Long-term follow-up of patients with neuromyelitis optica after repeated therapy with rituximab

Drugs Targeting CD20 in Multiple Sclerosis: Pharmacology, Efficacy, Safety, and Tolerability

Currently, there are four monoclonal antibodies (mAbs) that target the cluster of differentiation (CD) 20 receptor available to treat multiple sclerosis (MS): rituximab, ocrelizumab, ofatumumab, and ublituximab. B-cell depletion therapy has changed the therapeutic landscape of MS through robust efficacy on clinical manifestations and MRI lesion activity, and the currently available anti-CD20 mAb therapies for use in MS are a cornerstone of highly effective disease-modifying treatment. Ocrelizumab is currently the only therapy with regulatory approval for primary progressive MS. There are currently few data regarding the relative efficacy of these therapies, though several clinical trials are ongoing. Safety concerns applicable to this class of therapeutics relate primarily to immunogenicity and mechanism of action, and include infusion-related or injection-related reactions, development of hypogammaglobulinemia (leading to increased infection and malignancy risk), and decreased vaccine response. Exploration of alternative dose/dosing schedules might be an effective strategy for mitigating these risks. Future development of biosimilar medications might make these therapies more readily available. Although anti-CD20 mAb therapies have led to significant improvements in disease outcomes, CNS-penetrant therapies are still needed to more effectively address the compartmentalized inflammation thought to play an important role in disability progression.

Treatment of neuromyelitis optica spectrum disorder: revisiting the complement system and other aspects of pathogenesis

Neuromyelitis optica spectrum disorder (NMOSD) represents a rare neuroimmunological disease causing recurrent attacks and accumulation of permanent disability in affected patients. The discovery of the pathogenic IgG‑1 antibody targeting a water channel expressed in astrocytes, aquaporin 4, constitutes a milestone achievement. Subsequently, multiple pathophysiological aspects of this distinct disease entity have been investigated. Demyelinating lesions and axonal damage ensue from autoantibodies targeting an astroglial epitope. This conundrum has been addressed in the current disease model, where activation of the complement system as well as B cells and interleukin 6 (IL-6) emerged as key contributors. It is the aim of this review to address these factors in light of novel treatment compounds which reflect these pathophysiological concepts in aiming for attack prevention, thus reducing disease burden in patients with NMOSD.

Intruders or protectors - the multifaceted role of B cells in CNS disorders

B lymphocytes are immune cells studied predominantly in the context of peripheral humoral immune responses against pathogens. Evidence has been accumulating in recent years on the diversity of immunomodulatory functions that B cells undertake, with particular relevance for pathologies of the central nervous system (CNS). This review summarizes current knowledge on B cell populations, localization, infiltration mechanisms, and function in the CNS and associated tissues. Acute and chronic neurodegenerative pathologies are examined in order to explore the complex, and sometimes conflicting, effects that B cells can have in each context, with implications for disease progression and treatment outcomes. Additional factors such as aging modulate the proportions and function of B cell subpopulations over time and are also discussed in the context of neuroinflammatory response and disease susceptibility. A better understanding of the multifactorial role of B cell populations in the CNS may ultimately lead to innovative therapeutic strategies for a variety of neurological conditions.

Evidence-based management of optic neuritis

PURPOSE OF REVIEW

Optic neuritis can result from several distinct causes, including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody disease (MOGAD), when not idiopathic. This review discusses evidence-based treatment approaches contingent upon each specific cause of optic neuritis.

RECENT FINDINGS

Current evidence highlights the need for prompt plasmapheresis as adjunct to intravenous methylprednisolone (IVMP) in patients with NMOSD-associated optic neuritis. Recent advances have included a proliferation of novel disease modifying therapies (DMTs) for long-term management of NMOSD and an understanding of how existing therapeutic options can be leveraged to optimally treat MOGAD.

SUMMARY

In acute idiopathic or MS-associated optic neuritis, IVMP hastens visual recovery, though it does not substantially affect final visual outcomes. IVMP and adjunctive plasmapheresis are beneficial in the treatment of NMOSD-associated optic neuritis, with a shorter time-to-treatment associated with a higher likelihood of recovery. The natural history of untreated MOGAD-associated optic neuritis is unclear but treatment with IVMP is near-universal given phenotypic similarities with NMOSD. Long-term immunosuppressive therapy is warranted in patients with NMOSD as well as in patients with MOGAD with poor visual recovery or recurrent attacks.

Therapeutic targeting of gut-originating regulatory B cells in neuroinflammatory diseases

Regulatory B cells (Bregs) are immunosuppressive cells that support immunological tolerance by the production of IL-10, IL-35, and TGF-β. Bregs arise from different developmental stages in response to inflammatory stimuli. In that regard, mounting evidence points towards a direct influence of gut microbiota on mucosal B cell development, activation, and regulation in health and disease. While an increasing number of diseases are associated with alterations in gut microbiome (dysbiosis), little is known about the role of microbiota on Breg development and induction in neuroinflammatory disorders. Notably, gut-originating, IL-10- and IgA-producing regulatory plasma cells have recently been demonstrated to egress from the gut to suppress inflammation in the CNS raising fundamental questions about the triggers and functions of mucosal-originating Bregs in systemic inflammation. Advancing our understanding of Bregs in neuroinflammatory diseases could lead to novel therapeutic approaches. Here, we summarize the main aspects of Breg differentiation and functions and evidence about their involvement in neuroinflammatory diseases. Further, we highlight current data of gut-originating Bregs and their microbial interactions and discuss future microbiota-regulatory B cell-targeted therapies in immune-mediated diseases.

Alterations in Aquaporin-4-IgG Serostatus in 986 Patients: A Laboratory-Based Longitudinal Analysis

OBJECTIVE

This study was undertaken to investigate factors associated with aquaporin-4 (AQP4)-IgG serostatus change using a large serological database.

METHODS

This retrospective study utilizes Mayo Clinic Neuroimmunology Laboratory data from 2007 to 2021. We included all patients with ≥2 AQP4-IgG tests (by cell-based assay). The frequency and clinical factors associated with serostatus change were evaluated. Multivariable logistic regression analysis examined whether age, sex, or initial titer was associated with serostatus change.

RESULTS

There were 933 patients who had ≥2 AQP4-IgG tests with an initial positive result. Of those, 830 (89%) remained seropositive and 103 (11%) seroreverted to negative. Median interval to seroreversion was 1.2 years (interquartile range [IQR] = 0.4-3.5). Of those with sustained seropositivity, titers were stable in 92%. Seroreversion was associated with age ≤ 20 years (odds ratio [OR] = 2.25; 95% confidence interval [CI] = 1.09-4.63; p = 0.028) and low initial titer of ≤1:100 (OR = 11.44, 95% CI = 3.17-41.26, p < 0.001), and 5 had clinical attacks despite seroreversion. Among 62 retested after seroreversion, 50% returned to seropositive (median = 224 days, IQR = 160-371). An initial negative AQP4-IgG test occurred in 9,308 patients. Of those, 99% remained seronegative and 53 (0.3%) seroconverted at a median interval of 0.76 years (IQR = 0.37-1.68).

INTERPRETATION

AQP4-IgG seropositivity usually persists over time with little change in titer. Seroreversion to negative is uncommon (11%) and associated with lower titers and younger age. Seroreversion was often transient, and attacks occasionally occurred despite prior seroreversion, suggesting it may not reliably reflect disease activity. Seroconversion to positive is rare (<1%), limiting the utility of repeat testing in seronegative patients unless clinical suspicion is high. ANN NEUROL 2023;94:727-735.

A Clinical Approach to Existing and Emerging Therapeutics in Neuromyelitis Optica Spectrum Disorder

PURPOSE OF REVIEW

Neuromyelitis optica spectrum disorder (NMOSD) is a rare but highly disabling disease of the central nervous system. Unlike multiple sclerosis, disability in NMOSD occurs secondary to relapses that, not uncommonly, lead to blindness, paralysis, and death. Recently, newer, targeted immunotherapies have been trialed and are now in the treatment arsenal. We have endeavoured to evaluate the current state of NMOSD therapeutics.

RECENT FINDINGS

This review provides a pragmatic evaluation of recent clinical trials and post-marketing data for rituximab, inebilizumab, satralizumab, eculizumab, and ravalizumab, contrasted to older agents. We also review contemporary issues such as treatment in the context of SARS-CoV2 infection and pregnancy. There has been a dramatic shift in NMOSD morbidity and mortality with earlier and improved disease recognition, diagnostic accuracy, and the advent of more effective, targeted therapies. Choosing a maintenance therapy remains nuanced depending on patient factors and accessibility. With over 100 putative agents in trials, disease-free survival is now a realistic goal for NMOSD patients.

ALSUntangled #67: rituximab

ALSUntangled reviews alternative and off-label treatments on behalf of people with ALS who ask about them. Here we review rituximab, a drug which specifically depletes B lymphocytes. We show a current lack of evidence for a role of these cells in ALS progression. The one patient we found who described using Rituximab for their ALS found no benefit. Given all this, and the known serious risks of rituximab, we advise against its use as an ALS treatment.

Therapeutic response to rituximab in seropositive neuromyelitis optica: Experience from a tertiary care center in South India

Objectives

Neuromyelitis optica (NMO) is a severe central nervous system demyelinating disease caused by autoantibodies to anti-aquaporin-4 immunoglobulin-G (AQP4-IgG). Rituximab, a monoclonal antibody targeting CD20 cells, is effective in neuromyelitis optica spectrum disorder (NMOSD) in several observational studies and small randomized controlled trials. However, this includes both AQP4-IgG antibody positive and negative cases. Whether rituximab is more effective in seropositive NMO is unknown. The aim of the study was to determine the efficacy of rituximab in seropositive NMO.

