Secondary antibody deficiency: a complication of anti-CD20 therapy for neuroinflammation

Sequelae of B-Cell Depleting Therapy: An Immunologist's Perspective

B-cell depleting therapy (BCDT) has revolutionised the treatment of B-cell malignancies and autoimmune diseases by targeting specific B-cell surface antigens, receptors, ligands, and signalling pathways. This narrative review explores the mechanisms, applications, and complications of BCDT, focusing on the therapeutic advancements since the introduction of rituximab in 1997. Various monoclonal antibodies and kinase inhibitors are examined for their roles in depleting B cells through antibody-dependent and independent mechanisms. The off-target effects, such as hypogammaglobulinemia, infections, and cytokine release syndrome, are discussed, emphasising the need for immunologists to identify and help manage these complications. The increasing prevalence of BCDT has necessitated the involvement of clinical immunologists in addressing treatment-associated immunological abnormalities, including persistent hypogammaglobulinemia and neutropenia. We highlight the importance of considering underlying inborn errors of immunity (IEI) in patients presenting with these complications. Furthermore, we discuss the impact of BCDT on other immune cell populations and the challenges in predicting and managing long-term immunological sequelae. The potential for novel BCDT agents targeting the BAFF/APRIL-TACI/BCMA axis and B-cell receptor signalling pathways to treat autoimmune disorders is also explored, underscoring the rapidly evolving landscape of B-cell targeted therapies.

COVID-19 Vaccination Response in Patients with Multiple Sclerosis Treated with Ofatumumab in the United States: A Medical Record Review

INTRODUCTION

Real-world data are required to provide a greater understanding of the impact of ofatumumab on the ability to mount an effective immune response following the receipt of approved COVID-19 vaccinations. This retrospective real-world analysis aimed to describe the humoral immune response to COVID-19 vaccination during ofatumumab treatment in patients with multiple sclerosis (MS).

METHODS

Data from patients with MS treated with ofatumumab who were fully vaccinated against COVID-19 infection were abstracted from medical charts at four clinical sites in the USA. Patient characteristics and humoral response were summarized descriptively. Differences in humoral response were documented on the basis of vaccination status during ofatumumab treatment (i.e., after full vaccination and after booster vaccination) and prior disease-modifying treatment (DMT) exposure (i.e., DMT naïve, prior anti-CD20/sphingosine 1-phosphate [S1P] therapy, prior non-anti-CD20/S1P therapy). The sample size precluded formal statistical analysis.

RESULTS

Thirty-eight patients were included. The mean (standard deviation) duration of ofatumumab treatment upon data collection was 20.4 (4.6) months (treatment ongoing for 35 [92%] patients). Definitive humoral response after full vaccination was documented for 34 patients, of whom 20 (60%) were seropositive. Definitive humoral response after booster vaccination was documented among five patients, of whom three (60%) were seropositive. Among patients who were DMT naïve prior to ofatumumab (n = 15), 73% were seropositive; among patients exposed to prior anti-CD20/S1P therapy (n = 14), 33% were seropositive; and among patients exposed to prior non-anti-CD20/S1P therapy (n = 9), 56% were seropositive. Patients naïve to DMT had been living with an MS diagnosis for a shorter duration than those experienced with DMTs.

CONCLUSION

Patients with MS receiving ongoing treatment with ofatumumab can mount a positive humoral response to a COVID-19 vaccination. Prior treatment with anti-CD20 or S1P DMTs may be a risk factor for lower humoral response.

Profiling the impact of anti-human CD20 monoclonal antibodies on lymphocyte B cell subsets and their precursors in the bone marrow and in lymphoid tissues in an immunocompromised mouse engrafted with human cells

Ofatumumab (OFA) and ocrelizumab (OCRE) are two anti-CD20 monoclonal antibodies approved for the treatment of relapsing forms of multiple sclerosis due to their ability to deplete B lymphocytes. The aim of this study was to investigate the impact of these anti-hCD20 antibodies on B lymphocyte subsets in the circulation and in primary and secondary lymphoid organs in an immune system humanized mouse model (immunocompromised Rag2-/-Il2rg-/-CD47-/-) engrafted with human CD34+ hematopoietic stem cells. Three months after humanization, mice, which present adaptive immune cells only of human origin, were treated with OFA (0.3 mg/Kg; day 1, 3 and 5), or OCRE (10 mg/kg; day 1) or saline. Seven days after the last injection a robust (>90 %) decrease of circulating human CD20+ B lymphocytes was observed in both OFA- and OCRE-treated mice. A partial replenishment of B lymphocytes was detectable in blood 36 days from the last injection in OFA-treated mice, while no B lymphocytes could be detected in OCRE-treated mice up to 65 days post injection. Bone marrow profiling showed that during hCD20+ B cell depletion and replenishment, OCRE-treated mice preserved only preB-I cells in the bone marrow, while the bone marrow of OFA-treated mice presented both preB-I as well as preB-II cells, with the latter subset being the one closest to differentiate into immature B cells. These data together with changes in B cell distribution in other tissues suggest that ofatumumab preserve BM niches, critical for B lymphocyte replenishment, limiting potential side effects of the treatment associated with the increased risk of infection.

Safety of high efficacy therapies in older people with Multiple Sclerosis: A real-world evidence study

INTRODUCTION

the increase of older adults living with Multiple Sclerosis (MS) is associated with higher use of high efficacy therapies (HETs) in a clinical practice. The are no data regarding the safety of HET in this patient group.

OBJECTIVE

to analyze the safety of HETs in older people with MS (pwMS) in a real-life cohort.

METHODS

retrospective cohort study including pwMS under HETs (cladribine and monoclonal antibodies) treated in two specialized MS centers in Latin America. We compare: pwMS ≥ 50 years old (G1) and < 50 years old (G2). In all pwMS, presence and type of adverse events, and comorbidities were recorded.

RESULTS

882 pwMS were included, 141 (15.9 %) had ≥50 years old, 47 (33.3 %) werunde HETs (G1). The most used DMT in G1 was ocrelizumab (48.9 %), mean time under HETs: 2.06 ± 0.8 years. The most frequent adverse event in G1 was urinary tract infection (UTI) (21.3 %). We did not find significant differences between G1 and G2 in infusion reactions, lymphopenia, neoplasms, respiratory infections, and liver disease. We found differences in the frequency of urinary tract infections (p = 0.004). No cases of VZV reactivation, tuberculosis or progressive multifocal leukoencephalopathy were registered. In a regression model adjusted for MS evolution, time under HET, EDSS, Charlson comorbidity index and phenotype, patients 50 ≥ under HETs did not have a higher incidence of adverse events compared to < 50 (Adjusted OR 0.72; CI95 % 0.143 -3.43, p = 0.67)} CONCLUSION: the short term use of HETs in pwMS older than 50 years old seems to be safe.

Real-world effectiveness, safety and immunogenicity of ocrelizumab in turkish multiple sclerosis patients: a single-center experience for 4-year follow-up

OBJECTIVE

The aim of this study was to evaluate postmarketing ocrelizumab safety and effectiveness in a real-world population with multiple sclerosis (MS) and matching these parameters among MS disease types.

METHODS

This was a retrospective, single-center study with MS patients treated with ocrelizumab. Demographic, clinical characteristics and immunological data were analyzed, including annualized relapse rate (ARR), relapse-free rate, Expanded Disability Status Scale (EDSS), complete blood count parameters, immunoglobulin (Ig) levels, liver function tests (LFT), hepatitis markers and adverse events in the 4-year follow-up. A total of 96 patients, 22 with relapsing-remitting MS (RRMS), 54 with secondary progressive MS (SPMS), and 20 with primary progressive MS (PPMS) who were treated with at least two doses of ocrelizumab between January 2018 and September 2023 were included in the study.

