Churg-Strauss syndrome: localization of eosinophil major basic protein in damaged tissues

Eosinophil ETosis-Mediated Release of Galectin-10 in Eosinophilic Granulomatosis With Polyangiitis

OBJECTIVE

Eosinophils are tissue-dwelling immune cells. Accumulating evidence indicates that a type of cell death termed ETosis is an important cell fate involved in the pathophysiology of inflammatory diseases. Although the critical role of eosinophils in eosinophilic granulomatosis with polyangiitis (EGPA; formerly Churg-Strauss syndrome) is well established, the presence of eosinophil ETosis (EETosis) is poorly understood. We undertook this study to better understand the characteristics of EETosis.

METHODS

In vitro studies using blood-derived eosinophils were conducted to characterize EETosis. The occurrence of EETosis in tissues from patients with EGPA was studied by immunostaining and electron microscopy. Serum concentrations of eosinophil-derived proteins in healthy controls, patients with asthma, and EGPA patients with active disease or with disease in remission (n = 15 per group) were examined.

RESULTS

EETosis was reliant on reactive oxygen species and peptidylarginine deiminase type 4-dependent histone citrullination, resulting in the cytolytic release of net-like eosinophil extracellular traps, free galectin-10, and membrane-bound intact granules. The signature of EETosis, including loss of cytoplasmic galectin-10 and deposition of granules, was observed in eosinophils infiltrating various tissues from EGPA patients. Serum eosinophil granule proteins and galectin-10 levels were increased in EGPA and positively correlated with disease activity as assessed by the Birmingham Vasculitis Activity Score (r = 0.8531, P < 0.0001 for galectin-10). When normalized to blood eosinophil counts, this correlation remained for galectin-10 (r = 0.7168, P < 0.0001) but not for granule proteins. Galectin-10 levels in active EGPA positively correlated with serum interleukin-5 levels.

CONCLUSION

Eosinophils infiltrating diseased tissues in EGPA undergo EETosis. Considering the exclusive expression and large pool of cytoplasmic galectin-10 in eosinophils, elevated serum galectin-10 levels in patients with EGPA might reflect the systemic occurrence of cytolytic EETosis.

Cardiac manifestations of eosinophilic granulomatosis with polyangiitis from a single-center cohort in China: clinical features and associated factors

Background:

Cardiac manifestations are common and life-threatening in eosinophilic granulomatosis with polyangiitis (EGPA), which remains poorly studied in China. We aim to investigate its clinical features, associated factors, treatment, and outcomes.

Methods:

We reviewed the clinical records of 110 EGPA patients and examined the independent factors associated with cardiac manifestations using multivariate logistic regression. Receiver operating characteristic curves determined the cut-off values, and survival was calculated via Kaplan–Meier curves.

Results:

Cardiac involvement was present in 36.4% (40/110) of EGPA patients, which mainly manifested as pericardial effusion (16.4%, 18/110), myocardial involvement (13.6%, 15/110), and heart failure (8.2%, 9/110). The mean age was 42.1 ± 14.23 years with no female/male predominance. Compared with the cardiac-unaffected group, the cardiac-affected group showed a lower rate of biopsy-proved vasculitis (0% versus 20%, p = 0.002). The eosinophil count [odds ratio (OR) = 1.142, 95% confidence interval (CI) 1.029–1.267] was independently associated with cardiac manifestations in EGPA, with a cut-off value of 3.66 × 10⁹/L [area under the curve (AUC) = 0.692, p = 0.001]. Regarding treatment, the cardiac-affected group displayed a higher ratio of glucocorticoid pulse combined with intravenous cyclophosphamide (CYC-IV) (40% versus 21.4%, p = 0.037), and intravenous immunoglobulin combined with glucocorticoid plus CYC-IV (17.5% versus 4.3%, p = 0.035) than the control group. Outcomes (p = 0.131) and survival (p = 0.1972) were not significantly different between the groups.

Conclusion:

In this single-center Chinese EGPA cohort, cardiac manifestations are observed in 36.4% of patients, which primarily presents as myocardial involvement, pericardial effusion, and heart failure, independently associated with eosinophil count. Glucocorticoid combined with cyclophosphamide is the treatment cornerstone for EGPA patients with cardiac manifestations.