Materials and Methods

This single-center ambispective study with retrospective data collection and prospective follow-up included patients with NMOSD who were positive for AQP4-Ig-G and treated with rituximab. Efficacy outcomes assessed were annualized relapse rate (ARR), disability progression by expanded disability status scale (EDSS), very good outcome (defined as no relapse and an EDSS ≤3.5), and persistent antibody positivity. Safety was also monitored.

Results

Between June 2017 and December 2019, 15 AQP4-IgG-positive cases were identified. The mean (± SD) age was 36 ± 17.9 years and 73.3% were females. Transverse myelitis followed by optic neuritis was the most common presentations. Rituximab was initiated after a median period of 19-weeks from the disease onset. The mean number of rituximab doses received was 6.4 ± 2.3. After a mean follow-up duration of 107 ± 74.7 weeks from the first dose of rituximab, ARR significantly reduced from 0.5 ± 0.9 to 0.02 ± 0.08, difference 0.48 ± 0.86 (95% confidence intervals [CI], 0.0009-0.96; P = 0.05). The number of relapses also reduced significantly from 0.6 ± 0.8-0.07 ± 0.26 , a difference of 0.53 ± 0.91 (95% CI, 0.026-1.05; P = 0.041). EDSS also significantly reduced from 5.6 ± 2.5-3.3 ± 2.9 , a difference of 2.23 ± 2.36 (95% CI, 0.93-3.54; P = 0.003). Very good outcome was obtained in 73.3% (11 of 15); P = 0.002. AQP4-IgG remained positive in 66.7% (4 of 6) when repeated after a mean period of 149.5 ± 51.1 weeks after the first dose of rituximab. Neither pre-treatment ARR, EDSS, time to initiate rituximab, the total number of rituximab doses, or time to repeat AQP4-IgG were significantly associated with persistent antibody positivity. No serious adverse events were observed.

Conclusion

Rituximab exhibited high efficacy and good safety in seropositive NMO. Larger trials in this subgroup are warranted to confirm these findings.

Clinical and epidemiological correlates of treatment change in patients with NMOSD: insights from the CIRCLES cohort

OBJECTIVE

Neuromyelitis optica spectrum disorders (NMOSD) represent rare autoimmune diseases of the central nervous system largely targeting optic nerve(s) and spinal cord. The present analysis used real-world data to identify clinical and epidemiological correlates of treatment change in patients with NMOSD.

METHODS

CIRCLES is a longitudinal, observational study of NMOSD conducted at 15 centers across North America. Patients with ≥ 60 days of follow-up and receiving on-study maintenance treatment were evaluated. The mean annual relapse rate (ARR) was estimated using negative binomial models; the likelihood of treatment change was estimated using Cox proportional hazards models. Relapses were included as time-varying covariates to estimate the relationship to treatment change.

RESULTS

Of 542 patients included, 171 (31.5%) experienced ≥ 1 relapse on the study and 133 patients (24.5%) had ≥ 1 change in the treatment regimen. Two categories of variables significantly correlated with the likelihood of treatment change: (1) relapse: any on-study relapse (hazard ratio [HR] = 2.91; p < 0.001), relapse phenotypes (HR range = 2.15-5.49; p < 0.001), and pre-study ARR > 0.75 (HR 2.28; p < 0.001); 2) disease phenotype: brain syndrome only vs transverse myelitis involvement at onset (HR 2.44; p = 0.008), disease duration < 1 vs > 5 years (HR 1.66; p = 0.028), or autoimmune comorbidity (HR 1.55; p = 0.015). A subset of these factors significantly correlated with shorter time to first rituximab discontinuation.

CONCLUSIONS

In CIRCLES, relapse patterns and disease phenotype significantly correlated with changes in the maintenance treatment regimen. Such findings may facilitate the identification of patients with NMOSD who are likely to benefit from treatment change to reduce relapse risk or disease burden and enhance the quality of life.

Pharmaceutical care of rituximab in the treatment of children with refractory anti-NMDAR encephalitis: A case report

RATIONALE

Anti- N -methyl- d -aspartate receptor (NMDAR) encephalitis is a rare disease of nervous system, which is mediated by autoimmune mechanisms. The treatment of anti-NMDAR encephalitis includes Immunotherapy, symptomatic and supportive treatment for seizures and psychiatric symptoms. There are many kinds of drugs, so drug treatment management and pharmaceutical care for children are particularly important. At present, there are few reports on pharmaceutical care for children with this disease. Clinical pharmacists participated in the pharmaceutical care of a child with refractory anti-NMDAR encephalitis treated with rituximab, conducted drug treatment management on the dosage, administration method, complications and other aspects of off-label use of rituximab, combined with the children's clinical manifestations, inflammatory indicators, pathogenic detection, blood concentration, liver and kidney functions, drug interactions and other factors. The treatment plan of anti-infective drugs shall be adjusted, and attention shall be paid to whether there are adverse reactions during the treatment.

PATIENT CONCERNS

A 4-year-old girl presented with epileptic seizure, intermittent recurrent fever, high inflammatory markers, abnormal psychiatric function/cognitive impairment, language disorder, consciousness disturbance, and movement disorder/involuntary movement.

DIAGNOSIS

Refractory anti-NMDAR encephalitis.

INTERVENTIONS

The patient was given first-line (3 rounds of methylprednisolone pulse therapy and gamma globulin) and second-line (rituximab) immunotherapy. On the advice of a clinical pharmacist, the patient wasn't given Advanced antibacterial agents (voriconazole, vancomycin) therapy. On the 41st day of admission, the patient's temperature and inflammatory indicators were normal, CD19 + B cells were reduced to 0.

OUTCOMES

The patient consciousness level, cognition and orientation were gradually improved, mental disorder was improved, involuntary movement was obviously controlled, no seizure occurred again, and the patient was discharged with stable condition.

LESSONS

Clinical pharmacists ensure the safety, effectiveness and economy of patients' medication by carrying out the whole process of individualized drug treatment management and care for patients.

B-cell proliferation characteristics and monitoring significance under the modified reduced-dose rituximab regimen for NMOSD: A real-world case series study

OBJECTIVE

To explore the B-cell proliferation characteristics and monitoring significance under the modified reduced-dose rituximab (mRTX) regimen for neuromyelitis optica spectrum disorder (NMOSD).

METHODS

NMOSD patients treated with mRTX were recruited, and the percentages of total CD19⁺ B cells and CD27⁺ memory B cells were dynamically detected by flow cytometry. The annualized relapse rate (ARR) and expanded disability status scale (EDSS) scores were compared before and after mRTX treatment, and the differences in B-cell values were compared between groups.

RESULTS

A total of 34 patients with NMOSD were ultimately enrolled. The EDSS score decreased from 2.5 (1.5, 3.0) to 1.3 (1.0, 2.0), and the ARR decreased from 1.0 (0, 2.0) to 0 (0, 0) (p < 0.001). Relapses occurred in 6 patients, with total CD19⁺ B-cell percentages of 3.25% (2.7%, 3.7%) and CD27⁺ memory B-cell percentages of 0.3% (0.2%, 0.3%) at initial relapse. Twenty-eight patients (82.4%) remained relapse-free with 84 doses of mRTX. Before 56 repeated doses, the total CD19⁺ B cells and CD27⁺ memory B cells were 4.00% (3.14%, 5.32%) and 0.26% (0.17%, 0.40%), respectively. The mean dosing interval was 9.2 months. Both total CD19⁺ B cells and CD27⁺ memory B cells proliferated over time after mRTX use, with significantly faster proliferation rates in the later stages. In 28 relapse-free patients, the mean time to reach 1% for total CD19⁺ B cells was 210 days, and the mean time to reach 3% was 240 days, with the mean interval from 1% to 3% of 65 days. Twenty-five relapse-free patients had no significant differences in maximum, minimum, and mean B-cell values compared to those of 6 patients with relapse.

CONCLUSION

The high rate of B-cell proliferation under the mRTX regimen indicates that closer dynamic B-cell monitoring is required to guide repeated mRTX dosing. Sustained depletion of total CD19⁺ B cells targeting < 3% of lymphocytes may be feasible, enabling extended dosing intervals.

Ocrelizumab Treatment Modulates B-Cell Regulating Factors in Multiple Sclerosis

BACKGROUND AND OBJECTIVES

Antibodies to CD20 efficiently reduce new relapses in multiple sclerosis (MS), and ocrelizumab has been shown to be effective also in primary progressive MS. Although anti-CD20 treatments efficiently deplete B cells in blood, some B cells and CD20^- plasma cells persist in lymphatic organs and the inflamed CNS; their survival is regulated by the B cell-activating factor (BAFF)/A proliferation-inducing ligand (APRIL) system. The administration of a soluble receptor for BAFF and APRIL, atacicept, unexpectedly worsened MS. Here, we explored the long-term effects of ocrelizumab on immune cell subsets as well as on cytokines and endogenous soluble receptors comprising the BAFF-APRIL system.

METHODS

We analyzed immune cell subsets and B cell-regulating factors longitudinally for up to 2.5 years in patients with MS treated with ocrelizumab. In a second cohort, we determined B-cell regulatory factors in the CSF before and after ocrelizumab. We quantified the cytokines BAFF and APRIL along with their endogenous soluble receptors soluble B-cell maturation antigen (sBCMA) and soluble transmembrane activator and calcium-modulator and cyclophilin ligand (CAML) interactor (sTACI) using enzyme-linked immunosorbent assays (ELISAs). In addition, we established an in-house ELISA to measure sTACI-BAFF complexes.

RESULTS

Ocrelizumab treatment of people with MS persistently depleted B cells and CD20⁺ T cells. This treatment enhanced BAFF and reduced the free endogenous soluble receptor and decoy sTACI in both serum and CSF. Levels of sTACI negatively correlated with BAFF levels. Reduction of sTACI was associated with formation of sTACI-BAFF complexes.

