Rituximab for ANCA-associated vasculitis in the setting of severe infection

Kidney Failure in Pauci-immune Crescentic Glomerulonephritis: Rationale for Immunosuppression to Improve Kidney Outcome

PURPOSE OF REVIEW

Pauci-immune crescentic glomerulonephritis is the hallmark finding in ANCA-associated vasculitis (AAV) when the kidneys are affected. The rationale for immunosuppression in AAV is based on the underlying autoimmune nature of the disease. Overall remission rates, kidney outcomes, and the burden of disease have greatly improved since the discovery of various immunosuppressive therapies, but relapses remain common, and a significant proportion of patients continue to progress to end-stage kidney disease. Here, we review the role of immunosuppressive therapies for the treatment of pauci-immune crescentic glomerulonephritis.

RECENT FINDINGS

Besides the recognized role of B and T cells in the pathogenies of AAV, the focus on the contribution of inflammatory cytokines, neutrophil extracellular traps (NETs), and the complement system allowed the discovery of new therapies. Specifically, the C5a receptor blocker (avacopan) has been approved as a glucocorticoid-sparing agent. Additionally, based on observational data, more clinicians are now using combination therapies during the induction phase. There is also an evolving understanding of the role of plasma exchange in removing ANCA antibodies. Furthermore, the recent development of risk score systems provides physicians with valuable prognostic information that can influence decisions on immunosuppression, although future validation from larger cohorts is needed. The over-activation of various immune pathways plays a significant role in the pathogenesis of pauci-immune crescentic glomerulonephritis in AAV. Immunosuppression is, therefore, an important strategy to halt disease progression and improve overall outcomes. Relapse prevention while minimizing adverse events of immunosuppression is a major long-term goal in AAV management.

[General recommendations for the management of glomerular diseases-2023]

Glomerular diseases are associated with extrarenal complications, such as thromboembolism, cardiovascular events and particularly infections. A thorough knowledge of the various immunosuppressants and their associated toxicity profile is therefore of great importance. While nephrologists usually have extensive experience with calcineurin inhibitors and antimetabolites, two other compounds (rituximab, in severe cases cyclophosphamide) are used comparatively infrequently and will be discussed in more detail. Moreover, practical recommendations for the prevention of thromboembolism in states of nephrosis and for the prophylaxis of Pneumcystic jirovecii pneumonia are provided.

The Efficacy and Safety of Rituximab in ANCA-Associated Vasculitis: A Systematic Review

Background and aim: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare multisystem autoimmune disease developed by autoantibody production against human neutrophilic granulocytes, including proteinase-3 (PR3) and myeloperoxidase (MPO). The management of AAV patients is difficult due to the multiorgan involvement, high rate of relapse, and complications of immunosuppressive agents that make it challenging. This study aims to investigate the efficacy and safety of rituximab (RTX) therapy in patients with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) subtypes. Method: The PubMed/Medline database was searched for any studies related to RTX therapy in ANCA-associated vasculitis (GPA and MPA subtypes), from inception to 1 August 2022, and proceeded in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results: Our search resulted in 1082 initial records. After the elimination of review papers, irrelevant studies, and non-English records, 223 articles were included, and the data related to the efficacy and safety of RTX therapy were extracted. Several randomized and non-randomized studies showed that RTX is an effective treatment option for patients with AAV. Most of the studies showed the very effective effect of RTX in controlling disease in AAV patients, including pediatrics, adults, and elderlies, although RTX cannot completely prevent relapse. However, maintenance therapy helps delay the disease's relapse and causes sustained remission. Not only the licensed dose (375 mg/m² intravenous per week for 4 weeks) could induce disease remission, but studies also showed that a single infusion of RTX could be effective. Although RTX could resolve many rare manifestations in AAV patients, there are few reports showing treatment failure. Additionally, few sudies have reported the unexpeted worsening of the disease after RTX administration. Generally, RTX is relatively safe compared to conventional therapies, but some serious adverse effects, mainly infections, cytopenia, hypogammaglobinemia, malignancy, and hypersensitivity have been reported. Conclusions: RTX is an effective and relatively safe therapeutic option for AAV. Studies on the evaluation of the safety profiles of RTX and the prevention of severe RTX-related side effects in AAV patients are required.

Comparison of Two Rituximab Induction Regimens for Antineutrophil Cytoplasm Antibody-Associated Vasculitis: Systematic Review and Meta-Analysis

Objective

The objective of this study was to compare the efficacy and safety of two rituximab (RTX) regimens for the induction of remission in severe antineutrophil cytoplasm antibody–associated vasculitis (AAV): the four‐dose (375 mg/m² intravenously weekly) versus the two‐dose (1000 mg intravenously biweekly) regimen.

