C1 esterase inhibitor concentrate in 1085 Hereditary Angioedema attacks--final results of the I.M.P.A.C.T.2 study.

BACKGROUND: The placebo-controlled study International Multicentre Prospective Angioedema C1-INH Trial 1 (I.M.P.A.C.T.1) demonstrated that 20 U/kg C1 esterase inhibitor (C1-INH) concentrate (Berinert®; CSL Behring, Marburg, Germany) is effective in treating acute abdominal and facial Hereditary Angioedema (HAE) attacks. METHODS: I.M.P.A.C.T.2 was an open-label extension study of I.M.P.A.C.T.1 to evaluate the safety and efficacy of long-term treatment with 20 U/kg C1-INH for successive HAE attacks at any body location. Efficacy outcomes included patient-reported time to onset of symptom relief (primary) and time to complete resolution of all symptoms (secondary), analysed on a per-patient and per-attack basis. Safety assessments included adverse events, vital signs, viral safety and anti-C1-INH antibodies. RESULTS: During a median study duration of 24 months, 1085 attacks were treated in 57 patients (10-53 years of age). In the per-patient analysis, the median time to onset of symptom relief was 0.46 h and was similar for all types of attacks (0.39-0.48 h); the median time to complete resolution of symptoms was 15.5 h (shortest for laryngeal attacks: 5.8 h; 12.8-26.6 h for abdominal, peripheral and facial attacks). Demographic factors, type of HAE, intensity of attacks, time to treatment, use of androgens and presence of anti-C1-INH antibodies had no clinically relevant effect on the efficacy outcomes. There were no treatment-related safety concerns. No inhibitory anti-C1-INH antibodies were detected in any patient. CONCLUSIONS: A single dose of 20 U/kg C1-INH concentrate is safe and provides reliable efficacy in the long-term treatment of successive HAE attacks at any body location.

Glucocorticosteroids inhibit leukotriene production.

BACKGROUND: The mode of action of corticosteroids, important drugs in the treatment of inflammatory disease, is not yet fully understood. Corticosteroids are known to inhibit phospholipase A2 in unprimed eosinophils and basophils, preventing leukotriene synthesis, but their effect on cells that are already primed is unknown. OBJECTIVE: As inflammatory cells from atopic subjects are often primed in vivo, we studied the effects of two potent corticosteroids on basophil sulfidoleukotriene production in peripheral blood mixed leukocytes (PBML) from in-season and out-of-season atopic individuals. METHODS: Cells were incubated for 24 hours with mometasone furoate or beclomethasone dipropionate, primed with IL-3, stimulated with calcium ionophore, buffer, allergen or anti-IgE, and leukotriene production was quantified. RESULTS: Peripheral blood mononuclear leukocytes from five of ten donors (in season) produced elevated sulfidoleukotrienes without a stimulus; cells from seven donors responded to anti-IgE by increased sulfidoleukotrienes. Neither steroid consistently affected sulfidoleukotriene production in anti-IgE-stimulated cells which were releasing sulfidoleukotrienes in the absence of a stimulant. In comparison, sulfidoleukotriene production was significantly reduced by 0.01 to 10 nM beclomethasone dipropionate or mometasone furoate when the cells were primed with IL-3 after exposure to the drug and stimulated with calcium ionophore or allergen, but no dose-relationship was apparent. Leukotriene production by PBML in response to anti-IgE was potently inhibited by all concentrations of mometasone furoate (0.01 nM to 1 microM) with an inhibitory concentration50 of less than 0.01 nM. Beclomethasone dipropionate inhibited sulfidoleukotriene production in this group (inhibitory concentration50 6 nM) in a dose-dependent manner. CONCLUSIONS: Sulfidoleukotriene production and, conceivably, priming may be more effectively inhibited by mometasone furoate than beclomethasone dipropionate.

The usefulness of questionnaire-derived information to predict the degree of nonspecific bronchial hyperresponsiveness.