DISCUSSION

We describe a novel effect of anti-CD20 therapy on the BAFF-APRIL system, namely reduction of sTACI. Because sTACI is a decoy for APRIL, its reduction may enhance local APRIL activity, thereby promoting regulatory IgA⁺ plasma cells and astrocytic interleukin (IL)-10 production. Thus, reducing sTACI might contribute to the beneficial effect of anti-CD20 as exogenous sTACI (atacicept) worsened MS.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that endogenous sTACI in blood and CSF is decreased after ocrelizumab treatment.

Acquired B-cell deficiency secondary to B-cell-depleting therapies

The advantage of the newer biological therapies is that the immunosuppressive effect is targeted, in contrast, to the standard, traditional immunomodulatory agents, which have a more global effect. However, there are unintended targets and consequences, even to these "precise" therapeutics, leading to acquired or secondary immunodeficiencies. Besides depleting specific cellular immune subsets, these biological agents, which include monoclonal antibodies against biologically relevant molecules, often have broader functional immune consequences, which become apparent over time. This review focuses on acquired B-cell immunodeficiency, secondary to the use of B-cell depleting therapeutic agents. Among the many adverse consequences of B-cell depletion is the risk of hypogammaglobulinemia, failure of B-cell recovery, impaired B-cell differentiation, and risk of infections. Factors, which modulate the outcomes of B-cell depleting therapies, include the intrinsic nature of the underlying disease, the concomitant use of other immunomodulatory agents, and the clinical status of the patient and other co-existing morbidities. This article seeks to explore the mechanism of action of B-cell depleting agents, the clinical utility and adverse effects of these therapies, and the relevance of systematic and serial laboratory immune monitoring in identifying patients at risk for developing immunological complications, and who may benefit from early intervention to mitigate the secondary consequences. Though these biological drugs are gaining widespread use, a harmonized approach to immune evaluation pre-and post-treatment has not yet gained traction across multiple clinical specialties, because of which, the true prevalence of these adverse events cannot be determined in the treated population, and a systematic and evidence-based dosing schedule cannot be developed. The aim of this review is to bring these issues into focus, and initiate a multi-specialty, data-driven approach to immune monitoring.

A meta-analysis on efficacy and safety of rituximab for neuromyelitis optica spectrum disorders

BACKGROUND

To assess the efficacy and safety of rituximab (RTX) in the treatment of neuromyelitis optica spectrum diseases (NMOSDs), and give a guideline on clinical medication.

METHODS

The databases of Pubmed, Embase, Cochrane Library, CNKI, and Wan fang were systematically searched by computer, and the search period was from the establishment of the databases until January 2022. To collect the trials of RTX in the treatment of NMOSDs, two researchers completed literature screening, quality assessment, and data extraction independently. Statistical analysis was performed using Review Manager 5.3 and Stata 15.1 software.

RESULTS

There were 37 studies in the meta-analysis, including 5 randomized controlled trials (RCTs) and 32 observational studies. Meta-analysis results revealed that NMOSDs patients treated with RTX significantly reduced the annualized relapse rate (ARR) (weighted mean difference [WMD] = 1.45, 95% confidence interval [CI]: 1.24-1.66, P < .01) and the Expanded disability status scale (EDSS) scores (WMD = 1.34, 95%CI: 1.25-1.44, P < .01). RTX is more effective than azathioprine (AZA) in the treatment of NMOSDs (ARR: WMD = -0.54, 95% CI: -0.75 to -0.33; EDSS: WMD = -0.65, 95% CI: -0.83 to -0.48; P < .0001).There was no difference in ARR and EDSS scores between anti-aquapor in-4-antibody seropositive NMOSD and seronegative NMOSD patients treated with RTX (ARR: WMD = -0.01, 95% CI: -0.25 to 0.24, P = .96 > 0.05; EDSS: WMD = 0, 95% CI: -0.30 to 0.31, P = .99 > 0.05). In this study, 681 patients were recorded safety data of RTX therapy, 23% (156 patients) had adverse events, and 0.7% (5 patients) of NMOSDs discontinued due to severe adverse reactions.

CONCLUSIONS

NMOSDs patients treated with RTX can significantly reduce the relapse frequency and EDSS scores, and also improve neurological dysfunction, besides the efficacy is better than azathioprine. RTX has a high incidence of adverse reactions, which are mild and with certain self limited, it should be cautious in clinical medication.

Ocrelizumab in Patients with Active Primary Progressive Multiple Sclerosis: Clinical Outcomes and Immune Markers of Treatment Response

Ocrelizumab is a B-cell-depleting monoclonal antibody approved for the treatment of relapsing-remitting multiple sclerosis (RRMS) and active primary progressive MS (aPPMS). This prospective, uncontrolled, open-label, observational study aimed to assess the efficacy of ocrelizumab in patients with aPPMS and to dissect the clinical, radiological and laboratory attributes of treatment response. In total, 22 patients with aPPMS followed for 24 months were included. The primary efficacy outcome was the proportion of patients with optimal response at 24 months, defined as patients free of relapses, free of confirmed disability accumulation (CDA) and free of T1 Gd-enhancing lesions and new/enlarging T2 lesions on the brain and cervical MRI. In total, 14 (63.6%) patients and 13 patients (59.1%) were classified as responders at 12 and 24 months, respectively. Time exhibited a significant effect on mean absolute and normalized gray matter cerebellar volume (F = 4.342, p = 0.23 and F = 4.279, p = 0.024, respectively). Responders at 24 months exhibited reduced peripheral blood ((%) of CD19+ cells) plasmablasts compared to non-responders at the 6-month point estimate (7.69 ± 4.4 vs. 22.66 ± 7.19, respectively, p = 0.043). Response to ocrelizumab was linked to lower total and gray matter cerebellar volume loss over time. Reduced plasmablast depletion was linked for the first time to sub-optimal response to ocrelizumab in aPPMS.

Rituximab abrogates aquaporin-4-specific germinal center activity in patients with neuromyelitis optica spectrum disorders

By studying paired blood and deep cervical lymph node samples from patients with neuromyelitis optica spectrum disorders, our data provide evidence for a germinal center–based generation of aquaporin-4 antibodies. Frequent serum aquaporin-4 immunoglobulin Ms (IgMs) and shifts in IgG subclasses were observed alongside preferential synthesis of aquaporin-4 IgGs and aquaporin-4–reactive B cells within lymph nodes. Both intranodal synthesis of aquaporin-4 antibodies and intranodal aquaporin-4–reactive B cells were robustly eliminated with rituximab administration. This study systematically explores lymph nodes that drain the central nervous system (CNS) in patients with CNS autoimmunity and offers a potential explanation as to why rituximab is clinically highly efficacious in autoantibody-mediated diseases despite no accompanying reduction in serum autoantibody levels.

Neuromyelitis optica spectrum disorders (NMOSDs) are caused by immunoglobulin G (IgG) autoantibodies directed against the water channel aquaporin-4 (AQP4). In NMOSDs, discrete clinical relapses lead to disability and are robustly prevented by the anti-CD20 therapeutic rituximab; however, its mechanism of action in autoantibody-mediated disorders remains poorly understood. We hypothesized that AQP4-IgG production in germinal centers (GCs) was a core feature of NMOSDs and could be terminated by rituximab. To investigate this directly, deep cervical lymph node (dCLN) aspirates (n = 36) and blood (n = 406) were studied in a total of 63 NMOSD patients. Clinical relapses were associated with AQP4-IgM generation or shifts in AQP4-IgG subclasses (odds ratio = 6.0; range of 3.3 to 10.8; P < 0.0001), features consistent with GC activity. From seven dCLN aspirates of patients not administered rituximab, AQP4-IgGs were detected alongside specific intranodal synthesis of AQP4-IgG. AQP4-reactive B cells were isolated from unmutated naive and mutated memory populations in both blood and dCLNs. After rituximab administration, fewer clinical relapses (annual relapse rate of 0.79 to 0; P < 0.001) were accompanied by marked reductions in both AQP4-IgG (fourfold; P = 0.004) and intranodal B cells (430-fold; P < 0.0001) from 11 dCLNs. Our findings implicate ongoing GC activity as a rituximab-sensitive driver of AQP4 antibody production. They may explain rituximab’s clinical efficacy in several autoantibody-mediated diseases and highlight the potential value of direct GC measurements across autoimmune conditions.

Comparison of Long-Term Use of Low Dose Rituximab and Mycophenolate Mofetil in Chinese Patients With Neuromyelitis Optica Spectrum Disorder

Background

Several studies have reported the efficacy and safety of rituximab (RTX) and mycophenolate mofetil (MMF) in neuromyelitis optica spectrum disorder (NMOSD). This study aimed to evaluate the efficacy and safety of long-term use of low-dose RTX and MMF in Chinese patients with NMOSD.

Methods

We retrospectively reviewed data from patients with NMOSD in our hospital. The enrolled patients were administrated different immunosuppressive agents. We accessed annual relapse rate (ARR), neurological disability (Expanded Disability Status Scale, EDSS), time to the next relapse, and adverse events.

Results

EDSS and ARR were both reduced after RTX and MMF treatment. Kaplan-Meier analysis indicated that patients treated with RTX had a longer time to next relapse compared other immunosuppressive agents before RTX (log-rank test: p &lt; 0.001). Furthermore, we evaluated the change of EDSS and ARR in RTX and MMF, and patients treated with RTX showed a better reduction. Eleven relapses from seven patients in group RTX and 20 relapses from 14 patients in group MMF were reported during follow-up.

Conclusion

Long-term using of low dose of RTX and MMF were effective and tolerable in Chinese patients with NMOSD. Compared with MMF, RTX showed a better way to reduce the ARR.

