Serious infections in ANCA-associated vasculitides in the biologic era: real-life data from a multicenter cohort of 162 patients

Current perspective on infections and mitigation strategies in primary systemic vasculitis

PURPOSE OF REVIEW

The purpose of this review is to summarize and evaluate most recent evidence on the epidemiology of infections and associated risk factors in patients with primary systemic vasculitides (PSV), as well as discuss mitigation strategies including the risk of antibiotic prophylaxis.

RECENT FINDINGS

Infections remain one of the leading causes of mortality in patients with PSV, with rates of severe infection ranging from 16 to 40% in different cohorts. Older age, frailty, renal and pulmonary involvement, and higher burden of comorbidities have been recognized as important patient-associated risk factors. Treatments including higher cumulative doses of glucocorticoids are associated with an increased risk of infections, and recent studies show the potential benefit of interventions such as reduced-dose glucocorticoid regimens. Existing mitigation strategies include screening, vaccination, and infection prophylaxis. The latter remains particularly important for Pneumocystis jirovecii pneumonia; however, the benefit-risk ratio seems to be less clear outside of induction phase (i.e., high dose of glucocorticoids) and optimal treatment duration remains less clear. Patients with PSV are at increased risk of infections, due to disease itself, comorbidities, and treatment side effects. Awareness of the timing and types of infection, as well as mitigation strategies are imperative to ensure treatment success and survival for patients.

Application of biological agents in the treatment of anti-neutrophil cytoplasmic antibody-associated vasculitis

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) has been traditionally treated using glucocorticoids and immunosuppressants. However, these treatment modes are associated with high recurrence AAV rates and adverse reactions. Therefore, treatment strategies for AAV need to be urgently optimized. The efficacy and safety of biological agents in the treatment of vasculitis have been clinically validated. This review comprehensively summarizes the evidence-based support for the clinical use of existing biological agents in AAV. The findings reveal that multiple biological agents not only effectively reduce the adverse reactions associated with glucocorticoids and immunosuppressants but also demonstrate significant therapeutic efficacy. Notably, rituximab, an anti-CD20 antibody, has emerged as a first-line treatment option for AAV. Mepolizumab has shown promising results in relapsed and refractory eosinophilic granulomatosis with polyangiitis. Other biological agents targeting cytokines, complement, and other pathways have also demonstrated clinical benefits in recent studies. The widespread application of biological agents provides new insights into the treatment of AAV and is expected to drive further clinical research. These advancements not only improve patient outcomes but also offer more possibilities and hope in the field of AAV treatment.

Evolution of therapeutic management of patients with ANCA associated vasculitis in France after licensing Rituximab use

INTRODUCTION

In 2013, rituximab was approved in France for the treatment of ANCA-associated vasculitis (AAV). The aim of the study was to compare the treatment and health events of adult incident patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), included before rituximab approval (over 2010-2012, Group 1) and those included after rituximab approval (over 2014-2017, Group 2).

METHOD

Data were extracted from the French National Health Insurance database (SNDS) including outpatient health care consumption and hospital discharge forms. Comparisons between inclusion periods were performed using Wilcoxon and χ² tests. Kaplan-Meier method was used to model the duration of treatment induction, maintenance, and off-drug periods. Fine and Gray tests were used to compare treatment phase durations.

RESULTS

A total of 694 GPA and 283 MPA patients were included in Group 1, while 668 GPA and 463 MPA patients were included in Group 2. Between the two inclusion periods, the proportions of patients treated with rituximab increased in the induction and maintenance phases whereas treatment with azathioprine declined. These proportions remained stable in the case of methotrexate, cyclophosphamide, and glucocorticoid-treated patients. Frequency of first-time hospitalized infections, diabetes and renal failure during the first year after inclusion increased for both groups.

LIMITATIONS OF THE STUDY

This is a retrospective study based on claims data including only 76% of people covered by health insurance in France. The period studied includes the learning phase of using rituximab. This study lacks biological data and precise quantitative analysis for the use of steroids, therefore the criteria for establishing diagnosis and therapeutic choice were unknown.

CONCLUSIONS

Introduction of rituximab reduced the use of azathioprine without affecting the use of glucocorticoids or cyclophosphamide.

Association between hypogammaglobulinaemia and severe infections during induction therapy in ANCA-associated vasculitis: from J-CANVAS study

OBJECTIVES

To investigate the association between decreased serum IgG levels caused by remission-induction immunosuppressive therapy of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and the development of severe infections.

METHODS

We conducted a retrospective cohort study of patients with new-onset or severe relapsing AAV enrolled in the J-CANVAS registry, which was established at 24 referral sites in Japan. The minimum serum IgG levels up to 24 weeks and the incidence of severe infection up to 48 weeks after treatment initiation were evaluated. After multiple imputations for all explanatory variables, we performed the multivariate analysis using a Fine-Gray model to assess the association between low IgG (the minimum IgG levels <500 mg/dl) and severe infections. In addition, the association was expressed as a restricted cubic spline (RCS) and analysed by treatment subgroups.