Methods

A systematic review was performed to identify studies using the four‐ and/or two‐dose RTX regimens for induction of remission in severe AAV. Disease status 6 months after RTX infusion was required for inclusion. Patients were excluded if they received concomitant cyclophosphamide or plasma exchange. The primary end point was the proportion of patients in complete remission at 6 months. The pooled estimate was obtained by using meta‐analysis methods for proportions with random effects. Secondary end points included antineutrophil cytoplasm antibody status, number of patients with B‐cell depletion, mean prednisone dose, infections, and death.

Results

A total of 27 studies and 506 patients were included for analysis: 361 patients received the four‐dose regimen, and 145 patients received the two‐dose regimen. Most patients had relapsing disease at inclusion (83% and 92% of patients, respectively). There was no significant difference between the four‐ and two‐dose regimens, with a complete remission achieved in 85% (95% confidence interval [CI]: 70‐96) and 91% (95% CI: 79‐99) of patients, respectively. At 6 months, both regimens were associated with a similar mean daily prednisone dose (8.1 mg), infections (12% in both), and death (1% vs 0%, respectively).

Conclusion

No difference was found in terms of efficacy or safety between the four‐ and two‐dose RTX regimens for induction of remission in severe AAV.

Immunosuppressive and glucocorticoid therapy for the treatment of ANCA-asssociated vasculitis

ANCA-associated vasculitis (AAV) is a systemic, potentially organ and life threatening chronic autoimmune disease. With current management strategies, such as high-dose glucocorticoids in combination with cyclophosphamide or rituximab, outcomes have progressively improved with overall remission rates of 70–90%. However, relapse rates after discontinuation of therapy are consistently high, and treatment-related toxicity, mainly driven by glucocorticoids, still determines morbidity and quality of life. Prevention of relapses while minimizing adverse events is a major goal of long-term treatment, but the optimal duration of maintenance therapy and the role and utility of glucocorticoids in this context remains controversial. This review of induction and maintenance treatment of AAV aims to offer practical advice on immunosuppressive therapies and patient care, addressing individual risk factors and their therapeutic implications. It will discuss benefits and harms of the use of glucocorticoids, particularly focusing on recent advances in steroid sparing concepts.

Severe infections in patients with anti-neutrophil cytoplasmic antibody-associated vasculitides receiving rituximab: A meta-analysis

INTRODUCTION

The efficacy of rituximab (RTX) for remission induction and maintenance in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) is now established, but the safety, particularly concerning severe infection risk, is not well known.

OBJECTIVE

The purpose of this meta-analysis is to assess the prevalence and incidence of severe infections and the factors explaining heterogeneity in AAV patients treated with RTX.

METHODS

PubMed and Embase were searched up to December 2017. Prevalence and incidence was pooled using a random-effects model in case of significant heterogeneity (I² > 50%). Severe infection was defined as severe when it led to hospitalization, intravenous antibiotics therapy, and/or death. The heterogeneity was explored by subgroup analyses and meta-regression.

RESULTS

The included studies encompassed 1434 patients with a median age of 51.9 years. The overall prevalence and incidence of severe infections was 15.4% (95% CI [8.9; 23.3], I² = 90%, 33 studies) and 6.5 per 100 person-years (PY) (95% CI [2.9; 11.4], I² = 76%, 18 studies), respectively. The most common infections were bacterial (9.4%, 95% CI [5.1; 14.8]). The prevalence of opportunistic infection was 1.5% (95% CI [0.5; 3.1], I² = 58%) including pneumocytis jirovecii infections (0.2%, 95% CI [0.0; 0.6], I² = 0), irrespective of prophylaxis administration. Mortality related to infection was estimated at 0.7% (95% CI [0.2; 1.2], I² = 27%). The RTX cumulative dose was positively associated with prevalence of infections (13 studies, prevalence increase of 4% per 100 mg, p < .0001). The incidence of infection was negatively associated with duration of follow-up (8 studies, incidence decrease of 9% per year, p = .03).

CONCLUSION

Prevalence and incidence of severe infections, mainly bacterial ones, were high in AAV patients treated with RTX. This meta-analysis highlights the need for prospective studies to stratify infectious risk and validate cumulative RTX dose and duration of follow-up as modifying factors.