Experience with tocilizumab in patients with neuromyelitis optica spectrum disorders

INTRODUCTION

Neuromyelitis optica spectrum disorders (NMOSD) are immune-mediated inflammatory disorders of the central nervous system involving astrocytes, B lymphocytes, anti-aquaporin 4, and such inflammatory mediators as interleukin-6. Several immunosuppressants are used in their treatment. Tocilizumab, an interleukin-6 receptor antagonist, may be a treatment option.

METHOD

We performed an observational, retrospective study analysing parameters of effectiveness (annualised relapse rate, disability, and radiological progression) and safety of tocilizumab in patients with NMOSD in whom previous immunosuppressant treatment had failed. We aimed to evaluate the effectiveness and safety of tocilizumab in clinical practice in patients with NMOSD not responding to other immunosuppressants.

RESULTS

Five patients with NMOSD were analysed. Sixty percent of patients were women; mean age at diagnosis was 50±5.3 years and mean progression time was 4.5±3.6 years. Previously administered immunosuppressants were rituximab (in all 5), cyclophosphamide (2), and azathioprine (1). Mean time of exposure to tocilizumab was 2.3±1 years. Mean annualised relapse rate was 1.8±1.3 in the year prior to the introduction of tocilizumab and 0.2±0.4 the year after (P<.05), representing a reduction of 88.9%.

CONCLUSIONS

In our experience, tocilizumab is safe and effective in patients with NMOSD showing no response to other immunosuppressants.

Adverse Events in NMOSD Therapy

Neuromyelitis optica spectrum disorders (NMOSD) are rare neurologic autoimmune diseases that have a poor prognosis if left untreated. For many years, generic oral immunosuppressants and repurposed monoclonal antibodies that target the interleukin-6 pathway or B cells were the mainstays of drug treatment. Recently, these drug treatments have been complemented by new biologics developed and approved specifically for NMOSD. In principle, all of these drugs are effective, but treatment recommendations that take this into account are still pending. Instead, the choice of a drug may depend on other criteria such as drug safety or tolerability. In this review, we summarise current knowledge on the adverse effects of azathioprine, mycophenolate mofetil, rituximab, tocilizumab, eculizumab, satralizumab, and inebilizumab in NMOSD. Infections, cytopenias, and infusion-related reactions are most common, but the data are as heterogeneous as the manifestations are diverse. Nevertheless, knowledge of safety issues may facilitate treatment choices for individual patients.

Monoclonal Antibody Therapies Beyond Complement for NMOSD and MOGAD

Aquaporin-4 (AQP4)-IgG seropositive neuromyelitis optica spectrum disorders (AQP4-IgG seropositive NMOSD) and myelin oligodendrocyte glycoprotein (MOG)-IgG-associated disease (MOGAD) are inflammatory demyelinating disorders distinct from each other and from multiple sclerosis (MS).While anti-CD20 treatments can be used to treat MS and AQP4-IgG seropositive NMOSD, some MS medications are ineffective or could exacerbate AQP4-IgG seropositive NMOSD including beta-interferons, natalizumab, and fingolimod. AQP4-IgG seropositive NMOSD has a relapsing course in most cases, and preventative maintenance treatments should be started after the initial attack. Rituximab, eculizumab, inebilizumab, and satralizumab all have class 1 evidence for use in AQP4-IgG seropositive NMOSD, and the latter three have been approved by the US Food and Drug Administration (FDA). MOGAD is much more likely to be monophasic than AQP4-IgG seropositive NMOSD, and preventative therapy is usually reserved for those who have had a disease relapse. There is a lack of any class 1 evidence for MOGAD preventative treatment. Observational benefit has been suggested from oral immunosuppressants, intravenous immunoglobulin (IVIg), rituximab, and tocilizumab. Randomized placebo-controlled trials are urgently needed in this area.

Evolution of Anti-B Cell Therapeutics in Autoimmune Neurological Diseases

B cells have an ever-increasing role in the etiopathology of a number of autoimmune neurological disorders, acting as antigen-presenting cells facilitating antibody production but also as sensors, coordinators, and regulators of the immune response. In particular, B cells can regulate the T cell activation process through their participation in antigen presentation, production of proinflammatory cytokines (bystander activation or suppression), and contribution to ectopic lymphoid aggregates. Such an important interplay between B and T cells makes therapeutic depletion of B cells an attractive treatment strategy. The last decade, anti-B cell therapies using monoclonal antibodies against B cell surface molecules have evolved into a rational approach for successfully treating autoimmune neurological disorders, even when T cells seem to be the main effector cells. The paper summarizes basic aspects of B cell biology, discusses the roles of B cells in neurological autoimmunities, and highlights how the currently available or under development anti-B cell therapeutics exert their action in the wide spectrum and immunologically diverse neurological disorders. The efficacy of the various anti-B cell therapies and practical issues on induction and maintenance therapy is specifically detailed for the treatment of patients with multiple sclerosis, neuromyelitis-spectrum disorders, autoimmune encephalitis and hyperexcitability CNS disorders, autoimmune neuropathies, myasthenia gravis, and inflammatory myopathies. The success of anti-B cell therapies in inducing long-term remission in IgG4 neuroautoimmunities is also highlighted pointing out potential biomarkers for follow-up infusions.

Experience with tocilizumab in patients with neuromyelitis optica spectrum disorders

INTRODUCTION

Neuromyelitis optica spectrum disorders (NMOSD) are immune-mediated inflammatory disorders of the central nervous system involving astrocytes, B lymphocytes, anti-aquaporin 4, and such inflammatory mediators as interleukin-6. Several immunosuppressants are used in their treatment. Tocilizumab, an interleukin-6 receptor antagonist, may be a treatment option.

METHOD

We performed an observational, retrospective study analysing parameters of effectiveness (annualised relapse rate, disability, and radiological progression) and safety of tocilizumab in patients with NMOSD in whom previous immunosuppressant treatment had failed. We aimed to evaluate the effectiveness and safety of tocilizumab in clinical practice in patients with NMOSD not responding to other immunosuppressants.

RESULTS

Five patients with NMOSD were analysed. Sixty percent of patients were women; mean age at diagnosis was 50±5.3 years and mean progression time was 4.5±3.6 years. Previously administered immunosuppressants were rituximab (in all 5), cyclophosphamide (2), and azathioprine (1). Mean time of exposure to tocilizumab was 2.3±1 years. Mean annualised relapse rate was 1.8±1.3 in the year prior to the introduction of tocilizumab and 0.2±0.4 the year after (P <.05), representing a reduction of 88.9%.

CONCLUSIONS

In our experience, tocilizumab is safe and effective in patients with NMOSD showing no response to other immunosuppressants.

Lymphocyte Subsets Are Associated with Disease Status in Neuromyelitis Optica Spectrum Disorders

OBJECTIVE

At present, studies on lymphocytes are mostly conducted on CD19+ B cells and CD27+ B cells in neuromyelitis optica spectrum disorders (NMOSDs), but the exact changes in lymphocyte subsets (CD19+ B cells, CD3+ T cells, CD4+ Th cells, CD8+ Ts cells, the CD4+/CD8+ ratio, and NK [CD56+ CD16] cells) have rarely been studied. This study aimed to assess lymphocyte subset changes in patients with NMOSD.

METHODS

We performed a cross-sectional study of consecutive patients with acute NMOSD (n = 41), chronic NMOSD (n = 21), and healthy individuals (n = 44). Peripheral blood samples were obtained upon admission, and lymphocyte subsets were analyzed by flow cytometry. Levels of lymphocyte subsets among 3 groups were compared and its correlation with the length of spinal cord lesions was analyzed.

RESULTS

The levels of peripheral blood CD19+ B cells were significantly higher in patients with acute and chronic NMOSD than in healthy controls (HCs) (17.91 ± 8.7%, 13.08 ± 7.562%, and 12.48 ± 3.575%, respectively; p < 0.001) and were positively correlated with the length of spinal cord lesions in acute NMOSD (r = 0.433, p < 0.05). The peripheral blood CD4+/CD8+ ratio was significantly lower in patients with acute NMOSD and chronic NMOSD than in HCs (1.497 ± 0.6387, 1.33 ± 0.5574, and 1.753 ± 0.659, respectively; p < 0.05), and the levels of peripheral blood NK (CD56+ CD16) cells were significantly lower in patients with acute and chronic NMOSD than in HCs (13.6 ± 10.13, 11.11 ± 7.057, and 14.7 [interquartile range = 9.28], respectively; p < 0.01).

CONCLUSIONS

The levels of certain subsets of peripheral blood lymphocytes are associated with disease status in NMOSD.

Evaluation of effect of empirical attack-preventive immunotherapies in neuromyelitis optica spectrum disorders: An update systematic review and meta -analysis

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system, which mainly involves the optic nerve and spinal cord. Frequent relapse can accumulate the degree of disability. At present, the main treatment options are immunosuppressants and blood purification. The first-line immunosuppressants for NMOSD are mainly rituximab (RTX), mycophenolate mofetil (MMF) and azathioprine (AZA). Therefore, we designed this systematic review and meta-analysis to evaluate the safety and effect of the above three drugs in the treatment of NMOSD patients.