RESULTS

Of 657 included patients (microscopic polyangiitis, 392; granulomatosis with polyangiitis, 139; eosinophilic granulomatosis with polyangiitis, 126), 111 (16.9%) developed severe infections. The minimum serum IgG levels were measured in 510 patients, of whom 77 (15.1%) had low IgG. After multiple imputations, the confounder-adjusted hazard ratio of low IgG for the incidence of severe infections was 1.75 (95% confidence interval: 1.03-3.00). The RCS revealed a U-shaped association between serum IgG levels and the incidence of severe infection with serum IgG 946 mg/dl as the lowest point. Subgroup analysis showed no obvious heterogeneity between treatment regimens.

CONCLUSION

Regardless of treatment regimens, low IgG after remission-induction treatment was associated with the development of severe infections up to 48 weeks after treatment initiation.

Systematic literature review informing the 2022 update of the EULAR recommendations for the management of ANCA-associated vasculitis (AAV): part 1-treatment of granulomatosis with polyangiitis and microscopic polyangiitis

OBJECTIVE

To summarise and update evidence to inform the 2022 update of the EULAR recommendations for the management of antineutrophil cytoplasm antibody-associated vasculitis (AAV).

METHODS

A systematic literature review (SLR) was performed to identify current evidence regarding treatment of AAV. PubMed, EMBASE and the Cochrane library were searched from 1 February 2015 to 25 February 2022. The evidence presented here is focused on the treatment of granulomatosis with polyangiitis and microscopic polyangiitis.

RESULTS

3517 articles were screened and 175 assessed by full-text review. Ninety articles were included in the final evidence synthesis. Cyclophosphamide and rituximab (RTX) show similar efficacy for remission induction (level of evidence (LoE) 1a) but RTX is more effective in relapsing disease (LoE 1b). Glucocorticoid (GC) protocols with faster tapering result in similar remission rates but lower rates of serious infections (LoE 1b). Avacopan can be used to rapidly taper and replace GC (LoE 1b). Data on plasma exchange are inconsistent depending on the analysed trial populations but meta-analyses based on randomised controlled trials demonstrate a reduction of the risk of end-stage kidney disease at 1 year but not during long-term follow-up (LoE 1a). Use of RTX for maintenance of remission is associated with lower relapse rates compared with azathioprine (AZA, LoE 1b). Prolonged maintenance treatment results in lower relapse rates for both, AZA (LoE 1b) and RTX (LoE 1b).

CONCLUSION

This SLR provides current evidence to inform the 2022 update of the EULAR recommendations for the management of AAV.

Outcomes in ANCA-associated vasculitis patients with end-stage kidney disease on renal replacement therapy-A meta-analysis

BACKGROUND

End-stage kidney disease (ESKD) is associated with poor prognosis in patients with anti-neutrophilic cytoplasmic antibody (ANCA)-associated vasculitis (AAV). This study summarizes the existing evidence regarding outcomes in AAV patients with ESKD on renal replacement therapy.

METHODS

Searches of the MEDLINE and Embase databases were performed from inception until December 2021. Any study reporting outcomes after ESKD in patients with AAV on haemodialysis or peritoneal dialysis was included. The mortality rate per 100 person-years (100 py) calculated with a random-effects meta-analysis model was the primary outcome. Rates of infections and relapses were secondary outcomes.

RESULTS

2470 citations were found; 22 studies of 952 adult patients with over 3600 person-years of follow-up were included. The pooled mortality rate was 10.90 per 100 py (95% CI: 7.11 - 14.68, I² = 90.8%). The pooled 1-year survival was 80.9% (95% CI: 75.6 - 86.1%, I² = 86.1%) while the pooled 5-year survival was 61.0% (95% CI: 46.0 - 76.0%, I² = 0.0%). The pooled severe infection rate was 66.57 per 100 py (95% CI: 13.64 - 119.50, I² = 99.6%). The pooled relapse rate was 6.22 per 100 py (95% CI: 4.64 - 7.80, I² = 46.6%). Only 1 paediatric study met the inclusion criteria and reported a mortality rate of 11.7 ± 1.9 deaths per 100 py (95% CI: 0.23 - 23.20) amongst 9 patients.

CONCLUSIONS

Patients with AAV and ESKD have a lower risk of relapse, but higher infection and mortality rates. More prospective research exploring the role of immunosuppression after ESKD is needed.

Risk factors for serious infections in ANCA-associated vasculitis

OBJECTIVES

Severe infections contribute to morbidity and mortality in antineutrophil cytoplasm antibody-associated vasculitis (AAV). This study aimed to identify risk factors associated with severe infections in participants of the Rituximab versus Cyclophosphamide for ANCA-Associated Vasculitis (RAVE) trial.

