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Background: Three anti-IL-5 pathway-directed therapies are approved for use in patients with severe eosinophilic asthma (SEA); however, no head-to-head comparison data are available., Objective: We sought to compare the efficacy of licensed doses of mepolizumab, benralizumab, and reslizumab in patients with SEA, according to baseline blood eosinophil counts., Methods: This indirect treatment comparison (ITC) used data from a Cochrane review and independent searches. Eligible studies were randomized controlled trials in patients aged 12 years or greater with SEA. End points included annualized rate of clinically significant exacerbations and change from baseline in Asthma Control Questionnaire score and FEV 1 . An ITC was performed in patients with Asthma Control Questionnaire scores of 1.5 or greater and stratified by baseline blood eosinophil count., Results: Eleven studies were included. All treatments significantly reduced the rate of clinically significant exacerbations and improved asthma control versus placebo in all blood eosinophil count subgroups. Mepolizumab reduced clinically significant exacerbations by 34% to 45% versus benralizumab across subgroups (rate ratio ≥400 cells/μL: 0.55 [95% CI, 0.35-0.87]; ≥300 cells/μL: 0.61 [95% CI, 0.37-0.99]; and ≥150 cells/μL: 0.66 [95% CI, 0.49-0.89]; all P < .05) and by 45% versus reslizumab in the 400 cells/μL or greater subgroup (rate ratio, 0.55 [95% CI, 0.36-0.85]; P = .007). Asthma control was significantly improved with mepolizumab versus benralizumab (all subgroups: P < .05) and versus reslizumab in the 400 cells/μL or greater subgroup (P = .004). Benralizumab significantly improved lung function versus reslizumab in the 400 cells/μL or greater subgroup (P = .025)., Conclusions: This ITC of the licensed doses suggests that mepolizumab was associated with significantly greater improvements in clinically significant exacerbations and asthma control compared with reslizumab or benralizumab in patients with similar blood eosinophil counts., (Copyright © 2018 GlaxoSmithKline. Published by Elsevier Inc. All rights reserved.)

Background: Few data are available to assist clinicians with decisions regarding long-term use of asthma therapies, including omalizumab., Objective: We sought to evaluate the benefit and persistence of response in subjects continuing or withdrawing from long-term omalizumab treatment., Methods: Evaluating the Xolair Persistency Of Response After Long-Term Therapy (XPORT) was a randomized, double-blind, placebo-controlled withdrawal study that included subjects with moderate-to-severe persistent asthma receiving long-term omalizumab. Subjects were randomized by using a hierarchical dynamic randomization scheme to continue their same dose of omalizumab or withdraw to placebo and were then followed every 4 weeks for 1 year. The primary outcome was any protocol-defined severe asthma exacerbation. The secondary outcome was time to first protocol-defined severe asthma exacerbation. Exploratory outcomes included changes in Asthma Control Questionnaire and Asthma Control Test scores., Results: Significantly more subjects in the omalizumab group (67%) had no protocol-defined exacerbation than in the placebo group (47.7%); an absolute difference of 19.3% (95% CI, 5.0%, 33.6%) represents a 40.1% relative difference. Time to first protocol-defined exacerbation analysis revealed a significantly different between-group exacerbation pattern that was consistent with the primary analysis. Subjects continuing omalizumab had significantly better asthma control (mean [SD] change from baseline to week 52: Asthma Control Test score, -1.16 [4.14] vs placebo, -2.88 [5.38], P = .0188; Asthma Control Questionnaire score, 0.22 [0.66] vs placebo, 0.63 [1.13], P = .0039). Discontinuation of omalizumab was associated with an increase in free IgE levels and an increase in basophil expression of the high-affinity IgE receptor. No safety concerns were noted., Conclusion: Continuation of omalizumab after long-term treatment results in continued benefit, as evidenced by improved symptom control and reduced exacerbation risk., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Glucocorticoids remain a cornerstone of guideline-based management of persistent asthma and allergic diseases. Glucocorticoid-induced osteoporosis (GIO) is the most common iatrogenic cause of secondary osteoporosis and an issue of concern for physicians treating patients with inhaled or oral glucocorticoids either continuously or intermittently. Patients with GIO experience fragility fractures at better dual-energy x-ray absorptiometry T-scores than those with postmenopausal or age-related osteoporosis. This might be explained, at least in part, by the effects of glucocorticoids not only on osteoclasts but also on osteoblasts and osteocytes. Effective options to detect and manage GIO exist, and a management algorithm has been published by the American College of Rheumatology to provide treatment guidance for clinicians. This review will summarize GIO epidemiology and pathophysiology and assess the role of inhaled and oral glucocorticoids in asthmatic adults and children, with particular emphasis on the effect of such therapies on bone health. Lastly, we will review the American College of Rheumatology GIO guidelines and discuss diagnostic and therapeutic strategies to mitigate the risk of GIO and fragility fractures., (Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

Background: Since initial registration, the omalizumab clinical trial database has expanded considerably, with a doubling of patients exposed in the clinical trial environment. Previous pooled data (2003) from phase I to III studies of omalizumab showed a numeric imbalance in malignancies arising in omalizumab recipients (0.5%) compared with control subjects (0.2%). The previous analysis was based on limited available data, warranting further investigation., Objective: We sought to examine the incidence of malignancy using comprehensive pooled data from clinical trials of omalizumab-treated patients., Methods: This pooled analysis included data from 67 phase I to IV clinical trials. The prespecified primary analysis assessed the incidence of primary malignancy in 32 randomized, double-blind, placebo-controlled (RDBPC) trials., Results: There were 11,459 unique patients in all clinical trials (7,789 received omalizumab). The primary analysis identified malignancies in 25 patients (RDBPC trials): 14 in 4,254 omalizumab-treated patients and 11 in 3,178 placebo-treated patients. Incidence rates per 1,000 patient-years of observation time for omalizumab- and placebo-treated patients were 4.14 (95% CI, 2.26-6.94) and 4.45 (95% CI, 2.22-7.94), respectively; the corresponding rate ratio was 0.93 (95% CI, 0.39-2.27). Primary malignancies were of varying histologic type and occurred in a number of different organ systems; no cluster of histologies was identified., Conclusions: In this pooled analysis no association was observed between omalizumab treatment and risk of malignancy in RDBPC trials; the rate ratio was below unity. The data suggest that a causal relationship between omalizumab therapy and malignancy is unlikely., (Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

