Rituximab for eosinophilic granulomatosis with polyangiitis with severe vasculitic neuropathy: Case report and review of current clinical evidence

Update on targeted treatments for ANCA-associated vasculitis

Targeted therapy has revolutionized the management of ANCA-associated vasculitis (AAV) over the last fifteen years. Rituximab, an approved induction and maintenance agent for severe AAV, is no less effective than cyclophosphamide as induction therapy and particularly useful in relapsing or refractory disease, or in women. In patients with relapsing AAV, granulomatosis with polyangiitis or PR3-ANCA, it is more effective than cyclophosphamide. Rituximab maintenance is superior to the conventional immunosuppressive drugs that it replaces. Low-dose preemptive rituximab infusions are recommended every 6months for 18months, followed by re-evaluation to decide whether 4 additional biannual infusions should be administered, balancing the probability of relapse and the risk of serious infections on rituximab. A growing body of experimental and clinical data shows that C5a pathway inhibition is a promising therapeutic option for AAV, which could reduce glucocorticoids needs. Avacopan is a first approved oral C5A receptor antagonist, used when there is a high risk that glucocorticoids will cause serious adverse events. In eosinophilic granulomatosis with polyangiitis, the importance of IL-5 for eosinophil activation and survival led to evaluation and approval of mepolizumab, a humanized monoclonal antibody directed against IL-5. Mepolizumab showed a steroid-sparing effect. Its effectiveness in active vasculitis remains uncertain and is currently being evaluated. Benralizumab targeting the IL-5 receptor was recently shown to be noninferior to mepolizumab. Rituximab has had disappointing results in non-severe active vasculitis and is being evaluated as maintenance therapy. Plasma exchange is not indicated as first-line treatment but remains recommended when creatinine levels exceed 300μmol/L.

Long-term mepolizumab treatment reduces relapse rates in super-responders with eosinophilic granulomatosis with polyangiitis

BACKGROUND

The mainstay of treatment for eosinophilic granulomatosis with polyangiitis (EGPA) is systemic corticosteroid therapy; some patients also receive intravenous immunoglobulins, other immunosuppressive agents, and biologics. Mepolizumab, an anti-interleukin-5 monoclonal antibody, induces remission and decreases the daily corticosteroid dose; however, the clinical efficacy of mepolizumab in EGPA and the prognosis with long-term treatment with this drug are unknown.

METHODS

Seventy-one EGPA patients were treated at Hiratsuka City Hospital, Japan, between April 2018 and March 2022. We administered mepolizumab for a mean of 2.8 ± 1.7 years to 43 patients in whom remission could not be induced by conventional treatment. After excluding 18 patients who had received mepolizumab for less than 3 years, we classified 15 patients into a "super-responder group" (the daily dose of corticosteroids or other immunosuppressant could be decreased, or the interval between IVIG treatments could be prolonged) and 10 patients into a "responder group" (neither of these changes was achievable). Eosinophil numbers, serum IgG levels, daily doses of corticosteroids and other immunosuppressants, Birmingham Vasculitis Activity Score (BVAS), and relapse frequency before and after mepolizumab initiation were determined.

RESULTS

Blood eosinophil count at diagnosis and the lowest serum IgG level before mepolizumab treatment were significantly higher in super-responders than in responders (p < 0.05). In super-responders, the prednisolone dose at last visit on mepolizumab treatment was lower than that before treatment (p < 0.01) and lower than that at last visit in the responders (p < 0.01). In both groups, peripheral blood eosinophil numbers and BVAS were lower after starting mepolizumab than before (p < 0.01). BVAS before mepolizumab (p < 0.05) and at last visit (p < 0.01) were lower in super-responders than in responders. Relapse rates every year after the start of mepolizumab were lower in super-responders than in responder groups (p < 0.01). In super-responders, relapse rates were lower during the 3 years following mepolizumab initiation (p < 0.01) and at last visit (p < 0.01) were significantly lower than after 1 year of treatment.

