Long term azathioprine maintenance therapy in ANCA-associated vasculitis: combined results of long-term follow-up data

Objective

We studied whether in ANCA-associated vasculitis patients, duration of AZA maintenance influenced relapse rate during long-term follow-up.

Methods

Three hundred and eighty newly diagnosed ANCA-associated vasculitis patients from six European multicentre studies treated with AZA maintenance were included; 58% were male, median age at diagnosis 59.4 years (interquartile range: 48.3-68.2 years); granulomatosis with polyangiitis, n = 236; microscopic polyangiitis, n = 132; or renal limited vasculitis, n = 12. Patients were grouped according to the duration of AZA maintenance after remission induction: ⩽18 months, ⩽24 months, ⩽36 months, ⩽48 months or > 48 months. Primary outcome was relapse-free survival at 60 months.

Results

During follow-up, 84 first relapses occurred during AZA-maintenance therapy (1 relapse per 117 patient months) and 71 after withdrawal of AZA (1 relapse/113 months). During the first 12 months after withdrawal, 20 relapses occurred (1 relapse/119 months) and 29 relapses >12 months after withdrawal (1 relapse/186 months). Relapse-free survival at 60 months was 65.3% for patients receiving AZA maintenance >18 months after diagnosis vs 55% for those who discontinued maintenance ⩽18 months (P = 0.11). Relapse-free survival was associated with induction therapy (i.v. vs oral) and ANCA specificity (PR3-ANCA vs MPO-ANCA/negative).

Conclusion

Post hoc analysis of combined trial data suggest that stopping AZA maintenance therapy does not lead to a significant increase in relapse rate and AZA maintenance for more than 18 months after diagnosis does not significantly influence relapse-free survival. ANCA specificity has more effect on relapse-free survival than duration of maintenance therapy and should be used to tailor therapy individually.

Vasculitis for the internist: focus on ANCA-associated vasculitis

Vasculitides comprise several diseases affecting vessels of different sizes, mainly arteries, but also capillaries and veins. Antineutrophil cytoplasm antibody-associated vasculitides (AAVs) belong to the systemic necrotizing small-vessel vasculitis group that comprises granulomatosis with polyangiitis, microscopic polyangiitis and eosinophilic granulomatosis with polyangiitis. Internists often see AAV patients, and although their outcomes are usually good, the disease can be responsible for morbidity and mortality. Herein, after reviewing the literature, we concentrate on selected aspects important for the internist, including classification, diagnostic dilemmas, treatment novelties, and follow-up.

Rituximab for immunologic renal disease: What the nephrologist needs to know

Rituximab (RTX), a chimeric, monoclonal anti-CD20 antibody, is increasingly used in immune-mediated renal diseases. While licensed in the induction treatment of ANCA-associated vasculitis, it represents one of the most commonly prescribed off-label drugs. Much of the information regarding its safety has been drawn from experience in hematology and rheumatology. Ample evidence illustrates the safety of RTX, however, rare but serious adverse events have emerged that include progressive multifocal leucoencephalopathy and hepatitis B reactivation. Moderate to severe hypogammaglobulinemia and late-onset neutropenia following RTX therapy confer an increased infectious risk and factors predicting these side effects (i.e. a genetic basis) need to be identified. Nephrologists initiating RTX need to bear in mind that long-term risks and optimal dosing for many renal indications remain unclear. Special considerations must be given when RTX is used in women of childbearing age. We summarize practical aspects concerning the use of RTX. This review will provide nephrologists with information to guide their use of RTX alerting them to safety risks and the need for patient counselling.

Effect of Continuous B Cell Depletion With Rituximab on Pathogenic Autoantibodies and Total IgG Levels in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

OBJECTIVE

To evaluate the effect of rituximab on pathogenic autoantibodies and total Ig levels, and to identify serious adverse events in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) treated with continuous B cell depletion.

METHODS

We conducted a retrospective analysis of 239 patients with AAV treated with rituximab-induced continuous B cell depletion. Two treatment cohorts were analyzed: an induction group (n = 52) and a maintenance group (n = 237). Changes in ANCA titers and total Ig levels over time were evaluated using mixed-effects models. Risk factors for serious infections during maintenance treatment were evaluated using Poisson regression.

RESULTS

During induction, IgG levels fell at a mean rate of 6% per month (95% confidence interval [95% CI] 4, 8%), while ANCA levels declined at a mean rate of 47% per month (95% CI 42, 52%) and 48% per month (95% CI 42, 54%) for patients with antimyeloperoxidase (anti-MPO) antibodies and those with anti-proteinase 3 (anti-PR3) antibodies, respectively. During maintenance treatment, with a median duration of 2.4 years (interquartile range 1.5, 4.0 years), IgG levels declined a mean of 0.6% per year (95% CI -0.2, 1.4%). New significant hypogammaglobulinemia (IgG level of <400 mg/dl) during maintenance treatment occurred in 4.6% of the patients, all of whom were in the lowest baseline IgG quartile. Serious infections during maintenance therapy occurred at a rate of 0.85 per 10 patient-years (95% CI 0.66, 1.1) and were independently associated with an IgG level of <400 mg/dl.