Eosinophilic Granulomatosis with Polyangiitis: Clinical Pathology Conference and Review

Eosinophilic granulomatosis with polyangiitis (EGPA) (formerly Churg-Strauss syndrome) is a small vessel vasculitis associated with asthma and eosinophilia. Despite its rarity, continuous gains are being made in understanding the disease with knowledge advancements regarding its epidemiology, heterogeneous clinical manifestations, management, and outcomes. Large knowledge gaps remain, however, particularly surrounding pathophysiologic and diagnostic uncertainties. There is still an incomplete understanding of the interplay between the eosinophilic and vasculitic processes that are features of disease pathogenesis. EGPA is also a conceptually difficult disorder given its dual categorization with hypereosinophilic syndromes and systemic vasculitides and the absence of a biomarker that can reliably distinguish between the two. In addition, recent evidence points to distinct, but partly overlapping, disease phenotypes, yet there is insufficient understanding to inform phenotype-tailored therapies. EGPA also remains a diagnostic challenge in part because asthma may be the primary or predominant manifestation for years, and the chronic corticosteroid requirement may mask other disease features. Efforts are ongoing to better elucidate pathophysiologic mechanisms, resolve classification issues, better characterize disease manifestations, and further clarify disease subcategorization, all of which will translate into better diagnosis and treatment with the possibility of specifically adapted therapies.

Cutting edge issues in the Churg-Strauss syndrome

Churg-Strauss syndrome (CSS) is a rare systemic small-vessel vasculitis that develops in the background of bronchial asthma, which is characterized by eosinophilia and eosinophilic infiltration of various tissues. It belongs to the group of antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides. The triggering factors and pathogenesis of CSS are still unknown. The possible role of eotaxin-3 and CCR4-related chemokines in selective recruitment of eosinophils to the target tissues in CSS has been recently suggested, but the role of eosinophilic inflammation in the development of vasculitic lesions is not completely understood. From the clinical view, two distinct phenotypes of the disease are slowly emerging depending on the ANCA-positivity status. Glucocorticoids are still the mainstay of treatment; however, data are accumulating regarding the beneficial role of novel immunosuppressants and biologic compounds, especially in patients with poorer prognosis.

[Update Churg-Strauss syndrome]

The Churg-Strauss syndrome (CSS) is the rarest subtype of the so-called anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) and has the lowest frequency of ANCA-positivity (around 30%). In addition to asthma and blood eosinophilia, CSS is characterized by end-organ damage, which can be caused by either vasculitis and/or tissue infiltration of eosinophilic granulocytes. The CSS shares many etiological and clinical features of other hypereosinophilic syndromes. Recently, a distinct genetic background could be demonstrated for both the ANCA-positive and ANCA-negative subtypes of CSS as compared to the other two forms of AAV. Among other cytokines, interleukin-5 (IL-5) could be identified as a key mediator of eosinophilia. Therefore, recent clinical trials in CSS aimed to target IL-5. Outside of clinical trials, treatment of CSS is adapted to disease stage and activity, as recommended for other types of AAV.

Churg-Strauss syndrome: case series

Churg-Strauss syndrome (CSS) is a systemic necrotizing vasculitis of the small and medium vessels, associated with extravascular eosinophilic granulomas, peripheral eosinophilia and asthma. This is a rare syndrome of unknown etiology, affecting both genders and all age groups. CSS patients usually respond well to steroid treatment, although relapses are common after it ends. Timely diagnosis and treatment generally lead to a good prognosis with a 90% survival rate at one year. A brief review of CSS is presented, with particular attention to diagnosis, therapy and recent developments in this area. The authors then report and discuss the clinical, laboratory and imaging characteristics of four patients admitted to an Internal Medicine Department with this diagnosis. The treatment, response and follow-up of the cases are also described.

Mepolizumab as a steroid-sparing treatment option in patients with Churg-Strauss syndrome

BACKGROUND

Treatments for Churg-Strauss syndrome (CSS), a rare eosinophilic vasculitis characterized by asthma, sinusitis, peripheral eosinophilia, pulmonary infiltrates, and tissue infiltration, are limited by toxicity or poor efficacy. Levels of IL-5, a cytokine regulating eosinophils, can be increased in patients with CSS. Mepolizumab, a humanized monoclonal anti-IL-5 antibody, decreases steroid requirements in patients with non-CSS hypereosinophilic syndromes.

