Pathogenesis and Diagnosis of Otitis Media with ANCA-Associated Vasculitis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is histologically characterized by systemic necrotizing vasculitis and is clinically classified into two phases, systemic or localized. Recently, otologi- cal symptoms such as otitis media and hearing loss, not previously often associated with AAV, have been reported in AAV cases. In these cases we propose a diagnosis of otitis media with AAV (OMAAV). The ANCA titer is important for the diagnosis of OMAAV, and in most cases rapid progressive hearing loss is observed as localized AAV. Peripheral facial nerve palsy or hypertrophic pachymeningitis are coupled with 25% of cases and 18% of cases respectively. Proteinase 3-ANCA (PR3-ANCA) positive otitis media causes granulomatous formation or middle ear effusion in the middle ear, on the other hand myeloperoxidase-ANCA (MPO-ANCA) positive otitis media predominantly presents as otitis media with effusion. The early diagnosed case and the sensorineural hearing loss not progressed deaf could be recovered by the immunosuppressive therapy. Delayed diagnosis of AAV occasionally leads to progression to the irreversible phase; therefore, diagnosis at the early-localized stage is important for treating AAV. In this review, we discuss the current understanding of this newly proposed concept of OMAAV.     

Biomarkers in ANCA-Associated Vasculitis

Despite recent advances in the treatment of antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV), relapse remains common and patients often experience a variable clinical course after initial treatment. New biomarkers are needed to aid the management of these complex diseases. Discoveries regarding the pathogenesis of AAV, from the importance both of activated B and T cells and the alternative complement pathway to genomic data, may lay the groundwork for identification of novel biomarkers.     

Damage Assessment in ANCA-Associated Vasculitis

Antineutrophil cytoplasm antibody associated vasculitis has been transformed from life-threatening conditions to chronic relapsing long-term diseases as a result of significant advances in immunosuppressive therapy. Although mortality still occurs, it is much less frequent, with an average 5-year survival of over 70?%. In the setting of chronic conditions, it becomes increasingly important to monitor the burden of disease in terms of both active inflammation requiring immunosuppression and chronic damage (scarring) from vasculitis and its treatment and associated comorbidity. The damage that accumulates in patients with vasculitis does not respond to immunosuppressive treatment. It is important to distinguish disease activity from disease damage to prevent unnecessary immunosuppression, but it is equally important to recognize damage for what it is, so that it can be addressed appropriately. Damage is an inevitable consequence of long-term vasculitis for over 80?% of patients, which should not surprise us given the severity of the original illness. There is potential value in measuring damage as a means of providing prognostic information. Using a quantified score such as the Vasculitis Damage Index (VDI) allows us to predict mortality. Patients with at least five items of damage on the VDI score have substantially worse mortality (7- to 11-fold worse risk), as compared with those with lesser amounts of damage. These findings should be taken into context when planning the management of patients with vasculitis, as well as in clinical trials of vasculitis. Disease damage is an important surrogate for long-term outcome in vasculitis, and studies should be designed to limit the amount of damage accumulating as a result of therapeutic intervention, rather than simply controlling disease activity, as is currently the aim in recent randomized controlled trials in vasculitis. Furthermore, careful cataloguing of damage, as well as disease activity items, provides much greater detail in describing and observing the long-term natural history of primary systemic vasculitis in patients treated with immunosuppressive agents who survive their initial disease process.     

Advances in Therapy for ANCA-Associated Vasculitis

The anti-neutrophil cytoplasmic antibody-associated vasculitides include granulomatosis with polyangiitis (Wegener??s granulomatosis) and microscopic polyangiitis. The introduction of therapy with cytotoxic agents such as cyclophosphamide transformed these diseases from fatal diagnoses to chronic conditions characterized by cycles of relapse and remission. Modern treatment strategies have focused on minimizing cyclophosphamide exposure or eliminating its use altogether. Two randomized clinical trials have shown that rituximab is not inferior to cyclophosphamide for induction of remission in patients with severe granulomatosis with polyangiitis (Wegener??s) or microscopic polyangiitis. For patients with non-life threatening disease, methotrexate may be used to induce and maintain remission, although some patients may have a higher long-term risk of relapse as a result. For patients with life-threatening disease, plasma exchange may be an effective adjuvant therapy. This article reviews seminal studies from the past decade that have contributed to the current standard of care.     