Nonspecific bronchial hyperresponsiveness (BHR) is a hallmark of clinical asthma, but can be present in nonasthmatics as well. The diagnosis of asthma is based on clinical grounds, and no laboratory procedure can definitely establish its presence. This poses a problem in studies of asthma. If epidemiological studies are to provide valid information, the tools used must have a relative degree of predictive or diagnostic ability. This report determined whether the American Thoracic Society-Division of Lung Disease (ATS-DLD) respiratory questionnaire has the ability to predict different degrees of non-specific BHR. In the years 1983-1990, when the ATS-DLD questionnaire was used in our Natural History of Asthma study, 192 subjects completed the ATS-DLD questionnaire and underwent a standardized methacholine challenge. A recursive partitioning analysis of the ATS-DLD questionnaire was able to predict which questions would likely be answered if the subject had nonspecific bronchial reactivity to inhaled methacholine of 100 and 200 breath units. Positive responses for questions concerning treatment for asthma, wheezing, or shortness of breath, and emergency treatment for asthma predicted the presence of increased bronchial reactivity.

Eosinophil accumulation and activation in antigen-induced late asthmatic response in guinea pigs.

The purpose of this study was to investigate the participation of airway eosinophils in the antigen-induced late asthmatic response (LAR) and increased airway responsiveness in the guinea pig model of asthma. After antigen challenge, guinea pigs sensitized with aerosolized ovalbumin showed a late-phase decrease in specific airway conductance, which was accompanied by airway hyperresponsiveness to histamine, eosinophilia in the bronchoalveolar lavage fluid (BALF), decreased BALF eosinophil density, and increased generation of superoxide anions from purified BALF eosinophils. We demonstrated an association of the LAR with eosinophil accumulation and activation in the airway.

The effect of RP 59227, a platelet-activating factor antagonist, against antigen challenge and eosinophil and neutrophil chemotaxis in asthmatics.

STUDY OBJECTIVES: Platelet-activating factor (PAF), an inflammatory mediator, induces microvascular leak, eosinophil chemotaxis, and possibly increases non-specific bronchial hyperresponsiveness in humans. PAF antagonists may have clinical benefits in asthma. DESIGN: We determined the safety and efficacy of a 240 mg oral dose of RP-59227 in attenuating the early and late phase antigen challenge in eight asthmatics, using a double-blind, placebo-controlled, crossover design. Also determined was the effect of the ex vivo addition of PAF following placebo or drug and the level of neutrophil (NCA) and eosinophil chemotactic activity (ECA) in the serum immediately, and 4 h after antigen challenge with either drug or placebo. RESULTS: There was not a significant difference in the maximum percent fall in FEV1 during the early and late phase on screening or placebo days or drug RP-59227 days. There was a significant inhibitory effect (p < 0.05) in peak ECA and NCA in blood after RP-59227. The addition of PAF to ex vivo serum was less effective in inducing chemotaxis to eosinophils following RP-59227 (p < 0.05). CONCLUSIONS: RP-59227 attenuated the release of NCA and ECA after antigen challenge, and reduced the effect of exogenously added PAF in inducing eosinophil chemotaxis but did not protect against the antigen-induced early or late phase response.

Longitudinal measurement of airway hyperresponsiveness in selected subjects with persisting pulmonary symptoms.