OBJECTIVE

The purpose of this study was to assess whether mepolizumab would safely allow corticosteroid tapering in patients with steroid-dependent CSS while decreasing serum markers of disease activity.

METHODS

This open-label pilot study treated 7 patients with 4 monthly doses of mepolizumab to assess whether it safely decreased CSS disease activity and permitted tapering of systemic corticosteroids.

RESULTS

Mepolizumab was safe and well tolerated in patients with CSS. Mepolizumab reduced eosinophil counts and allowed for safe corticosteroid reduction in all 7 subjects. On cessation of mepolizumab, CSS manifestations recurred, necessitating corticosteroid bursts.

CONCLUSION

Mepolizumab is a safe and well-tolerated therapy in patients with CSS, offering clinical benefit by enabling corticosteroid tapering while maintaining clinical stability.

An aggressive and lethal course of Churg-Strauss syndrome with alveolar hemorrhage, intestinal perforation, cardiac failure and peripheral neuropathy

Churg-Strauss syndrome (CSS) is a rare type of necrotizing vasculitis affecting small to medium-sized vessels typically characterized by asthma, lung infiltrates, necrotizing granulomas and hypereosinophilia. Herein, we describe a case of CSS presenting severe and aggressive course. A 35-year-old male patient with weight loss, dyspepsia, dyspnea and hemoptysis was admitted. The laboratory analyses indicated a remarkable eosinophilia, elevated levels of serum total IgE and positive cANCA. Thorax CT findings were suggestive of alveolar hemorrhage. Bronchoalveolar lavage revealed alveolar hemorrhage with eosinophilia and transbronchial lung biopsy showed eosinophilic vasculitis. Cardiac enzymes were increased and murmurs were audible revealing cardiomyopathy proven by echocardiography. Pulse cyclophosphamide and methyl prednisolone was immediately started. On the 21st day, intestinal perforation developed and urgent surgery was performed. During a follow-up, although a radiological improvement was observed in the chest X-ray, cardiac failure, peripheral neuropathy and skin lesions developed and high-dose intravenous immunoglobulin and anti-TNF therapy (adalimumab) were applied. Despite the therapy, he died from heart failure and septicemia at 68th day of therapy.

Anti-neutrophil cytoplasmic antibody pathogenesis in small-vessel vasculitis: an update

Vasculitides associated with serum positivity for anti-neutrophil cytoplasmic antibodies (ANCAs) that affect small- to medium-sized vessels are commonly known as ANCA-associated vasculitis (AAV) and include Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome. Evidence derived from both in vitro studies and recent animal models points to a pathogenic role of ANCAs in AAV. In 2002, the first in vivo breakthrough in the pathogenesis of ANCAs showed that mouse ANCAs against myeloperoxidase (MPO) led to intrinsic pauci-immune renal vasculitis in mice. In 2004, a report using both in vitro and in vivo studies proposed that proteinase 3 (PR3)-directed autoimmunity involved the complementary peptide of PR3 (cPR3), which is encoded by the antisense strand of the PR3 gene. The last breakthrough came in October 2008 with a previously undescribed molecular explanation for the origin and development of injury in pauci-immune renal vasculitis, with potential clinical implications. This report showed that infection by fimbriated bacteria may trigger cross-reactive autoimmunity to a previously characterized ANCA antigen, lysosomal membrane protein-2, which is contained in the same vesicles that harbor MPO and PR3. Infection by fimbriated bacteria resulted in the production of autoantibodies, which activated neutrophils and killed human microvascular endothelium in vitro and caused renal vasculitis in rats. Although the evidence for a pathogenic role of ANCAs, mainly MPO-ANCAs, is striking, various questions remain unanswered. Understanding the key pathogenic mechanisms of AAV may provide a safer, more rational therapeutic approach than the traditional (ie, corticosteroids and immunosuppressants) treatment strategy.

