalence and isotypes of anti-nodal/paranodal antibodies to nodal/paranodal proteins in a large chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) cohort, compare clinical features in seronegative vs seropositive patients, and gather evidence of their isotype-specific pathogenic role.MethodsAntibodies to neurofascin-155 (Nfasc155), neurofascin-140/186 (Nfasc140/186), contactin-1 (CNTN1), and contactin-associated protein 1 (Caspr1) were detected with ELISA and/or cell-based assay. Antibody pathogenicity was tested by immunohistochemistry on skin biopsy, intraneural injection, and cell aggregation assay.ResultsOf 342 patients with CIDP, 19 (5.5%) had antibodies against Nfasc155 (n = 9), Nfasc140/186 and Nfasc155 (n = 1), CNTN1 (n = 3), and Caspr1 (n = 6). Antibodies were absent from healthy and disease controls, including neuropathies of different causes, and were mostly detected in patients with European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) definite CIDP (n = 18). Predominant antibody isotypes were immunoglobulin G (IgG)4 (n = 13), IgG3 (n = 2), IgG1 (n = 2), or undetectable (n = 2). IgG4 antibody-associated phenotypes included onset before 30 years, severe neuropathy, subacute onset, tremor, sensory ataxia, and poor response to intravenous immunoglobulin (IVIG). Immunosuppressive treatments, including rituximab, cyclophosphamide, and methotrexate, proved effective if started early in IVIG-resistant IgG4-seropositive cases. Five patients with an IgG1, IgG3, or undetectable isotype showed clinical features indistinguishable from seronegative patients, including good response to IVIG. IgG4 autoantibodies were associated with morphological changes at paranodes in patients' skin biopsies. We also provided preliminary evidence from a single patient about the pathogenicity of anti-Caspr1 IgG4, showing their ability to penetrate paranodal regions and disrupt the integrity of the Nfasc155/CNTN1/Caspr1 complex.ConclusionsOur findings confirm previous data on the tight clinico-serological correlation between antibodies to nodal/paranodal proteins and CIDP. Despite the low prevalence, testing for their presence and isotype could ultimately be part of the diagnostic workup in suspected inflammatory demyelinating neuropathy to improve diagnostic accuracy and guide treatment.Classification of evidenceThis study provides Class III evidence that antibodies to nodal/paranodal proteins identify patients with CIDP (sensitivity 6%, specificity 100%).

ObjectivesA few variants of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) have been described, but their frequency and evolution to typical CIDP remain unclear. To determine the frequency and characteristics of the CIDP variants, their possible evolution to typical CIDP, and treatment response.MethodsWe applied a set of diagnostic criteria to 460 patients included in a database of Italian patients with CIDP. Clinical characteristics and treatment response were reviewed for each patient. The Kaplan-Meier curve was used to estimate the progression rate from atypical to typical CIDP.ResultsAt the time of inclusion, 376 (82%) patients had a diagnosis of typical CIDP while 84 (18%) had atypical CIDP, including 34 (7%) with distal acquired demyelinating symmetric neuropathy (DADS), 17 (4%) with purely motor, 17 (4%) with Lewis-Sumner syndrome (LSS) and 16 (3.5%) with purely sensory CIDP. Based on retrospective review of the symptoms and signs present at onset and for at least 1 year, 180 (39%) patients had an initial diagnosis compatible with atypical CIDP that in 96 (53%) patients evolved to typical CIDP. Mean disease duration was longer in patients evolving to typical CIDP than in those not evolving (p=0.0016). Patients with DADS and LSS had a less frequent response to immunoglobulin than those with typical CIDP, while patients with purely motor and sensory CIDP had a similar treatment response.ConclusionsThe proportion of patients with atypical CIDP varies during the disease course. DADS and LSS have a less frequent response to intravenous immunoglobulin compared with typical CIDP, raising the possibility of a different underlying pathogenetic mechanism.

