Churg-strauss syndrome: an update

Association of the blood eosinophil count with end-organ symptoms

Introduction

Eosinophilia may cause organ dysfunction, but an exact relation between eosinophil blood counts and adverse outcomes has not been described. The aim of the study is to associate in one model both normal and increased blood eosinophil counts to the subsequent development of common conditions in internal medicine, in which eosinophil granulocytes may play a role for the symptoms.

Methods

From the Copenhagen Primary Care Differential Count (CopDiff) Database, we identified 359,950 individuals with at least one differential cell count (DIFF) during 2000–2007. From these, one DIFF was randomly chosen. From the Danish National Patient Register we ascertained organ damage, within four years following the DIFF. Using multivariable logistic regression, odds ratios were calculated and adjusted for previous eosinophilia, sex, age, year, month, CRP and comorbid conditions.

Results

Risks for skin- and respiratory disease were increased from above the median eosinophil count of 0.16 × 10⁹/l and reached a plateau around 1.0 × 10⁹/l. Furthermore, risks of most outcomes also increased when the eosinophil count approached zero.

Conclusions

The observed U-shaped association with a plateau of risks around 1 × 10⁹/l indicates that the risk for symptoms due to eosinophilia do not increase proportionate at higher counts. This study demonstrates for the first time that there is indeed an increased risk below median count of 0.16 × 10⁹/l for an increased risk for the same manifestations. Clinically, it means that a normal or even low count of eosinophils do not rule out a risk for organ affection by eosinophils, and may contribute to explain, why patients may have normal eosinophil counts in e.g. asthma or allergy and still have symptoms from the lungs and skin, most likely explained by the extravasation of eosinophils.

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Blood eosinophilia may cause end-organ symptoms.

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An exact relation between eosinophil count and outcome has not been demonstrated.

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Eosinophil numbers correlate to organ damage even below the definition of eosinophilia.

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This association is U-shaped between organ manifestations and eosinophil count in blood.

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A plateau of risks is observed around 1 × 10⁹/l.

Mepolizumab as the first targeted treatment for eosinophilic granulomatosis with polyangiitis: a review of current evidence and potential place in therapy

Mepolizumab is an anti-interleukin-5 (IL-5) humanized monoclonal antibody that binds to free IL-5. It induces bone marrow eosinophil maturation arrest and decreases eosinophil progenitors and subsequent maturation in the blood and bronchial mucosa. Its use has been extensively studied in severe eosinophilic asthma at a dose of 100 mg subcutaneously (SC) every 4 weeks and, more recently, in other hypereosinophilic syndromes. Eosinophilic granulomatosis with polyangiitis (EGPA) is an eosinophilic vasculitis that may involve multiple organs. Characteristic clinical manifestations are asthma, sinusitis, transient pulmonary infiltrates and neuropathy. Among the numerous pathways involved in the pathogenesis of EGPA, the Th-2 phenotype has a main role, as suggested by the prominence of the asthmatic component, in triggering the release of key cytokines for the activation, maturation and survival of eosinophils. In particular, IL-5 is highly increased in active EGPA and its inhibition can represent a potential therapeutic target. In this scenario, mepolizumab may play a therapeutic role. After some positive preliminary observations on the use of mepolizumab in small case series of EGPA patients with refractory or relapsing disease despite standard of care treatment, a randomized controlled trial was published in 2017. Mepolizumab at a dose of 300 mg administered by SC injection every 4 weeks proved effective in prolonging the period of remission of the disease, allowing for reduced steroid use. The positive results of this study, which met both of the primary endpoints, led to the approval in the USA of mepolizumab in adult patients with EGPA by the Food and Drug Administration in 2017. Therefore, mepolizumab can be officially considered as an add-on therapy with steroid-sparing effect in cases of relapsing or refractory EGPA. However, the most appropriate dose and duration of therapy still need to be determined. Future studies on larger multinational populations with prolonged follow-up are warranted.

Syndrome of Inappropriate Antidiuretic Hormone Associated with Eosinophilic Granulomatosis with Polyangiitis

A 78-year-old woman with a history of bronchial asthma presented with distal dominant sensory disturbance and weakness in the upper and lower extremities. A biopsy of the left peroneus brevis muscle showed active vasculitis with inflammation extending into muscle fascicles and fibrinoid necrosis of the vessel wall, consistent with eosinophilic granulomatosis with polyangiitis (EGPA). Despite her decreased serum osmolarity, her serum antidiuretic hormone level was not reduced, consistent with the syndrome of inappropriate antidiuretic hormone (SIADH). Intravenous and oral steroid therapy improved her neurological symptoms. Clinicians should consider EGPA as a concurrent, and potentially causative, disorder in cases of SIADH.