METHODS

The following Medical Subject Heading (MeSH) and related entry terms are used to search English literature in PubMed, MEDLINE and CENTRAL databases, respectively. MeSH include: Neuromyelitis optic and Rituximab or Azathioprine or Mycophenolate Mofetil; entry terms include: NMO Spectrum Disorder, NMO Spectrum Disorders, Neuromyelitis Optica (NMO) Spectrum Disorder, Neuromyelitis Optica Spectrum Disorders, Devic Neuromyelitis Optica, Neuromyelitis Optica, Devic, Devic's Disease, Devic Syndrome, Devic's Neuromyelitis Optica, Neuromyelitis Optica (NMO) Spectrum Disorders, CD20 Antibody, Rituximab CD20 Antibody, Mabthera, IDEC-C2B8 Antibody, GP2013, Rituxan, Mycophenolate Mofetil, Mofetil, Mycophenolate, Mycophenolic Acid, Morpholinoethyl Ester, Cellcept, Mycophenolate Sodium, Myfortic, Mycophenolate Mofetil Hydrochloride, Mofetil Hydrochloride, Mycophenolate, RS 61443, RS-61443, RS61443, azathioprine sodium, azathioprine sulfate (note: literature retrieval operators "AND" "OR" "NOT" are used to link MeSH with Entry Terms.) The literature search found a total of 3058 articles about rituximab, mycophenolate mofetil and azathioprine in the treatment of NMOSD, 63 of which were included in this study after a series of screening.

RESULTS

930,933,732 patients with NMOSD were enrolled, who had been treated with MMF, AZA and RTX, respectively. The pooled standardized mean difference (SMD) of EDSS before and after RTX treated was -0.58 (95%CI: -0.72, -0.44) (I² = 0%, p = 0.477), before and after MMF treated was -0.47 (95%CI: -0.73, -0.21) (I² = 85.6%, p<0.001), before and after AZA treated was -0.41 (95%CI: -0.60, -0.23) (I² = 65.4%, p<0.001). there was no significant difference in the effect of the three drugs on reducing EDSS scores (RTX vs MMF, p = 0.522; RTX vs AZA, p = 0.214; MMF vs AZA, p = 0.732). The pooled standardized mean difference (SMD) of ARR before and after RTX treated was -1.45 (95%CI: -1.72, -1.18) (I² = 72.4%, p<0.001), before and after MMF treated was -1.14 (95%CI: -1.31, -0.97) (I² = 54.5%, p<0.001), before and after AZA treated was -1.11 (95%CI: -1.39, -0.83) (I² = 83.4%, p<0.001). RTX significantly reduced ARR compared with the other two drugs (RTX vs MMF, p = 0.039; RTX vs AZA, p = 0.049; MMF vs AZA, p = 0.436).

CONCLUSION

The results of this systematic review and meta-analysis showed that the treatment of NMOSD patients with RTX, MMF and AZA is associated with decreased number of relapses and disability improvement as well, and there was no significant difference in the effect of the three drugs on reducing EDSS scores, but RTX significantly reduced ARR compared with the other two drugs.

Functional impairment of CD19+CD24hiCD38hi B cells in neuromyelitis optica spectrum disorder is restored by B cell depletion therapy

[Figure: see text].

Effective Rituximab Treatment in Patients with Neuromyelitis Optica Spectrum Disorders Compared with Azathioprine and Mycophenolate

Introduction

As an autoimmune central nervous system disease characterized by inflammation and demyelination, neuromyelitis optica (NMO) has been extensively investigated. A specific antigenic target, astrocytic water channel aquaporin-4 (AQP4) has already been identified, and it can be recognized explicitly by the autoantibody marker NMO-IgG. Along with the immune attacks, clinical disabilities would gradually accumulate. As there has been no validated and well-recognized therapy for NMO till now, preventing and postponing attack using immunosuppressive therapies is the primary treatment option.

Methods

In the current retrospective study, the effect of immunosuppressive agents was investigated through a long-term follow-up. To assess the long-term effectiveness and safety of rituximab (RTX), azathioprine (AZA), and mycophenolate mofetil (MMF) therapies, all 129 patients with NMO spectrum disorders (NMOSD) who received at least one of these treatments were studied, including 55 seropositive for AQP4-Ab and 74 seronegative for AQP4-Ab.

Results

The median post-treatment annualized relapse rate (ARR) was lower than the pre-treatment rates in all AQP4⁺Ab groups (from 1.0 to 0.7 in RTX, from 0.8 to 0.3 in AZA, and from 0.85 to 0.35 in MMF). Meanwhile, the ARR also decreased in all AQP4⁻Ab groups (from 0.3 to 0.2 in RTX, from 0.9 to 0.5 in AZA, and from 0.9 to 0.4 in MMF). Disability condition improved in the Expanded Disability Status Scale (EDSS) in all AQP4⁺Ab groups (from 4.0 to 2.75 in RTX, from 3.5 to 2.5 in AZA, and from 3.0 to 2.0 in MMF) and in all AQP4⁻Ab groups (from 3.0 to 2.5 in RTX, from 3.0 to 2.5 in AZA, and from 3.5 to 2.0 in MMF). There was no statistically significant difference between the post-treatment and pre-treatment changes of EDSS and ARR in the RTX, AZA, and MMF groups (P > 0.05). However, according to Kaplan–Meier survival analysis, RTX-treated patients were more likely to be relapse-free after long-term follow-up than those who received AZA or MMF therapy. Meanwhile, adverse effects were noted in three out of 23 patients with RTX treatment, five of 32 with AZA treatment, and three of 21 with MMF treatment. No serious adverse events were observed in all treatment groups during the study.

Conclusions

RTX, AZA, and MMF therapies efficiently lowered the relapse frequency and disability in both of the AQP4-Ab seropositive or seronegative patients with NMO. Furthermore, low dosage of RTX is recommended for the patients with NMO owing to its long-term effectiveness and safety.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-021-00298-5.

Efficacy and safety of modified reduced-dose rituximab in Chinese patients with neuromyelitis optica spectrum disorder: A retrospective cohort study

OBJECTIVE

To evaluate the long-term efficacy and safety of a modified reduced-dose rituximab (mRTX) regimen compared with azathioprine (AZA) and mycophenolate mofetil (MMF) in Chinese patients with neuromyelitis optica spectrum disorder (NMOSD).

METHODS

In this retrospective cohort study, 71 patients with NMOSD were treated with AZA (n = 24), MMF (n = 18), or mRTX (n = 29). The primary outcome was initial relapse after first-line immunosuppressant therapy. The annualized relapse rate (ARR), expanded disability status scale (EDSS) score, activities of daily living (ADL) scale score, and treatment-related adverse events were compared between groups.

RESULTS

Significant ARR reductions were observed in the three groups, with relapse-free rates of 37.5%, 72.2%, and 79.3% in the AZA, MMF, and RTX groups, respectively. Compared with AZA, mRTX and MMF significantly reduced the NMOSD relapse risk. Relapse within 1 year before immunosuppressant therapy or ARR before immunosuppressant therapy increased the NMOSD relapse risk. mRTX and MMF were superior to AZA in reducing the EDSS score and increasing the ADL score, but there was no significant difference between the mRTX and MMF groups. Additionally, mRTX-treated patients were less likely to use steroids concurrently than those treated with AZA and MMF. The adverse event rate in the AZA group was relatively higher than that in the MMF and mRTX groups, though no significant difference was noted among the three groups.

CONCLUSIONS

Compared with AZA, mRTX and MMF significantly reduced the NMOSD relapse risk. mRTX-treated patients presented less concomitant steroid use than those treated with AZA and MMF, fewer adverse events, and better tolerance.

Neuromyelitis optica spectrum disorders: from pathophysiology to therapeutic strategies

Neuromyelitis optica (NMO) is a chronic inflammatory autoimmune disease of the central nervous system (CNS) characterized by acute optic neuritis (ON) and transverse myelitis (TM). NMO is caused by a pathogenic serum IgG antibody against the water channel aquoporin 4 (AQP4) in the majority of patients. AQP4-antibody (AQP4-ab) presence is highly specific, and differentiates NMO from multiple sclerosis. It binds to AQP4 channels on astrocytes, triggering activation of the classical complement cascade, causing granulocyte, eosinophil, and lymphocyte infiltration, culminating in injury first to astrocyte, then oligodendrocytes followed by demyelination and neuronal loss. NMO spectrum disorder (NMOSD) has recently been defined and stratified based on AQP4-ab serology status. Most NMOSD patients experience severe relapses leading to permanent neurologic disability, making suppression of relapse frequency and severity, the primary objective in disease management. The most common treatments used for relapses are steroids and plasma exchange.Currently, long-term NMOSD relapse prevention includes off-label use of immunosuppressants, particularly rituximab. In the last 2 years however, three pivotal clinical trials have expanded the spectrum of drugs available for NMOSD patients. Phase III studies have shown significant relapse reduction compared to placebo in AQP4-ab-positive patients treated with satralizumab, an interleukin-6 receptor (IL-6R) inhibitor, inebilizumab, an antibody against CD19⁺ B cells; and eculizumab, an antibody blocking the C5 component of complement. In light of the new evidence on NMOSD pathophysiology and of preliminary results from ongoing trials with new drugs, we present this descriptive review, highlighting promising treatment modalities as well as auspicious preclinical and clinical studies.

Immune cell compartmentalization for brain surveillance and protection

For decades, it was commonly accepted that the brain is secluded from peripheral immune activity and is self-sufficient for its maintenance and repair. This simplistic perception was based on the presence of resident immune cells, the microglia, and barrier systems within the brain, and the assumption that the central nervous system (CNS) lacks lymphatic drainage. This view was revised with the discoveries that higher functions of the CNS, homeostasis and repair are supported by peripheral innate and adaptive immune cells. The findings of bone marrow-derived immune cells in specialized niches, and the renewed observation that a lymphatic drainage system exists within the brain, further contributed to this revised model. In this Review, we describe the immune niches within the brain, the contribution of professional immune cells to brain functions, the bidirectional relationships between the CNS and the immune system and the relevance of immune components to brain aging and neurodegenerative diseases.

Early implementation of intended exercise improves quality of life in Parkinson's disease patients

OBJECTIVE

Recent data have shown that regular exercise may ameliorate motor symptoms in Parkinson's disease (PD). This study aims to investigate how intended exercise impacts motor and non-movement symptoms of PD.