Antineutrophil cytoplasmic antibody associated vasculitides with renal involvement: Open challenges in the remission induction therapy

Renal involvement with rapidly progressive glomerulonephritis is a common manifestation of antineutrophil cytoplasmic antibody (ANCA) associated vasculitides, which is characterized by end-stage renal disease and high mortality rates in untreated and/or late referral patients. The long-term renal survival has improved dramatically since the addition of cyclophosphamide (CYC) and recently of rituximab (RTX) in association with corticosteroids in the remission induction therapeutic regimens. However, renal prognosis remains unfavorable for many patients and the mortality rate is still significantly high. In this review, we analyze the open challenges to be addressed to optimize the induction remission therapy, principally in patients with advanced kidney failure. This concern the first-line therapy (CYC or RTX) based on different parameters (estimated glomerular filtration rate at baseline, new or relapsed disease, ANCA specificity, tissue injury, safety), the role of plasma exchange and the role of new therapies. Indeed, we discuss future perspectives in induction remission therapy by reporting recent advances in new targeted therapies with particular reference to avacopan, an orally administered selective C5a receptor inhibitor.

Tuberculosis and pauci-immune crescentic glomerulonephritis

We report here a case that highlights tuberculosis (TB) as a possible cause for pauci-immune crescentic glomerulonephritis (c-GN), an important and often treatable cause of kidney injury. A 47-year-old HIV-negative man of mixed ethnicity presented with a 2-week history of cough, haemoptysis and unintentional weight loss. Chest examination revealed crepitations over the right upper zone and urinalysis demonstrated an active urinary sediment with red cell casts. Chest radiograph confirmed right upper lobe cavitation. Serum laboratory investigations revealed a serum creatinine of 632 µmol/L and were negative for antineutrophil cytoplasmic antibodies. A diagnosis of pauci-immune c-GN was made on renal biopsy. In addition, sputum PCR confirmed infection with drug-sensitive Mycobacterium tuberculosis Standard TB treatment and immunosuppression with prednisone and cyclophosphamide was commenced, and over the course of 6 months, renal function improved to an estimated glomerular filtration rate >60 mL/min.

Rituximab for anti-neutrophil cytoplasmic antibodies-associated vasculitis: experience of a single center and systematic review of non-randomized studies

Rituximab (RTX) is becoming a standard treatment for patients with anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) but heterogeneity exists regarding its use. We present our uncontrolled experience with RTX in patients with refractory AAV and also the results of a systematic review of non-randomized studies on RTX in AAV patients. We retrospectively reviewed the records of AAV patients treated with RTX following an inadequate response to immunosuppressives between 2011 and 2015. The systematic review covered all English articles listed in PubMed until June 2017. There were 25 AAV patients (21 GPA, four unclassified) treated with RTX (median 2, IQR 1-3 courses; median follow-up 24, IQR 17-50 months). The kidney and the lung were the most commonly affected organs, observed in 14 and 16 patients, respectively. Complete remission rate was 72% at month 6 and 88% at month 12. Two patients had died and three serious adverse events occurred. The systematic review included 56 studies on 1422 patients with the majority being on refractory or relapsing disease. There was wide variability regarding disease characteristics, endpoints, concomitant immunosuppressives and RTX schedule. Most studies reported > 80% complete or partial remission rates with the lowest response (37.5%) for granulomatous lesions. The relapse rate was 30%. Infections and infusion reactions were the main adverse events. Our experience with RTX in refractory AAV is in line with the literature in terms of efficacy and safety. The systematic review underlines many uncertainties on its optimal use.

Conventional induction and maintenance treatment of Antineutrophil cytoplasmic antibodies-associated vasculitis - still of value for our patients?

INTRODUCTION

Antineutrophil cytoplasmic antibodies-associated vasculitis (AAV) is a group of autoimmune diseases characterized by the necrotizing inflammation of small vessels and associated with the antineutrophil cytoplasmic antibodies. Treatment of AAV can be divided into the induction phase aimed at achieving remission of the disease and the maintenance phase aimed at prevention of relapses. Long-term outcome of AAV dramatically improved with the introduction of cyclophosphamide. Recent clinical studies resulted in the reduction of the cumulative dose of cyclophosphamide and introduction of new treatment options, namely B-cell-depleting antibody rituximab, into both induction and maintenance treatment. This paper aims to evaluate the current role of the conventional induction and maintenance treatment in view of the gradually increasing use of rituximab.

AREAS COVERED

This paper provides an overview of the main clinical studies in induction and maintenance treatment of adult patients with AAV, treatment of relapses of AAV and shortly comments also on the treatment of refractory AAV, treatment of different subgroups of AAV (based on the age, renal function, clinical presentation and type of autoantibody), long-term outcome of patients with AAV, adverse events of treatment and treatment of end-stage renal disease in AAV.