Factors that predict in-hospital mortality in eosinophilic granulomatosis with polyangiitis

BACKGROUND

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic small-vessel vasculitis associated with asthma, eosinophilia, and necrotizing vasculitis. EGPA is potentially life-threatening and often involves peripheral neuropathies, peptic ulcers, cerebral vessel disease, and cardiovascular disease. However, there is limited understanding of the prognostics factors for patients with EGPA. We investigated the clinical features and factors affecting patients' in-hospital mortality, using a national inpatient database in Japan.

METHODS

We retrospectively collected data of EGPA patients who required hospitalization between July 2010 and March 2013, using the Diagnosis Procedure Combination database. We evaluated EGPA patients' characteristics and performed multivariate logistic regression analyses to assess the factors associated with in-hospital mortality.

RESULTS

A total of 2195 EGPA patients were identified. The mean age was 61.9 years, 42.1% (924/2195) were male, and 41.6% (914/2195) had emergent admission. In-hospital deaths occurred in 97/2195 patients (4.4%). Higher in-hospital mortality was associated with age older than 65 years, disturbance of consciousness on admission, unscheduled admission, respiratory disease, cardio-cerebrovascular disease, renal disease, sepsis, and malignant disease on admission. Lower mortality was associated with female gender and peripheral neuropathies.

CONCLUSIONS

Our study revealed the clinical features of EGPA patients who required hospitalization and the factors associated with their mortality. These results may be useful for physicians when assessing disease severity or treatments for hospitalized EGPA patients.

Churg-Strauss angiitis

Churg-Strauss angiitis is a rare vasculitic disorder affecting small- and medium-sized blood vessels. It is clinically characterized by the presence of a wide spectrum of multisystem organ involvement, with allergic rhinitis, asthma and peripheral blood eosinophilia as the most typical manifestations. The authors describe 2 cases of Churg-Strauss angiitis from an urban community of Southern Louisiana, exhibiting an atypical presentation with myocardial ischemia and cerebrovascular complications. Epidemiology, pathophysiology and clinical overview are presented. The therapeutic management is also discussed.

Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome) presenting as diffuse myositis

Background

Eosinophilic granulomatosis with polyangiitis is a complex multisystemic syndrome with heterogeneous presentation. Most often, there is a clinical history of asthma or other atopic conditions, and current presentation generally includes signs of cutaneous or pulmonary involvement. Very few reports described myalgia or weakness as the chief complaint. Of these, only a few included muscle biopsy evaluation and none showed convincing evidence of primary myositis. We believe this report is the first to demonstrate true myositis in the setting of early eosinophilic granulomatosis with polyangiitis.

Case presentation

This report describes a 74 year old Caucasian man, with no known allergies, presenting severe myalgia, muscle weakness, jaw claudication, and fever. Blood work showed marked eosinophilia and high creatine kinase levels. Biceps brachialis muscle biopsy revealed eosinophilic necrotizing vasculitis and true myositis with myophagocytosis of non-necrotic fibers and strong sarcolemmal MHC-1 overexpression by immunohistochemistry. This patient was successfully treated with prednisone and azathioprine.

Conclusion

Our finding of true myositis in a case of eosinophilic granulomatosis with polyangiitis suggests that primary auto-immunity against muscle fibers, distinct from the secondary effects of vasculitis, can occur in this entity and may represent an overlap syndrome. Early recognition of eosinophilic granulomatosis with polyangiitis in patients presenting with myositis may provide an opportunity to treat the vasculitis before onset of severe multisystemic disease. We recommend the use of muscle biopsy with immunohistochemistry for MHC-1 to confirm the diagnosis of myositis in the setting of eosinophilic granulomatosis with polyangiitis.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-388) contains supplementary material, which is available to authorized users.

Other asthma considerations

Asthma is a heterogeneous syndrome of cough, wheeze, dyspnea, and chest tightness. However, in a subset of patients, these symptoms may indicate a different underlying disease process with variable responsiveness to classic asthma therapies. Disease may progress while practitioners attempt conventional asthma therapy. Additionally, some types of asthma may require alternative approaches to relieve symptoms successfully. This article describes the differential diagnosis of asthma and discusses some of the more common asthma variants and asthma mimickers.