RESULTS

Sixty-five (68%) were women and 31 (32%) were men. The mean age was 48.4 ± 11.1 years (20-70 years). Ninety-three patients were evaluated in the first year, 65 in the second year, 39 in the third year and 24 in the fourth year of treatment. 96% of patients were relapse-free rate in the first year, 91% in the second year, 85% in the third year and 75% in the fourth year. Eighty-six percent of patients were progression free in the 1st year of treatment, 71% in the 2nd year, in 64% in the 3rd year, and in 62% in the 4th year. During the follow-up of the cases, EDSS remained stable in 77% of RRMS patients, improved in 14%, and worsened in 9%; while EDSS remained stable in 65% of SPMS patients with attacks, it improved in 9% and worsened in 26%; while EDSS remained stable in 60% of PPMS patients, worsening was observed in 40%. There is a significant decrease in IgM and IgG values during the follow-up of ocrelizumab therapy (p < 0.001, p = 0.014). There is no significant difference in IgA, lymphocyte and neutrophil values (p = 0.713, p = 0.086, p = 0.999). No significant relationship was found between low serum IgM levels and the risk of developing infection (p > 0.05). Liver function tests was found to be within normal limits in 94% of the patients over a 4-year period. No hepatitis B, C or A infection, hepatitis B reactivation, tuberculosis, HIV infection, malignancy or drug related death occurred during 4-years follow-up. The most common side effect during ocrelizumab treatment is urinary tract infection (29%); others were upper respiratory tract infections (13%), numbness/tingling of the face, trunk, or extremities (8%), insomnia (6%), headache (5%), and soft tissue infections (cellulitis and dental abscess, 2%).

CONCLUSIONS

Our results show that ocrelizumab reduces the frequency of attacks and prevent the disease progression in RRMS patients, and reducing the disease progression by primarily stabilizing EDSS scores in SPMS with attacks and PPMS. It is thought that the relatively high rates of urinary tract infection detected in this study may be related with advanced stage of the disease. The absence of hepatitis B reactivation, chronic infection or malignancy in the 4-year follow-up of our cases supports the long-term safety of ocrelizumab treatment. Ocrelizumab may be preferred as an effective and reliable treatment of different types of MS due to non-serious side effects.

Clinical and Immunological Impact of Ocrelizumab Extended Interval Dosing in Multiple Sclerosis: A Single-Center, Real-World Experience

Ocrelizumab (OCR), an anti-CD20 monoclonal antibody, is approved for treating relapsing remitting (RR) and primary progressive (PP) multiple sclerosis (MS). The standard interval dosing (SID) regimen requires intravenous infusions every six months. Experience of extended dosing due to COVID-19 pandemic-related issues suggests that this strategy may provide comparable efficacy while reducing treatment burden and healthcare costs. This study aimed to evaluate clinical effectiveness, changes in B- and T-cell count, and immunoglobulin dynamics associated with extended interval dosing (EID) of ocrelizumab in a real-world setting. We retrospectively included RRMS or PPMS patients treated with OCR that had already received two OCR cycles and with at least 6 months of follow up after the last infusion. EID was defined as a ≥4 weeks delay compared to SID. Clinical outcomes were occurrence of relapses, MRI activity, 6-months confirmed disability progression (CDP) and their combination (No Evidence of Disease Activity, NEDA-3). We also evaluated changes in CD19+ B cell count, CD4+ and CD8+ T cell count, immunoglobulin titers, and occurrence of hypogammaglobulinemia (hypo-Ig). Frequency tests, multivariate regression models, and survival analysis were applied as appropriate. We analyzed data on 93 subjects (75.3% RRMS) for a total of 389 infusions (272 SID, 117 EID). Clinical and MRI activity, CDP, and NEDA 3 did not significantly differ between EID and SID. EID was associated with lower rates of B-cell depletion. T-cell dynamics and incidence of hypo-Ig were comparable following EID and SID. Hypo-IgG at index infusion was associated with further occurrence of hypo-IgG; male sex and hypo-IgM at index infusion were independently associated with hypo-IgM. In conclusion, OCR EID does not impact MS clinical and radiological outcomes, although it interferes with B-cell dynamics. These findings provide support for a tailored schedule of OCR in MS.

Long-term efficacy and safety of rituximab in the treatment of neuromyelitis Optica Spectrum disorder

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing, autoimmune, inflammatory astrocytopathy. Rituximab for B-cell suppression is a common treatment for NMOSD; however, large-scale randomised controlled trials are lacking.

Objective

Evaluate long-term efficacy and safety of rituximab for NMOSD.

Methods

Retrospective observational study of patients with NMOSD treated with rituximab. Annualised relapse rates (ARRs) before and during rituximab treatment were evaluated; Modified Rankin Scores (mRS) were measured as a marker of disability.

Results

In total, 37 patients were included: 27 aquaporin-4-IgG-seropositive and 10 seronegative NMOSD. The predominant rituximab dosing regimen was an initial 1000 mg, split over two 500 mg infusions, two weeks apart, followed by single 500 mg doses. Over a median follow-up of 54 months, ARR for the whole cohort was 0.136 (95% CI 0.088-0.201), significantly lower than the pretreatment ARR of 0.366 (95% CI 0.271-0.483, p < 0.001). There was a significant reduction in ARR for the seropositive subgroup, but not seronegative. Significant improvement in mRS was seen post-treatment. Infections were reported in 32% of patients during follow-up; most were mild.

Conclusion

Rituximab, at doses lower than traditionally used, may be an efficacious therapy for NMOSD, with a favourable safety profile.

A comprehensive review of the advances in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing neuroinflammatory autoimmune astrocytopathy, with a predilection for the optic nerves and spinal cord. Most cases are characterised by aquaporin-4-antibody positivity and have a relapsing disease course, which is associated with accrual of disability. Although the prognosis in NMOSD has improved markedly over the past few years owing to advances in diagnosis and therapeutics, it remains a severe disease. In this article, we review the evolution of our understanding of NMOSD, its pathogenesis, clinical features, disease course, treatment options and associated symptoms. We also address the gaps in knowledge and areas for future research focus.

T lymphocyte subsets and immunoglobulin and complement levels are associated with the infection status of patients with antineutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND

Infection is the leading cause of death in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). The aim of this study was to characterize the immunological features of infectious events occurring in patients with newly diagnosed AAV and to identify possible risk factors associated with infection.

METHODS

The T lymphocyte subsets, immunoglobulin, and complement levels of the groups were compared between infected group and the noninfected group. Further, regression analysis was conducted to determine the association of each variable with the risk of infection.

RESULTS

280 patients with newly diagnosed AAV were enrolled. The average levels of CD3+ T cells (720.0 vs. 920.5, P < 0.001), CD3+CD4+ T cells (392.0 vs. 547.0, P < 0.001), and CD3+CD8+ T cells (248.0 vs. 335.0, P = 0.001), serum IgG (11.66 g/L vs. 13.59 g/L, P = 0.002), IgA (1.70 g/L vs. 2.44 g/L, P < 0.001), C3 (1.03 g/L vs. 1.09 g/L, P = 0.015), and C4 (0.24 g/L vs. 0.27 g/L, P < 0.001) were significantly lower in the infected group than in the noninfected group. The levels of CD3+CD4+ T cells (adjusted OR 0.997, P = 0.018), IgG (adjusted OR 0.804, P = 0.004), and C4 (adjusted OR 0.001, P = 0.013) were found independently associated with infection.

CONCLUSIONS

Patients of infected AAV and those without infection differ in T lymphocyte subsets and immunoglobulin and complement levels. Furthermore, CD3+CD4+ T cells counts and serum IgG and C4 levels were independent risk factors with infection in patients with newly diagnosed AAV.

Antibody response to SARS-CoV-2 vaccines in patients with relapsing multiple sclerosis treated with evobrutinib: A Bruton's tyrosine kinase inhibitor

BACKGROUND

Evobrutinib is an oral, central nervous system (CNS)-penetrant and highly selective covalent Bruton's tyrosine kinase inhibitor under clinical development for patients with relapsing multiple sclerosis (RMS).

OBJECTIVE

To investigate the effect of evobrutinib on immune responses in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccinated patients with RMS from a Phase II trial (NCT02975349).

METHODS

A post hoc analysis of patients with RMS who received evobrutinib 75 mg twice daily and SARS-CoV-2 vaccines during the open-label extension (n = 45) was conducted. Immunoglobulin (Ig)G anti-S1/S2-specific SARS-CoV-2 antibodies were measured using an indirect chemiluminescence immunoassay.