CONCLUSION

Mepolizumab treatment of super-responders sustainably reduced the relapse rate.

Association between Serum Biomarkers and Peripheral Neuropathy in Microscopic Polyangiitis

This study aimed to elucidate the pathomechanism of peripheral neuropathy (PN) in microscopic polyangiitis (MPA) and to identify biomarkers useful for diagnosis and severity assessment. Patients with MPA (n = 37) and other non-inflammatory neurological diseases (ONDs; n = 12) were enrolled, and the peripheral nerves of all patients were evaluated using nerve conduction studies. We compared the clinical characteristics and 14 serum biomarker profiles among patients with MPA and PN, MPA without PN, and ONDs. Patients with MPA had a higher prevalence of motor neuropathy than patients with ONDs. Among the patients with MPA, those with motor neuropathy had significantly higher total Birmingham Vasculitis Activity Scores and serum levels of C-reactive protein (CRP), tissue inhibitor of metalloproteinase-1 (TIMP-1), and interleukin-6 than patients without motor neuropathy. Multivariable analyses adjusted for age, serum CRP level, and diabetes mellitus showed that high serum levels of TIMP-1 were independently related to a diagnosis of motor neuropathy in MPA. Additionally, there were significant negative correlations between the serum levels of TIMP-1 and compound muscle action potential amplitudes. Serum levels of TIMP-1 may be associated with the pathomechanism of motor neuropathy in MPA and could be a useful biomarker for diagnosing and evaluating the severity of motor neuropathy in MPA.

Rituximab and dupilumab improve eosinophilic granulomatosis with polyangiitis with multiple pulmonary thrombi

Background

Eosinophilic granulomatosis with polyangiitis (EGPA) is characterized by a necrotizing vasculitis with tissue and peripheral blood eosinophilia affecting small and medium-sized arteries, capillaries, and veins. Venous thromboembolic events are uncommon in EGPA. Moreover, there are only a few reported cases of EGPA complicated by pulmonary embolism or infarction.

Case presentation

We report the case of a 43-year-old woman with eosinophilic granulomatosis with polyangiitis and acute respiratory and heart failure due to bilateral pulmonary artery thrombosis and left femoral vein thrombosis 12 years after disease onset. She also had cardiac involvement (myocarditis, pericardial effusion, and diastolic dysfunction), gastrointestinal symptoms, and peripheral neuropathy. The condition was refractory to treatment with systemic corticosteroids, intravenous cyclophosphamide, and mepolizumab, but the thrombosis and associated acute cardiac failure, as well as the cardiac and gastrointestinal symptoms and multiple polyneuropathy, improved after a switch to rituximab. However, the heart failure did not improve sufficiently and the patient continued to need inhaled oxygen at 1 L/min and asthma exacerbations occurred. We then swapped the patient’s mepolizumab treatment for dupilumab. Not only did she have no further asthma attacks after switching to dupilumab, but also her vasculitis symptoms improved. Oxygen therapy was discontinued as the heart failure improved 5 months after starting the dupilumab.

Conclusions

This may be the first case report of the successful treatment by rituximab of pulmonary thromboembolism associated with EGPA. In addition, in this patient, treatment with dupilumab was effective not only for the asthma symptoms but also for the symptoms of vasculitis and heart failure.

Rituximab for eosinophilic granulomatosis with polyangiitis: a systematic review of observational studies

OBJECTIVE

To analyse the available evidence about the use of rituximab (RTX) and other biologic agents in eosinophilic granulomatosis with polyangiitis (EGPA) patients and to provide useful findings to inform the design of future, reliable clinical trials.

METHODS

A systematic review was performed. A systematic search was conducted in PubMed/MEDLINE, Scopus, Web of Science and the Cochrane library databases on RTX, and an extensive literature search was conducted on other biologic agents.

RESULTS

Forty-five papers pertinent to our questions were found: 16 retrospective cohort studies, 8 case series, 3 prospective cohort studies and 18 single case reports, for a total of 368 EGPA patients. More than 80% of evaluable patients achieved complete or partial remission with a tendency towards a higher rate of complete response in the pANCA-positive subgroup.