METHODS

Data on 197 patients recruited into the RAVE trial were analysed. Participants received either rituximab (RTX) or cyclophosphamide (CYC), followed by azathioprine (AZA). Clinical and laboratory data of patients with and without severe infections (≥grade 3, according to the Common Terminology Criteria for Adverse Events version 3.0) were compared. Risk factors for severe infections were investigated using Cox-regression models.

RESULTS

Eighteen of 22 (82%) severe infections occurred within 6 months after trial entry, most commonly respiratory tract infections (15/22, 68%). At baseline, lower absolute numbers of CD19+ cells were observed in patients with severe infections either receiving RTX or CYC/AZA at baseline, while CD5+B and CD3+T cells did not differ between groups. In Cox-regression analysis, higher baseline serum immunoglobulin M levels were associated with the risk of severe infections, whereby a higher baseline total CD19+B cell number and prophylaxis against Pneumocystis jirovecii with trimethoprim-sulfamethoxazole (TMP/SMX) with decreased risk of severe infections. Use of TMP/SMX was associated with lower risk of severe infections in both groups, receiving either RTX or CYC/AZA.

CONCLUSIONS

The use of low-dose TMP/SMX is associated with reduced risk of severe infections in patients with AAV treated with either RTX or CYC/AZA. Reduced B cell subpopulations at start of treatment might be a useful correlate of reduced immunocompetence.

Incidence of serious infections in patients with ANCA-associated vasculitis receiving immunosuppressive therapy: A systematic review and meta-analysis

Introduction

Rituximab and azathioprine are used to induce or maintain remission in patients with ANCA-associated vasculitis (AAV). We evaluated the incidence of serious infections and infection-related deaths in patients with AAV treated with rituximab and azathioprine, during the maintenance of remission period.

Methods

We searched PubMed and EMBASE for randomized clinical trials (RCTs) and observational studies evaluating immunosuppressive agents in patients with AAV. We defined serious or severe infections according to the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. The study was registered on PROSPERO (CRD42022366269).

Results

From 1,265 abstracts, we identified 21 studies (7 RCTs and 14 observational), with relevant data. We included data from 1,284 and 2,938 individuals for assessment in our primary and secondary outcomes, respectively. The overall cumulative incidence of serious infections was 15.99% (CI 95%: 6.95-27.53%) during the total follow-up period (induction and maintenance) and 7.62% (CI 95%: 4.43-11.43%) during the maintenance period. Additionally, we found a 0.49% overall case fatality rate (CI 95%: 0.02-1.37%) and a 0.09% infection-related mortality rate (CI 95%: 0.00-0.51%) during maintenance treatment. Notably, we found a 14.61% (CI 95%: 10.19-19.61%) cumulative incidence of serious infections among patients who received rituximab and a 5.93% (CI 95%: 1.19-13.26%) cumulative incidence of serious infections among patients who received azathioprine during maintenance. Moreover, the cumulative incidence of serious infections during the total follow-up period (induction and maintenance) was 20.81% (CI 95%:4.56-43.70%) for the combination of cyclophosphamide and azathioprine and 14.12% (CI 95%: 5.20-26.00%) for rituximab.

Discussion

The cumulative incidence of serious infections during total follow-up and maintenance was within expected limits, while fatal infections during maintenance treatment were uncommon. Additionally, treatment with rituximab for both induction and maintenance did not exceed the anticipated by previous studies incidence of serious infections. Clinical practice and long-term follow up data are needed to corroborate these findings.

Systematic review registration

Identifier: PROSPERO (CRD42022366269).

Neutrophils in ANCA-associated vasculitis: Mechanisms and implications for management

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of systemic autoimmune diseases, which is typified by inflammatory necrosis predominantly affecting the small vessels and often accompanied by positive ANCA. Clinically, AAV primarily includes microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (EGPA). It has been found that in AAV pathogenesis, both innate and adaptive immunity are related to neutrophil function mutually. Many proteins, such as myeloperoxidase (MPO) and proteinase 3 (PR3), in neutrophil cytoplasm lead to the production of proteins such as MPO-ANCA and PR3-ANCA by activating adaptive immunity. In addition, through the process of neutrophil extracellular trap (NET) formation, activation of an alternative complement pathway and the respiratory burst can stimulate the neutrophils close to vascular endothelial cells and will participate the vessel inflammation. This review aims to reveal the potential mechanisms regulating the association between the neutrophils and various types of AAVs and to emphasize the results of recent findings on these interactions. Moreover, multiple underlying signaling pathways involved in the regulation of neutrophils during AAV processes have also been discussed. The ultimate goal of this review is to identify novel biomarkers and therapeutic targets for AAV management in the future.