METHODS

Eighty-eight patients were randomly assigned to an early exercise group (E-EG), late exercise group (L-EG), or a control group (CG) using a randomized delayed-start design. The E-EG carried out a rigorous, formal exercise program for 1 h, twice per week, for 18 months (May 2018-November 2019). The L-EG took part in the exercise program in the final 6-12 months of the study. We assessed outcomes using the Unified Parkinson's Disease Rating Scale (UPDRS), PDQ-39 Questionnaire, Line A test, Line B test, Nine-hole column test, 30 s squat and stand-up test (30 s SST), 10-m walk test (10mW), Balance Evaluation Systems Mini Test (MiniBESTest), FAB, and Time Up and Go Test (TUG).

RESULTS

The patients with PD in the E-EG had lower performance in the UPDRS and Line B test compared to those in the L-EG at post-exercise (p < 0.05). Moreover, the patients with PD in the E-EG had much lower performance in the PDQ-39 and 9-Hole Peg test compared to those in the L-EG at post-exercise (p < 0.01).

CONCLUSION

Implementation of an exercise regimen improved the movement abilities and quality of life in PD patients, especially in the E-EG. This data supports the idea that intended exercise should be implemented as part of the treatment strategy for PD patients as early as possible.

Treatment of Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune central nervous system (CNS) inflammatory disorder that can lead to serious disability and mortality. Females are predominantly affected, including those within the reproductive age. Most patients develop relapsing attacks of optic neuritis; longitudinally extensive transverse myelitis; and encephalitis, especially brainstem encephalitis. The majority of NMOSD patients are seropositive for IgG autoantibodies against the water channel protein aquaporin-4 (AQP4-IgG), reflecting underlying aquaporin-4 autoimmunity. Histological findings of the affected CNS tissues of patients from in-vitro and in-vivo studies support that AQP4-IgG is directly pathogenic in NMOSD. It is believed that the binding of AQP4-IgG to CNS aquaporin-4 (abundantly expressed at the endfoot processes of astrocytes) triggers astrocytopathy and neuroinflammation, resulting in acute attacks. These attacks of neuroinflammation can lead to pathologies, including aquaporin-4 loss, astrocytic activation, injury and loss, glutamate excitotoxicity, microglial activation, neuroinflammation, demyelination, and neuronal injury, via both complement-dependent and complement-independent pathophysiological mechanisms. With the increased understanding of these mechanisms underlying this serious autoimmune astrocytopathy, effective treatments for both active attacks and long-term immunosuppression to prevent relapses in NMOSD are increasingly available based on the evidence from retrospective observational data and prospective clinical trials. Knowledge on the indications and potential side effects of these medications are essential for a clear evaluation of the potential benefits and risks to NMOSD patients in a personalized manner. Special issues such as pregnancy and the coexistence of other autoimmune diseases require additional concern and meticulous care. Future directions include the identification of clinically useful biomarkers for the prediction of relapse and monitoring of the therapeutic response, as well as the development of effective medications with minimal side effects, especially opportunistic infections complicated by long-term immunosuppression.

CD19 Cell Count at Baseline Predicts B Cell Repopulation at 6 and 12 Months in Multiple Sclerosis Patients Treated with Ocrelizumab

BACKGROUND

The kinetics of B cell repopulation in MS patients treated with Ocrelizumab is highly variable, suggesting that a fixed dosage and time scheduling might be not optimal. We aimed to investigate whether B cell repopulation kinetics influences clinical and radiological outcomes and whether circulating immune asset at baseline affects B cell repopulation kinetics.

METHODS

218 MS patients treated with Ocrelizumab were included. Every six months we collected data on clinical and magnetic resonance imaging (MRI) activity and lymphocyte subsets at baseline. According to B cell counts at six and twelve months, we identified two groups of patients, those with fast repopulation rate (FR) and those with slow repopulation rate (SR).

RESULTS

A significant reduction in clinical and radiological activity was found. One hundred fifty-five patients had complete data and received at least three treatment cycles (twelve-month follow-up). After six months, the FR patients were 41/155 (26.45%) and 10/41 (29.27%) remained non-depleted after twelve months. FR patients showed a significantly higher percentage of active MRI scan at twelve months (17.39% vs. 2.53%; p = 0,008). Furthermore, FR patients had a higher baseline B cell count compared to patients with an SR (p = 0.02 and p = 0.002, at the six- and twelve-month follow-ups, respectively).

CONCLUSION

A considerable proportion of MS patients did not achieve a complete CD19 cell depletion and these patients had a higher baseline CD19 cell count. These findings, together with the higher MRI activity found in FR patients, suggest that the Ocrelizumab dosage could be tailored depending on CD19 cell counts at baseline in order to achieve complete disease control in all patients.

Ocrelizumab Extended Interval Dosing in Multiple Sclerosis in Times of COVID-19

Objective

To evaluate the clinical consequences of extended interval dosing (EID) of ocrelizumab in relapsing-remitting multiple sclerosis (RRMS) during the coronavirus disease 2019 (COVID-19) pandemic.

Methods

In our retrospective, multicenter cohort study, we compared patients with RRMS on EID (defined as ≥4-week delay of dose interval) with a control group on standard interval dosing (SID) at the same period (January to December 2020).

Results

Three hundred eighteen patients with RRMS were longitudinally evaluated in 5 German centers. One hundred sixteen patients received ocrelizumab on EID (median delay [interquartile range 8.68 [5.09–13.07] weeks). Three months after the last ocrelizumab infusion, 182 (90.1%) patients following SID and 105 (90.5%) EID patients remained relapse free (p = 0.903). Three-month confirmed progression of disability was observed in 18 SID patients (8.9%) and 11 EID patients (9.5%, p = 0.433). MRI progression was documented in 9 SID patients (4.5%) and 8 EID patients (6.9%) at 3-month follow-up (p = 0.232). Multivariate logistic regression showed no association between treatment regimen and no evidence of disease activity status at follow-up (OR: 1.266 [95% CI: 0.695–2.305]; p = 0.441). Clinical stability was accompanied by persistent peripheral CD19⁺ B-cell depletion in both groups (SID vs EID: 82.6% vs 83.3%, p = 0.463). Disease activity in our cohort was not associated with CD19⁺ B-cell repopulation.

Conclusion

Our data support EID of ocrelizumab as potential risk mitigation strategy in times of the COVID-19 pandemic.

Classification of Evidence

This study provides Class IV evidence that for patients with RRMS, an EID of at least 4 weeks does not diminish effectiveness of ocrelizumab.

The efficacy of rituximab in patients with neuromyelitis optica spectrum disorder: A real-world study from Turkey

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) are a group of antibody-mediated chronic inflammatory diseases of the central nervous system. Rituximab is a monoclonal antibody that leads to a reduction in disease activity.

OBJECTIVE

To evaluate the efficacy of rituximab as monotherapy in NMOSD and to determine whether the efficacy varies depending on the presence of antibodies in this cohort.

METHOD

This multicentre national retrospective study included patients with NMOSD treated with rituximab at least for 12 months from Turkey. The primary outcomes were the change in the annualised relapse rate, the Expanded Disability Status Scale (EDSS), the number of relapse and radiological activity-free patients.

RESULTS

A total of 85 patients with NMOSD were included in the study. Of 85 patients, 58 (68.2%) were seropositive for anti-Aquaporin4-IgG (antI-AQP4-IgG). All patients were Anti-Myelin Oligodendrocyte Glycoprotein IgG (anti-MOG-IgG) negative. The median follow-up for rituximab treatment was 21 months (Q1 16-Q3 34.5). During rituximab treatment, the mean annualised relapse rate (ARR) significantly decreased from 1.45 ± 1.53 to 0.15 ± 0.34 (P < .001). In subgroup analyses, the mean ARR decreased from 1.61 ± 1.65 to 0.20 ± 0.39 in the seropositive group and 1.10 ± 1.19 to 0.05 ± 0.13 in the seronegative group. The mean EDSS improved from 3.98 ± 2.04 (prior to treatment onset) to 2.71 ± 1.59 (at follow-up) (P < .001). In the seropositive group, mean EDSS decreased from 3.94 ± 1.98 to 2.67 ± 1.54, and in the seronegative group, mean EDSS decreased from 4.07 ± 2.21 to 2.79 ± 1.73. There was no significant difference between anti-AQP4-IgG (+) and (-) groups in terms of ARR and EDSS. Sixty-four patients (75.2%) were relapse-free after the initiation of treatment. Seventy patients (82.3%) were radiological activity-free in the optic nerve, area postrema and brainstem. Additionally, 78 patients (91.7%) showed no spinal cord involvement after the treatment.

CONCLUSION

Rituximab therapy is efficacious in the treatment of Turkish NMOSD patients independent of the presence of the anti-AQP4-IgG antibody.

Targeting Neuromyelitis Optica Pathogenesis: Results from Randomized Controlled Trials of Biologics

Advances in neuromyelitis optica spectrum disorder pathogenesis have allowed the development of targeted drugs. These treatments act on core elements of the disease, including the pro-inflammatory IL-6 pathway (tocilizumab and satralizumab), B cells (rituximab and inebilizumab), and complement (eculizumab). According to recent phase II-III trials, biologics significantly reduced the risk of relapses in aquaporin-4-seropositive patients, whereas results were less striking in the small cohorts of aquaporin-4-seronegative patients. Most adverse events were mild to moderate, with systemic symptoms (headache, arthralgia) or infections (upper respiratory and urinary tracts) being most commonly reported.

