Low-dose rituximab treatment in a patient with anti-neurofascin-155 IgG4 autoimmune nodopathy.

Autoimmune nodopathy is a new entity of immune-mediated neuropathies associated with antibodies against nodal-paranodal epitopes. We present a detailed clinical and serological work-up of a patient with autoimmune nodopathy with anti-neurofascin-155 (anti-NF-155) IgG4 antibodies who was treated with low-dose (500 mg) rituximab, which led to a decrease of anti-NF-155 antibody titer, depletion of B cells, normalization of the levels of neurofilament light chain in serum, and significant clinical improvement. This case suggests that a low-dose rituximab could be as effective as previously reported much higher doses, and presumably with a lower risk of adverse effects and infections.

Neurodegenerative biomarkers outperform neuroinflammatory biomarkers in amyotrophic lateral sclerosis.

OBJECTIVE: To describe the diagnostic and prognostic performance, and longitudinal trajectories, of potential biomarkers of neuroaxonal degeneration and neuroinflammation in amyotrophic lateral sclerosis (ALS). METHODS: This case-control study included 192 incident ALS patients, 42 ALS mimics, 114 neurological controls, and 117 healthy controls from Stockholm, Sweden. Forty-four ALS patients provided repeated measurements. We assessed biomarkers of (1)neuroaxonal degeneration: neurofilament light (NfL) and phosphorylated neurofilament heavy (pNfH) in cerebrospinal fluid (CSF) and NfL in serum, and (2)neuroinflammation: chitotriosidase-1 (CHIT1) and monocyte chemoattractant protein 1 (MCP-1) in CSF. To evaluate diagnostic performance, we calculated the area under the curve (AUC). To estimate prognostic performance, we applied quantile regression and Cox regression. We used linear regression models with robust standard errors to assess temporal changes over time. RESULTS: Neurofilaments performed better at differentiating ALS patients from mimics (AUC: pNfH 0.92, CSF NfL 0.86, serum NfL 0.91) than neuroinflammatory biomarkers (AUC: CHIT1 0.71, MCP-1 0.56). Combining biomarkers did not improve diagnostic performance. Similarly, neurofilaments performed better than neuroinflammatory biomarkers at predicting functional decline and survival. The stratified analysis revealed differences according to the site of onset: in bulbar patients, neurofilaments and CHIT1 performed worse at predicting survival and correlations were lower between biomarkers. Finally, in bulbar patients, neurofilaments and CHIT1 increased longitudinally but were stable in spinal patients. CONCLUSIONS: Biomarkers of neuroaxonal degeneration displayed better diagnostic and prognostic value compared with neuroinflammatory biomarkers. However, in contrast to spinal patients, in bulbar patients neurofilaments and CHIT1 performed worse at predicting survival and seemed to increase over time.

Validation of elevated levels of interleukin-8 in the cerebrospinal fluid, and discovery of new biomarkers in patients with GBS and CIDP using a proximity extension assay.

Background: Biomarkers for diagnosis of inflammatory neuropathies, assessment of prognosis, and treatment response are lacking. Methods: CSF and EDTA plasma from patients with Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), healthy controls (HC) and disease controls were analyzed with Olink multiplex proximity extension assay (PEA) from two independent cohorts. Levels of interleukin-8 (IL8) were further analyzed with ELISA in patients with GBS, CIDP, paraproteinemia-related demyelinating polyneuropathy (PDN), multifocal motor neuropathy (MMN), HC and disease controls. ROC analysis was performed. Outcome was measured with the GBS-disability score (GBS-ds) or Inflammatory Neuropathy Cause and Treatment (INCAT) score. Results: In CSF, multiplex PEA analysis revealed up-regulation of IL8 in GBS compared to CIDP and HC respectively, and CIDP compared to HC. In addition, levels of IL2RA were upregulated in GBS compared to both HC and CIDP, SELE in GBS compared to HC, and ITGAM, IL6, and NRP1 in GBS compared to CIDP. In plasma, levels of MMP3, THBD and ITGAM were upregulated in CIDP compared to HC. Validation of multiplex IL8 results using ELISA, revealed increased levels of IL8 in CSF in patients with GBS and CIDP versus HC and non-inflammatory polyneuropathies (NIP) respectively, as well as in PDN versus NIP and HC. Levels of IL8 in CSF correlated with impairment in the acute phase of GBS as well as outcome at 6-months follow up. Conclusion: IL8 in CSF is validated as a diagnostic biomarker in GBS and CIDP, and a prognostic biomarker in GBS. Multiplex PEA hereby identifies several potential biomarkers in GBS and CIDP.