CONCLUSION

B cell-targeted therapy causes a preferential decline in ANCA titers relative to total IgG levels. Despite prolonged maintenance therapy with rituximab, IgG levels remain essentially constant. Serious infections were rare.

The significance and predictive value of free light chains in the urine of patients with chronic inflammatory rheumatic disease

In patients with rheumatic diseases, reliable markers for determining disease activity are scarce. One potential parameter is the level of immunoglobulin free light chains (FLCs), which is known to be elevated in the blood of patients with certain rheumatic diseases. Few studies have quantified FLCs in urine, a convenient source of test sample, in patients with different rheumatic diseases. We carried out a retrospective analysis of patients with rheumatic disease attending the University hospital of Goettingen, Germany. Subjects were included if they had urine levels of both κ and λ FLCs available and did not have myeloma. Data regarding systemic inflammation and kidney function were recorded, and FLC levels were correlated with inflammatory markers. Of the 382 patients with rheumatic disease, 40.1 % had chronic polyarthritis, 21.2 % connective tissue disease, 18.6 % spondyloarthritis and 15.7 % vasculitis. Elevated levels of κ FLCs were found for 84 % of patients and elevated λ for 52.7 %. For the patients with rheumatoid arthritis, FLCs correlated with C-reactive protein (κ, r = 0.368, p < 0.001; λ, r = 0.398, p < 0.001) and erythrocyte sedimentation rate (κ, r = 0.692, p < 0.001; λ, r = 0.612, p < 0.001). Patients being treated with rituximab displayed FLC levels similar to those of the reference group. There were clear elevations in both κ and λ FLCs in patients with rheumatic disease, but not in κ/λ ratio. The correlation between FLCs and inflammatory markers in patients with rheumatoid arthritis demonstrates their potential for predicting disease activity.

Overview of the Pathogenesis of ANCA-Associated Vasculitis

BACKGROUND

Antineutrophil cytoplasmic autoantibodies (ANCA) are associated with a spectrum of necrotizing vasculitis including granulomatosis with polyangiitis, microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis, and renal-limited necrotizing and crescentic glomerulonephritis. Clinical observations and in vitro and in vivo experimental evidence strongly indicate that ANCA are pathogenic.

SUMMARY

The etiology and pathogenesis of ANCA-associated vasculitis (AAV) are multifactorial, with contributions from genetic factors, environmental exposures, infections, characteristics of the innate and adaptive immune system, and the intensity and duration of the injury. Acute vascular inflammation is induced when resting neutrophils that have ANCA autoantigens sequestered in cytoplasmic granules are exposed to priming factors - for example, cytokines induced by infection or phlogogenic factors released by complement activation - that cause the release of ANCA antigens on the surface of neutrophils and in the microenvironment around the neutrophils. ANCA bind to these ANCA antigens, which activates neutrophils by Fcγ receptor engagement and F(ab')2 binding at the neutrophil cell surface. ANCA-activated neutrophils release factors that activate the alternative complement pathway, which generates C5a, a chemoattractant for neutrophils; C5a also primes the arriving neutrophils for activation by ANCA. Activated neutrophils adhere to and penetrate vessel walls, and they release toxic oxygen radicals and destructive enzymes that cause apoptosis and necrosis of the neutrophils as well as of the adjacent vessel wall cells and matrix.

KEY MESSAGES

Patients with active AAV have ongoing asynchronous onsets of countless acute lesions, with each lesion evolving through stereotypical phases within 1 or 2 weeks. Induction of remission results in termination of new waves of acute lesions and allows all lesions to progress to scarring or resolution.

Rituximab as maintenance therapy for ANCA associated vasculitis: how, when and why?

ANCA-associated vasculitides (AAV) are chronic autoimmune diseases characterized by inflammation and destruction of small vessels. Rituximab is now licensed for use as a remission-induction agent in the treatment of these disorders. During recent years, several non-controlled studies have suggested that rituximab may be of value in maintaining disease remission in AAV. In these series, 3 techniques have been tried: "watch-and-wait", repeated cycles in fixed intervals, or administration based on proposed biomarkers. More importantly, the results of the MAINRITSAN trial showed that this anti-CD20 agent is superior to azathioprine for preventing major relapses in AAV. This review summarizes current information regarding the effectiveness, timing, dosing, duration and safety of rituximab as a valid option for remission maintenance.

Successful use of Rituximab in a patient with recalcitrant multisystemic eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare eosinophil-rich disorder characterised by necrotising granulomatous inflammation affecting small to medium sized vessels. Extrapulmonary manifestations can be life-threatening when heart, central nervous system (CNS), gastrointestinal tract or kidneys are affected. We describe a case of a 56-year-old woman with a long-standing history of asthma, who presented with an acute sudden painless loss of vision after she had been recently diagnosed with EGPA and induced with pulse steroids and cyclophosphamide. The patient had a complicated hospital course with multisystemic involvement of active vasculitis, involving heart, kidneys, muscles, eyes and CNS. The patient's devastating condition responded remarkably to Rituximab. The role of Rituximab in EGPA is not yet proven. Few cases are reported in the literature about the role of Rituximab in EGPA, of which only one described retinal artery occlusion as a presentation of a recently treated patient with EGPA.