Neutropenia complicating anti-CD20 treatment in patients with multiple sclerosis: A retrospective case series and a systematic review of reported cases

Recurrent late-onset neutropenia after ofatumumab treatment in a case of multiple sclerosis

OBJECTIVE

Immunomodulatory treatment options for multiple sclerosis show an inverse risk‒benefit ratio of side effects and treatment efficacy. Although rare, anti-B-cell therapies can cause acute or late-onset neutropenia.

METHODS

We report a case of severe recurrent fluctuating neutropenia after ofatumumab treatment.

RESULTS

We observed four recurrences even after pausing with ofatumumab and repeated granulocyte stimulating factor (G-CSF) treatment. In total, neutropenia occurred five times and was associated with recurrent pulmonary, urinary tract, and skin infections. Bone marrow investigation revealed no signs of lymphoma or leukemia. Interestingly, routine molecular testing revealed two gene variants of unknown significance for BCORL1 and ASXL1, both of which play a role in hematopoiesis. The neutrophil count recovered spontaneously six months after the cessation of treatment with ofatumumab.

DISCUSSION

This case highlights the necessity of identifying patients at risk and monitoring white blood cell counts regularly for up to 6 months after initial neutropenia.

Severe Late-Onset Neutropenia in a Pregnant Patient with Multiple Sclerosis after Ocrelizumab

Introduction

Ocrelizumab is a recombinant humanized anti-CD20 monoclonal antibody used to treat multiple sclerosis. Late-onset neutropenia, absolute neutrophil count <1.5 × 109/L that develops >4 weeks after last drug administration, is a known adverse event associated with anti-CD20 monoclonal antibodies, including rituximab and ocrelizumab.

Case Presentation

We present the case of a 27-year-old woman who developed severe late-onset neutropenia during her third trimester of pregnancy after treatment with ocrelizumab 6 months prior.

Conclusion

Neurologists should be aware of this risk and consider additional hematologic monitoring for pregnant patients who received anti-CD20 therapy as therapies such as G-CSF are available to help prevent serious infections.

B-cell Depletion Therapy in Pediatric Neuroinflammatory Disease

PURPOSE OF REVIEW

B-cell depletion therapy, including anti-CD20 and anti-CD19 therapies, is increasingly used for a variety of autoimmune and conditions, including those affecting the central nervous system. However, B-cell depletion therapy use can be complicated by adverse effects associated with administration and immunosuppression. This review aims to summarize the application of anti-CD20 and anti-CD19 therapies for the pediatric neurologist and neuroimmunologist.

RECENT FINDINGS

Most existing literature come from clinical trials with adult patients, although more recent studies are now capturing the effects of these therapies in children. The most common side effects include infusion related reactions and increased infection risk from immunosuppression. Several strategies can mitigate infusion related reactions. Increased infections due to persistent hypogammaglobulinemia can benefit from replacement immunoglobulin. B-cell depletion therapies can be safe and effective in pediatric patients. Anticipation and mitigation of common adverse effects through primary prevention strategies, close monitoring, and appropriate symptomatic management can improve safety and tolerability.

Disease-modifying therapies and hematological disorders: a systematic review of case reports and case series

Introduction

Disease modifying therapies (DMTs) used to treat multiple sclerosis (MS) can be associated to the occurrence of hematological disorders. This systematic review aims to provide an overview of these events occurring in real-life conditions, by describing case reports and series published in the literature.

Methods

A literature search of all publications up to January 5th 2024 on the Medline and Embase databases was carried out. The results were presented both in the text and in tables.

Results

Sixty-seven case reports/series were included in this review, of which more than half related to alemtuzumab, natalizumab and ocrelizumab. The publication date of included studies ranged from 2006 to 2024. The majority of case reports and series described the occurrence of late-onset hematological disorders (events that occurred more than 30 days after the first DMT administration), mainly represented by case of neutropenia, autoimmune hemolytic anemia and immune thrombocytopenia. All cases reported a favorable outcome, apart one case report that described a fatal case. Among included cases, 4 articles, all related to natalizumab, described the occurrence of myeloid disorders in 13 newborns from mother receiving the DMT.