CONCLUSION

Although the majority of the evaluable EGPA patients treated with RTX appears to achieve complete remission, we strongly believe that a number of sources of heterogeneity impair a clear interpretation of results and limit their transferability in clinical practice. Differences in design, enrolment criteria, outcome definition and measurement make a comparison among data obtained from studies on RTX and other biologic agents unreliable.

Clinical Features of Patients with Active Eosinophilic Granulomatosis with Polyangiitis Successfully Treated with Mepolizumab

BACKGROUND

In some patients with eosinophilic granulomatosis with polyangiitis (EGPA), remission cannot be induced, despite treatment with corticosteroids and immunosuppressants. We evaluated the clinical features of patients with EGPA in whom mepolizumab was effective.

METHODS

There were 59 EGPA patients treated at Hiratsuka City Hospital, Japan, between April 2018 and September 2020, and 30 of them received mepolizumab. Twenty (66.7%) experienced a "marked effect" (the daily dose of corticosteroid or immunosuppressant could be decreased, or the interval between intravenous immunoglobulin (IVIG) treatments could be prolonged) and 10 (33.3%) experienced a "weak effect" (these measures were not achieved). Eosinophil numbers, serum IgG levels, daily doses of corticosteroids and immunosuppressants, and the interval between IVIG treatments at diagnosis and before and after mepolizumab initiation were determined.

RESULTS

Eosinophil numbers at diagnosis were significantly higher in the marked-effect group than in the weak-effect group (p < 0.05) but not before mepolizumab initiation or at the last visit. Birmingham Vasculitis Activity Scores (BVASs) before mepolizumab initiation (p < 0.05) and at last visit (p < 0.01), and frequency of relapse before treatment initiation (p < 0.05) were significantly higher, and the serum IgG level before mepolizumab treatment was significantly lower in the weak-effect group than in the marked-effect group. The weak-effect group received higher doses of corticosteroids, even if the corticosteroid dose could be reduced for a while after mepolizumab initiation.

CONCLUSION

High peripheral blood eosinophil numbers at EGPA diagnosis were suggestive of a positive clinical response to mepolizumab.

Chronic Immune-Mediated Polyneuropathies

This article discusses the chronic immune-mediated polyneuropathies, a broad category of acquired polyneuropathies that encompasses chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), the most common immune-mediated neuropathy, the CIDP variants, and the vasculitic neuropathies. Polyneuropathies associated with rheumatological diseases and systemic inflammatory diseases, such as sarcoidosis, will also be briefly covered. These patients' history, examination, serum studies, and electrodiagnostic studies, as well as histopathological findings in the case of vasculitis, confirm the diagnosis and differentiate them from the more common length-dependent polyneuropathies. Prompt identification and initiation of treatment is imperative for these chronic immune-mediated polyneuropathies to prevent disability and even death.

Clinical Characteristics of Peripheral Neuropathy in Eosinophilic Granulomatosis with Polyangiitis: A Retrospective Single-Center Study in China

OBJECTIVE

To investigate clinical features, independent associated factors, treatment, and outcome of patients with peripheral neuropathy (PN) in eosinophilic granulomatosis with polyangiitis (EGPA).

METHODS

We retrospectively analyzed clinical data of 110 EGPA patients from 2007 to 2019 in Peking Union Medical College Hospital. The independent factors associated with PN in EGPA were analyzed with univariate and multivariate logistic regressions.

RESULTS

In EGPA with PN, paresthesia and muscle weakness were observed in 82% and 33% of patients, respectively. Both the upper and lower limbs were involved in 51% of patients. 30% of EGPA patients had symmetrical multiple peripheral neuropathy, whereas only 16.4% presented with mononeuritis multiplex. Compared to patients without PN, patients with PN had a higher erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, Birmingham vasculitis activity score (BVAS), and positivity of myeloperoxidase-antineutrophil cytoplasmic antibodies (MPO-ANCA). Regarding manifestations, patients with PN tended to develop weight loss and arthritis or joint pain. Notably, ANCA positivity, arthritis or joint pain, and higher BVAS were found to be independent associated factors for PN in EGPA. Patients with PN more frequently need glucocorticoid pulses and intravenous infusion of cyclophosphamide. With the longest follow-up of 11.0 years, we found that age and cardiac involvement were risk factors for survival, and female was the protective factor.