RESULTS

In the vaccinated subgroup, mean/minimum evobrutinib exposure pre-vaccination was 105.2/88.7 weeks. In total, 43 of 45 patients developed/increased S1/S2 IgG antibody levels post-vaccination; one patient's antibody response remained negative post-vaccination and the other had antibody levels above the upper limit of detection, both pre- and post-vaccination. Most patients (n = 36/45), regardless of pre-vaccination serostatus, had a 10-100-fold increase of antibody levels pre- to post-vaccination. Antibody levels post-booster were higher versus post-vaccination.

CONCLUSION

These results suggest evobrutinib, an investigational drug with therapeutic potential for patients with RMS, acts as an immunomodulator, that is, it inhibits aberrant immune cell responses in patients with RMS, while responsiveness to foreign de novo and recall antigens is maintained.

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.

Hypogammaglobulinemia, late-onset neutropenia, and infections following rituximab

Rituximab is a chimeric anti-CD20 monoclonal antibody that targets CD20-expressing B lymphocytes, has a well-defined efficacy and safety profile, and is broadly used to treat a wide array of diseases. In this review, we cover the mechanism of action of rituximab and focus on hypogammaglobulinemia and late-onset neutropenia-2 immune effects secondary to rituximab-and subsequent infection. We review risk factors and highlight key considerations for immunologic monitoring and clinical management of rituximab-induced secondary immune deficiencies. In patients treated with rituximab, monitoring for hypogammaglobulinemia and infections may help to identify the subset of patients at high risk for developing poor B cell reconstitution, subsequent infections, and adverse complications. These patients may benefit from early interventions such as vaccination, antibacterial prophylaxis, and immunoglobulin replacement therapy. Systematic evaluation of immunoglobulin levels and peripheral B cell counts by flow cytometry, both at baseline and periodically after therapy, is recommended for monitoring. In addition, in those patients with prolonged hypogammaglobulinemia and increased infections after rituximab use, immunologic evaluation for inborn errors of immunity may be warranted to further risk stratification, increase monitoring, and assist in therapeutic decision-making. As the immunologic effects of rituximab are further elucidated, personalized approaches to minimize the risk of adverse reactions while maximizing benefit will allow for improved care of patients with decreased morbidity and mortality.

Effect of Previous Disease-Modifying Therapy on Treatment Effectiveness for Patients Treated With Ocrelizumab

BACKGROUND AND OBJECTIVES

B cell-depleting antibodies were proven as effective strategy for the treatment of relapsing multiple sclerosis (RMS). The monoclonal antibody ocrelizumab was approved in 2017 in the United States and in 2018 in the European Union, but despite proven efficacy in randomized, controlled clinical trials, its effectiveness in the real-world setting remains to be fully elucidated. In particular, most study patients were treatment naive or switched from injectable therapies, whereas oral substances or monoclonal antibodies made up >1% of previous treatments.

METHODS

We evaluated ocrelizumab-treated patients with RMS enrolled in the prospective cohorts at the University Hospitals Duesseldorf and Essen, Germany. Epidemiologic data at baseline were compared, and Cox proportional hazard models were applied to evaluate outcomes.

RESULTS

Two hundred eighty patients were included (median age: 37 years, 35% male patients). Compared with using ocrelizumab as a first-line treatment, its use as a third-line therapy increased hazard ratios (HRs) for relapse and disability progression, whereas differences between first- vs second-line and second- vs third-line remained smaller. We stratified patients according to their last previous disease-modifying treatment and here identified fingolimod (FTY) (45 patients, median age 40 years, 33% male patients) as a relevant risk factor for ongoing relapse activity despite 2nd-line (HR: 3.417 [1.007-11.600]) or 3rd-line (HR: 5.903 [2.489-13.999]) ocrelizumab treatment, disability worsening (2nd line: HR: 3.571 [1.013-12.589]; 3rd line: HR: 4.502 [1.728-11.729]), and occurrence of new/enlarging MRI lesions (2nd line: HR: 1.939 [0.604-6.228]; 3rd line: HR: 4.627 [1.982-10.802]). Effects were persistent throughout the whole follow-up. Neither peripheral B-cell repopulation nor immunoglobulin G levels were associated with rekindling disease activity.

DISCUSSION

Our prospectively collected observational data suggest suboptimal effectiveness of ocrelizumab in patients switching from FTY compared with those switching from other substances or having been treatment naive. These findings support previous studies indicating abated effectiveness of immune cell-depleting therapies following FTY treatment in patients with RMS.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for patients with RMS, previous treatment with FTY compared with previous treatment with other immunomodulating therapies decreases the effectiveness of ocrelizumab.

Hypogammaglobulinemia secondary to B-cell depleting therapies in neuroimmunology: Comparing management strategies

Background

Anti-CD20 agents are commonly used in MS, NMOSD, and MOGAD. Few studies have compared strategies to address hypogammaglobulinemia.

Objective

To compare strategies to manage secondary hypogammaglobulinemia in neuroimmunology patients, including reducing anti-CD20 dose and dosing frequency, IVIG/SCIG, anti-CD20 cessation, and DMT switches.

Methods

All MS, NMOSD, and MOGAD patients at our institution with hypogammaglobulinemia on anti-CD20 agents from 2001 to 2022 were analyzed. The median change in IgG, infection frequency, and infection severity before and after the treatment was calculated.

Results

In total, 257 patients were screened, and 30 had a treatment for hypogammaglobulinemia. IVIG/SCIG yielded the largest increase in IgG per year (674.0 mg/dL), followed by B-cell therapy cessation (34.7 mg/dL), and DMT switch (5.9 mg/dL). Dose reduction had the largest decrease in yearly infection frequency (2.7 fewer infections), followed by IVIG/SCIG (2.5 fewer), DMT switch (2 fewer), and reduced dosing frequency (0.5 fewer). Infection grade decreased by 1.9 for reduced dosing frequency (less severe infections), by 1.3 for IVIG/SCIG, and by 0.6 for DMT switch.

Conclusion

This data suggests that IVIG/SCIG may yield the greatest recovery in IgG while also reducing infection frequency and severity. Stopping anti-CD20 therapy and/or switching DMTs also increase IgG and may lower infection risk.

Predictors of hypogammaglobulinemia and serious infections among patients receiving ocrelizumab or rituximab for treatment of MS and NMOSD

BACKGROUND AND OBJECTIVES

Ocrelizumab and rituximab are monoclonal antibodies targeting the CD20 marker on B lymphocytes. The enhanced efficacy of B lymphocyte depleting therapies poses a greater risk of decreased immunoglobulin (Ig) levels. The rate and risk factors of hypogammaglobulinemia in MS and NMOSD patients treated with anti-CD20 therapies are unknown.

METHODS

A retrospective study was conducted among patients who received anti-CD20 therapy for the treatment of MS, NMOSD, and other related neurological disorders. The goal was to determine the incidence and risk factors of hypogammaglobulinemia and serious infections in patients receiving ocrelizumab versus rituximab. The secondary goals were to determine the rates of lymphopenia, neutropenia, and early B cell repopulation among patients on anti-CD20 therapy.

RESULTS

Overall, 184 patients (mean age 48.4 ± 13.7, 66.8% female) met inclusion criteria; 152 patients received ocrelizumab and 32 patients received rituximab. A total of 22 patients (12%) developed hypogammaglobulinemia. Patients who developed hypogammaglobulinemia were more likely to have been ≥50 years of age (p = .0275) with lower baseline IgG (p = .001) and IgA (p = .0038) levels. Serious infections were observed in 21 patients (11%) and seen more commonly in those that developed total lymphopenia (<1.0 × 109/L) and had longer duration of B-cell therapy. Multivariate analysis identified age ≥ 50 years, white race, and rituximab as independent predictors of hypogammaglobulinemia, and absolute lymphopenia as an independent risk factor for serious infections.

DISCUSSION

Among patients receiving anti-CD20 therapy, 12% of patients experienced hypogammaglobulinemia which was seen more commonly in white patients, at least 50 years old, with lower baseline IgG and IgA levels and in those treated with rituximab. Serious infections were seen more commonly in patients with total lymphopenia and longer exposure to anti-CD20 therapy.