Discussion

Considering the limitations identified in the majority of included studies, further ad hoc studies are strongly needed to better evaluate the hematological disorders of DMTs. Meantime, the strict monitoring of treated patients for the occurrence of these toxicities should be highly recommended.

Neutropenia following immune-depletion, notably CD20 targeting, therapies in multiple sclerosis

Neutropenia serves as a risk factor for severe infection and is a consequence of some immune-depleting immunotherapies. This occurs in people with multiple sclerosis following chemotherapy-conditioning in haematopoietic stem cell transplantation and potent B cell targeting agents. Whilst CD52 is expressed by neutrophils and may contribute to early-onset neutropenia following alemtuzumab treatment, deoxycytidine kinase and CD20 antigen required for activity of cladribine tablets, off-label rituximab, ocrelizumab, ofatumumab and ublituximab are not or only weakly expressed by neutrophils. Therefore, alternative explanations are needed for the rare occurrence of early and late-onset neutropenia following such treatments. This probably occurs due to alterations in the balance of granulopoiesis and neutrophil removal. Neutrophils are short-lived, and their removal may be influenced by drug-associated infections, the killing mechanisms of the therapies and amplified by immune dyscrasia due to influences on neutropoiesis following growth factor rerouting for B cell recovery and cytokine deficits following lymphocyte depletion. This highlights the small but evident neutropenia risks following sustained B cell depletion with some treatments.

Recurrence of severe symptomatic late-onset neutropenia on ocrelizumab

BACKGROUND

Late-onset neutropenia (LON), defined as an absolute neutrophil count (ANC) < 1500/mm3 that develops between 4 weeks and 6 months after the last drug administration, is a rare side effect of anti-CD20 drugs including ocrelizumab. Although continuation of ocrelizumab after LON is not contraindicated, the risk of LON recurrence is not well known.

CASES

We report three cases of recurrent symptomatic agranulocytosis (ANC < 500/mm3) occurring under ocrelizumab.

CONCLUSION

Given the risk of recurrence of symptomatic agranulocytosis and the availability of other treatments, a therapeutic switch may be discussed after the first episode of LON.

Anti-CD20 treatment and neutrophil function in central nervous system demyelinating diseases

INTRODUCTION

A contribution of neutrophil granulocytes to the pathogenesis of multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) is recognized. Anti-CD20 treatments applied in these diseases are associated with infectious complications and neutropenia. No data is available about functional characteristics of neutrophils obtained from patients with anti-CD20 treatments.

METHODS

In neutrophils isolated from 13 patients with anti-CD20 treatment (9 MS, 4 NMOSD), 11 patients without anti-CD20 treatment (9 MS, 2 NMOSD) and 5 healthy controls, we analyzed chemotaxis, production of reactive oxygen species (ROS), phagocytosis, and formation of neutrophil extracellular traps (NET) in vitro.

RESULTS

Chemotaxis and ROS production were found unchanged between patients with and without anti-CD20 treatment or between patients and healthy controls. We found a higher proportion of non-phagocytosing cells in patients without anti-CD20 treatment compared to patients with anti-CD20 treatment and healthy controls. As compared to healthy controls, a higher proportion of neutrophils from patients without anti-CD20 treatments underwent NET formation, either unstimulated or stimulated with phorbol 12-myristate 3-acetate for 3 h. In about half of patients with anti-CD20 treatment (n = 7), NET formation of unstimulated neutrophils occurred already within 20 min of incubation. This was not observed in patients without anti-CD20 treatment and healthy controls.

CONCLUSION

Anti-CD20 treatment in MS and NMOSD patients does not alter chemotaxis and ROS production of neutrophils in vitro but might restore their impaired phagocytosis in these diseases. Our study reveals a predisposition to early NET formation in vitro of neutrophils obtained from patients with anti-CD20 treatment. This may contribute to associated risks of neutropenia and infections.