The relationship between airway hyperresponsiveness and pulmonary symptoms was examined longitudinally in 52 subjects. Subjects were part of a larger study, the Natural History of Asthma, and had repeated measures of airway hyperresponsiveness using methacholine. Atopy was determined using skin tests and serum IgE levels. The subjects completed a standardized respiratory questionnaire. Each subject reported respiratory and pulmonary symptoms at either their initial or follow-up visit. The subjects did not, however, have a physician-confirmed diagnosis of asthma. Subjects were divided into groups according to the current status of their respiratory symptoms. The four groups included subjects who were initially normal but developed respiratory symptoms at follow-up; subjects who had symptoms at all visits; subjects with respiratory symptoms at their initial visit but who had no symptoms at follow-up; and subjects who had respiratory symptoms prior to their initial visit and who did not have a recurrence during follow-up. There was no statistical difference in airway hyperresponsiveness, IgE, or skin test scores at the initial visits. Subjects who had airway responsiveness were significantly more atopic than subjects who did not have airway responsiveness. Subjects were classified as "consistently positive," "variable," or "consistently negative" responders according to the pattern of methacholine-induced airway hyperresponsiveness. Overall, among the four groups, 33% were consistently positive at all visits, 43% were variable, and 22% were consistently negative. Airway hyperresponsiveness was statistically associated with atopy, but not necessarily associated with questionnaire-based respiratory symptomatology. These factors need to be considered in epidemiological studies of asthma utilizing respiratory questionnaires.

Effect of cetirizine on human eosinophil superoxide generation, eosinophil chemotaxis and eosinophil peroxidase in vitro.

Cetirizine, a potent H1-antagonist, has been reported to inhibit eosinophil migration into human skin. We, therefore, further evaluated the effect of cetirizine on eosinophil function, including superoxide anion generation, chemotaxis, and eosinophil peroxidase (EP) release. In allergic subjects, superoxide anion generation 60 min after platelet-activating factor (PAF) activation was inhibited by concentrations of cetirizine ranging from 0.01 to 1 microgram/ml (2.612 x 10(-8) to 2.612 x 10(-6) M). No significant inhibition was observed in normal subjects. PAF (10(-6) M)-induced eosinophil chemotaxis was also inhibited by cetirizine. In allergic subjects, percent inhibitions were 47.5 +/- 6.1% at 0.01 microgram/ml, 50.8 +/- 5.1% at 0.1 microgram/ml and 58.9 +/- 6.4% at 1 microgram/ml of cetirizine. In allergic subjects, N-formyl-methionyl-lencyl-phenylalanine induced eosinophil chemotaxis was inhibited by cetirizine, although EP release was not. These results suggest cetirizine has effects on eosinophils which can not be explained by H1-blockade alone.

Effect of loratadine on human eosinophil function in vitro.

We investigated the in vitro effect of loratadine, a new nonsedating H1 histamine antagonist, on the eosinophil functions of chemotaxis, superoxide anion (O2-) generation and eosinophil cationic protein (ECP) release, using purified eosinophils obtained from allergic patients. Loratadine significantly attenuated platelet-activating factor (PAF)-induced eosinophil chemotaxis and O2- generation at therapeutic concentrations (equivalent to serum concentrations after single oral administration of 20 mg or 40 mg). Loratadine, however, had no effect on PAF-induced ECP release. These findings suggest that loratadine has a direct inhibitory effect on eosinophil activation and may be beneficial in the therapy of allergic disorders with its anti-allergic properties.

Density change of neutrophils from allergic subjects by granulocyte-macrophage colony stimulating factor.

We investigated neutrophil density change by platelet activating factor or granulocyte-macrophage colony-stimulating factor (GM-CSF). Although PAF significantly converted neutrophil density, there was no significant difference in density change between allergic subjects and normal subjects by platelet activating factor. Neutrophils from allergic subjects, however, were significantly converted by GM-CSF when compared with neutrophils from normals (P < .05). We conclude that neutrophils from allergic subjects are more sensitive to density change by GM-CSF than neutrophils from normal subjects. This might be due to preactivation or priming by biologic agents.

Importance of interleukin-3 on histamine release from human basophils.

We investigated the effects of interleukin-3 (IL-3) on histamine release (direct releasing and indirect enhancing effects) from basophils in allergic asthmatic subjects. Interleukin-3 caused direct histamine release (HR) in selected donors (IL-3 responders) and enhanced anti-IgE-induced HR in other IL-3 nonresponders, although both direct releasing and indirect enhancing activities of IL-3 on HR did not coexist with each other. There was a significant correlation between IL-3-induced HR and spontaneous histamine release (r = .8532, P < .0001).