Background: Biologic factors are known to contribute to asthma severity. It is unknown whether these factors differentially contribute to asthma severity in black compared with white subjects., Objective: We sought to assess the extent to which racial disparities between black and white subjects with severe asthma are attributable to physiologic, immunoinflammatory, and sociodemographic variables., Methods: Black and white asthmatic adults enrolled in a cross-sectional study focused on severe asthma were evaluated. Severe asthma was identified by using the American Thoracic Society definition. After initial univariable analyses, unconditional logistic regression models were used to estimate the probability of having severe asthma for black and white subjects., Results: Differences in severe asthma in black compared with white subjects were observed. In univariable analysis IgE level was not associated with severe asthma in black or white subjects, whereas in multivariable analysis IgE level was significantly associated with severe asthma for black subjects (P = .014) but not for white subjects. The odds of having severe asthma more than doubled for black subjects with 2 or more family members with asthma (P = .026), whereas the odds of severe asthma for white participants with a strong family history of asthma decreased by almost half (P = .05). Atopy was negatively associated with severe asthma in both races in univariable analysis but remained significant only in black subjects, whereas comorbidities were associated with severe asthma in white subjects., Conclusion: Biologic factors were distinctly associated with severe asthma only in black subjects. Studies that incorporate comprehensive evaluation of biologic factors associated with asthma might lead to the development of therapies that target biologic abnormalities in black subjects., (Copyright © 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

Background: Although specific immunotherapy is a valuable treatment option for patients with allergic asthma, the potential for systemic allergic reactions has limited its use, especially for patients with symptomatic disease., Objective: To evaluate omalizumab's effect on the tolerability of specific immunotherapy in patients with symptomatic persistent asthma not adequately controlled with inhaled corticosteroids., Methods: This multicenter, double-blind, parallel-group study randomized patients to treatment with omalizumab or placebo, after which they received specific immunotherapy to at least 1 of 3 perennial aeroallergens (cat, dog, and house dust mite) according to a 4-week, 18-injection cluster regimen, followed by 7 weeks of maintenance therapy. The primary efficacy variable, a systemic allergic reaction after immunotherapy, was analyzed by using the Cochrane-Mantel-Haenszel test., Results: A total of 248 randomized patients (126 omalizumab, 122 placebo) received at least 1 dose of immunotherapy and were evaluated for efficacy. Patients receiving omalizumab experienced significantly fewer systemic allergic reactions to immunotherapy than those receiving placebo (17/126 [13.5%] vs 32/122 [26.2%]; P = .017; 95% CI, 2.91% to 22.56%) and had fewer respiratory-related (grade 3) systemic allergic reactions (6 vs 24, respectively). Grade 4 reactions were reported in 2 patients in each group. More omalizumab patients were able to reach the target maintenance immunotherapy dose (110 [87.3%] vs 88 [72.1%], respectively; P = .004)., Conclusion: Use of omalizumab in patients whose asthma was symptomatic despite use of inhaled corticosteroids was associated with fewer systemic allergic reactions to specific immunotherapy and enabled more patients to achieve the target immunotherapy maintenance dose., (Copyright 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

Background: Concurrent use of an inhaled corticosteroid (ICS) and an inhaled long-acting beta2-agonist provides better overall asthma control than the use of higher doses of ICS alone., Objective: The purpose of this investigation was to determine whether fluticasone propionate (FP) combined with salmeterol in the Diskus device can be used to reduce the dose of ICS in patients currently stable on medium-dose ICS while maintaining asthma control., Methods: This was a randomized, double-blind, parallel-group, 12- to 24-week trial consisting of a 3-part run-in period. The run-in period was designed to first establish FP 250 microg administered twice a day (bid) via Diskus as the minimum effective dose. During run-in period 1, patients received FP 220 microg bid or the equivalent for 10 to 14 days. Controlled patients moved to run-in period 2 (5-28 days), which assessed asthma stability on FP 100 microg bid administered via Diskus. Only patients who became unstable on FP 100 microg bid were eligible to enter run-in period 3 (26-30 days), during which they were placed on FP 250 microg bid and those regaining asthma control were eligible for randomization. The primary efficacy endpoint was the proportion of patients who remained in the study with no evidence of worsening asthma. Secondary efficacy measures included FEV1, morning peak expiratory flow, percent of symptom-free days, and daily albuterol use., Results: Only 5% of patients treated with FP100/salmeterol withdrew because of worsening asthma in the first 12 weeks; this compared with 7% in the FP250 group. All patients from a subset of sites continued in the study for an additional 12 weeks; only an additional 1% of patients treated with either FP100/salmeterol or FP250 withdrew because of worsening asthma. Secondary efficacy measures confirmed primary efficacy results., Conclusion: In patients requiring FP250 bid for asthma stability, FP100/salmeterol bid was steroid-sparing, allowing a 60% reduction in the FP dose while maintaining overall asthma control.

Background: A recombinant humanized anti-IgE mAb, omalizumab, forms complexes with free IgE, blocking its interaction with mast cells and basophils; as a consequence, it might be effective in the treatment of asthma., Objective: The purpose of this study was to evaluate the efficacy and safety of omalizumab in the treatment of inhaled corticosteroid-dependent asthma., Methods: In this phase III, double-blinded, placebo-controlled trial, 525 subjects with severe allergic asthma requiring daily inhaled corticosteroids were randomized to receive placebo or omalizumab subcutaneously every 2 or 4 weeks, depending on baseline IgE level and body weight. Inhaled corticosteroid doses were kept stable over the initial 16 weeks of treatment and tapered during a further 12-week treatment period., Results: Omalizumab treatment resulted in significantly fewer asthma exacerbations per subject and in lower percentages of subjects experiencing an exacerbation than placebo treatment during the stable steroid phase (0.28 vs 0.54 [P =.006] and 14.6% vs 23.3% [P =.009], respectively) and during the steroid reduction phase (0.39 vs 0.66 [P =.003] and 21.3% vs 32.3% [P =.004], respectively). Beclomethasone dipropionate reduction was significantly greater with omalizumab treatment than with placebo (median 75% vs 50% [P <.001]), and beclomethasone dipropionate discontinuation was more likely with omalizumab (39.6% vs 19.1% [P <.001]). Improvements in asthma symptoms and pulmonary function occurred along with a reduction in rescue beta-agonist use. Omalizumab was well tolerated, with an adverse-events profile similar to that of placebo., Conclusion: The addition of omalizumab to standard asthma therapy reduces asthma exacerbations and decreases inhaled corticosteroid and rescue medication use.