CONCLUSION

PN in EGPA frequently displays with symmetrical multiple peripheral neuropathy in China. Positive ANCA, arthritis or joint pain, and higher BVAS are the independent associated factors of PN in EGPA. Glucocorticoids with immunosuppressants are vital therapeutic strategy.

Rituximab treatment of ANCA-associated vasculitis

INTRODUCTION

Rituximab, an anti-B-cell biological therapy, has been investigated in several clinical trials on antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs).

AREAS COVERED

In this paper, the clinical trials and open-label studies on rituximab efficacy and safety in treating AAVs are reviewed.

EXPERT OPINION

Rituximab achieved high remission-induction and sustained-maintenance rates for patients with these severe diseases, thereby challenging the cornerstone treatment of corticosteroids and cyclophosphamide followed by azathioprine. Rituximab should be used as first-line therapy with corticosteroids to induce remission of severe AAVs, especially in situations in which cyclophosphamide may be problematic (relapse after cyclophosphamide, women of childbearing age, risk of malignancy). Cyclophosphamide indications are likely to be restricted in the future. Whenever possible, rituximab should be preferred to azathioprine to maintain remission. The current maintenance regimen has been extended to at least 18 months but its optimal duration remains unknown and recent data suggest the possibility to extend treatment to 4 years. Future challenges include defining the best dose regimen: at present, different schedules are used as alternatives to those recognized as standards by health authorities. In addition, it remains to identify which patients will benefit the most from long-term retreatment: potentially those with relapsing disease or anti-proteinase-3 ANCA-positivity.

Ten-year experience with rituximab for induction and maintenance therapy in patients with ANCA-associated systemic vasculitis

Rituximab (RTM), a monoclonal antibody against CD20+ receptors on the membrane of B-cells, is becoming increasingly important for the induction and maintenance treatment of antineutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis (ANCA-SV). The challenge facing us is to optimize its efficacy, while limiting adverse events (AEs).

Objective: to evaluate the efficacy and safety of RTM used for the induction and maintenance of remission in ANCA-SV on the basis of 10-year single-center experience.

Patients and methods. The paper presents the authors’ own 10-year experience with RTM used for the induction and maintenance of remission in 103 patients with ANCA-SV, including granulomatosis with polyangiitis (GPA) (n=58), microscopic polyangiitis (MPA) (n=35), ANCA-positive eosinophilic granulomatosis with polyangiitis (EGPA) (n=4), and ANCA-negative EGPA (n=6). The duration of a follow-up after initiation of RTM treatment was more than a year (with the exception of death cases) and averaged 25 to 58 months in different ANCA-SV groups. The patients were monitored every 3 months. The intervals between repeated cycles were dependent on the time course of changes in clinical and laboratory parameters. The mean cumulative RTM dose exceeded 3 g; 75% of patients received repeated cycles of RMT usually at a cumulative dose of 0.5–1.0 g at a 4–12-month interval.