Targeting B Cells and Microglia in Multiple Sclerosis With Bruton Tyrosine Kinase Inhibitors: A Review

Importance

Currently, disease-modifying therapies for multiple sclerosis (MS) use 4 mechanisms of action: immune modulation, suppressing immune cell proliferation, inhibiting immune cell migration, or cellular depletion. Over the last decades, the repertoire substantially increased because of the conceptual progress that not only T cells but also B cells play an important pathogenic role in MS, fostered by the empirical success of B cell-depleting antibodies against the surface molecule CD20. Notwithstanding this advance, a continuous absence of B cells may harbor safety risks, such as a decline in the endogenous production of immunoglobulins. Accordingly, novel B cell-directed MS therapies are in development, such as inhibitors targeting Bruton tyrosine kinase (BTK).

Observations

BTK is centrally involved in the B cell receptor-mediated activation of B cells, one key requirement in the development of autoreactive B cells, but also in the activation of myeloid cells, such as macrophages and microglia. Various compounds in development differ in their binding mode, selectivity and specificity, relative inhibitory concentration, and potential to enter the central nervous system. The latter may be important in assessing whether BTK inhibition is a promising strategy to control inflammatory circuits within the brain, the key process that is assumed to drive MS progression. Accordingly, clinical trials using BTK inhibitors are currently conducted in patients with relapsing-remitting MS as well as progressive MS, so far generating encouraging data regarding efficacy and safety.

Conclusions and Relevance

While the novel approach of targeting BTK is highly promising, several questions remain unanswered, such as the long-term effects of using BTK inhibitors in the treatment of inflammatory CNS disease. Potential changes in circulating antibody levels should be evaluated and compared with B cell depletion. Also important is the potential of BTK inhibitors to enter the CNS, which depends on the given compound. Remaining questions involve where BTK inhibitors fit in the landscape of MS therapeutics. A comparative analysis of their distinct properties is necessary to identify which inhibitors may be used in relapsing vs progressive forms of MS as well as to clarify which agent may be most suitable for sequential use after anti-CD20 treatment.

The impact of disease-modifying therapies on immunoglobulin blood levels in patients with multiple sclerosis: a retrospective cross-sectional study

Background

Although disease-modifying therapies (DMTs) in multiple sclerosis (MS) are known to target the immune system, mechanisms of action, efficacy, safety, and tolerability profiles differ. The long-term impact of DMTs on the immune system and its relation to infectious complications is still poorly understood.

Objectives

To analyze the effect of DMTs on serum immunoglobulin (Ig) levels under consideration of patient demographics and therapy duration.

Design

We included 483 patients on DMTs, 69 patients without DMTs, and 51 controls in this retrospective cross-sectional study.

Methods

IgG, IgM, and IgG subclass 1-4 levels of patients with MS under treatment with DMTs were compared with treatment naive MS patients and controls by multivariate linear regression. Further, Ig levels stratified by DMTs were analyzed regarding therapy duration.

Results

MS patients treated with fingolimod (FG), natalizumab, and B-cell depleting therapies (BCDT) demonstrated significantly lower IgG and IgM levels than healthy controls after a median treatment of 37, 31, and 23 months, respectively (p < 0.05). Treatment with dimethyl fumarate (DMF) and teriflunomide was associated with lower IgG, but not IgM levels. DMF and BCDT were also associated with lower IgG1 levels, while FG led to a reduction of IgG2. Treatment with interferon-beta (IFN) and glatiramer acetate (GA) had no impact on Ig levels. Analysis of subgroups by linear regression also showed a time-dependent decrease of Igs levels in patients treated with BCDT with a median annual reduction of IgG of 3.2% and IgM of 6.2%.

Conclusion

Treatment with DMTs, except GA and IFN, was associated with a decrease in Ig levels. DMTs differed in the extent of decreasing Ig levels but also in their differential effects on Ig subclasses. Monitoring of Ig levels should be considered in patients on long-term treatment with DMTs, particularly those on BCDT, to identify patients at risk of low immunoglobulin levels.

Characterisation of the safety profile of evobrutinib in over 1000 patients from phase II clinical trials in multiple sclerosis, rheumatoid arthritis and systemic lupus erythematosus: an integrated safety analysis

OBJECTIVE

Analyse the integrated safety profile of evobrutinib, a Bruton's tyrosine kinase inhibitor (BTKi), using pooled data from multiple sclerosis (MS), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) trials.

METHODS

Phase II, randomised, double-blind, placebo-controlled trial data were analysed (N=1083; MS: n=213, 48 weeks (W); RA: n=390, 12W; SLE: n=480, 52W). The analysis included all patients who received ≥1 dose of evobrutinib (25 mg or 75 mg once daily, or 50 mg or 75 mgtwice daily) or placebo. Descriptive statistics and exposure-adjusted incidence rates (EAIR) were used to report treatment-emergent adverse events (TEAEs).

RESULTS

Data from 1083 patients were pooled: evobrutinib, n=861; placebo, n=271 (sum >1083 due to MS trial design: n=49 received both placebo (W0-24) and evobrutinib 25 mg (W25-48)); median follow-up time (pt-years): evobrutinib, 0.501; placebo, 0.463. Across indications, the proportion of patients with TEAEs and the EAIR were similar for evobrutinib and placebo (66.2% (247.6 events/100 pt-years) vs 62.4% (261.4 events/100 pt-years)). By indication, the EAIR (events/100 pt-years) of TEAEs for evobrutinib versus placebo were: MS: 119.7 vs 148.3; RA: 331.8 vs 306.8; SLE: 343.0 vs 302.1. Two fatal events occurred (in SLE). The serious infections EAIR was 2.7 and 2.1 events/100 pt-years for evobrutinib and placebo. For previously reported BTKi-class effects, the EAIR of transient elevated alanine aminotransferase/aspartate aminotransferase TEAEs (events/100 pt-years) with evobrutinib versus placebo was 4.8 vs 2.8/3.5 vs 0.7, respectively. IgG levels were similar in evobrutinib/placebo-treated patients.

CONCLUSIONS

This is the first BTKi-integrated safety analysis that includes patients with MS. Overall, evobrutinib treatment (all doses) was generally well tolerated across indications.

TRIAL REGISTRATION NUMBERS

NCT02975349, NCT03233230, NCT02975336.

Rituximab-Induced Hypogammaglobulinemia and Risk of Infection in Neuromyelitis Optica Spectrum Disorders

Background and Objectives

To investigate the frequency and predictors of hypogammaglobulinemia during long-term rituximab (RTX) treatment in patients with neuromyelitis optica spectrum disorder (NMOSD) and its association with infections.

Methods

We retrospectively reviewed the data of patients with NMOSD who received RTX through the maintenance regimen based on memory B-cell detection for at least 1 year from 2006 to 2021 at an institutional referral center for NMOSD.

Results

A total of 169 patients received a median of 10 courses (range 1–27) of RTX reinfusion after induction over a median of 8 (range, 1–15) years. Their mean serum immunoglobulin (Ig)G level began to decline significantly after 2 years of treatment, steadily declined at a rate of 2%–8% per year for the following 8 years, and then plateaued after 10 years. The proportion of patients with hypo-IgG (<6 g/L) increased from 1.2% after 1 year of treatment to 41% after 14 years of treatment. While being treated with RTX, 58 (34%) patients had 114 infections, of whom 14 (8%) patients had 15 severe infections. Multivariable logistic regression analyses identified duration of RTX treatment in years (odds ratio [OR] 1.234, 95% confidence interval [CI] 1.015–1.502), mean annual RTX dose (OR 0.063, 95% CI 0.009–0.434), history of mitoxantrone (OR 3.318, 95% CI 1.109–9.93), hypo-IgG at baseline (OR 40.552, 95% CI 3.024–543.786), and body mass index >25 kg/m² (OR 4.798, 95% CI 1.468–15.678) as independent predictors of hypo-IgG. The risk of infection during RTX treatment was independently associated with high Expanded Disability Status Scale scores (OR 1.427, 95% CI 1.2–1.697) and relapses during RTX treatment (OR 1.665, 95% CI 1.112–2.492), but not with hypogammaglobulinemia.

Discussion

Over 14 years of long-term RTX treatment, IgG levels gradually decreased, and the frequency of hypo-IgG increased to 41% of the patients. Patients with prolonged memory B-cell depletion after RTX, previous mitoxantrone history, hypo-IgG at baseline, or obesity were at risk of developing RTX-induced hypogammaglobulinemia. Nevertheless, infection rates remained low during treatment, and reduced immunoglobulin levels were not associated with an increased incidence of infections.