Background: IL-4 mediates important proinflammatory functions in asthma, including induction of the IgE isotype switch, increased expression of vascular cell adhesion molecule 1 and promotion of eosinophil transmigration across the endothelium, stimulation of mucus production, and T(H)2 lymphocyte differentiation, leading to release of IL-4, IL-5, IL-9, and IL-13., Objective: The current study evaluated the therapeutic potential of inhaled recombinant human soluble interleukin-4 receptor (IL-4R) as an IL-4 antagonist., Methods: This study was a randomized, double-blind, placebo-controlled study in 62 subjects involving 12 once weekly nebulizations of 0.75, 1.5, or 3.0 mg of IL-4R or placebo. During screening, subjects documented dependence on inhaled corticosteroids by an exacerbation in asthma induced by one or two 50% dose reductions at 2-week intervals. After restabilization for 2 weeks on the dose above which their asthma flared, inhaled steroids were discontinued, patients were randomized, and study medication was started on day 0., Results: IL-4R was well tolerated. Efficacy was demonstrated by a decline in FEV(1) observed in the placebo group (-0.4 L and -13% predicted), which did not occur in the group receiving 3.0 mg of IL-4R (-0.1 L and -2% predicted; P =.05 over the 3-month treatment period). Daily patient-measured morning FEV(1) also demonstrated a significant decline in the placebo group (-0.5 L and -18% predicted), which did not occur in the group receiving 3.0 mg of IL-4R (-0.1 L and -4% predicted; P =.02 over the 3-month treatment period). The efficacy of IL-4R was further confirmed by the absence of increase in asthma symptom scores in the group receiving 3.0 mg of IL-4R (Delta 0.1) compared with that seen in the placebo group (Delta 1.4 over 1 month; P =.07). Study discontinuation for asthma exacerbation was not significantly different between groups (placebo, 56%; 3.0 mg of IL-4R, 47%; P = not significant)., Conclusion: These promising data suggest that IL-4R is safe and effective in the treatment of moderate persistent asthma.

Background: Both inhaled corticosteroids and leukotriene modifiers are used in the maintenance treatment of persistent asthma., Objective: The goal was to compare the efficacy and safety of low-dose fluticasone propionate (FP) and montelukast as first-line maintenance therapy in symptomatic patients by using short-acting beta2-agonists alone to treat persistent asthma., Methods: In this multicenter, randomized, double-blind, double-dummy, parallel-group study, 533 patients (>15 years old) with persistent asthma who remained symptomatic while taking short-acting beta2-agonists alone were treated with FP (88 microg [2 puffs of 44 microg] twice daily) or montelukast (10 mg once daily) for 24 weeks., Results: Compared with treatment with montelukast, treatment with FP resulted in significantly greater improvements at endpoint in morning predose FEV(1) (22.9% vs 14.5%, P <.001), forced midexpiratory flow (0.66 vs 0.41 L/sec, P <.001), forced vital capacity (0.42 vs 0.29 L, P =.002), morning peak expiratory flow (PEF) (68.5 vs 34.1 L/min, P <.001), and evening PEF (53.9 vs 28.7 L/min, P <.001). Similar improvements in PEF were observed in patients with milder asthma (>70%-80% predicted FEV(1)). At endpoint, FP was more effective than montelukast at decreasing rescue albuterol use (3.1 puffs/day vs 2.3 puffs/day, P <.001), asthma symptom scores (-0.85 [48.6% decrease] vs -0.60 [30.5%], P <.001), and nighttime awakenings due to asthma (-0.64 awakenings/night [62% decrease] vs -0.48 awakenings/night [47.5%], P =.023), and FP increased the percentage of symptom-free days (32.0% vs 18.4% of days, P <.001) compared with montelukast. The adverse event and asthma exacerbation profiles for FP and montelukast were similar., Conclusions: Low-dose FP is more effective than montelukast as first-line maintenance therapy for patients with persistent asthma who are undertreated and remain symptomatic while taking short-acting beta2-agonists alone.

Chlorofluorocarbon (CFC)-containing inhalers are gradually being phased out and replaced with hydrofluoroalkane (HFA)-based alternatives. The reformulation provided the opportunity to improve the inhalation technology and physical characteristics of corticosteroid formulations. QVAR contains HFA-beclomethasone dipropionate (HFA-BDP) with the steroid in solution rather than suspension, which, in combination with improved inhaler technology, produces an extrafine aerosol with a mass median aerodynamic diameter of 1.1 microm (smaller than the 3.5-4.0 microm found with CFC-BDP). It was predicted and demonstrated that the smaller particle size of QVAR would be deposited in the lung to a greater extent than that found with CFC-BDP, particularly in the small airway, a major site of inflammation. Increased lung deposition of QVAR permits a reduction in dosage relative to CFC-BDP. Clinical evidence confirms that adult and elderly patients required approximately half the dose of QVAR to achieve the same degree of asthma control as with CFC-BDP. In long-term assessments, patients taking CFC-BDP could be switched to QVAR at half the daily dose without exacerbation of their asthma symptoms. QVAR was associated with a low overall incidence of side effects and, at the maximum recommended dose of 640 microg/d, caused no more adrenal suppression than 672 microg/d CFC-BDP.

Although asthma affects nearly 8% of the adult population, most of these patients have mild-to-moderate disease that can be controlled with appropriate treatment. It is estimated, however, that 5% to 10% of patients with asthma have severe disease that is unresponsive to typical therapeutics, including corticosteroids. Because patients with severe asthma are disproportionately affected by their disease, in terms of both impaired lifestyle and health care costs, the National Heart, Lung, and Blood Institute sponsored a workshop on the pathogenesis of severe asthma. The goals of this workshop were to begin to define the characteristics of severe asthma. In these discussions, it was clear that many characteristics need to be considered in defining this phenotype of asthma, including symptoms, intensity of therapy (including administration of systemic corticosteroids), and impairment of lung function. Also discussed were potential mechanisms of severe asthma including the role of allergic diseases, which may play less of a role in severe asthma than in mild-to-moderate disease, and infections. A major limitation to control of severe asthma is the recalcitrant response of these patients to usual therapy including systemic corticosteroids; the potential of other therapies was reviewed. From these discussions, recommendations were made for future research needs to gain insights into a difficult therapeutic and possibly novel mechanistic area of asthma.

Background: Eosinophil recruitment to the airway after antigen challenge is regulated by many factors, including airway cell generation of cytokines., Objectives: The purpose of this study was to determine the relationship between sputum cell generation of IL-5 and the appearance of eosinophils in the sputum after antigen challenge., Methods: Sputum samples from 11 allergic subjects were collected before and again 4 and 24 hours after antigen challenge. In 6 of these subjects, induced sputum samples were also obtained 48 hours and 7 days after challenge. Sputum leukocyte differential and cell counts and eosinophil-derived neurotoxin levels were determined. Sputum cells were then cultured with PHA (10 microg/mL) to stimulate IL-5 and IFN-gamma, which were measured in culture supernatants., Results: An increase in sputum eosinophils and eosinophil-derived neurotoxin levels was detected at 4 hours after antigen challenge, with peak values at 24 hours. In contrast, significant increases in ex vivo generation of IL-5 by sputum cells was not seen until 24 hours after challenge. At 24 hours, PHA-induced IL-5 correlated with airspace eosinophil values (r (s) = 0.78, P <.01). In addition, the ratio of IFN-gamma/IL-5 decreased at 24 hours (P <.05) and had an inverse correlation with sputum eosinophils (r (s)= -0.68, P <.05)., Conclusion: Although eosinophils are increased in the airway lumen as early as 4 hours, the ex vivo generation of IL-5 by sputum cells is first noted in samples obtained 24 hours after antigen challenge. This suggests that the early (4 hours) recruitment of eosinophils to the airway lumen may be regulated by factors other than IL-5 or that mucosal cells (rather than airspace cells) contribute to the IL-5 generation at this time point. Furthermore, IL-5 generation by airspace cells may be more responsible for either eosinophil recruitment or retention at later time points.