Serum Eosinophil Cationic Protein: A Marker of Disease Activity in Churg-Strauss Syndrome

The cytotoxic proteins released by activated eosinophils should play a role in the development of Churg-Strauss syndrome (CSS). Eighteen patients (15 males and 3 females, age 41 +/- 13.3 years) with CSS according to the American College of Rheumatology criteria were included in the study. Thirteen serum samples from 11 patients were obtained at the time of disease flare, and the sera from 6 of them were also obtained at the time of clinical remission. Sera from seven other patients were obtained in clinical remission. Anti-neutrophil cytoplasm antibodies were detected in four (22.2%) patients. Fifteen healthy individuals were used as controls. Mean eosinophil count differed significantly between CSS patients with active disease and patients in clinical remission (3,407/mm(3) vs. 258/mm(3); P < 0.01), between CSS patients with active disease and healthy individuals (3,407/mm(3) vs. 211/mm(3); P < 0.01). Mean serum ECP levels differed significantly between patients with active or inactive disease (219 microg/L vs. 56.8 microg/L; P < 0.0001), between patients with active disease and healthy individuals (219 microg/L vs. 26.2 microg/L; P < 0.0001), but not between patients with inactive disease and healthy individuals (ns). Peripheral blood eosinophils count correlated with serum ECP during CSS flares disease (R = 0.6264; P < 0.05) and during periods of remission (R = 0.4798; P < 0.05). Our results support that ECP might be used as a disease activity marker in CSS.

Indications for biotherapy in systemic vasculitides

Biotherapy now holds a specific place in the therapeutic armamentarium for systemic vasculitides. Such therapy includes cytokines, such as (pegylated) alpha-interferon for hepatitis B virus-related polyarteritis nodosa and hepatitis C virus-related cryoglobulinemic vasculitis, and polyvalent immunoglobulin (IVIg), with well-defined indications and pending positive results. More specifically targeted monoclonal antibodies include antitumor necrosis factor-alpha or anti-CD20 for antineutrophil cytoplasmic antibody-associated vasculitides or anti-interleukin-5 and anti-IgE for Churg-Strauss syndrome. However, the exact indications of these latter new agents, as well as their optimal dosage and duration, are not defined. Therefore, they are prescribed mainly for patients with disease refractory to conventional therapy, in whom results are promising. Results of international ongoing trials will determine whether the agents may also have a place as first-line treatment.

[New insights into the pathogenesis of ANCA-positive vasculitides]

Recent studies provided new insights into the pathogenesis of vasculitides associated with antineutrophil cytoplasm antibodies (ANCA). They yield more information about the pathogenic role of ANCA, the initiation of the immune response against proteinase 3, the expression of ANCA target antigens on neutrophil surfaces, endothelial damage and the mechanisms of vasculitis associated with propylthiouracil. The pathogenic role of antimyeloperoxidase antibodies has been established in vitro and in vivo in animal models and in human. A pathogenic role for antiproteinase 3 antibodies has not yet been clearly established in vivo although it is well documented in vitro.

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.

Ear, nose and throat manifestations of Churg-Strauss syndrome

CONCLUSION

Ear, nose and throat (ENT) involvement is common in Churg-Strauss syndrome (CSS), usually manifesting as allergic rhinitis and chronic rhinosinusitis with or without polyps. Otolaryngologists may play a pivotal role in making an early diagnosis of this disease.

OBJECTIVES

CSS is a systemic vasculitic disorder that affects small to medium-sized blood vessels. Although the cause of CSS remains unknown, tissue damage seems more likely to be mediated by activated eosinophils. Patients affected by CSS frequently have ENT manifestations, which are often present at the time of disease onset and may represent relevant clues for the diagnosis. Thus, our objective was to present the ENT manifestations at the onset, at the diagnosis and at some point during the course of the disease in a series of patients with CSS collected at a single center.

MATERIALS AND METHODS

Twenty-eight patients with CSS, as defined according to the 1990 American College of Rheumatology classification criteria, were identified. Twenty-one (75%) of these patients had ENT involvement. We evaluated the clinical course, laboratory data, histologic findings, treatment and outcomes.

RESULTS

Of the 21 patients, 13 (61.9%) had ENT involvement at asthma onset and 8 (38%) at diagnosis or during follow-up. The most common ENT manifestations were allergic rhinitis in 9 (42.8%) patients and nasal polyposis in 16 (76.1%). Three (14.2%) patients developed chronic rhinosinusitis without polyps, three (14.2%) had nasal crusting, one (4.7%) serous otitis media, one (4.7%) purulent otitis media, two (9.5%) progressive sensorineural hearing loss, and one (4.7%) unilateral facial palsy. Corticosteroid therapy associated with immunosuppressive drugs usually yielded improvement or stabilization.