Multiple sclerosis and the risk of infection: Association of British Neurologists consensus guideline

Infection in people with multiple sclerosis (MS) is of major concern, particularly for those receiving disease-modifying therapies. This article explores the risk of infection in people with MS and provides guidance-developed by Delphi consensus by specialists involved in their management-on how to screen for, prevent and manage infection in this population.

Anti-cytokine autoantibodies and inborn errors of immunity

The past quarter of a century has witnessed an inordinate increase in our understanding of primary immunodeficiencies / inborn errors of immunity. These include a significant increase in the number of identified conditions, broadening the phenotypes of existing entities, delineation of classical inborn errors of immunity from those with a narrow phenotype, and a gradual shift from supportive to definitive care in patients afflicted with these diseases. It has also seen the discovery of conditions broadly defined as phenocopies of primary immunodeficiencies, where somatic mutations or autoantibodies mimic a recognised primary immunodeficiency's presentation in the absence of the underlying genetic basis for that disease. This article will provide a review of the anti-cytokine autoantibody-mediated phenocopies of inborn errors of immunity and discuss the therapeutic and laboratory aspects of this group of diseases.

Practical guidance for the diagnosis and management of secondary hypogammaglobulinemia: A Work Group Report of the AAAAI Primary Immunodeficiency and Altered Immune Response Committees

Secondary hypogammaglobulinemia (SHG) is characterized by reduced immunoglobulin levels due to acquired causes of decreased antibody production or increased antibody loss. Clarification regarding whether the hypogammaglobulinemia is secondary or primary is important because this has implications for evaluation and management. Prior receipt of immunosuppressive medications and/or presence of conditions associated with SHG development, including protein loss syndromes, are histories that raise suspicion for SHG. In patients with these histories, a thorough investigation of potential etiologies of SHG reviewed in this report is needed to devise an effective treatment plan focused on removal of iatrogenic causes (eg, discontinuation of an offending drug) or treatment of the underlying condition (eg, management of nephrotic syndrome). When iatrogenic causes cannot be removed or underlying conditions cannot be reversed, therapeutic options are not clearly delineated but include heightened monitoring for clinical infections, supportive antimicrobials, and in some cases, immunoglobulin replacement therapy. This report serves to summarize the existing literature regarding immunosuppressive medications and populations (autoimmune, neurologic, hematologic/oncologic, pulmonary, posttransplant, protein-losing) associated with SHG and highlights key areas for future investigation.

Risk of COVID-19 infection and severe disease in MS patients on different disease-modifying therapies

BACKGROUND

The risk of SARS-CoV-2 infection and severity with disease modifying therapies (DMTs) in multiple sclerosis (MS) remains unclear, with some studies demonstrating increased risks of infection with B-cell-depleting (anti-CD20) therapies and severity, while others fail to observe an association. Most existing studies are limited by a reliance on 'numerator' data (i.e., COVID-19 cases) only.

OBJECTIVE

To assess the risks of COVID-19 by DMT, this study aimed to assess both 'numerator' (patients with SARS-CoV-2 infection) and 'denominator' data (all patients treated with DMTs of interest) to determine if any DMTs impart an increased risk of SARS-CoV-2 infection or disease severity.

METHODS

We systematically reviewed charts and queried patients during clinic encounters in the NYU MS Comprehensive Care Center (MSCCC) for evidence of COVID-19 in all patients who were on the most commonly used DMTs in our clinic (sphingosine-1-phosphate receptor (S1P) modulators (fingolimod/siponimod), rituximab, ocrelizumab, fumarates (dimethyl fumarate/diroximel fumarate), and natalizumab). COVID-19 status was determined by clinical symptoms (CDC case definition) and laboratory testing where available (SARS-CoV-2 PCR, SARS-CoV-2 IgG). Multivariable analyses were conducted to determine predictors of infection and severe disease (hospitalization or death) using SARS-CoV-2 infected individuals per DMT group and all individuals on a given DMT as denominator.

RESULTS

We identified 1,439 MS patients on DMTs of interest, of which 230 had lab-confirmed (n = 173; 75.2%) or suspected (n = 57; 24.8%) COVID-19. Infection was most frequent in those on rituximab (35/138; 25.4%), followed by fumarates (39/217; 18.0%), S1P modulators (43/250; 17.2%), natalizumab (36/245; 14.7%), and ocrelizumab (77/589; 13.1%). There were 14 hospitalizations and 2 deaths. No DMT was found to be significantly associated with increased risk of SARS-CoV-2 infection. Rituximab was a predictor of severe SARS-CoV-2 infection among patients with SARS-CoV-2 infection (OR 6.7; 95% CI 1.1-41.7) but did not reach statistical significance when the entire patient population on DMT was used (OR 2.8; 95% CI 0.6-12.2). No other DMT was associated with an increased risk of severe COVID-19.

CONCLUSIONS

Analysis of COVID-19 risk among all patients on the commonly used DMTs did not demonstrate increased risk of infection with any DMT. Rituximab was associated with increased risk for severe disease.

Monoclonal Antibodies in the Treatment of Relapsing Multiple Sclerosis: an Overview with Emphasis on Pregnancy, Vaccination, and Risk Management

Monoclonal antibodies have become a mainstay in the treatment of patients with relapsing multiple sclerosis (RMS) and provide some benefit to patients with primary progressive MS. They are highly precise by specifically targeting molecules displayed on cells involved in distinct immune mechanisms of MS pathophysiology. They not only differ in the target antigen they recognize but also by the mode of action that generates their therapeutic effect. Natalizumab, an [Formula: see text]4[Formula: see text]1 integrin antagonist, works via binding to cell surface receptors, blocking the interaction with their ligands and, in that way, preventing the migration of leukocytes across the blood-brain barrier. On the other hand, the anti-CD52 monoclonal antibody alemtuzumab and the anti-CD20 monoclonal antibodies rituximab, ocrelizumab, ofatumumab, and ublituximab work via eliminating selected pathogenic cell populations. However, potential adverse effects may be serious and can necessitate treatment discontinuation. Most importantly, those are the risk for (opportunistic) infections, but also secondary autoimmune diseases or malignancies. Monoclonal antibodies also carry the risk of infusion/injection-related reactions, primarily in early phases of treatment. By careful patient selection and monitoring during therapy, the occurrence of these potentially serious adverse effects can be minimized. Monoclonal antibodies are characterized by a relatively long pharmacologic half-life and pharmacodynamic effects, which provides advantages such as permitting infrequent dosing, but also creates disadvantages regarding vaccination and family planning. This review presents an overview of currently available monoclonal antibodies for the treatment of RMS, including their mechanism of action, efficacy and safety profile. Furthermore, we provide practical recommendations for risk management, vaccination, and family planning.

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.

Derisking CD20-therapies for long-term use

Anti-CD20 have quickly become the mainstay in the treatment of multiple sclerosis (MS) and other neuroinflammatory conditions. However, when they are used as a maintenance therapy the balance between risks and benefits changes. In this review, we suggested six steps to derisk anti-CD20. Firstly and secondly, adequate infectious screening followed by vaccinations before starting anti-CD20 are paramount. Third, family planning needs to be discussed upfront with every woman of childbearing age. Fourth, infusion reactions should be adequately managed to avoid treatment interruption. After repeated infusions, it becomes important to detect and prevent anti-CD20-related adverse events. Fifth, we recommended measuring immunoglobulin levels and reviewing vaccinations annually as well as counselling adequate fever management. For female patients, we emphasised the importance to engage with the local breast cancer screening programs. Sixth, to fundamentally derisk anti-CD20 therapies, we need evidence-based approaches to reduce dosing intervals and guide retreatment.