Background: Asthma is a disease of chronic inflammation and bronchoconstriction. Inhaled corticosteroids (ICSs) provide important anti-inflammatory treatment but may not provide optimal control of asthma when taken alone. Two therapeutic alternatives for enhanced asthma control are to substitute the combination of fluticasone propionate (FP) and salmeterol (FP/Salm Combo) through the Diskus inhaler or to add montelukast to existing ICS therapy., Objective: We compared the efficacy and safety of FP/Salm Combo through the Diskus inhaler versus montelukast added to FP (FP + montelukast) in patients whose symptoms were suboptimally controlled with ICS therapy., Methods: We performed a multicenter, double-blind, double-dummy, parallel-group, 12-week study in 447 patients with asthma who were symptomatic at baseline while receiving low-dose FP. Patients were treated for 12 weeks with one of the following: (1) combination of FP 100 microg plus salmeterol 50 microg twice daily through the Diskus inhaler, or (2) FP 100 microg twice daily through the Diskus inhaler plus oral montelukast 10 mg once daily., Results: FP/Salm Combo treatment provided better overall asthma control than FP + montelukast with significantly greater improvements in morning peak expiratory flow (+24.9 L/min vs +13.0 L/min, P <.001), evening peak expiratory flow (+18.9 L/min vs +9.6 L/min, P <.001), and forced expiratory volume in 1 second (+0.34 L vs +0.20 L, P <.001), as well as a change in the percentage of days with no albuterol use (+26.3% vs +19.1%, P =.032) and the shortness of breath symptom score (-0.56 vs -0.40, P =.017). The groups had comparable improvements in chest tightness, wheeze, and overall symptom scores. Asthma exacerbation rates were significantly lower (P =.031) in the FP/Salm Combo group (4 patients, 2%) than in the FP + montelukast group (13 patients, 6%). Adverse event profiles were comparable., Conclusion: Symptomatic patients on low-dose ICS therapy had significantly greater improvement in asthma control when switched to the FP/Salm Combo than when montelukast was added to ICS therapy.

Background: Intranasal glucocorticoids are effective in the treatment of allergic rhinitis. Their effectiveness as an anti-inflammatory adjunct in the treatment of acute recurrent sinusitis has not been adequately established in a controlled clinical study., Objective: The purpose of this study was to test the hypothesis that intranasal corticosteroid treatment produces additional relief in the treatment of acute sinusitis with oral antibiotics., Methods: Patients who were 12 years old and older with a history of recurrent sinusitis were treated while experiencing a new episode of acute sinusitis, which was diagnosed by symptoms and confirmed by computed tomography scan of the paranasal sinuses. Patients were treated for 21 days with amoxicillin clavulanate potassium and randomized to receive concurrent mometasone furoate nasal spray (MFNS; Nasonex [400 microg, twice daily]; n = 200 patients) or placebo spray (twice daily; n = 207 patients). Symptom scores for headache, facial pain, congestion, purulent rhinorrhea, postnasal drip, and cough were recorded at baseline and throughout treatment., Results: Baseline symptom scores showed a moderate level of symptom severity comparable in both groups. Patient-recorded twice daily symptom scores showed that adjunctive treatment with MFNS caused a significantly greater decrease in total symptom score (primary efficacy variable) and in individual scores of inflammatory symptoms associated with the obstruction process (headache, congestion, and facial pain) compared with placebo. Symptoms associated with the secretory processes were improved to a lesser degree. Therapy-related local adverse events were not significantly different between groups., Conclusion: The addition of intranasal corticosteroid, MFNS 400 microg twice daily, to antibiotics significantly reduces symptoms of acute sinusitis compared with antibiotic treatment alone.

Viral infections have been related to the inception of recurrent wheezing illnesses and asthma in infants and are probably the most frequent cause of exacerbations of established disease in older children and adults. The well-recognized clinical effects of viral infections are mainly caused by virus-induced immune responses. Clinical studies of natural and experimentally induced viral infections have led to the identification of mechanisms of inflammation that could be involved in producing airway obstruction and lower airway symptoms. In addition, host factors that are associated with more vigorous viral replication or severe clinical illness are beginning to be identified. Advances in molecular virology and our understanding of immune responses to viral infections may lead to the development of new strategies for the prevention and treatment of virus-induced respiratory disorders.

There have been many attempts to explain the increases in the incidence of allergic diseases, including hay fever and allergic asthma, that have been documented worldwide in recent decades. Epidemiologic studies offer rich opportunities to uncover sometimes unexpected correlations between lifestyle, environmental exposures, temporal development of the immune system, and genetics. Examples include the differing prevalence of atopy, bronchial hyperresponsiveness, and asthma in East and West Germany around the time of reunification, which suggests that a "western lifestyle presents a greater risk for the development of allergic responses than the more traditionally suspected factor of outdoor air pollutant levels. Other epidemiologic studies suggest how infections may interface with an atopic patterning: Evidence from natural measles exposure and nonwheeze-inducing lower respiratory tract infections in young children implicate early childhood viral infections as protective against the development of atopy and airway allergic sensitivity, although in later life viral airway infections exacerbate asthma symptoms. These studies and others involving the scrutiny of lymphocyte subtypes in atopic individuals, notably T(H1) and T(H2) cells, are helping to formulate a theory of interdependence between the early development of the immune system, allergen exposure, and the diverse community of airway cells whose secretory products generate the final physiologic response pattern.

Background: Viral respiratory tract infections are the most frequent cause of asthma exacerbations. Of the respiratory viruses associated with these exacerbations, rhinovirus (RV) is the most common. It is proposed that these RV infections may enhance airway inflammation and thus provoke asthma., Objective: It is our hypothesis that RV infections generate nasal proinflammatory mediators that are associated with an initial increase in circulating leukocytes and may contribute to later development of neutrophilic airway inflammation., Methods: To evaluate this hypothesis, subjects with a history of allergic asthma were experimentally inoculated with strain 16 RV (RV16). The effect of this experimental infection was evaluated on circulating leukocytes, nasal-derived mediators, and markers of bronchial inflammation that were obtained by bronchoscopy and lavage., Results: RV16 inoculation was associated with an initial increase in circulating neutrophils. Paralleling these acute changes in circulating neutrophils was an increase in nasal concentrations of IL-8 and granulocyte-colony-stimulating factor (G-CSF). The RV16-associated changes in circulating and nasal G-CSF correlated with increases in peripheral blood neutrophils (r(s) = 0.874, P <. 001 and r(s) = 0.898, P <.001, respectively). Bronchial lavage samples showed no increase in neutrophils 48 hours after RV16 inoculation; however, 96 hours after RV inoculation there was a significant increase in bronchial neutrophils compared with preinoculation values., Conclusions: These results suggest that the production of nasal mediators associated with the RV infection, particularly G-CSF, may be important to the eventual development of neutrophilic bronchial inflammation and thus contribute to asthma exacerbations.