EXPERT OPINION

Our analysis demonstrates that although the introduction of rituximab modified the approach to both the induction and maintenance treatment of AAV, more conventional induction and maintenance treatment with standard immunosuppressive drugs still retains its importance as we need more data on long-term efficacy and safety of biologic treatment, and also its cost-effectiveness still remains an open issue.

Rituximab for treatment of severe renal disease in ANCA associated vasculitis

BACKGROUND

Rituximab (RTX) is approved for remission induction in ANCA associated vasculitis (AAV). However, data on use of RTX in patients with severe renal disease is lacking.

METHODS

We conducted a retrospective multi-center study to evaluate the efficacy and safety of RTX with glucocorticoids (GC) with and without use of concomitant cyclophosphamide (CYC) for remission induction in patients presenting with e GFR less than 20 ml/min/1.73 m(2). We evaluated outcomes of remission at 6 months (6 M), renal recovery after acute dialysis at diagnosis, e-GFR rise at 6 M, patient and renal survival and adverse events.

RESULTS

A total 37 patients met the inclusion criteria. The median age was 61 years. (55-73), 62 % were males, 78 % had new diagnosis and 59 % were MPO ANCA positive. The median (IQR) e-GFR at diagnosis was 13 ml/min/1.73 m(2) (7-16) and 15 required acute dialysis. Eleven (30 %) had alveolar hemorrhage. Twelve (32 %) received RTX with GC, 25 (68 %) received RTX with GC and CYC and seventeen (46 %) received plasma exchange. The median (IQR) follow up was 973 (200-1656) days. Thirty two of 33 patients (97 %) achieved remission at 6 M and 10 of 15 patients (67 %) requiring dialysis recovered renal function. The median prednisone dose at 6 M was 6 mg/day. The mean (SD) increase in e-GFR at 6 months was 14.5 (22) ml/min/m(2). Twelve patients developed ESRD during follow up. There were 3 deaths in the first 6 months. When stratified by use of concomitant CYC, there were no differences in baseline e GFR, use of plasmapheresis, RTX dosing regimen or median follow up days between the groups. No differences in remission, renal recovery ESRD or death were observed.

CONCLUSIONS

This study of AAV patients with severe renal disease demonstrates that the outcomes appear equivalent when treated with RTX and GC with or without concomitant CYC.

Current therapy of granulomatosis with polyangiitis and microscopic polyangiitis: the role of rituximab

Granulomatosis with polyangiitis and microscopic polyangiitis are anti-neutrophil cytoplasmic antibody-associated vasculitides (AAVs) that are prone to cycles of remission and relapse. The introduction of cytotoxic therapy has changed the prognosis for these diseases from typically fatal to manageable chronic illnesses with a relapsing course. Despite improvements in outcomes, recurrence of disease and drug-related toxicity continue to produce significant morbidity and mortality. Better understanding of the pathogenesis of AAV and the mechanism of action of cyclophosphamide has led to investigation of therapies that target B cells. Two randomized controlled trials have shown that rituximab is not inferior to cyclophosphamide for induction of remission in severe AAV, with no significant difference in the incidence of overall adverse events in rituximab- versus cyclophosphamide-treated patients. Data from ongoing clinical trials will determine the role of rituximab in the maintenance of remission.

Impact of rituximab trials on the treatment of ANCA-associated vasculitis

ANCA-associated vasculitis (AAV) is a subgrouping of autoimmune disorders characterized by a chronic relapsing course. Induction therapy is usually effective, but 70% of patients will relapse and 20% develop refractory disease. In the relapsing and refractory subgroups, treatment is complicated by the cumulative exposure to toxic drugs that contribute to poor long-term outcomes. The anti-CD20 monoclonal antibody rituximab (RTX) depletes B cells, and the success of this targeted therapy has contributed to the evidence supporting a central role for B cells in AAV pathogenesis. Initial proof of RTX effectiveness originated from small, prospective trials and retrospective surveys conducted in AAV patients with relapsing and refractory disease; high remission rates permitted the reduction of glucocorticoids (GCS) doses and withdrawal of immunosuppressives. There has been controversy over the effectiveness of RTX in patients with predominantly granulomatous manifestations, where response rates have varied between studies, in part due to different RTX dosing regimens. These studies were followed by comparison of RTX against cyclophosphamide (CYC) for remission induction of new or relapsing AAV in two randomized trials, which led to the licensing of RTX for this indication. Subsequent attention has been turned to the use of RTX as a relapse prevention agent, to the potential for GCS sparing and to RTX-associated toxicity. We will discuss the impact that the results of RTX clinical trials have had on the management of AAV patients.