Secondary Immunodeficiency and Risk of Infection Following Immune Therapies in Neurology

Secondary immunodeficiencies (SIDs) are acquired conditions that may occur as sequelae of immune therapy. In recent years a number of disease-modifying therapies (DMTs) has been approved for multiple sclerosis and related disorders such as neuromyelitis optica spectrum disorders, some of which are frequently also used in- or off-label to treat conditions such as chronic inflammatory demyelinating polyneuropathy (CIDP), myasthenia gravis, myositis, and encephalitis. In this review, we focus on currently available immune therapeutics in neurology to explore their specific modes of action that might contribute to SID, with particular emphasis on their potential to induce secondary antibody deficiency. Considering evidence from clinical trials as well as long-term observational studies related to the patients' immune status and risks of severe infections, we delineate long-term anti-CD20 therapy, with the greatest data availability for rituximab, as a major risk factor for the development of SID, particularly through secondary antibody deficiency. Alemtuzumab and cladribine have relevant effects on circulating B-cell counts; however, evidence for SID mediated by antibody deficiency appears limited and urgently warrants further systematic evaluation. To date, there has been no evidence suggesting that treatment with fingolimod, dimethyl fumarate, or natalizumab leads to antibody deficiency. Risk factors predisposing to development of SID include duration of therapy, increasing age, and pre-existing low immunoglobulin (Ig) levels. Prevention strategies of SID comprise awareness of risk factors, individualized treatment protocols, and vaccination concepts. Immune supplementation employing Ig replacement therapy might reduce morbidity and mortality associated with SIDs in neurological conditions. In light of the broad range of existing and emerging therapies, the potential for SID warrants urgent consideration among neurologists and other healthcare professionals.

Case Report: Covid-19 in Multiple Sclerosis Patients Treated With Ocrelizumab: A Case Series

Introduction: Limited data are available on the course of Coronavirus disease 2019 (COVID-19) in people with Multiple Sclerosis (MS). More real-world data are needed to help the MS community to manage MS treatment properly. In particular, it is important to understand the impact of immunosuppressive therapies used to treat MS on the outcome of COVID-19. Methods: We retrospectively collected data on all confirmed cases of COVID-19 in MS patients treated with ocrelizumab, followed in two MS Centers based in University Hospitals in Northern Italy from February 2020 to June 2021. Results: We identified 15 MS patients treated with ocrelizumab with confirmed COVID-19 (mean age, 50.47 ± 9.1 years; median EDSS, 3.0; range 1.0-7.0). Of these, 14 were confirmed by nasal swab and 1 was confirmed by a serological test. COVID-19 severity was mild to moderate in the majority of patients (n = 11, 73.3%; mean age, 49.73; median EDSS 3.0). Four patients (26.7%; mean age, 52.5 years; median EDSS, 6) had severe disease and were hospitalized; one of them died (age 50, EDSS 6.0, no other comorbidities). None of them had underlying respiratory comorbidities. Conclusion: This case series highlights the large variability of the course of COVID-19 in ocrelizumab-treated MS patients. The challenges encountered by the healthcare system in the early phase of the COVID-19 pandemic might have contributed to the case fatality ratio observed in this series. Higher MS-related disability was associated with a more severe COVID-19 course.

Rituximab in Multiple Sclerosis: Are We Ready for Regulatory Approval?

Despite the availability of a lot of effective disease-modifying drugs, multiple sclerosis (MS) (in particular the progressive forms) still represents an important unmet medical need, because of issues in terms of effectiveness, duration of response, safety, and patient compliance. An increasing body of evidence from randomized clinical trials and real-world data suggest that rituximab is a highly effective alternative in both relapsing and progressive MS, with a low discontinuation rate, related to a good benefit/risk profile, and a good compliance. To date, the use of rituximab in patients with multiple sclerosis is not in accordance with the authorized product information (off-label use). However, the use of this medicine is widespread in several countries, and in some cases, it is the most commonly used disease-modifying drug for MS subtypes. This use could be officially recognized by national regulatory authorities, according to specific procedures, to ensure equal access for patients to a safe and effective option.

Intrathecal Immunoglobulin M Synthesis is an Independent Biomarker for Higher Disease Activity and Severity in Multiple Sclerosis

OBJECTIVE

We aimed to determine in relapsing multiple sclerosis (MS) whether intrathecal synthesis of immunoglobulin (Ig) M and IgG is associated with outcomes reflecting inflammatory activity and chronic worsening.

METHODS

We compared cerebrospinal fluid analysis, clinical and magnetic resonance imaging data, and serum neurofilament light chain (sNfL) levels at baseline and follow-up in 530 patients with relapsing MS. Patients were categorized by the presence of oligoclonal IgG bands (OCGB) and intrathecal synthesis of IgG and IgM (intrathecal fraction [IF]: IgG_IF and IgM_IF ). Relationships with the time to first relapse, sNfL concentrations, T2-weighted (T2w) lesions, MS Severity Score (MSSS), and time to initiation of high-efficacy therapy were analyzed in covariate-adjusted statistical models.

RESULTS

By categorical analysis, in patients with IgM_IF the median time to first relapse was 28 months shorter and MSSS on average higher by 1.11 steps compared with patients without intrathecal immunoglobulin synthesis. Moreover, patients with IgM_IF had higher sNfL concentrations, more new/enlarging T2w lesions, and higher total T2w lesion counts (all p ≤ 0.01). These associations were absent or equally smaller in patients who were positive for only OCGB or OCGB/IgG_IF . Furthermore, quantitative analyses revealed that in patients with IgM_IF  ≥ median, the time to first relapse and to initiation of high-efficacy therapy was shorter by 32 and by 203 months, respectively (both p < 0.01), in comparison to patients with IgM_IF  < median. Dose-dependent associations were also found for IgM_IF but not for IgG_IF with magnetic resonance imaging-defined disease activity and sNfL.

INTERPRETATION

This large study supports the value of intrathecal IgM synthesis as an independent biomarker of disease activity and severity in relapsing MS. ANN NEUROL 2021.

Rituximab-induced hypogammaglobulinemia and infection risk in pediatric patients

BACKGROUND

Rituximab is a B-cell depleting agent used in B-cell malignancies and autoimmune diseases. A subset of adult patients may develop prolonged and symptomatic hypogammaglobulinemia following rituximab treatment. However, this phenomenon has not been well delineated in the pediatric population.

OBJECTIVES

This study sought to determine the prevalence, risk factors, and clinical significance of hypogammaglobulinemia following rituximab therapy in children.

METHODS

This was a multicenter, retrospective cohort study that extracted clinical and immunological data from pediatric patients who received rituximab.

RESULTS

The cohort comprised 207 patients (median age, 12.0 years). Compared to baseline values, there was a significant increase in hypogammaglobulinemia post-rituximab therapy, with an increase in prevalence of hypo-IgG (28.7%-42.6%; P = .009), hypo-IgA (11.1%-20.4%; P = .02), and hypo-IgM (20.0%-62.0%; P < .0001). Additionally, low IgG levels at any time post-rituximab therapy were associated with a higher risk of serious infections (34.4% vs 18.9%; odds ratio, 2.3; 95% CI, 1.1-4.8; P = .03). Persistent IgG hypogammaglobulinemia was observed in 27 of 101 evaluable patients (26.7%). Significant risk factors for persistent IgG hypogammaglobulinemia included low IgG and IgA levels pre-rituximab therapy. Nine patients (4.3%) within the study were subsequently diagnosed with a primary immunodeficiency, 7 of which received rituximab for autoimmune cytopenias.

CONCLUSIONS

Hypogammaglobulinemia post-rituximab treatment is frequently diagnosed within the pediatric population. Low IgG levels are associated with a significant increase in serious infections, and underlying primary immunodeficiencies are relatively common in children receiving rituximab, thus highlighting the importance of immunologic monitoring both before and after rituximab therapy.

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.

Rituximab-Induced Hypogammaglobulinemia and Infections in AQP4 and MOG Antibody-Associated Diseases

Objective

To determine the potential association between infections and rituximab (RTX)-induced hypogammaglobulinemia among patients with CNS inflammatory diseases.

Methods

We included in a prospective observational study all consecutive adults with aquaporin 4 (AQP4) or myelin oligodendrocyte glycoprotein (MOG) antibody–positive disorders treated with RTX. Dosing schedule was adapted to memory B-cell measurement.