Background: The immune response to rhinovirus (RV) infections is considered to contribute to upper respiratory symptoms and may also be an important contributor to lower airway dysfunction in patients with asthma., Objective: This study was conducted to determine the relationship of RV-specific responses in PBMCs to the outcome of experimentally induced infection with RV16., Methods: Twenty-two subjects with either allergic rhinitis or asthma were inoculated with RV16: virus-induced proliferation and cytokine production were determined on PBMCs obtained before and then again 7 and 28 days after inoculation., Results: Several subjects had proliferative responses to RV16 before inoculation, and precold RV-specific proliferative responses were inversely correlated (r(s) = -0.62, P <. 005) with RV shedding after inoculation. In addition, there was a negative correlation (r(s) = -0.58, P = 0.01) between precold RV-induced IFN-gamma secretion ex vivo and peak RV shedding during the cold., Conclusions: Certain RV-specific lymphocyte responses before the cold (vigorous proliferation or IFN-gamma secretion) were associated with reduced viral shedding after inoculation. These findings suggest that variations in mononuclear cell responses to RV could contribute to the individual variability in viral shedding during experimentally induced, and perhaps naturally acquired, RV infections in subjects with respiratory allergy or asthma.

Background: This study tested the hypothesis that there would be improved asthma control with increasing doses of beclomethasone dipropionate (BDP) formulated in hydrofluoroalkane-134a (HFA-BDP) and the standard chlorofluorocarbon propellants (CFC-BDP). Because HFA-BDP has improved lung deposition compared with CFC-BDP, this study also tested the hypothesis that HFA-BDP would provide more effective control of asthma than CFC-BDP., Methods: In this multicenter, randomized, parallel-group blinded study, asthmatic subjects who had deterioration in asthma control after discontinuation of inhaled corticosteroids were randomized to receive one of 6 possible treatments: 100 microg/d, 400 microg/d, or 800 microg/d of HFA-BDP or 100 microg/d, 400 microg/d, or 800 microg/d of CFC-BDP for 6 weeks. Changes in spirometry, daytime asthma symptom and nighttime asthma-related sleep disturbance scores, morning and evening peak expiratory flows, and daily use of inhaled beta-agonist for symptom control on diary cards were assessed over 6 weeks of treatment., Results: Three hundred twenty-three patients were randomized to the 6 treatment groups, which had similar demographics and baseline lung function. There were significantly larger changes from baseline at week 6 in FEV(1) percent predicted with increasing doses of both HFA-BDP and CFC-BDP. The FEV(1) percent predicted dose-response curve for HFA-BDP was shifted to the left compared with the dose-response curve for CFC-BDP. By using the Finney bioassay method, it was calculated that 2.6 times as much CFC-BDP would be required to achieve the same improvement in FEV(1) percent predicted as HFA-BDP (95% confidence interval, 1.1-11.6). All treatment groups except the 100 microg/d CFC-BDP group tolerated study drug well. Ten (17%) of 59 patients in this group reported an acute asthma episode, increased asthma symptoms (6 of the 8 reports of increased asthma symptoms were classified as severe), or both, and 8 patients withdrew from the study (3 for adverse events related to asthma)., Conclusions: Increasing doses of inhaled corticosteroids lead to improved lung function and asthma control. Moreover, the reformulation of BDP in HFA enables effective asthma control at much lower doses than CFC-BDP.

Background: Salmeterol, a long-acting beta2 -agonist, and zafirlukast, a leukotriene receptor antagonist, are both indicated for the treatment of asthma in adolescent and adult patients., Objective: We sought to compare the effect of 4 weeks of treatment with inhaled salmeterol xinafoate versus oral zafirlukast in the treatment of persistent asthma., Methods: This was a randomized, double-blind, double-dummy, parallel-group, multicenter clinical trial. Patients, over 80% of whom were on a concurrent inhaled corticosteroid regimen, were treated for 4 weeks with either inhaled salmeterol xinafoate 42 microgram twice daily administered by means of a metered-dose inhaler or oral zafirlukast 20 mg twice daily. The primary efficacy measure was morning peak expiratory flow (PEF); secondary efficacy measures included evening PEF, asthma symptom scores, supplemental albuterol use, nighttime awakenings, sleep symptoms, asthma exacerbations, and FEV1., Results: Both inhaled salmeterol and oral zafirlukast resulted in within-group improvements from baseline in measures of pulmonary function, asthma symptoms, and supplemental albuterol use. Salmeterol treatment resulted in significantly greater improvements from baseline compared with zafirlukast for most efficacy measurements, including morning PEF (29.6 vs 13.0 L/min; P

Background: Many patients with severe asthma are dependent on oral corticosteroids for maintenance control of their disease. Treatments that allow patients to be weaned off oral corticosteroids may help to minimize the risk of side effects associated with their chronic use., Objective: This study evaluated whether inhaled fluticasone propionate powder could maintain pulmonary function while reducing the dose of oral prednisone in patients with chronic, severe asthma., Methods: Oral prednisone-dependent (5 to 40 mg/day) adolescents and adults with asthma (n = 111; mean FEV1 = 61% of predicted value) were randomized to placebo or twice daily fluticasone propionate 500 or 1000 microg administered by means of a multidose powder inhaler for 16 weeks in a double-blind, parallel-group study. Patients underwent controlled prednisone reduction on the basis of predetermined asthma stability criteria., Results: Oral prednisone was eliminated by 75% and 89% of patients in the twice daily 500 and 1000 microg fluticasone propionate groups, respectively, versus 9% of the placebo group (P <.001). FEV1, morning and evening peak expiratory flow, asthma symptoms, albuterol use, and nighttime awakenings improved with fluticasone propionate treatment, achieving statistical significance (P

Asthma is a chronic disease associated with variable levels of airflow obstruction. Considerable evidence has been obtained to show that airway inflammation is a major factor in the pathogenesis of asthma in associated bronchial hyperresponsiveness, and in the level of disease severity. The inflammatory pattern in asthma is multicellular in nature, with mast cells, neutrophils, eosinophils, T lymphocytes, and epithelial cells participating in the response. Furthermore, it is known that mediators, cytokines, and chemokines from these cells contribute to the orchestration of the inflammatory process. Because airway inflammation appears to be a critical etiologic feature of asthma, it has become the target of therapy. In this review the features of airway inflammation will be examined, and the effect of therapeutic agents on markers of airway injury will be discussed. Establishing, understanding, and finally controlling the features of airway inflammation have given insight to disease pathogenesis and the effectiveness of various treatments. The integral role of inhaled corticosteroids in modifying the complex inflammatory component of asthma will be explored, with special focus on the high degree of efficacy associated with this treatment--vis-á-vis other therapeutic agents--in preventing or blocking specific proinflammatory markers.