Effect of formoterol on superoxide anion generation from bronchoalveolar lavage cells after antigen challenge in guinea pigs.

It is well known that antigen challenge of sensitized subjects can induce an immediate and late asthmatic response, airway eosinophilia, and hyperreactivity. Using our modified guinea pig asthma model, we investigated the superoxide anion generation from eosinophils and macrophages recovered from bronchoalveolar lavage (BAL) 24 h after antigen (ovalbumin) challenge. We also investigated the effect of formoterol, a new long-acting selective beta 2-agonist, on these functions. Antigen challenge increased the total cell counts and the ratio of eosinophils in BAL. Eosinophils and macrophages were collected using discontinuous density centrifugation. Antigen challenge enhanced superoxide anion generation from eosinophils, from 5.39 +/- 1.08 to 13.19 +/- 1.95 nmol 60 min after phorbol myristate acetate (PMA) (1 ng/ml) activation, and 0.22 +/- 0.49 to 3.34 +/- 1.67 nmol 40 min after platelet-activating factor (PAF) (10(-6) M) activation. Formoterol treatment before antigen challenge prevented these enhancements. Superoxide anion generation from macrophages was also enhanced by antigen challenge, from 6.57 +/- 0.76 to 10.66 +/- 0.88 nmol 60 min after PMA activation, and 4.20 +/- 1.17 to 6.63 +/- 0.64 nmol 60 min after PAF activation. Formoterol, however, failed to inhibit enhancement of superoxide anion generation from macrophages. These results show antigen challenge of sensitized guinea pigs induces an increase of eosinophils and macrophages in BAL and enhances the functional characteristics of both cells. Formoterol had inhibitory effects on the enhancement of superoxide anion generation from eosinophils but did not have this effect on macrophages.

Effect of inhaled amiloride on the bronchial response to methacholine and cold air hyperventilation challenges.

Inhaled amiloride has been recently demonstrated to have an effect on the decline of pulmonary function in patients with cystic fibrosis. Other diuretics have been demonstrated to provide protection against bronchoconstriction in asthmatic subjects. We report on the effect of inhaled amiloride on cold air hyperventilation challenge (CAHC) and methacholine challenge in asthmatics. We studied nine subjects with mild-moderate asthma in a double-blind, placebo-controlled, crossover study. Our results showed amiloride did not significantly protect against the bronchoconstriction induced by CAHC. Inhaled amiloride did not affect FEV1 in the hour after inhalation, and there was no significant difference between placebo or amiloride on the dose of methacholine causing a 20 percent fall in FEV1. Inhaled amiloride appears not to have a profile of action as previously seen with inhaled furosemide.

Inhibitory effects of formoterol on platelet-activating factor induced eosinophil chemotaxis and degranulation.

A new long-acting beta 2-agonist, formoterol, has been reported to have a greater efficacy and duration of action in asthmatic patients as compared to conventional beta 2-agonists. We recently demonstrated that formoterol inhibited antigen-induced late asthmatic response (LAR) and accompanying airway eosinophilia in guinea pigs. In this study, we investigated the direct effect of formoterol in vitro on human eosinophil function, focusing on platelet-activating factor (PAF)-induced eosinophil chemotaxis and eosinophil cationic protein (ECP) release. Purified normodense eosinophils were separated by discontinuous gradient from 12 mild asthmatic patients. Formoterol in concentrations of 1-100 microM significantly inhibited PAF-induced eosinophil chemotaxis in a dose-dependent manner with a concentration of drug required to produce 50% inhibition (IC50) of 10.16 microM; % inhibition: 22.9 +/- 13.0% (1 microM), 51.6 +/- 12.7% (10 microM), 75.0 +/- 11.3% (100 microM). When formyl-methionyl-leucyl-phenylamine (FMLP) was used as a chemoattractant, a similar inhibition of eosinophil chemotaxis by formoterol was observed; % inhibition: 13.1 +/- 5.0% (1 microM). 47.7 +/- 7.6% (10 microM), 65.5 +/- 16.5% (100 microM). A conventional beta 2-agonist, salbutamol, at doses to 100 microM did not show any inhibitory effects on PAF-induced eosinophil chemotaxis. Formoterol in concentrations of 1-100 microM also significantly inhibited PAF-induced ECP release from eosinophils; % inhibition: 21.7 +/- 9.0% (1 microM), 39.3 +/- 7.4% (10 microM), 39.6 +/- 8.4% (100 microM). In the presence of phosphodiesterase inhibitors, theophylline or isobutylmethyl xanthine (IBMX), the inhibition by formoterol on PAF-induced ECP release was enhanced.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of WEB 2086 on PAF-induced eosinophil chemotaxis and LTC4 production from eosinophils.