B Cells in Neuroinflammation: New Perspectives and Mechanistic Insights

In recent years, the role of B cells in neurological disorders has substantially expanded our perspectives on mechanisms of neuroinflammation. The success of B cell-depleting therapies in patients with CNS diseases such as neuromyelitis optica and multiple sclerosis has highlighted the importance of neuroimmune crosstalk in inflammatory processes. While B cells are essential for the adaptive immune system and antibody production, they are also major contributors of pro- and anti-inflammatory cytokine responses in a number of inflammatory diseases. B cells can contribute to neurological diseases through peripheral immune mechanisms, including production of cytokines and antibodies, or through CNS mechanisms following compartmentalization. Emerging evidence suggests that aberrant pro- or anti-inflammatory B cell populations contribute to neurological processes, including glial activation, which has been implicated in the pathogenesis of several neurodegenerative diseases. In this review, we summarize recent findings on B cell involvement in neuroinflammatory diseases and discuss evidence to support pathogenic immunomodulatory functions of B cells in neurological disorders, highlighting the importance of B cell-directed therapies.

Short- and Long-Lived Autoantibody-Secreting Cells in Autoimmune Neurological Disorders

As B cells differentiate into antibody-secreting cells (ASCs), short-lived plasmablasts (SLPBs) are produced by a primary extrafollicular response, followed by the generation of memory B cells and long-lived plasma cells (LLPCs) in germinal centers (GCs). Generation of IgG4 antibodies is T helper type 2 (Th2) and IL-4, -13, and -10-driven and can occur parallel to IgE, in response to chronic stimulation by allergens and helminths. Although IgG4 antibodies are non-crosslinking and have limited ability to mobilize complement and cellular cytotoxicity, when self-tolerance is lost, they can disrupt ligand-receptor binding and cause a wide range of autoimmune disorders including neurological autoimmunity. In myasthenia gravis with predominantly IgG4 autoantibodies against muscle-specific kinase (MuSK), it has been observed that one-time CD20⁺ B cell depletion with rituximab commonly leads to long-term remission and a marked reduction in autoantibody titer, pointing to a short-lived nature of autoantibody-secreting cells. This is also observed in other predominantly IgG4 autoantibody-mediated neurological disorders, such as chronic inflammatory demyelinating polyneuropathy and autoimmune encephalitis with autoantibodies against the Ranvier paranode and juxtaparanode, respectively, and extends beyond neurological autoimmunity as well. Although IgG1 autoantibody-mediated neurological disorders can also respond well to rituximab induction therapy in combination with an autoantibody titer drop, remission tends to be less long-lasting and cases where titers are refractory tend to occur more often than in IgG4 autoimmunity. Moreover, presence of GC-like structures in the thymus of myasthenic patients with predominantly IgG1 autoantibodies against the acetylcholine receptor and in ovarian teratomas of autoimmune encephalitis patients with predominantly IgG1 autoantibodies against the N‐methyl‐d‐aspartate receptor (NMDAR) confers increased the ability to generate LLPCs. Here, we review available information on the short-and long-lived nature of ASCs in IgG1 and IgG4 autoantibody-mediated neurological disorders and highlight common mechanisms as well as differences, all of which can inform therapeutic strategies and personalized medical approaches.

A comparison of the effects of rituximab versus other immunotherapies for MOG-IgG-associated central nervous system demyelination: A meta-analysis

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) antibody disease (MOG-AD) is now recognised as a nosological entity with specific clinical and paraclinical features to aid early diagnosis. Rituximab (RTX) is a chimeric monoclonal antibody directed against CD20 epitope expressed on pre-B and mature B cells and is used to treat B-cell-derived lymphoid neoplasms and antibody-mediated autoimmune diseases. In this review, we performed a meta-analysis to evaluate RTX efficacy and assessed the treatment efficacies based on relapse rates.

METHODS

This study was conducted according to the PRISMA (Preferred Reporting Items for Systemic review and Meta-Analysis) statement. We searched for publications on the PubMed, Embase, Cochrane Library, clinical trials up to December 2020. We compiled 5 studies, Meta-analysis forest plots was conducted for the ARR ratio change pre and post-treatment between rituximab and other disease modifying drugs. A sensitivity analysis was performed with mean difference (MD) of the efficacy of RTX versus other immunotherapies and subgroup analysis was also performed based on site of study.

RESULTS

A meta-analysis of 5 studies with 239 participants was conducted. Patients have received rituximab were recorded in 82 of 239 (34.31%). The mean difference of ARR ratio of rituximab therapy versus other immunotherapies was 0.16 (95%CI, -0.15 to 0.47). No studies found to significantly affect heterogeneity. No major differences occurred in 9.2% of China patients (95% CI: -0.20-1.86; I2=0%) and 90.8% of non- China patients (95% CI: -0.24-0.42; I2=0%). Meanwhile there was no significant subgroup difference (p = 0.18) between them.

CONCLUSION

RTX reduces the relapse frequency in most patients with MOG antibody disease, but there is no differences between rituximab and other immunotherapies in MOG antibody disease. Future a large multicenter randomized controlled clinical trial to thoroughly characterize the efficacy of rituximab for MOG antibody disease is necessary.

Efficacy of Low-Dose Rituximab on Neuromyelitis Optica-Associated Optic Neuritis

Purpose: To prospectively investigate the efficacy and tolerance of low-dose rituximab (RTX) for the treatment of neuromyelitis optica-associated optic neuritis (NMO-ON). Methods: Optic Neuritis patients with seropositive aquaporin 4-antibody (AQP4-Ab) were diagnosed with NMO-ON and recruited for treatment with low-dose RTX (100 mg ^* 4 infusions) and were then followed monthly for a minimum of 3 months. Reinfusion of 100 mg RTX was given when the CD19+ B lymphocyte frequency was elevated to above 1%. The serum AQP4-Ab level was tested by an enzyme-linked immunosorbent assay (ELISA). Results: A total of 43 NMO-ON patients (1 male/42 female, 75 involved eyes) were included in this study. CD19+ B cell clearance in the peripheral blood was induced in 97.7% of patients after induction treatment. A significant decrease in serum AQP4-Ab concentration was observed after induction treatment (P = 0.0123). The maintenance time of B cell clearance was 5.2 ± 2.25 months. The relapse-free rate was 92.3% in patients followed-up for over 12 months, and patients with non-organ-specific autoimmune antibodies tended to relapse within 6 months. A total of 96.2% of patients had stable or improved vision, and a decrease in the average expanded disability status scale (EDSS) score was found. Structural alterations revealed by optic coherence tomography were observed in both ON and unaffected eyes. The rates of infusion-related reactions and long-term adverse events (AEs) were 18.6 and 23.1%, respectively. No severe AEs was observed. Conclusions: Low-dose rituximab is efficient and well-tolerated in treating NMO-ON.

New Therapeutic Landscape in Neuromyelitis Optica

Purpose of review

This review discusses the current treatment trends and emerging therapeutic landscape for patients with neuromyelitis optica spectrum disorder (NMOSD).

Recent findings

Conventional immune suppressive therapies, such as B cell depletion, have been used for long-term treatment. However, the availability of recent FDA-approved and investigational drugs has made therapeutic choices for NMOSD more complex.

Summary

Recent randomized clinical trials have shown that eculizumab, inebilizumab, and satralizumab are efficacious therapies for AQP4 seropositive NMOSD. These therapies may not have the same benefit in patients with seronegative NMOSD, including MOG-associated disease, and further investigation is required in this population. Reliable biomarkers to guide therapy decisions are urgently needed. There is a plethora of promising investigational therapies currently in the pipeline with exciting and novel mechanisms of action.

Drug Treatment of Neuromyelitis Optica Spectrum Disorders: Out with the Old, in with the New?

Introduction

Neuromyelitis optica spectrum disorders (NMOSD) are rare neuroinflammatory demyelinating diseases of the CNS, mainly affecting optic nerves, spinal cord and brainstem regions. The diagnosis depends on clinical symptoms, MRI findings and the detection of autoantibodies against the water channel aquaporin 4 (AQP4-Ab). This autoantibody is particularly important for diagnostic sensitivity and specificity and further sets the course for major therapeutic decisions. Due to a relapsing course with the accumulation of disability, relapse prevention by immunotherapy is crucial in NMOSD. Until recently, disease-modifying agents specific to NMOSD were not available, and patients were treated with various immunosuppressive drugs and regimens - with variable success. Fortunately, since 2019, three new therapeutic antibodies have entered the market.

Areas Covered

We aim to shortly summarise the pathogenesis and biological targets for acute and preventive therapy of adult NMOSD. We will focus on conventional immunotherapies and the recently approved novel biological drugs satralizumab, eculizumab and inebilizumab, and conclude with a brief outlook on future therapeutic approaches.

Expert Opinion

Although satralizumab, eculizumab and inebilizumab are a breakthrough concerning short-term efficacy, important questions on their future use remain open. There is no data from head-to-head comparisons, and data on long-term safety and efficacy of the new medicines are pending. Whether any of the biologics are efficacious in AQP4-Ab negative NMOSD patients is not yet known – as is how they will succeed in non-responders to conventional immunotherapies. Further, (autoimmune) comorbidities, affordability, and market availability of drugs may be decisive factors for choosing treatments in the near future. We are fortunate to have these new drugs available now, but they will not immediately supersede established off-label drugs in this indication. It is still too early to definitively revise the treatment algorithms for NMOSD - although we are probably on the way.

Efficacy of rituximab in the treatment of neuromyelitis optica spectrum disorders: An update systematic review and meta -analysis

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) is an autoimmune astrocyte disease that mainly affects the optic nerve and spinal cord resulting in blindness or paralysis. Rituximab (RTX) is a chimeric monoclonal antibody directed against the surface antigen of CD20 on B lymphocytes and is an emerging treatment option in NMOSD. The present review aimed to conduct an update systematic review and meta-analysis for the efficacy of RTX in the treatment of NMOSD and analyze main factors affecting the efficacy of RTX.