Background: Airway inflammation is a hallmark of asthma, therefore current treatment recommendations include the use of inhaled glucocorticosteroids (GCS). However, there is little evidence that the effects of inhaled GCS are dose dependent., Objectives: The objective of this study was to assess the efficacy and safety of a second-generation GCS, budesonide, delivered by Turbuhaler, in adults with chronic asthma., Methods: In a 12-week, randomized, double-blind, multicenter, parallel-group study, 473 subjects 18 to 70 years of age received either placebo or budesonide (200, 400, 800, or 1600 microg total daily dose) administered twice daily. Primary efficacy end points were mean change from baseline for FEV1 and morning peak expiratory flow. Safety was assessed by reported adverse events and by a cosyntropin-stimulation test., Results: The mean baseline FEV1 was 63% to 66% of predicted normal value between groups. All doses of budesonide were more effective than placebo (p < 0.001). The mean changes in morning peak expiratory flow were 12, 22, 27, and 30 L/min in the 200, 400, 800, and 1600 microg budesonide total daily dose groups, respectively, and -27 L/min for the placebo group. A statistically significant dose-response effect for the mean change from baseline over the 12-week study was seen for both morning peak expiratory flow and FEV1. Budesonide-treated subjects also demonstrated significant reduction in asthma symptoms and bronchodilator use compared with placebo. There were no clinically significant differences in treatment-related adverse experiences among groups., Conclusions: Budesonide administered by Turbuhaler exhibited a dose response and was effective at low doses. It was well tolerated and significantly more effective than placebo.

Background: Increased serum levels of antigen-specific IgE are often associated with allergic respiratory disorders. RhuMAb-E25, a recombinant humanized monoclonal antibody, decreases free serum IgE by forming biologically inactive immune complexes with free IgE., Objective: We hypothesized that rhuMAb-E25 would decrease total serum IgE and reduce symptoms., Methods: Two hundred forty subjects were enrolled into five groups to determine the safety, tolerance, and efficacy of repeated administration of rhuMAb-E25 in adults with ragweed-induced allergic rhinitis and to explore the pharmacodynamic relationship of rhuMAb-E25 and IgE. One hundred eighty-one subjects received an initial intravenous loading dose (day 0, 1 month before ragweed season), followed by administration of rhuMAb-E25 (in mg/kg body weight) of 0.15 mg/kg subcutaneously, 0.15 mg/kg intravenously, or 0.5 mg/kg intravenously on days 7, 14, 28, 42, 56, 70, and 84. A subcutaneous placebo group and an intravenous placebo group were included. The total evaluation time included the 84-day treatment period, followed by a 42-day observation period., Results: Adverse events were mild, and no differences were observed in the rates between the three active and two placebo treatment groups. Ragweed-specific IgE levels correlated with symptom scores. RhuMAb-E25 decreased serum free IgE levels in a dose- and baseline IgE-dependent fashion. However, only 11 subjects had IgE levels that were suppressed to undetectable levels (< or = 24 ng/ml), a sample too small to demonstrate significant differences and clinical efficacy. Thus the case for efficacy was not proven. Nonetheless, the study confirms that it is safe to repeatedly administer rhuMAb-E25 over a period of months., Conclusions: Because rhuMAb-E25 decreased serum free IgE in a dose-dependent fashion and because symptom scores correlated with antigen-specific IgE levels, the results suggest that if given in adequate doses, rhuMAb-E25 should be an effective therapy for allergic diseases.

Background: Basophil histamine release has been found to correlate with the presence and severity of allergic disease. However, it remains to be established whether airway response to antigen is related to basophil involvement and its release of histamine., Objective: The purpose of this study was to investigate whether the intensity of airway response to an inhaled antigen challenge in allergic subjects is related to IgE-dependent peripheral blood basophil histamine release., Methods: The response to segmental bronchoprovocation with antigen was examined in 34 subjects with allergic rhinitis. Bronchoalveolar lavage samples were obtained 5 minutes (immediate response) and 48 hours (late response) after allergen challenge. Peripheral blood maximal basophil histamine release (MBHR) in response to in vitro antigen stimulation was determined in each subject before segmental bronchoprovocation., Results: Bronchoalveolar lavage samples obtained during immediate response showed an increase in histamine, whereas the late response was noted for a marked enhancement in airway cells, particularly eosinophils. Interestingly, a significant correlation (r = 0.73, p < 0.0001, Spearman Rank test) was noted between MBHR and intensity of bronchoalveolar lavage eosinophilia at 48 hours. Furthermore, subjects with high (> or = 20%) MBHR had significantly higher total cells and eosinophils in bronchoalveolar lavage fluid 48 hours after antigen segmental bronchoprovocation when compared with subjects with low (< 20%) MBHR., Conclusion: Our data suggest that the intensity of airway eosinophilia in response to antigen challenge is correlated with the magnitude of basophil mediator release in allergic subjects.

In many patients with asthma, exposure to allergen results in worsening symptoms, pulmonary dysfunction, and increased airway inflammation. In this study, segmental allergen challenge and bronchoalveolar lavage were used to evaluate the airway responses at 5 minutes and 48 hours and to study the extent of inhibition of the response by pretreatment with nedocromil sodium in eight subjects with allergic asthma in a double-blind, placebo-controlled trial. At 5 minutes after challenge, nedocromil sodium pretreatment significantly reduced histamine concentrations, with a trend toward a concomitant reduction in tryptase levels. Nedocromil sodium did not affect the increase in total protein, total cell counts, or cell concentrations that occurred 48 hours after challenge, but it did significantly reduce eosinophil recruitment. Eosinophil activation, assessed as release of granule proteins, was unaffected. A significant positive correlation was shown between the degree of histamine reduction at 5 minutes and the degree of reduction of eosinophil influx at 48 hours, raising the possibility that eosinophil influx into the airway may depend on mediators or cytokines released during the immediate response to allergen.