Results and discussion. Repeated RTM cycles for ANCA-SV were highly effective; the clinical response rate was 97%, while 90–93% of patients with different types of ANCA-SV achieved complete clinical response. Despite the fact that the examined population included a high proportion of patients with a severe or refractory course of the disease; ANCA-SV patients showed 10% mortality rates during the entire follow-up period. Anti-B-cell therapy with RTM is of great importance in obtaining long-term optimal results, making it possible to improve ANCA-SV control and to minimize the cumulative dose of glucocorticoids. Since in ANCA-SV, the use of repeated cycles of RTM, including that at a reduced dose of 0.5 g, contributes to the higher efficiency of treatment and to the lower risk of relapse, it is advisable to perform long-term (≥2 years) RTM therapy, by controlling the parameters of clinical and immunological activities and the levels of circulating CD20+ B cells and serum immunoglobulins, deficiency of which can potentially increase the risk of infectious AEs. When planning RTM therapy, it is necessary to consider the specific features of the safety profile for individual nosological entities and to make a careful appropriate monitoring of ANCA-SV patients receiving RTM. The risk of late-onset neutropenia was highest in patients with all types of ANCA-SV (3–10%). Infections in patients with GPA and MPA constitute a substantial proportion (10–11%) in serious AEs. Management of EGPA patients requires alertness to the risk of infusion-related reactions, primarily bronchospasm.

Conclusion. There is a need for further investigation of an anti-B-cell therapy strategy, including the efficacy and safety of RTM in ANCA-SV and for clarification of indications and optimal RTM treatment regimens. 

Unmet Needs in the Pathogenesis and Treatment of Vasculitides

Despite the progress in the last years on the field of vasculitides, there are several unmet needs regarding classification, disease activity assessment, predictors of flares and complications, and type of treatment for the different forms. The 1990 American College of Rheumatology (ACR) classification criteria currently used to define giant cell arteritis and Takayasu arteritis were designed to discriminate between different types of vasculitides but not to differentiate vasculitis from other disorders. Recently, efforts have been made to overcome the shortcomings of the ACR criteria. The lack of an accepted definition of disease activity in large-vessel vasculitides presents a major challenge in creating useful and valid outcome tools for the assessment of disease course. Identification of predictors of flares can aid in optimizing therapeutic strategies, minimizing disease flares, and reducing treatment-related side effects. It is furthermore important to recognize and characterize the risk factor that might predict the manifestations associated with poor outcome and prognosis. Two RCTs have evidenced the efficacy of tocilizumab in addition to glucocorticoids (GCs) in the treatment of giant cell arteritis (GCA). However, the role of tocilizumab or other biological agents without GCs needs to be investigated. Recent observational studies have suggested that rituximab is also effective in patients with eosinophilic granulomatosis with polyangiitis and in antineutrophil cytoplasmic antibodies (ANCA)-negative patients with granulomatosis with polyangiitis and microscopic polyangiitis. Rituximab or anti-TNF alfa may represent a possible alternative therapy in case of refractory or difficult to treat polyarteritis nodosa (PAN) patients. The new International Criteria for Behçet's Disease have shown a better sensitivity and a better accuracy compared to the older International Study Group on Behçet's Disease criteria. The EULAR recommendations for the management of Behçet's disease (BD) have been recently updated. However, the treatment of refractory disease is still a real challenge.

Eosinophilic granulomatosis with polyangiitis (formerly known as Churg-Strauss syndrome) as a differential diagnosis of hypereosinophilic syndromes

Eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as Churg-Strauss syndrome, is a rare systemic disease situated between primary small vessel vasculitides associated with antineutrophil cytoplasmic antibodies (ANCAs) and hypereosinophilic syndromes (HES). Here, we present a case of EGPA in a 38-year-old male, with a previous diagnosis of asthma, who presented with fever, migratory lung infiltrates and systemic eosinophilia that was refractory to previous courses of antibiotics. This case highlights the importance of the primary care physician understanding the differential diagnosis of pulmonary eosinophilic syndromes.

[Current approaches to diagnosing and treating eosinophilic granulomatosis with polyangiitis: The 2015 international guidelines]

The 2015 international guidelines for the diagnosis and treatment of eosinophilic granulomatosis with polyangiitis, formerly known as the Churg-Strauss syndrome, are detailed and an attempt is made to expand an evidence base, by attracting more recent available publications. The new guidelines should not be regarded as final standards; these are primarily to extend the possibilities of choosing a personified management strategy for patients with eosinophilic granulomatosis with polyangiitis and to serve as the starting point for further in-depth investigations.