Eosinophilic granulomatosis with polyangiitis (Churg-Strauss) syndrome and pulmonary thromboembolism: an overlooked concomitance

The Eosinophilic Granulomatosis with Polyangiitis (formerly Churg- Strauss Syndrome) (EGPA) is a systemic inflammatory disease characterized by the presence of rhinitis, asthma, peripheral eosinophilia, and vasculitis-the latter being characteristic of the late stage of the disease. After several years from the onset of the disease, small- and medium-sized vessel vasculitis ensues, undertaking various organs and systems. Upper and lower airways, skin, nervous system, gastrointestinal tract, heart, and kidneys are the most commonly involved organs. It is believed that tissue injury is the result of processes mediated by antineutrophil cytoplasmic antibody (ANCA), or toxic mediators released by eosinophils. Although it is classified as ANCA-associated vasculitis, these autoantibodies are present in only 40% of cases. The authors report the case of a patient with EGPA, who had a history of asthma, peripheral and central neuropathy, palpable purpura, gastrointestinal micro perforation, peripheral eosinophilia, and the presence of myeloperoxidase-antineutrophil cytoplasmic antibody. Inflammatory parameters improved after the initiation of treatment, but 1 month after hospital discharge the patient developed symptoms compatible with pulmonary embolism and died. Thrombophilia that occurs in EGPA is due to the interaction between the inflammatory response and eosinophilia with the clotting system resulting in a pro-thrombotic state. Although not yet well-determined, the authors call attention to the possibility of the impact of thromboembolic events on the prognosis of patients with EGPA. In addition to the adequate immunosuppressive treatment, prophylaxis and treatment for thrombosis should never be overlooked.

Clinical study of renal impairment in patients with propylthiouracil-induced small-vessel vasculitis and patients with primary ANCA-associated small-vessel vasculitis

The aim of this study was to compare renal impairment in patients with propylthiouracil (PTU)-induced small-vessel vasculitis and patients with primary anti-neutrophil cytoplasmic antibody (ANCA)-induced small-vessel vasculitis. The study compared the pathology and clinical conditions of 10 patients with PTU-associated small-vessel vasculitis and 18 patients with primary ANCA-associated small-vessel vasculitis. All patients showed manifestations of renal impairment. Compared with the primary ANCA-induced small-vessel vasculitis, patients with PTU-induced small-vessel vasculitis were mostly female (P<0.05) and deleloped the disease at a younger age (P<0.05). They had a higher positive rate of perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA; P<0.05), lower 24 h proteinuria content, lower serum creatinine (P<0.05) and milder histopathological lesions (P<0.05). A number of them had gross hematuria (P<0.05). They rarely used hormone and cytotoxic drugs (P<0.05) during treatment and had a better prognosis (P<0.05). In conclusion, PTU-induced small-vessel vasculitis has a milder pathology and clinical manifestations with a better prognosis.

Churg-Strauss syndrome presenting as scar reactivation: histopathologic features and an illustration of 'locus minoris resistentiae'

We report a 33-year-old female with cutaneous involvement by Churg-Strauss syndrome confined to surgical scars that were obtained 13 years before. She presented to the emergency department with 2-day history of fever, night sweats, right-sided weakness, hoarseness and worsening asthma symptoms. She was found to have an eosinophilia and two sub-5-mm pulmonary nodules. The patient also reported that the scars on her right thumb, inner wrist and back had been swollen, red and painful for 2 days. Examination revealed tender, erythematous, well-healed edematous scars studded with small skin colored papules. She had no clinical findings that were classic for cutaneous vasculitis. A skin biopsy of a scar revealed perivascular and palisading granulomatous inflammation consisting of histiocytes and neutrophils with leukocytoclasia. Focal vascular injury was identified. Scattered tissue eosinophils were seen. Special stains were negative for infection. Thereafter, she was started on intravenous steroids, at which point the fever, pulmonary and cutaneous symptoms subsided. Although scar sarcoidosis is a well-described phenomenon, granulomatous inflammation and vasculitis seen in Churg-Strauss syndrome exclusively manifesting in well-healed surgical scars highlights the unique features seen in this case and draws attention to the concept of locus minoris resistentiae. This case also highlights how a skin biopsy in the setting of suspected systemic vasculitis can confirm the presence of vasculitis and/or granulomatous inflammation and obviate the need for more invasive, higher risk procedures such as lung biopsy.

Churg-Strauss syndrome associated with antiphospholipid antibodies in a patient with recurrent myocardial and cerebral ischemia

We report on a case of Churg-Strauss syndrome (CSS) associated with the presence of antiphospholipid antibodies. The patient had a history of recurrent myocardial infarction and presented with acute ischemic cerebral disease. Eosinophilia with typical lung and skin lesions led us to diagnose the patient with CCS. We hypothesize that the presence of antiphospholipid antibodies significantly contributed to the ischemic events. We suggest that the search for antiphospholipid antibodies should be included in the laboratory work-up in CSS patients and patients affected by primary systemic vasculitides in general. Moreover, anticoagulant treatment appears to be warranted in all CSS patients and antiphospholipid antibodies to counteract this thrombosis-favoring association.