This multi-center Italian prospective observational study reports the 4 months follow-up data of 87 patients affected by chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN) shifted from intravenous to subcutaneous immunoglobulin treatment. A therapeutic shift from intravenous to subcutaneous immunoglobulin was performed in 87 patients (66 CIDP; 21 MMN) affected by immune-mediated peripheral neuropathies with evidence of a sustained clinical response to intravenous immunoglobulin. Patients were evaluated by means of the Overall Neuropathy Limitation Scale, Medical Research Council Scale and Life Quality Index questionnaire, both at the time of therapeutic shift and after 4 months of subcutaneous immunoglobulin treatment. A sustained clinical efficacy was observed after the switch to subcutaneous immunoglobulin: the Overall Neuropathy Limitation Scale score improved in the group of 66 CIDP patients (P = 0.018), with only one subject reporting a worsening of 1 point, and remained stable in the group of 21 MMN patients (P = 0.841), with one subject reporting a worsening of two points. An improvement in the patient's perception of therapeutic setting was reported in both groups. This large multi-center study confirms the short-term clinical equivalence of subcutaneous versus intravenous immunoglobulin and a possible improvement in the patient's perception of therapeutic setting with the subcutaneous administration. However, further studies are required to extend the results to a longer observational period.

Background and purpose The role of lifestyle and dietary habits and antecedent events has not been clearly identified in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Methods Information was collected about modifiable environmental factors and antecedent infections and vaccinations in patients with CIDP included in an Italian CIDP Database. Only patients who reported not having changed their diet or the lifestyle habits investigated in the study after the appearance of CIDP were included. The partners of patients with CIDP were chosen as controls. Gender‐matched analysis was performed with randomly selected controls with a 1:1 ratio of patients and controls. Results Dietary and lifestyle data of 323 patients and 266 controls were available. A total of 195 cases and 195 sex‐matched controls were used in the analysis. Patients eating rice at least three times per week or eating fish at least once per week appeared to be at decreased risk of acquiring CIDP. Data on antecedent events were collected in 411 patients. Antecedent events within 1–42 days before CIDP onset were reported by 15.5% of the patients, including infections in 12% and vaccinations in 1.5%. Patients with CIDP and antecedent infections more often had an acute onset of CIDP and cranial nerve involvement than those without these antecedent events. Conclusions The results of this preliminary study seem to indicate that some dietary habits may influence the risk of CIDP and that antecedent infections may have an impact on the onset and clinical presentation of the disease.

BackgroundChronic immune sensory polyradiculopathy (CISP) identifies a progressive acquired peripheral dysimmune neuropathy recognized as a chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) variant. We describe a young woman with a thirteen-year history of CISP with a belated variable response to intravenous immunoglobulin (IVIG) and an almost erratic anticipation of symptoms between IVIG cycles. The association of IVIG and corticosteroids, immunosuppressants, plasmapheresis, did not lead to clinical improvement and was characterized by significant side effects. We evaluated a combined clinical and somatosensory evoked potentials (SSEPs) approach aimed to identify possible predictive parameters concerning the effect and duration of each IVIG administration. Neurologic disability was evaluated using INCAT - Overall Disability Sum Score (INCAT-ODSS).Case presentationA 30-year-old woman presented on 2004 for the subacute onset of asymmetric paresthesias in the lower limbs over the previous six months. The symptoms had been relapsing-remitting during the first four months, followed by a slow progression, resulting in limbs ataxia and a progressive gait disturbance requiring Canadian crutches. Motor and sensory nerve conduction studies and electromyographic evaluation were into normal limits. Median SSEPs were normal, while tibial SSEPs were characterised by the bilateral absence of both lumbar and cortical responses. Cerebrospinal fluid detected an increased protein concentration, while spinal MRI showed a pronounced thickening of the sacral nerve roots, together with a tube-shaped enlargement. These findings led to the diagnosis of CISP and the patient was treated with IVIG reaching a stable remission over the following 9 years. In early 2014, the patient began to show a variable response to treatment with erratic anticipation of sensory disturbances, and a more pronounced walking disability: corticosteroids, plasmapheresis, mycophenolate mofetil and cyclophosphamide were uneffective and burdened by relevant side effects. To better assess the response to IVIG in terms of time-effect, consistency and duration, we have combined a scheduled clinical and SSEPs evaluation during and after each IVIG cycle.ConclusionsThe correlation between the neurophysiological data and the INCAT-ODSS scores has allowed the modulation of IVIG cycles with a significant reduction of the clinical fluctuations and disability. SSEPs may therefore represent an useful and recommended additional aid for the treatment schedule of this rare clinical form.