Pathophysiology of ANCA-Associated Small Vessel Vasculitis

Antineutrophil cytoplasmic autoantibodies (ANCAs) directed to proteinase 3 (PR3-ANCA) or myeloperoxidase (MPO-ANCA) are strongly associated with the ANCA-associated vasculitides--Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome. Clinical observations, including the efficacy of B-cell depletion via rituximab treatment, support--but do not prove--a pathogenic role for ANCA in the ANCA-associated vasculitides. In vitro experimental studies show that the interplay of ANCA, neutrophils, the alternative pathway of the complement system, and endothelial cells could result in lysis of the endothelium. A pathogenic role for MPO-ANCA is strongly supported by in vivo experimental studies in mice and rats, which also elucidate the pathogenic mechanisms involved in lesion development. Unfortunately, an animal model for PR3-ANCA-associated Wegener's granulomatosis is not yet available. Here, cellular immunity appears to play a major role as well, particularly via interleukin-17-producing T cells, in line with granulomatous inflammation in the lesions. Finally, microbial factors, in particular Staphylococcus aureus and gram-negative bacteria, seem to be involved in disease induction and expression, but further studies are needed to define their precise role in disease development.     

Predictors of Poor Outcome in ANCA-Associated Vasculitis (AAV)

It is important to recognize factors that might predict poor outcome and prognosis in patients with AAV. The predictors reported in the literature encompass genetic, histopathological, and clinical ones. Genetic studies (genetic predictors) have found genes that are associated with prediction of poor response to treatment, deterioration of renal function, and risk of mortality. Histopathological studies (histopathological predictors) have shown that sclerotic renal lesions are associated with increased risk of progression to end-stage renal disease and death. Lastly, scores (clinical predictors) obtained with tool as FFS, Maldini risk score, VDI, and emerging new biomarkers could potentially be helpful in assessment of prognosis in the future.     

Treatment of Severe and/or Refractory ANCA-Associated Vasculitis

Most patients presenting with systemic necrotizing vasculitides improve when they are adequately treated. The presence of life-threatening manifestations or visceral involvement modifying organ function characterizes severe vasculitis, confirmed by disease-severity scores. Sequelae cannot always be predicted and prevented but organ involvement present at disease onset requires rapid therapeutic intervention. Some patients present a persistent active disease, which does not respond to treatments and deserve other drugs or combination of drugs. The therapeutic options for severe and/or relapsing and refractory diseases are described.     

ANCA-Associated Small Vessel Vasculitis: Clinical and Therapeutic Advances

The antineutrophil cytoplasmic antibodies-associated small vessel vasculitides are an encompassing group of diseases defined by serologic and anatomic criteria. Their diverse phenotype is an ongoing diagnostic challenge, and early diagnosis is paramount in optimizing outcomes and minimizing morbidity. Therapies targeted at components of the immune system, both cellular and cytokine, have been assessed as both inducers and sustainers of remission. As current data provide clarity in pathogenesis, treatment options and strategies have been evaluated to improve outcomes. However, challenges remain in limiting disease flares and therapy-associated morbidities, and cures are achieved only in cases in which a clear culprit exists.     

Predictors of Treatment Outcomes in ANCA-Associated Vasculitis with Severe Kidney Failure

Background and objectives

In ANCA-associated GN, severe renal dysfunction portends a poor prognosis for renal recovery and patient survival. This study evaluated the prognostic factors affecting renal and patient outcomes in patients presenting with severe kidney failure to guide immunosuppressive therapy.

Design, setting, participants, & measurements

This study retrospectively evaluated clinical and histopathologic characteristics of 155 patients who underwent biopsy between October 1985 and February 2011 (median eGFR at presentation, 7.1 ml/min per 1.73 m²; 87% required hemodialysis), all treated with immunosuppressive medications. Three outcomes of interest were measured: patient survival, renal survival, and treatment response (defined as dialysis-free survival without active vasculitis by 4 months after biopsy). Competing risk, Cox, and logistic regression analyses were conducted for each outcome measure.

