Churg-Strauss Syndrome and Leukotriene-Modifying Agents

The leukotriene receptor antagonist Montelukast can induce adverse skin reactions in asthmatic patients

Montelukast the leukotriene receptor antagonist is an anti-inflammatory drug that causes bronchodilation and for this reason it is used to improve inflammatory states in asthma and allergic rhinitis. Montelukast is generally considered a safe drug with the occurrence of a few adverse drug reactions (ADRs) and anti-leucotrienes are usually well-tolerated by adults and young patients. Starting from these premises the purpose of this review is so give un up-to-date scenario about skin adverse reactions due to Montelukast administration. Only few cases were reported during last years, however interestingly some recent reports let us enlarging our ADR data about Montelukast. We decided to divide the paragraph into sections evaluating the following skin lesions: vasculitic lesions, rash, urticaria and angioedema. As described in the results, CSS were the most frequent cases reported, belonging to the Vasculitis category. We speculated several mechanisms leading to the spread of the skin reactions. Montelukast still remains a safe drug used for the treatment of severe and moderate asthma. However, for some reasons still in course of analysis, in rare cases patients could develop ADR. Among these, about half of the patients show skin signs as rash, vescicles, bullous skin, purpura, maculopapular cutis, erythematous exanthema, urticaria and angioedema. Most of these symptoms are a consequence of the onset of a vasculitis as CSS and allergic granulomatous angiitis. In many cases the onset of the reactions happen within the first months of intake. For this reason, the prescribing physicians should be alert for signs, symptoms and genetic predisposition of these skin diseases.

Mepolizumab for the treatment of eosinophilic granulomatosis with polyangiitis

INTRODUCTION

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis characterized by asthma, hypereosinophilia, and progressive multiorgan involvement. Although not fully elucidated, advancement in our understanding of the pathophysiology of EGPA has led to the development of multiple new treatment targets.

AREAS COVERED

Herein we review the epidemiology, clinical manifestations, pathophysiology, treatments, and ongoing research in the management of EGPA. The central role of Interleukin-5 (IL-5) in the development and maintenance of hypereosinophilia will be discussed. The value of mepolizumab, an anti-IL-5 monoclonal antibody, in the treatment of EGPA is reviewed in detail.

EXPERT OPINION

The available literature supports the use of mepolizumab for the induction and maintenance of remission of refractory, relapsing, or glucocorticoid-dependent EGPA with potentially greater benefit in those who are ANCA-positive or those with greater eosinophilia ( ≥ 150 cells/ μ L). Despite these positive results, relapses remain frequent, and the need for both short- and long-term glucocorticoid use remains common. More research is needed to address these needs and determine the precise role of mepolizumab.

Churg-Strauss syndrome: evidence for disease subtypes?

PURPOSE OF REVIEW

Churg-Strauss syndrome (CSS) is a rare systemic small-vessel necrotizing vasculitis. Its main clinical characteristics, some potentially life-threatening, are now well known, as are its usual successive phases, from allergic rhinitis to asthma, and finally vasculitis. Conversely, physiopathogenetic mechanisms are not completely elucidated and clearly multiple, thereby suggesting the existence of different disease subtypes.

RECENT FINDINGS

Almost 40% of CSS patients have circulating antineutrophil cytoplasm autoantibodies (ANCAs), mostly directed against myeloperoxidase. ANCA-positive patients suffer more frequently from renal disease, peripheral nervous system involvement and/or alveolar hemorrhage, whereas frequent cardiac involvement, lung infiltrates and/or systemic manifestations are more common in those who are ANCA-negative. However, their respective global outcomes do not clearly differ. Patients might also be categorized according to other, more subtle clinical, radiological and/or biological parameters, for example, cardiac magnetic resonance imaging abnormalities or genetic background.

SUMMARY

Because of its practical and therapeutic repercussions, the priority remains the prompt, relatively easy identification of the most severely affected patients at CSS diagnosis, before searching for and trying to classify subsets. Large, collaborative studies are needed to determine whether other subgroups might be associated with outcomes and warrant different, and possibly new, therapeutic strategies.