We investigated the effect of WEB 2086, a selective platelet-activating factor (PAF) receptor antagonist, on PAF-induced eosinophil chemotaxis and LTC4 production. WEB 2086 inhibited PAF-induced eosinophil chemotaxis in normals and asthmatics. To further determine if WEB 2086 is a selective PAF receptor antagonist, we examined the effect of WEB 2086 against formyl-methionyl-leucyl-phenylalanine (fMLP)-induced or eosinophil chemotactic factor of anaphylaxis (ECF-A)-induced eosinophil chemotaxis. WEB 2086 did not have a significant inhibition against fMLP or ECF-A-induced eosinophil chemotaxis. These results suggest that WEB 2086 is a selective and potent inhibitor of PAF-induced eosinophil chemotaxis and LTC4 production from eosinophils, due to its antagonism of PAF-receptors.

The effect of formoterol on the late asthmatic phenomena in guinea pigs.

We investigated the effects of formoterol, a new, long-acting, selective beta 2-adrenoceptor agonist, on the antigen-induced late asthmatic response (LAR) and airway inflammation in guinea pigs. Animals were sensitized by exposure to aerosolized ovalbumin (2% in saline). After antigen challenge, preceded by administration of an H1-receptor antagonist, specific airway conductance was measured with a two-chambered whole-body plethysmograph. An aerosolized solution of formoterol, isoproterenol, or saline was inhaled 15 minutes before challenge. Bronchoalveolar lavage (BAL) was performed 24 hours after challenge. The provocative concentrations of histamine required to decrease specific airway conductance by 50% were obtained before challenge, at 24 hours, and at 72 hours after challenge. The LAR (52.7% +/- 7.7% of the baseline; p less than 0.02) was observed 6 to 8 hours after antigen challenge. An increased cellular influx in BAL (mainly eosinophils and macrophages) and an increased bronchial responsiveness to histamine occurred 24 hours after antigen challenge. Formoterol completely inhibited the LAR and the cellular increase in BAL; however, isoproterenol failed to prevent either the cellular infiltration or the LAR. Formoterol also decreased the antigen-induced increase in bronchial reactivity. These findings suggest that formoterol has inhibitory effects on the underlying inflammatory processes in antigen-induced asthma in addition to prolonged bronchodilation.

Longitudinal changes in bronchial hyperresponsiveness in asthmatic and previously asthmatic children.

To determine if nonspecific bronchial hyperresponsiveness is present to the same degree in previously asthmatic children compared with currently asthmatic children, a longitudinal study was conducted. On the basis of a standardized respiratory questionnaire, 139 children from asthmatic families, between the ages of 6 and 21 years, were identified. Subjects had skin tests, a serum IgE level, and a methacholine challenge test. IgE and skin tests demonstrated atopy in both the previously and currently asthmatic children, which persisted over time. Bronchial hyperresponsiveness within the asthmatic children was not significantly different between visits. Previously asthmatic children did have significantly decreased airway hyperresponsiveness over time. Age did not affect the results of the bronchial hyperresponsiveness in the currently asthmatic children. Currently asthmatic children, however, were significantly more atopic when compared with previously asthmatic children at their initial evaluation. Currently asthmatic children were also more bronchial responsive and remained so over time. Bronchial hyperresponsiveness is persistent in children with current asthma symptoms.