Results

Within 4 months after biopsy, treatment response was attained in 51% of patients, 35% remained on dialysis, and 14% died. In a competing risk analysis, estimated cumulative incidence rates of ESRD and disease-related mortality were 26% and 17% at 1 year and 32% and 28% at 5 years, respectively. Cyclophosphamide therapy and treatment response by 4 months were independently associated with patient and renal survival, adjusting for the percentage of normal glomeruli, histopathologic chronicity index score, and baseline clinical characteristics. Only 5% of patients still dialysis dependent at 4 months subsequently recovered renal function. Low chronicity index score (odds ratio [OR], 1.16; 95% confidence interval [95% CI], 1.04 to 1.30, per unit decrease) and baseline eGFR>10 ml/min per 1.73 m² (OR, 2.77; 95% CI, 1.09 to 7.01) were significantly associated with treatment response by 4 months. Among cyclophosphamide-treated patients, the likelihood of treatment response was >14% even with highest chronicity index score and eGFR<10 ml/min per 1.73 m².

Conclusions

Although low baseline renal function and severe renal scarring are associated with lower treatment response rate, no “futility” threshold could be identified. Conversely, continued immunosuppressive therapy beyond 4 months is unlikely to benefit patients who remain dialysis dependent.     

Prognostic Factors and Long-Term Outcome with ANCA-Associated Kidney Vasculitis in Childhood

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Long-Term Follow-Up of Cyclophosphamide Compared with Azathioprine for Initial Maintenance Therapy in ANCA-Associated Vasculitis

Background and objectives

Treatment with azathioprine within 3 months of remission induction with cyclophosphamide is a common treatment strategy for patients with ANCA-associated vasculitis. This study comprised patients undergoing long-term follow-up who were randomly allocated to azathioprine after 3–6 months or after 12 months of cyclophosphamide treatment.

Design, setting, participants, & measurements

Patients from 39 European centers between 1995 and 1997 with a new diagnosis of ANCA-associated vasculitis that involved the kidneys or another vital organ were eligible. At the time of diagnosis, participants were randomly allocated to convert to azathioprine after 3–6 months (the azathioprine group) or after 12 months of cyclophosphamide (the cyclophosphamide group). Patients who did not achieve a remission within 6 months were excluded. This study assessed relapses, ESRD, and death during long-term follow-up.

Results

Patients were allocated to the azathioprine group (n=71) and the cyclophosphamide group (n=73). Of these patients, 63 (43.8%) developed a relapse, 35 (24.3%) developed a renal relapse, 13 (9.0%) developed ESRD, and 21 (14.6%) died. Although there were worse outcomes in the azathioprine group, none were statistically significant. The subdistribution hazard ratio [sHR] for relapse was 1.63 (95% confidence interval [95% CI], 0.99 to 2.71), the composite of relapse or death hazard ratio [HR] was 1.59 (95% CI, 1.00 to 2.54), the ESRD sHR was 1.71 (95% CI, 0.56 to 5.19), and the death HR was 0.75 (95% CI, 0.32 to 1.79).

Conclusions

It remains uncertain whether converting to azathioprine after 3–6 months of induction cyclophosphamide therapy is as effective as converting after 12 months. Outcomes are still poor for this group of patients and further research is required to determine the optimal timing of maintenance therapy.     

ANCA-Associated Systemic Vasculitis Presenting With Hypertrophic Spinal Pachymeningitis: A Report of 2 Cases and Review of Literature

Reports of hypertrophic pachymeningitis associated with myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) localized exclusively in the spine were quite rare. Two cases of ANCA-associated systemic vasculitis (AASV) presenting with hypertrophic spinal pachymeningitis (HSP) causing low back pain and numbness are described. Two patients showed prominent systemic and local inflammatory reactions manifested as fever, elevated levels of erythrocyte sedimentation rate and C-reactive protein, and markedly increased levels of total protein of cerebrospinal fluid. The gadolinium (Gd)-enhanced T1-weighted magnetic resonance imaging scan of spinal cord demonstrated diffuse spinal dura matter thickening. Additionally, simple microscopic hematuria was found in 1 case suggestive of renal involvement and the other 1 complicated with interstitial lung disease. Then, a diagnosis of HSP secondary to AASV was made. Combination therapy of corticosteroids and cyclophosphamide produced a rapid improvement in the clinical symptoms and laboratory parameters. Followed up for 6 months, 1 case relapsed when the dosage of prednisone was tapered to 10 mg daily. Since the patient refused rituximab-based regimen, an immunosuppressive triple-therapy (corticosteroid, cyclophosphamide, and azathioprine) was initiated and brought control of the disease during the subsequent 6 months of follow-up.HSP is a relatively rare form of central nervous system involvement of AASV. Early recognition and intervention are of great significance since the pathogenesis of HSP starts with an inflammatory and fibrosing process.