Les protéines cationiques de l'éosinophile : marqueurs d'activation du polynucléaire éosinophile

INTRODUCTION

Eosinophils play a central role in the pathogenesis of allergic diseases and host protection against parasites, especially against helminths.

EXEGESIS

Eosinophil granules contain cytotoxic proteins, including cationic proteins: major basic protein (MBP), eosinophil cationic protein (ECP), eosinophil peroxidase (EPO) and eosinophil derived neurotoxin (EDN).

CONCLUSION

Eosinophil granule proteins are implicated in the occurrence of allergic diseases and Churg-Strauss syndrome. These proteins are activation markers of eosinophils and may be useful in clinical practice.

Pathogénie des vascularites systémiques primitives (I) : vascularites ANCA-positives

The pathogenesis of different types of systemic vasculitis positive for antineutrophil cytoplasmic antibodies (ANCA) remains incompletely understood. ANCA constitute a heterogeneous group of antibodies that are associated with different types of small-vessel vasculitis, including Wegener's granulomatosis (WG), microscopic polyangiitis (MPA) and Churg-Strauss syndrome (CSS). Anti-proteinase 3 ANCA are present in more than 90% of patients with systemic WG, and anti-myeloperoxidase (MPO) ANCA in 50-75% of those with MPA and 40-60 % of those with CSS. The pathogenic role of ANCA has been well documented in vivo: passive transfer of anti-MPO ANCA in an MPO knockout mouse model immunized with MPO is sufficient to induce the disease. In vitro, mouse and human anti-proteinase 3 ANCA can activate neutrophils primed with TNF-a and contribute to vasculitic lesions. T-cells are also involved: type 1 helper cytokines have been detected in tissue lesions of limited forms of WG, while type 2 helper cytokines have been identified in its systemic forms. Eosinophils may play a key role in the development of vasculitic lesions in CSS, although this remains to be proved.

Assessment of myocardial perfusion and fatty acid metabolism in a patient with Churg-Strauss syndrome associated with eosinophilic heart disease

Churg-Strauss syndrome is characterized by asthma, eosinophilia and systemic necrotizing vasculitis; cardiac involvement (ie, eosinophilic heart disease) is the major cause of morbidity and mortality, although there are no reports of an association between left ventricular dysfunction because of eosinophilic heart disease and myocardial blood flow or myocardial fatty acid metabolism. A patient presented with Churg-Strauss syndrome associated with eosinophilic heart disease that had progressed to dilated cardiomyopathy. Coronary angiography, thallium-201 ((201)Tl) and iodine-123 beta-methyl-iodophenyl pentadecanoic acid ((123)I BMIPP) myocardial single photon emission computed tomography (SPECT) were performed to evaluate left ventricular dysfunction. Although coronary angiography was normal and (201)Tl SPECT showed no apparent image defect, (123)I BMIPP SPECT showed diffuse decreased accumulation, excepting the apex. The left ventricular dysfunction in patients with eosinophilic heart disease is associated with impaired myocardial fatty acid metabolism rather than with impaired myocardial blood flow.

Clinicopathological studies of peripheral neuropathy in Churg-Strauss syndrome

Clinicopathological studies were performed on the visceral organs and the sural nerve of a male patient with Churg-Strauss syndrome (CSS) in order to understand the mechanisms of peripheral nervous system damage. A 67-year-old man, with a 2-year history of bronchial asthma, developed acutely painful paraplegia and dyspnea. Laboratory data showed a leukocytosis, an elevated serum creatinine kinase (CK) and marked eosionophilia. Autoantibodies including p- and c-ANCA were negative. Electrophysiological studies revealed a severe sensory-motor neuropathy of multiple mononeuritis type. Steroid pulse therapy performed a day after biopsy of skin, muscle and sural nerve was effective in resolving his respiratory and neurological dysfunction but a perforation of an intestinal ulcer occurred which required surgical intervention. In the biopsied sural nerve and the surgically resected intestine and mesentery there was vasculitis with fibrinoid necrosis accompanied by numerous eosinophils and macrophages containing eosinophil cationic protein (ECP). These findings suggest that in addition to ischemic changes due to vasculitis some neurotoxic substances generated by the eosinophils may be involved in the development of neuropathy in CSS.

Evidence for pathogenic involvementof eosinophils and neutrophilsin Churg-Strauss syndrome

BACKGROUND

Churg-Strauss syndrome (CSS) is a multi-organ disease with tissue and blood eosinophilia.