Efficacy and Safety of Rituximab for New-Onset Generalized Myasthenia Gravis: The RINOMAX Randomized Clinical Trial.

Importance: Rituximab is a third-line option for refractory generalized myasthenia gravis (MG) based on empirical evidence, but its effect in new-onset disease is unknown. Objective: To investigate the efficacy and safety of rituximab compared with placebo as an add-on to standard of care for MG. Design, Setting, and Participants: This randomized, double-blind, placebo-controlled study took place throughout 48 weeks at 7 regional clinics in Sweden. Key inclusion criteria were age older than 18 years, onset of generalized symptoms within 12 months or less, and a Quantitative Myasthenia Gravis (QMG) score of 6 or more. Patients were screened from October 20, 2016, to March 2, 2020. Key exclusion criteria included pure ocular MG, suspected thymoma, previous thymectomy, and prior noncorticosteroid immunosuppressants or high doses of corticosteroids. Interventions: Participants were randomized 1:1 without stratification to a single intravenous infusion of 500 mg of rituximab or matching placebo. Main Outcomes and Measures: Minimal disease manifestations at 16 weeks defined as a QMG score of 4 or less with prednisolone, 10 mg or less daily, and no rescue treatment. Results: Of 87 potentially eligible patients, 25 were randomized to rituximab (mean [SD] age, 67.4 [13.4] years; 7 [28%] female) and 22 to placebo (mean [SD] age, 58 [18.6] years; 7 [32%] female). Compared with placebo, a greater proportion with rituximab met the primary end point; 71% (17 of 24) in the rituximab group vs 29% (6 of 21) in the placebo group (Fisher exact test P = .007; probability ratio, 2.48 [95% CI, 1.20-5.11]). Secondary end points, comparing changes in Myasthenia Gravis Activities of Daily Living and Myasthenia Gravis Quality of Life at 16 weeks with QMG at 24 weeks did not differ between groups with censoring for rescue treatment (per-protocol analysis) but were in favor of active treatment when rescue treatment was taken into account by worst rank imputation (post hoc analysis). Rescue treatments were also more frequent in the placebo arm (rituximab: 1 [4%]; placebo, 8 [36%]). One patient in the placebo arm had a myocardial infarction with cardiac arrest and 1 patient in the active arm experienced a fatal cardiac event. Conclusions and Relevance: A single dose of 500 mg of rituximab was associated with greater probability of minimal MG manifestations and reduced need of rescue medications compared with placebo. Further studies are needed to address long-term benefit-risk balance with this treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT02950155.

Neurofilament light chain and total tau in the differential diagnosis and prognostic evaluation of acute and chronic inflammatory polyneuropathies.