METHODS

The following Medical Subject Heading (MeSH) and related entry terms are used to search English literature in PubMed, MEDLINE and CENTRAL databases, respectively. MeSH include: Neuromyelitis optic and Rituximab; entry terms include: NMO Spectrum Disorder, NMO Spectrum Disorders, Neuromyelitis Optica (NMO) Spectrum Disorder, Neuromyelitis Optica Spectrum Disorders, Devic Neuromyelitis Optica, Neuromyelitis Optica, Devic, Devic's Disease, Devic Syndrome, Devic's Neuromyelitis Optica, Neuromyelitis Optica (NMO) Spectrum Disorders, CD20 Antibody, Rituximab CD20 Antibody, Mabthera, IDEC-C2B8 Antibody, GP2013, Rituxan; (note: literature retrieval operators "AND" "OR" "NOT" are used to link MeSH with Entry Terms.) 54 studies were included in this systematic review and 29 studies were included in meta-analysis. The main efficacy indicators were the difference of the expanded disability status scale (EDSS) and annualized relapse rate (ARR) between before and after rituximab treatments.

RESULTS

In 29 studies involving 732 patients (643 women, 84 men, 5 with unknown gender), the EDSS and ARR were reduced by an average of -0.57 (95%CI, -0.69 to -0.44), -1.57 (95%CI, -1.78 to -1.35), respectively.

CONCLUSION

Our systematic review and update meta-analysis provide new evidences that RTX can effectively improve disability and reduce ARR ratio.

Monoclonal Antibodies as Neurological Therapeutics

Over the last 30 years the role of monoclonal antibodies in therapeutics has increased enormously, revolutionizing treatment in most medical specialties, including neurology. Monoclonal antibodies are key therapeutic agents for several neurological conditions with diverse pathophysiological mechanisms, including multiple sclerosis, migraines and neuromuscular disease. In addition, a great number of monoclonal antibodies against several targets are being investigated for many more neurological diseases, which reflects our advances in understanding the pathogenesis of these diseases. Untangling the molecular mechanisms of disease allows monoclonal antibodies to block disease pathways accurately and efficiently with exceptional target specificity, minimizing non-specific effects. On the other hand, accumulating experience shows that monoclonal antibodies may carry class-specific and target-associated risks. This article provides an overview of different types of monoclonal antibodies and their characteristics and reviews monoclonal antibodies currently in use or under development for neurological disease.

B cell depletion therapies in autoimmune disease: advances and mechanistic insights

In the past 15 years, B cells have been rediscovered to be not merely bystanders but rather active participants in autoimmune aetiology. This has been fuelled in part by the clinical success of B cell depletion therapies (BCDTs). Originally conceived as a method of eliminating cancerous B cells, BCDTs such as those targeting CD20, CD19 and BAFF are now used to treat autoimmune diseases, including systemic lupus erythematosus and multiple sclerosis. The use of BCDTs in autoimmune disease has led to some surprises. For example, although antibody-secreting plasma cells are thought to have a negative pathogenic role in autoimmune disease, BCDT, even when it controls the disease, has limited impact on these cells and on antibody levels. In this Review, we update our understanding of B cell biology, review the results of clinical trials using BCDT in autoimmune indications, discuss hypotheses for the mechanism of action of BCDT and speculate on evolving strategies for targeting B cells beyond depletion.

A Retrospective Study of Patients with GABABR Encephalitis: Therapy, Disease Activity and Prognostic Factors

PURPOSE

To explore the effects of immunotherapy and tumour treatment on patients with GABA_BR encephalitis, evaluate the correlation between immune cell subsets and disease activity, and investigate effective prognostic factors.

PATIENTS AND METHODS

Twenty patients with γ-aminobutyric acid B receptor (GABA_BR) encephalitis were enrolled from December 2015 to April 2020. The clinical data, modified Rankin Scale (mRS) score, prognosis and percentage of serum lymphocytes were recorded.

RESULTS

All patients received first-line immunotherapy. The median mRS scores were 4 and 3 before and after first-line immunotherapy (P<0.01). Seven patients received second-line immunotherapy and had median mRS scores of 3 and 2 before and after second-line immunotherapy (P=0.015). Small-cell lung cancer was detected in twelve patients. Among the patients who died because of tumours, patients who received tumour treatment lived longer than patients who did not receive tumour treatment (P=0.025). All four surviving patients who received tumour treatment had good outcomes (mRS≤2). The median serum CD19⁺B cell percentage in sixteen patients were 20.00% and 13.42% prior first-line immunotherapy and at the last follow-up (P<0.01). After a maximum follow-up of 54 months (median: 12; range: 3-54), eleven patients (55%) had a poor prognosis (mRS>2). Predictors of a poor prognosis were older age (P=0.031), delayed initial improvement after immunotherapy (>4 weeks) (P=0.038) and respiratory failure (P=0.038).

CONCLUSION

Aggressive immunotherapy and tumour treatment contribute to improvements in neurological function and a better prognosis of patients with GABA_BR encephalitis. The serum CD19⁺B cell percentage may be an indicator of disease activity. Older age, delayed initial improvement after immunotherapy, and respiratory failure may be associated with poor outcomes.

Targeting B Cells to Modify MS, NMOSD, and MOGAD: Part 1

Ocrelizumab, rituximab, ofatumumab, ublituximab, inebilizumab, and evobrutinib are immunotherapies that target various B cell-related proteins. Most of these treatments have proven efficacy in relapsing and progressive forms of MS and neuromyelitis optica spectrum disease (NMOSD), or are in advanced stages of clinical development. Currently, ocrelizumab, ofatumumab, and inebilizumab are licensed for treatment of MS and NMOSD, respectively. This review focuses on the current state of knowledge about the role of B lymphocytes in immune-mediated pathophysiology and its implications for the mode of action. To understand the significance of this breakthrough in the context of the current MS therapeutic armamentarium, this review more closely examines the clinical development of CD20 depletion and the pioneering contribution of rituximab. Phase 3 and the recently published postmarketing studies will be highlighted to better understand the relevant efficacy data and safety aspects of long-term B-cell depletion.

Influence of delaying ocrelizumab dosing in multiple sclerosis due to COVID-19 pandemics on clinical and laboratory effectiveness

Objective

To evaluate clinical and laboratory effects of delaying ocrelizumab infusions during the COVID-19 pandemics in people with multiple sclerosis (pwMS).

Methods

We have retrospectively searched our electronic database and identified 33 pwMS who had a delay in treatment due to COVID-19 pandemics. The following data were extracted: age, sex, multiple sclerosis (MS) phenotype: relapsing-remitting (RRMS) or primary progressive multiple sclerosis (PPMS), disease duration, Expanded Disability Status scale (EDSS), previous disease modifying therapy (DMT), number of ocrelizumab cycles prior to the lockdown, dates of first ocrelizumab infusion, last ocrelizumab infusion prior to the lockdown and delayed ocrelizumab infusion after the lockdown. Flow cytometry results, relapses and EDSS progression prior to the delayed ocrelizumab infusion after the lockdown were extracted.

Results

The mean time between two ocrelizumab infusion during the lockdown was 7.72±0.64 (range 6.07 to 8.92) months. The mean time between last ocrelizumab infusion and the lymphocyte sampling prior to post COVID infusion was 6.59±0.95 (range 5.18 to 8.49) months. In this period, none of the studied patients had a relapse. In a multivariable linear regression analysis, time from last ocrelizumab infusion to lymphocyte sampling prior to the next infusion was the only significant predictor for CD19⁺ B cells count, when corrected for the number of previous ocrelizumab cycles and MS phenotype (RRMS or PPMS) (B=7.981, 95% C.I. 3.277-12.686, p=0.002).

Conclusions

We have not shown clinical consequences of delaying ocrelizumab due to COVID-19 pandemics. However, the delay in dosing of ocrelizumab was an independent predictor of repopulation of B cells.

Anti-CD20 therapies and pregnancy in neuroimmunologic disorders: A cohort study from Germany

OBJECTIVE

To report pregnancy outcomes and disease activity (DA) in women with MS, neuromyelitis optica spectrum disorders (NMOSDs), and other neuroimmunologic diseases (ONID) after treatment with rituximab (RTX)/ocrelizumab (OCR) 12 months before or during pregnancy.

METHODS

Data were collected in the German MS and pregnancy registry and centers from the Neuromyelitis Optica Study Group. Sixty-eight known outcomes of 88 pregnancies from 81 women (64 MS, 10 NMOSD, and 7 ONID) were included and stratified in 3 exposure groups: >6M-group = RTX/OCR >6 but ≤12 months before the last menstrual period (LMP) (n = 8); <6M group = RTX/OCR <6 months before the LMP (n = 47); preg group = RTX/OCR after the LMP (n = 13).

RESULTS

Pregnancy outcomes were similar between groups, but significantly more preterm births (9.8% vs 45%) occurred after exposure during pregnancy. Overall, 2 major congenital abnormalities (3.3%), both in the preg group, were observed. Three women had severe infections during pregnancy. All women with MS (35) and 12/13 women with NMOSD, RTX/OCR exposure before the LMP and known pregnancy outcomes after gestational week 22 were relapse free during pregnancy. Five of 29 (17.2%) women with relapsing-remitting MS (RRMS) and 1 of 12 (8.3%) with NMOSD and at least 6 months postpartum follow-up experienced a relapse postpartum. Duration of RTX/OCR and early retreatment but not detection of B-cells were possible predictors for postpartum relapses in patients with RRMS/NMOSD.

CONCLUSIONS

Although RTX/OCR might be an interesting option for women with RRMS/NMOSD who plan to become pregnant to control DA, more data on pregnancy outcomes and rare risks are needed.