Probability of asthma based on methacholine challenge.

Methacholine inhalation challenge has become an accepted test to determine the presence of airway hyperresponsiveness, a hallmark of asthma. To help physicians interpret the results of a methacholine challenge test in a clinical setting, we analyzed the test data of 1,105 subjects, asthmatics and nonasthmatics. Applying Bayes' theorem, a nomogram was constructed incorporating the prechallenge clinical diagnosis with the response to methacholine to give a posttest probability of the diagnosis of asthma. The resulting curves represent different levels of cumulative breath units at which a methacholine challenge can be considered positive. The results of a methacholine challenge test, in association with a physician's clinical assessment, can be a valuable tool in the diagnosis of asthma in those patients with an atypical history and/or physical examination.

The effect of a selective alpha 2-adrenergic receptor antagonist (midaglizole) on the cyclic 3',5'-adenosine monophosphate production in human mononuclear cells.

A selective alpha 2-adrenergic antagonist, midaglizole, has been recently reported to have efficacy in patients with asthma. To understand the mechanisms, we investigated the effect of midaglizole on the cyclic 3', 5'-adenosine monophosphate (cAMP) production in human mononuclear cells (MNCs). MNCs were separated by a histopaque gradient from 10 normal subjects and 10 subjects with asthma. cAMP was measured by RIA kits. Midaglizole (10 mumol/L) significantly enhanced isoproterenol-induced cAMP production in both groups, although midaglizole (from 1 to 100 mumol/L) did not increase the cAMP production by itself. The percent increase in cAMP was more in subjects with asthma (183.8%) than in normal subjects (140.4%); however, the absolute increase was not different. Platelet-activating factor has been demonstrated to inhibit beta-agonist-induced cAMP production in several mammalian tissues, including human MNCs. Midaglizole also prevented platelet-activating factor-induced desensitization of the cAMP response to isoproterenol in MNCs. These findings suggest that midaglizole may be a useful additional agent for the therapy of bronchial asthma through an enhancement of the cAMP production.

Effect of terfenadine on neutrophil and eosinophil chemotactic activities after inhalation of platelet-activating factor in vivo and on neutrophil chemotaxis in vitro.

In this double-blind crossover study we evaluated the effect of terfenadine on the rise in neutrophil chemotactic activity (NCA) and eosinophil chemotactic activity (ECA) in serum induced by platelet-activating factor (PAF) inhalation in 8 asthmatics. Additionally, we examined the direct effect of terfenadine on neutrophil chemotaxis in vitro in 7 allergic subjects. NCA and ECA in serum after PAF inhalation and neutrophil chemotaxis were measured using a modified Boyden chamber method. An initial elevation of NCA after PAF inhalation was inhibited by terfenadine, but the effect was diminished after subsequent PAF inhalations. Terfenadine showed no effect on ECA. In vitro PAF- and fMLP-induced neutrophil chemotaxis were significantly inhibited by terfenadine. These results suggest that terfenadine may have antiallergic properties in addition to its H1 receptor blockade.

Long-term cultured mouse mast cells: ultrastructure, histamine and leukotriene levels.

Interleukin 3 (IL3), dependent cells were obtained from bone marrow (9/10 experiments) and spleen cells (4/5 experiments), but not from the thymus. These cells were similar to mucosal mast cell toluidine blue staining and electron microscopy. They had heterogenous metachromatic granules, and some had large scroll-like structures. They also contained histamine (200-800 ng/10(6) cells) for the first 2-5 weeks, whose level diminished to less than 30 ng/10(6) cells by 10 weeks of culture. They also generated leukotriene (LT) C4/D4 (10-40 ng/10(6) cells) and LTB4 (2-5 ng/10(6) cells) for over 100 days of culture. In one experiment, bone marrow-derived mast cells after 150 days of culture began to produce an IL3-like substance and proliferated exponentially without exogenous IL3.