[Pregnancy and vasculitides]

Systemic vasculitides, like Takayasu's arteritis, polyarteritis nodosa, Wegener's granulomatosis, Churg-Strauss syndrome, Henoch-Schönlein purpura, or Behçet's disease can affect women of child-bearing years. The rarity of these vasculitides, their frequent fatal outcomes until recent years, and the use of toxic immunosuppressants to treat patients, contra-indicating pregnancy and/or potentially inducing hypofertility or sterility, explain the few pregnancies reported in the literature so far. Notably, it does not seem that pregnancy has a major impact on vasculitis outcome, in contrast with systemic lupus erythematosus, but a specialized management of these pregnant patients is mandatory. There are some reported cases of vasculitis revealed during pregnancy. Even though some of these pregnant patients had a severe disease and died, most of them had a favourable outcome, and a living inborn, providing prompt care and adequate treatment. When vasculitis is already known and treated, pregnancy should at best be planned, when the disease is in sustained remission and all toxic immunosuppressants have been stopped for months. Vasculitis sequella, like hypertension, renal insufficiency, or asthma, must also be taken into account, monitored and appropriately managed throughout the pregnancy and a few weeks following delivery. In case of vasculitis' flare during pregnancy, potential treatments include corticosteroids, intravenous immunoglobulins, azathioprine, plasma exchanges, and, for limited skin manifestations or Behçet's disease, hydroxychloroquine or colchicine. Importantly, when the disease is severe, a delay in the prescription of a stronger, immunosuppressant, chiefly intravenous cyclophosphamide, can be more detrimental, although being potentially toxic, for both the mother and the foetus than an ineffective and/or inappropriate regimen with less active drugs. Safety data on biologics, like rituximab, for pregnant women are very sparse to date and their use is therefore not recommended, unless confronted with a severe and refractory disease, and after referring to a specialized center for vasculitides.

[Progress in pathogenesis and therapy of vasculitis syndrome]

Since antineutrophil cytoplasmic autoantibody (ANCA) was found, the researches in the pathogenesis of vasculitis syndrome have been developing. Proinflammatory cytokines including tumor necrosis factor-alpha are induced by certain infections, by which ANCA that binds to granule components of cytoplasm adhesions to endothelial cells. These endothelial cells produce proteolytic enzymes and oxygen radicals, which leads to vasculitis. It might be contributed in the production of ANCA that bacterial organisms are mimicry to the peptide sequences of granule components. The multicentric randomized clinical trials undertaken by the European Vasculitis Study Group (EUVAS) optimized that cyclophosphamide-corticosteroid combination therapy was useful to ANCA-associated vasculitis. It is increasing evidences that biologics are useful to ANCA-associated vasculitis, although it is necessary to take care of severe adverse effects.

Churg-Strauss syndrome

PURPOSE OF REVIEW

Churg-Strauss syndrome is a small-vessel necrotizing vasculitis typically characterized by asthma, lung infiltrates, extravascular necrotizing granulomas and hypereosinophilia. The most recent clinical studies on its pathogenesis and therapeutic management are reviewed here.

RECENT FINDINGS

French and Italian clinical studies found that the clinical characteristics of patients with Churg-Strauss syndrome differed according to their antineutrophil cytoplasmic autoantibody status: cardiomyopathy predominated in antineutrophil cytoplasmic autoantibody-negative patients while necrotizing glomerulonephritis was more often observed in antineutrophil cytoplasmic autoantibody-positive patients. These histologically documented findings suggest the existence of different Churg-Strauss syndrome subtypes, characterized by the predominance of distinct pathogenetic mechanisms. To date, following the therapeutic recommendations for Churg-Strauss syndrome (i.e. corticosteroids and, when required, immunosuppressants), patient outcomes are good, with 5-year survival exceeding 90%, but often with the need to continue low-dose corticosteroids to control residual asthma.

SUMMARY

The precise pathogenetic mechanisms of Churg-Strauss syndrome are only partly elucidated. Recent results suggest that antineutrophil cytoplasmic autoantibodies are probably more involved in the vasculitic manifestations of Churg-Strauss syndrome (e.g. glomerulonephritis) whereas eosinophil tissue infiltration and associated cytotoxicity would be responsible for cardiomyopathy. If confirmed, these results could support individual therapeutic stratification according to the clinical pattern. Furthermore, some patients may benefit from new biologic therapies under development, for example antiinterleukin-5 or antiimmunoglobulin E monoclonal antibodies.