BACKGROUND AND PURPOSE: To investigate the diagnostic and prognostic value of axonal injury biomarkers in patients with inflammatory polyneuropathies. METHODS: Neurofilament light chain (NfL) and total tau (T-tau) were measured in the cerebrospinal fluid (CSF) and plasma in 41 patients with Guillain-Barré syndrome (GBS), 32 patients with chronic inflammatory demyelinating polyneuropathy (CIDP), 10 with paraproteinemia-related demyelinating polyneuropathy (PDN), and 8 with multifocal motor neuropathy (MMN), in comparison with 39 disease-free controls and 59 other controls. Outcome was measured with the GBS-disability score (GBS-ds) or Inflammatory Neuropathy Cause and Treatment (INCAT) disability score. RESULTS: Neurofilament light chain levels in CSF and plasma were higher in GBS, CIDP, and PDN vs. disease-free controls. Patients with MMN had higher NfL levels in plasma vs. disease-free controls, but lower levels in CSF and plasma vs. patients with amyotrophic lateral sclerosis (ALS). T-tau levels in plasma were higher in GBS, CIDP, PDN, and MMN vs. all control groups. Neurofilament light chain levels in CSF and plasma in patients with GBS correlated with GBS-ds, as higher levels were associated with inability to run after 6 and 12 months. NfL levels in CSF and plasma in CIDP did not correlate significantly with outcome. CONCLUSIONS: Acute and chronic inflammatory neuropathies are associated with an increase in levels of NfL in CSF and plasma, but NfL is validated as a prognostic biomarker only in GBS. NfL could be used in differentiating patients with MMN from ALS. T-tau in plasma is a novel biomarker that could be used in a diagnostic assessment of patients with acute and chronic inflammatory polyneuropathies.

Measurement of sCD27 in the cerebrospinal fluid identifies patients with neuroinflammatory disease.

BACKGROUND: Laboratory tests to assist in the diagnosis and monitoring of neuroinflammatory diseases are scarce. The soluble form of the CD27 molecule (sCD27) is shed in high concentrations by activated T cells and can be detected in the cerebrospinal fluid. The aim of this study was to investigate whether CSF quantitation of sCD27 could discriminate between inflammatory and non-inflammatory neurological diseases. METHODS: The concentration of sCD27 was measured using a commercially available ELISA in 803 well-defined subjects from a study cohort comprised of 338 patients with neuroinflammatory disease, 338 with non-inflammatory neurological disease and 127 controls without neurological disease. RESULTS: The median value of cerebrospinal fluid sCD27 was 64 pg/mL (IQR 0-200) in controls, 58 pg/mL (IQR 0-130) in patients with non-inflammatory disease and 740 pg/mL (IQR 230-1800) in patients with inflammatory disease. The likelihood ratio of having an inflammatory disease was 10 (sensitivity 74% and specificity 93%) if the sCD27 concentration was >250 pg/mL. In patients with a known inflammatory condition, the likelihood ratio of having an infection was 10 (sensitivity 40% and specificity 96%) if the sCD27 concentration was >2500 pg/mL. CONCLUSIONS: The likelihood of having an inflammatory neurological condition is increased with elevated concentrations of sCD27 in cerebrospinal fluid. Rapid tests of sCD27 should be developed to assist clinicians in diagnosis of neuroinflammatory disease.

An unusual cause of fatal rapid-onset ataxia plus syndrome.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a demyelinating disorder of the central nervous system caused by reactivation of the JC-virus and is in most cases associated with underlying immunosuppression. Acquired immune deficiency syndrome (AIDS) and hematological malignancies are well-known predisposing factors for PML. However, in the past ten years, various pharmacological agents have been associated with increased risk of PML. Based on the phenomenology PML can be divided into the cerebral form and the rare cerebellar form. CASE PRESENTATION: Here we describe a man affected by polycythemia vera (PCV) that was treated with hydroxyurea (HU) and developed PML. The initially PML presentation included ataxia as one of the main features. Brain MRI displayed widespread supratentorial and infratentorial lesions. Immunological analysis revealed absence of reactivity to a wide range of antigens. The course of disease was rapidly progressive with fatal outcome - autopsy ruled out leukemic transformation. CONCLUSION: The occurrence of PML in PCV patients is very rare and has been reported only once. Movement disorders, such as ataxia, are also less frequent. In the present case the PML was likely multifactorial.