Background: Few clinical trials have directly compared the efficacy of antihistamines with topical nasal corticosteroids., Objective: The study was performed to compare the efficacy and safety of triamcinolone acetonide nasal spray at a dose of 110 micro g in each nostril once daily with 10 mg of oral astemizole once daily for the treatment of seasonal allergic rhinitis., Methods: A multicenter, double-blind, parallel-group study was conducted in 239 patients who were randomized to receive either triamcinolone acetonide or astemizole. A 5-day, drug-free, lead-in period was followed by 4 weeks of double-blind treatment. One hundred four patients treated with triamcinolone acetonide and 105 patients treated with astemizole could be evaluated., Results: Overall, triamcinolone acetonide was more effective than astemizole in reducing total nasal symptoms, nasal stuffiness, nasal itching, and sneezing (p

Eosinophils are hypothesized to be crucial in the development of allergic airway inflammation; however, the actual mechanisms that determine their inflammatory activity are still largely undefined. To investigate the factors that regulate eosinophil function in allergic airway disease, we have previously used segmental bronchoprovocation with allergen to study ex vivo eosinophil function. To determine whether the functional changes associated with airway eosinophils obtained by bronchoalveolar lavage 48 hours after antigen challenge are caused by exposure to airway-generated cytokines, normodense blood eosinophils were cultured in vitro with recombinant human interleukin-5 (IL-5) or granulocyte-macrophage colony stimulating factor (GM-CSF). The effect of cytokine exposure was then evaluated on selected cell functions. In vitro incubation with these cytokines for 24 hours significantly increased eosinophil membrane expression of CD18 and CD11b compared with culture in medium alone or eosinophils obtained by bronchoalveolar lavage. N-formyl-methionyl-leucyl-phenylalanine-stimulated superoxide anion generation was slightly but significantly enhanced by incubation with IL-5 but not with GM-CSF. In addition, spontaneous adhesion to human umbilical vein endothelial cell monolayers was increased after exposure to both IL-5 and GM-CSF. However, activated adhesion was enhanced only by culture with IL-5 and stimulation with N-formyl-methionyl-leucyl-phenylalanine. The magnitude of functional changes after in vitro preincubation of eosinophils with these cytokines did not achieve levels of superoxide anion and adhesion noted with airway eosinophils obtained after segmental bronchoprovocation with allergen. These observations raise the possibility that the contribution of IL-5 and GM-CSF to phenotypic changes of airway eosinophils is principally to enhance survival and expression of adhesion proteins. These data also suggest that, in addition to the generation of proinflammatory cytokines, other factors contribute to phenotypic changes in eosinophils as they migrate from the blood to the airway.

Background: The diagnosis of sinusitis is difficult and there are few controlled studies of customary therapies. In particular, the possible role of topical intranasal steroid as an adjunct to antibiotic treatment has not been evaluated., Methods: The study was a multicenter, double-blind, randomized, parallel trial in which patients aged 14 years or older were recruited from allergy practices. All patients had maxillary sinusitis documented by radiographs. Treatment consisted of amoxicillin/clavulanate potassium 500 mg combined with nasal spray of either 100 micrograms flunisolide or placebo to each nostril three times a day for 3 weeks (phase I) followed by administration of flunisolide or placebo nasal spray alone three times a day for 4 weeks (phase II)., Results: Clinical symptoms and signs decreased significantly in both treatment groups during phase I (p < 0.01). There was a trend to greater improvement in the patients treated with flunisolide, but only the decrease in turbinate swelling/obstruction was statistically significant at the end of phase I when compared with placebo (p = 0.041). Patients' global assessment of overall effectiveness of treatment was higher for flunisolide than placebo after phase I (p = 0.007) and after phase II (p = 0.08). Maxillary sinus radiographs showed improvement in both treatment groups during phase I (p < 0.004) with somewhat greater regression of abnormal findings in patients treated with flunisolide after phase II (p = 0.066). However, 80% of radiographs were still abnormal at the end of phase I. All types of inflammatory cells were significantly decreased in nasal cytograms in patients treated with flunisolide in comparison with those treated with placebo. Flare-up of sinusitis during phase II occurred in 26% of with those treated with placebo. Flare-up of sinusitis during phase II occurred in 26% of patients treated with flunisolide and 35% of those treated with placebo and tended to be more severe in the latter, although these differences were not statistically significant. Adverse events, mainly gastrointestinal symptoms and headache, were similar in both groups and more frequent in phase I than in phase II, (42 vs 15 patients); these side effects were probably due to the antibiotic., Conclusion: The addition of flunisolide topical nasal spray as an adjunct to antibiotic therapy was most effective in global evaluations, tended to improve symptoms, to decrease inflammatory cells in nasal cytograms, to normalize ultrasound scans, and to aid regression of radiographic abnormalities compared with placebo spray.

The treatment of patients with asthma that is resistant to corticosteroids represents a therapeutic challenge, because corticosteroids are the most potent and potentially effective medications for severe asthma. Recent investigations have identified several functional defects in mononuclear cells and T lymphocytes isolated from patients with corticosteroid-resistant asthma, including abnormalities in proliferation, activation, and cytokine production. The development of medications with immunomodulatory effects on specific cellular functions represents an exciting step for more efficacious treatment for such patients.

Nedocromil sodium (NS) has been shown to inhibit the late asthma response to inhaled antigen and to control symptoms in chronic asthma; in both processes the eosinophil is thought to be an important contributor. To understand the antiinflammatory actions of NS in asthma, its effects on three eosinophil functions were evaluated: (1) change in cell density during in vitro culture, (2) synthesis of leukotriene C4 (LTC4), and (3) generation of superoxide anion. In these studies normal density (greater than 1.095 gm/ml) purified human peripheral blood eosinophils were cultured for 24 hours in 50% conditioned medium from cow pulmonary arterial endothelial cells. After incubation, 45.2% +/- 8.0% of the eosinophils had a density less than 1.085 gm/ml. In the presence of NS (10 mumol/L), only 32.0% +/- 7.3% became less dense (p = 0.0393). In contrast, NS had no effect on changes in cell density after a 20-minute exposure of eosinophils to functional activators N-formyl-methionyl-leucyl-phenylalanine (0.1 mumol/L) or platelet activating factor (0.1 mumol/L). Furthermore, calcium ionophore-activated LTC4 secretion was found to be significantly inhibited by NS (3.8 +/- 0.6 ng/ml vs. 2.4 +/- 0.3 ng/ml with 1 mumol/L NS or 1.7 +/- 0.6 ng/ml with 10 mumol/L NS, p less than 0.025). However, NS did not significantly alter eosinophil superoxide anion generation. The effects of NS on eosinophil function suggest a mechanism by which this medication may be effective in asthma, particularly in the regulation of the late asthmatic response. Furthermore, the selective regulatory effects of NS may also provide insight into the biologic activities of eosinophils.