Results

We included 48 patients (mean age 47 [SD: 14] years; 77% females; 31 AQP4 positive and 17 MOG positive). The median follow-up was 3.6 years (range: 0.9–8.1 years). The median number of RTX infusions was 8 (range: 2–14). The median dosing interval was 6 months (range: 1.7–13.7 months). Sixty-seven symptomatic infections (SIs) were observed in 26 of 48 (54%) patients, including 13 severe infections in 9 (19%). Urinary and lower respiratory tract infections were the most frequent, representing 42% and 21% of SI. At RTX onset, the immunoglobulin G (IgG) level was abnormal in 3 of 48 (6%) patients. After RTX, 15 (31%), 11 (23%), 3 (6%), and 0 of 48 patients showed sustained IgG level <7, <6, <4, and <2 g/L, respectively. On multivariate Cox proportional hazards analysis, the main variables explaining the risk of SI were the presence of urinary tract dysfunction (hazard ratio [HR] = 34, 95% CI 4–262, p < 0.001), the dosing intervals (HR = 0.98, 95% CI 0.97–0.99, p < 0.001), and the interaction between IgG level and urinary tract dysfunction (HR = 0.67, 95% CI 0.53–0.85, p < 0.005). IgG level <6 g/L during RTX was associated with male sex (HR = 4, 95% CI 1.4–11.4, p < 0.01) and previous immunosuppression (HR = 3.4, 95% CI 1.2–10, p < 0.05).

Conclusions

RTX used as maintenance therapy in CNS inflammatory diseases is frequently associated with reduced IgG level and increases the infection risk of the most vulnerable patients.

COVID-19 in Patients with Multiple Sclerosis: Associations with Disease-Modifying Therapies

BACKGROUND

Disease-modifying therapies (DMTs) for multiple sclerosis (MS) target immunity and have the potential to increase the risk of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and alter its clinical course. We assessed these risks in patients with MS (PwMS).

OBJECTIVE

The objective of this study was to describe the overall risk of coronavirus disease 2019 (COVID-19) infection, severe disease course, and potential population-level predictors of COVID-19 infection in PwMS, and to provide a context using a cohort of patients with systemic lupus erythematosus (SLE). In addition, the association of different MS DMTs with the incidence and clinical course of COVID-19 was evaluated. Safety data from the Biogen Global Safety Database are also presented on reported cases of COVID-19 in patients treated with Biogen MS therapies.

METHODS

The IBM® Explorys electronic health record database of > 72,000,000 patients from US healthcare networks identified patients with MS or SLE, with and without polymerase chain reaction-confirmed COVID-19. COVID-19 cumulative incidence, hospitalization, and deaths among DMT classes were compared using logistic regression (adjusted for age, sex, body mass index, comorbidities, and race/ethnicity). As a secondary data source to assess safety data, COVID-19 reports for Biogen MS therapies were extracted and described from Biogen's Global Safety Database.

RESULTS

30,478 PwMS with an open DMT prescription were identified within Explorys; 344 were COVID-19 positive. The most significant risk factors for acquiring COVID-19 were comorbidity score ≥ 1, body mass index ≥ 30, and Black/African ancestry. Similar risk factors were also identified for patients with SLE. Patients with MS were less likely to develop COVID-19 when treated with interferons (0.61%) and glatiramer acetate (0.51%), vs all other MS DMTs (both p < 0.001); anti-CD20 therapy was associated with the highest risk (3.45%; p < 0.0001). In the Biogen Global Safety Database, we identified 1217 patients who were COVID-19 positive treated with intramuscular interferon beta-1a, peginterferon beta-1a, natalizumab, dimethyl fumarate, diroximel fumarate, or fampridine.

CONCLUSIONS

Comorbidities, obesity, and Black/African ancestry, but not age, were associated with a higher risk of SARS-CoV-2 infection in PwMS. Interferons and glatiramer acetate were associated with a reduced COVID-19 risk, whereas anti-CD20 therapies were associated with an increased risk, within the treated MS cohort. COVID-19 safety reports for patients receiving Biogen MS therapies were consistent with the Explorys database and MS literature, illustrating the replicability and power of this approach.

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.

Predicting Infection Risk in Multiple Sclerosis Patients Treated with Ocrelizumab: A Retrospective Cohort Study

BACKGROUND

Ocrelizumab safety outcomes have been well evaluated in clinical trials and open-label extension (OLE) studies. However, risk factors for infection in patients with multiple sclerosis (MS) receiving ocrelizumab have not been extensively studied in the real-world setting.

OBJECTIVE

The aim of this study was to examine factors determining risk of self-reported infections and antimicrobial use in patients receiving ocrelizumab for MS.

METHODS

A retrospective, observational cohort study was conducted in patients receiving ocrelizumab at the Royal Melbourne Hospital. Infection type and number were reported by patients, and the associations of potential clinical and laboratory risk factors with self-reported infection and antimicrobial use were estimated using univariate and multivariable logistic regression models.

RESULTS

A total of 185 patients were included in the study; a total of 176 infections were reported in 89 patients (46.1%), and antimicrobial use was identified in 47 patients (25.3%). In univariate analyses, a higher serum IgA was associated with reduced odds of infection (OR 0.44, 95% CI 0.25-0.76). In multivariable analyses, older age (OR 0.94, 95% CI 0.88-0.99), higher serum IgA (OR 0.37, 95% CI 0.17-0.80) and higher serum IgG (OR 0.81, 95% CI 0.67-0.99) were associated with reduced odds of infection. Older age (OR 0.85, 95% CI 0.75-0.96) and higher serum IgA (OR 0.23, 95% CI 0.07-0.79) were associated with reduced odds of antimicrobial use, whilst longer MS disease duration (OR 1.22, 95% CI 1.06-1.41) and higher Expanded Disability Status Scale (EDSS) score (OR 1.99, 95% CI 1.02-3.86) were associated with increased odds of antimicrobial use.

CONCLUSIONS

Higher serum IgA and IgG and older age were associated with reduced odds of infection. Our findings highlight that infection risk is not uniform in patients with MS receiving ocrelizumab and substantiate the need to monitor immunoglobulin levels pre-treatment and whilst on therapy.

Maintenance Intravenous Immunoglobulin Treatment for Multiple Sclerosis Coexisting with Ehlers-Danlos Syndrome and Muir-Torre Syndrome: A Case Study

The therapeutic options for disease modification in relapsing-remitting multiple sclerosis (RRMS) have expanded remarkably in the last 15 years. Although intravenous immunoglobulins (IVIg) have shown some therapeutic effects in multiple sclerosis, reducing global supplies, restriction of treatment to essential indications and availability of effective alternative treatments for MS currently exclude IVIg from being an accepted therapy for MS, other than for some exceptional considerations. We report the case of a female patient with RRMS who was diagnosed with Ehlers-Danlos syndrome (EDS) and Muir-Torre syndrome (MTS) soon after the diagnosis of active RRMS was made. The coexisting conditions precluded the use of available disease-modifying treatments. She benefited from monthly and then bi-monthly IVIg, with a single mild relapse over 10 years. Discontinuation of IVIg due to reduced availability with a brief aborted course of subcutaneous PEGylated interferon-beta was followed by significant relapses. Five months after the first ocrelizumab infusion, she developed caecal cancer requiring colectomy. Reinstitution of IVIg is contemplated.

Secondary immunodeficiencies with predominant antibody deficiency: multidisciplinary perspectives of Polish experts

At present, secondary immune deficiencies have become a clinical problem, recognized in different specialties. The aim of this paper was to increase awareness and support the need for screening at-risk populations. Secondary immune deficiencies result in variety of conditions, but not all of them require immunoglobulin replacement therapy, as specific antibody response might be preserved. Moreover, the management of secondary immune deficiencies vary between countries and different medical disciplines. This literature review presents the most common causes and clinical presentation of secondary immunodeficiencies with predominant impaired antibody production. We present diagnostic guidelines for patients at-risk, with an emphasis on the role of prophylactic vaccination as a treatment and diagnostic tool. This review considers the specificity and disparities of the Polish healthcare system and ultimately, suggests that management teams should include a clinical immunologist experienced in the treatment of humoral immunodeficiencies.

Neuromyelitis optica

Neuromyelitis optica (NMO; also known as Devic syndrome) is a clinical syndrome characterized by attacks of acute optic neuritis and transverse myelitis. In most patients, NMO is caused by pathogenetic serum IgG autoantibodies to aquaporin 4 (AQP4), the most abundant water-channel protein in the central nervous system. In a subset of patients negative for AQP4-IgG, pathogenetic serum IgG antibodies to myelin oligodendrocyte glycoprotein, an antigen in the outer myelin sheath of central nervous system neurons, are present. Other causes of NMO (such as paraneoplastic disorders and neurosarcoidosis) are rare. NMO was previously associated with a poor prognosis; however, treatment with steroids and plasma exchange for acute attacks and with immunosuppressants (in particular, B cell-depleting agents) for attack prevention has greatly improved the long-term outcomes. Recently, a number of randomized controlled trials have been completed and the first drugs, all therapeutic monoclonal antibodies, have been approved for the treatment of AQP4-IgG-positive NMO and its formes frustes.