OBJECTIVE

Our aim was to study eosinophil and neutrophil involvement in CSS.

METHODS

Eight lesional skin biopsy specimens from 6 patients with CSS and serum and blister fluid from one patient were tested for eosinophil and neutrophil activity. Indirect immunofluorescence on skin specimens used antibodies to eosinophil granule major basic protein (MBP), eosinophil-derived neurotoxin (EDN), and neutrophil elastase (NE). Serum and blister fluid specimens were analyzed for granule protein levels and for eosinophil-activating cytokines.

RESULTS

Indirect immunofluorescence showed prominent cellular and extracellular staining for EDN in skin biopsy specimens; MBP staining was less extensive. Five biopsy specimens showed marked cellular NE staining; 4 showed prominent extracellular NE. Serum and blister fluid specimens contained elevated MBP, EDN, and interleukin 5 levels and enhanced eosinophil survival in culture. Granulocyte-macrophage colony-stimulating factor and interleukin 5 were detected in blister fluid. Blister fluid contained more NE than normal serum.

CONCLUSIONS

Both eosinophils and neutrophils likely participate in skin lesion development in CSS.

Asthma therapies and Churg-Strauss syndrome

The pulmonary vasculitides are a group of rare but serious disorders that require early recognition, accurate diagnosis, and effective therapy. Churg-Strauss syndrome (CSS) is classified as small vessel vasculitis. Four different definitions for the diagnosis of CSS have been developed: (1) the pathologic criteria put forth by Churg and Strauss, (2) the criteria based on clinical grounds from Lanham and colleagues, (3) the criteria based on clinical grounds from the American College of Rheumatology, and (4) the criteria from the Chapel Hill Consensus Conference, which closely concur with the Churg and Strauss definition. It is apparent that cessation, diminution, or even a switch from low-dose systemic to inhaled corticosteroid therapy can precipitate the appearance of CSS. The term forme fruste has been used to indicate that the signs and symptoms of CSS were (inadvertently) suppressed by cortico-steroids. The clinical risk factors for CSS are moderately severe or severe asthma, chronic sinusitis, or reductions in systemic corticosteroid therapy. Differential diagnosis, treatment, and ongoing monitoring of CSS therapeutic responses are reviewed. The introduction of leukotriene modifiers and high-potency inhaled corticosteroids have allowed control of asthma symptoms, which results in avoidance or reduction in oral corticosteroid use. The advent of these agents has been associated with reports of CSS appearing in patients with asthma. The available data regarding the association of CSS and antiasthma agents are most consistent with the unmasking of a previously contained pathologic condition (forme-fruste CSS) or disease that progresses because systemic corticosteroids were avoided. Early recognition and immunosuppressive therapy are the keystones of successful treatment of this rare disorder.

Churg-Strauss syndrome: update on recent developments

Churg-Strauss syndrome (CSS) is a form of primary vasculitis characterized by allergy and angiitis. In the organ systems involved (lung, heart, peripheral nervous system, and so forth), eosinophilic infiltration can be found. Eosinophilia and normochromic normocytic anemia are leading laboratory findings together with elevated IgE. New seromarkers for the activation of endothelial cells, lymphocytes, and eosinophils (soluble thrombomodulin, soluble interleukin-2 receptor, eosinophil cationic protein) may be able to predict a relapse. Antineutrophil cytoplasmic antibodies are found in only approximately 50% of all patients with CSS, and their diagnostic value is questionable. Etiologically, hyperresponsiveness to an antigenic stimulus seems to underlie the syndrome. In asthmatics, cysteinyl leukotriene receptor type 1 antagonists are reported to trigger the disease. Cytokine profile findings on the cells involved in CSS remain contradictory. Some think CSS may be a Th2-mediated disease; its pathophysiology is not known fully. Interleukin-5 and tumor necrosis factor-alpha are elevated in serum and fluid of bronchoalveolar lavage, suggesting target cytokines for future treatment protocols. Treatment consists of glucocorticoid monotherapy. Data on outcome and effectiveness is lacking for other immunosuppressive regimens, such as cyclophosphamide or glucocorticoid plus cyclophosphamide. Treatment with interferon-alpha has been effective in patients refractory to glucocorticoid plus cyclophosphamide.