The precise role of platelet-activating factor (PAF) in asthma has yet to be established. Nonetheless, the potential relationship between PAF and asthma appears to include the eosinophil (EOS) as an important link. Thus, to evaluate the effect of PAF on leukocyte-dependent inflammation, purified populations of human blood EOSs and neutrophils were isolated from the same subject. The two granulocyte populations were then incubated with PAF, and superoxide anion (O2-) generation was measured by reduction of cytochrome c in a microassay system. Both granulocyte cell types generated O2- when they were incubated with PAF. However, the generation of O2- was 3.4 times greater with EOSs (9.8 +/- 1.5 nmole of cytochrome c reduced per 5 x 10(5) cells) than neutrophils (2.9 +/- 0.4 nmole of cytochrome c reduced per 5 x 10(5) cells; p less than 0.0001). When the effect of PAF on [Ca++]i was measured with the fluorescent label, Indo-1, PAF caused similar increases in cellular fluorescence in both neutrophils and EOSs, but the increase in [Ca++]i of neutrophils occurred with lower concentrations of PAF. Furthermore, when similar experiments were conducted in the presence of an extracellular calcium chelator, ethylene glycol-bis-(beta-aminoethylether)-N,N,N',N'-tetraacetic acid, there was partial suppression in both the cellular fluorescence and O2- generation to PAF; this suggests that full expression of EOS generation of O2- by PAF requires both intracellular mobilization and a transmembrane influx of Ca++. Our data indicate that PAF can stimulate leukocyte O2- generation, but this response is greater in the EOS than the neutrophil. Therefore, our findings support the observation that the EOS is more responsive to PAF activation than other granulocytes and that this difference may contribute to participation of PAF in asthma.

The effects of RVIs on airway reactivity are multiple but do not necessarily include direct changes in the intrinsic contractile properties of airway smooth muscle. Rather, respiratory viruses influence bronchial smooth muscle function through a variety of other mechanisms: production of virus-specific IgE antibodies, epithelial injury, polymorphonuclear-dependent inflammation, and enhanced mediator release. Thus, a common pathway to airway hyper-reactivity during respiratory viral illnesses is an overall enhancement of factors that cause or lead to inflammation. When the airways become the target of enhanced inflammation, bronchial reactivity and obstruction are accentuated. Although many questions remain to be answered, future studies to evaluate the biology of respiratory virus effects on mechanisms of allergic sensitization and airway responsiveness promise to provide a greater understanding of the pathogenesis of asthma.

Based on membrane receptors, metabolic activity, and cell density, human eosinophils (EOSs) are a heterogeneous population of leukocytes. EOS heterogeneity translates into biologic significance, since low density cells can be metabolically more active and thus more capable of causing tissue injury. Efforts to identify mechanisms that lead to the development of hypodense EOSs have found that an in vitro exposure to cytokines reduces cell density and is associated with increased cell activity. Consequently, we evaluated the effect of an in vivo administration of interleukin-2 (IL-2) on the cell counts and density of circulating EOSs in six patients who received IL-2 as cancer biologic-modifier therapy. To determine the pattern of EOS density in relationship to IL-2 treatment, granulocyte suspensions were isolated from peripheral blood and then centrifuged over multiple discontinuous density Percoll gradients. During IL-2 treatment, the percentage of circulating hypodense EOSs increased significantly (p less than 0.01) until nearly all (97.6 +/- 1.6%) EOSs were hypodense (density less than 1.095 gm/ml). Similarly, the absolute blood EOS counts significantly increased throughout treatment. On completion of IL-2 therapy, the EOS counts and density distribution returned to pretreatment values. In contrast, no increase in blood EOS counts was observed in similar patients receiving interferon (gamma or beta) therapy. Our observations support a hypothesis that IL-2, either directly or, more likely, through the generation of other factors, participates in a change in EOS density that may, in turn, establish a subpopulation of cells with altered metabolic activity.

Many factors will influence the tissue response to catecholamine stimulation. Isolated human granulocytes (PMNs) release the lysosomal enzyme beta-glucuronidase following incubation with complement-activated zymosan particles. Isoproterenol, histamine, and prostaglandin E1 (PGE1) inhibit this PMN release of beta-glucuronidase. The effect of exercise on this in vitro granulocyte response was studied in two groups: highly conditioned marathon runners (n = 6) and unconditioned subjects (n = 7). A 13-km run did not produce leukocytosis in the highly conditioned marathon runners and the granulocyte response to isoproterenol was unchanged in cells obtained immediately following the run. In contrast, the seven unconditioned subjects exercised to a maximal response on the treadmill. Following exercise there was an increase in plasma catecholamines, a significant leukocytosis, and granulocytes from the immediate postexercise period responded less well to isoproterenol.

The human eosinophil contains lysosomal enzymes that can contribute directly to tissue injury and inflammation. Characterization of lysosomal-enzyme release from the eosinophil has been largely limited to isolates from patients with hypereosinophilia. Because eosinophils from such individuals may not demonstrate normal functional responses, we established a method to obtain purified, normal human eosinophils with a Percoll gradient. With this method, it is possible to isolate eosinophils (95.5 +/- 3.9%) and neutrophils (greater than 99%) in high purity from normal subjects. With these granulocyte isolates, we evaluated and compared release of the lysosomal enzyme, beta-glucuronidase (BG), after cell activation with opsonized zymosan particles. Neutrophils released 33.0 +/- 1.2% (mean +/- SEM; n = 5) of total BG (30 minutes of incubation with zymosan), whereas eosinophil secretion was 24.2 +/- 1.7% (n = 5). The fungal metabolite, cytochalasin B (CB), which inhibits microfilament activity, enhanced BG secretion from neutrophils (33.0 +/- 1.2% to 42.8 +/- 2.8% with CB; p less than 0.01). In contrast, CB had no effect on eosinophil BG release. Interestingly, BG content in eosinophils is 101.2 +/- 3.9 micrograms phenolphthalein per 10(6) cells per 18 hours, which compares to a neutrophil level of 51.0 +/- 3.2 (p less than 0.001). Thus, although eosinophils and neutrophils release a similar percentage of total cellular BG on stimulation with zymosan particles, the absolute amount of enzyme per cell is greater in the eosinophil than in the neutrophil. Study of eosinophil function promises to elicit a more complete insight into its contribution to tissue injury.

Attenuated live intranasal influenza vaccine ("Alice") was given to 20 asthmatics and 9 control subjects. Pulmonary function were performed before and after, with emphasis on tests of small airways function (using flow volume curves with air and a helium-oxygen mixture). In subjects with a low influenza A antibody titer, there was a 4-fold rise in titer to the vaccine, whereas those subjects with a high titer showed no rise. There were no significant changes in pulmonary function in any parameters measured, and no significant symptoms were reported. We have concluded from this study that "Alice" appears safe for use in asthma and was capable of producing an antibody titer rise in persons with low titers.