Severe pneumonia with formation of a pulmonary cavity associated with long-term rituximab therapy in multiple sclerosis

Nowadays B-cell depletion via anti-CD20 antibodies is commonly applied in the treatment of multiple sclerosis (MS). Yet, not much is known about infection risks associated with long-term B-cell depletion in the specific context of MS.

We present the case of a 45-year-old male patient who developed severe pneumonia following 6 years of rituximab treatment for highly active relapsing-remitting MS. The patient had no additional chronic disease as well as no history of foreign travel. Although the unusual formation of a pulmonary cavity raised suspicion for tuberculosis, repeated testing via bronchoscopy and sputum remained negative. Prolonged antibiotic therapy with piperacillin/tazobactam and amoxicillin/ clavulanate led to complete recovery from symptoms.

This case shows the potential risk of serious infections following continuous B-cell depletion in MS and illustrates the importance of future vigilance.

Mild clinical manifestations of SARS-CoV-2 related pneumonia in two patients with multiple sclerosis under treatment with ocrelizumab

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Ocrelizumab is not associated to increased severity in MS patients with COVID-19.

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B-cell depleting treatment could impact on virus-specific antibody production.

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B-cell depleting therapies can reduce IL-6 production, thus modulating inflammation.

Background

Recently SARS-CoV-2 has spread worldwide causing a pandemic. Little is known about disease severity in immunocompromised hosts and people receiving disease modifying therapies (DMTs). In the last decades DMTs have been widely employed, and ocrelizumab represents one of the newest therapies for the relapsing remitting and progressive forms of multiple sclerosis (MS).

Objectives

to describe SARS-CoV-2 related pneumonia in two MS patients under ocrelizumab treatment.

Methods

Case series.

Results

Patients showed a mild clinical course of SARS-CoV-2 related pneumonia without complications or sequelae.

Conclusion

Ocrelizumab treatment is not necessarily associated to increased severity in MS patients with SARS-CoV-2 infection.

The underpinning biology relating to multiple sclerosis disease modifying treatments during the COVID-19 pandemic

BACKGROUND

SARS-CoV-2 viral infection causes COVID-19 that can result in severe acute respiratory distress syndrome (ARDS), which can cause significant mortality, leading to concern that immunosuppressive treatments for multiple sclerosis and other disorders have significant risks for both infection and ARDS.

OBJECTIVE

To examine the biology that potentially underpins immunity to the SARS-Cov-2 virus and the immunity-induced pathology related to COVID-19 and determine how this impinges on the use of current disease modifying treatments in multiple sclerosis.

OBSERVATIONS

Although information about the mechanisms of immunity are scant, it appears that monocyte/macrophages and then CD8 T cells are important in eliminating the SARS-CoV-2 virus. This may be facilitated via anti-viral antibody responses that may prevent re-infection. However, viral escape and infection of leucocytes to promote lymphopenia, apparent CD8 T cell exhaustion coupled with a cytokine storm and vascular pathology appears to contribute to the damage in ARDS.

IMPLICATIONS

In contrast to ablative haematopoietic stem cell therapy, most multiple-sclerosis-related disease modifying therapies do not particularly target the innate immune system and few have any major long-term impact on CD8 T cells to limit protection against COVID-19. In addition, few block the formation of immature B cells within lymphoid tissue that will provide antibody-mediated protection from (re)infection. However, adjustments to dosing schedules may help de-risk the chance of infection further and reduce the concerns of people with MS being treated during the COVID-19 pandemic.

Re-Evaluating the Use of IFN-β and Relapsing Multiple Sclerosis: Safety, Efficacy and Place in Therapy

The advent of interferon therapy for the treatment of multiple sclerosis (MS) was a massive advancement in the field and changed the course of the disease. While the exact mechanism of interferon therapy in MS is unknown, disease control is likely mediated by reducing Th1 and Th17 cells while increasing regulatory T cells and altering the cytokine profile. Interferon therapy not only gave physicians and patients an evidence-based treatment option to treat MS by decreasing relapses and the accrual of disability but it also provided valuable insight into disease pathophysiology that allowed for the development of further treatments. Currently, there are 18 disease-modifying therapies available for the treatment of MS with varying efficacies, routes of administration, and mechanisms. As treatment options in the field have evolved, interferon therapy is less commonly prescribed as first-line therapy, because the newer therapies are more effective and better tolerated. That being said, interferons still have a place in the field in both clinical practice and clinical trial research. In this review, we will summarize the safety and efficacy of interferon therapy and discuss its current place in MS care.

Decision-making on management of ms and nmosd patients during the COVID-19 pandemic: A latin american survey

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In this COVID-19 context, there is an urgent necessity of sharing information to enable evidence-based decision making on the clinical management.

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In LATAM, 60% of the experts had the possibility of monitoring their patients by telemedicine.

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Most neurologists postpone magnetic resonance and laboratory blood tests delay is associated with the type of MS or NMOSD treatment.

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Platform therapies, dimethyl-fumarate and natalizumab are considered safe options to initiate in naive patients.

Background

The emergence of COVID-19 and its vertiginous spreading speed represents a unique challenge to neurologists managing multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD). The need for data on the impact of the virus on these patients grows rapidly. There is an urgent necessity of sharing information to enable evidence-based decision making on the clinical management. There are no data on what physicians are doing on clinical practice in Latin American countries.

Aim

to investigate current management opinion of Latin American MS and/or NMOSD expert neurologists based on their experience and recommendations.

Methods

we developed a voluntary web-based survey based on hypothetical situations that these patients may encounter, while taking into account the potential risk of developing severe COVID-19 infection.

Results

60% of the experts had the possibility of monitoring their patients by telemedicine. Most neurologists postpone magnetic resonance. Laboratory blood tests delay is associated with the type of treatment. Platform therapies, dimethyl-fumarate and natalizumab are considered safe options to initiate in naive patients.

Conclusion

decision-making about MS and NMOSD patients has become even more complex in order to adapt to the COVID-19 pandemic. Risks and benefits should be taken into consideration throughout the patient follow-up.

Do plasma cells contribute to the determination of their lifespan?

Longevity of plasma cells is dependent on their ability to access and reside in so-called survival niches that are predominantly located in the bone marrow. It is proposed that by some process a small fraction of the plasma cells generated in response to new antigen challenges can enter into the long-lived repertoire by displacing existing plasma cells. Several lines of research show that this process is not stochastic as not all resident, long-lived plasma cells appear equally likely to be displaced. The basis of these differences might reside in the niches, the plasma cells or a combination of both factors that intersect to create a distribution of susceptibility to replacement and lifespans. In this review, I consider factors that might vary in plasma cells and thus influence their access to niches and the ability of newly generated plasma cells to survive over the long term.

[Ocrelizumab for treatment of multiple sclerosis]

Ocrelizumab ist ein monoklonaler Antikörper, der sich gegen das Differenzierungsantigen CD20 richtet und zu einer effektiven längerfristigen Depletion von Lymphozyten, insbesondere von B‑Zellen, führt. Unlängst publizierte Phase-3-Studien belegen, dass Ocrelizumab sowohl bei der Behandlung der schubförmigen als auch der primär progressiven Multiplen Sklerose (MS) wirksam ist. Darauf basierend wurde Ocrelizumab als erstes Medikament zur Behandlung der primär chronisch-progredienten MS zugelassen. Um diesen Durchbruch besser in den Kontext des heutigen MS-Therapiekanons einordnen zu können, lohnt sowohl ein Blick zurück auf die Entwicklung der antikörpervermittelten CD20-Depletion als auch auf die der Zulassung zugrunde liegenden Studien sowie deren Extensionsphasen. Diese Übersichtsarbeit diskutiert die verfügbaren Daten zur Wirksamkeit und Sicherheit der langfristigen B‑Zell-Depletion bei MS-Patienten und erörtert den aktuellen Kenntnisstand zur Rolle von B‑Lymphozyten in der Immunpathogenese der MS.