Effects of pranlukast on aspirin-induced bronchoconstriction: differences in chemical mediators between aspirin-intolerant and tolerant asthmatic patients.

BACKGROUND: Aspirin inhibits cyclooxygenase activity and modifies production of the arachidonate cascade in aspirin-induced asthma. The aim of the present study was to examine the effects of leukotriene (LT) receptor antagonist on aspirin challenge on eosinophil activity and chemical mediators released into the airway of asthmatic patients. METHODS: Aspirin oral provocation test was performed in aspirin-intolerant asthmatic patients (AIA; N = 7) and aspirin-tolerant asthmatic patients (ATA; N = 7). In AIA, LT receptor antagonist (pranlukast) was administered orally 2 hours before the test, and its inhibitory effects on sputum LTC4+C4, eosinophil cationic protein (ECP), eosinophil count, urinary LTE4/creatinine (Cr), 11-dehydrothromboxane (11-dhTX) B2/Cr, serum LTC4+D4, ECP, and peripheral blood eosinophil count were compared with the findings in ATA subjects. RESULTS: In AIA, aspirin induced an immediate reaction associated with increased urinary LTE4/Cr and sputum ECP and a fall in urinary 11-dhTXB2/Cr. Pranlukast inhibited the bronchial reaction and an increase in sputum ECP after threshold dosed of ASA, but failed to change aspirin-induced LT production in sputum and urine. In ATA, aspirin challenge was only associated with a fall in urinary 11-dhTXB2. CONCLUSIONS: Our results indicated that aspirin-induced asthma is associated with overproduction of LT with a shift to the 5-lipoxygenase series of the arachidonate cascade and that leukotriene receptor antagonist are useful for AIA through inhibition of production of LT and eosinophilic inflammation in the airway.     

Failure of tacrolimus to prevent aspirin-induced respiratory reactions in patients with aspirin-exacerbated respiratory disease

BACKGROUND: In patients with aspirin-exacerbated respiratory disease (AERD), pretreatment with asthma controller medications (leukotriene modifiers, inhaled or systemic corticosteroids, and salmeterol) partially modifies the severity of aspirin-induced asthmatic reactions. OBJECTIVE: A recent study showed that pretreatment with tacrolimus completely prevented aspirin-induced respiratory reactions and might allow silent aspirin desensitization. METHODS: Ten patients with rhinosinusitis, nasal polyps, and asthma had a history of asthma attacks after ingesting aspirin and nonsteroidal anti-inflammatory drugs. All underwent baseline oral aspirin challenges and had typical respiratory reactions. They were then randomized to receive tacrolimus (0.1 mg/kg weight; 8 patients) or placebo (2 patients) in a double-blind protocol before rechallenge with aspirin using the previous provoking dose of aspirin. In addition, respiratory reactions sustained by 50 consecutive patients with AERD during 2004 were recorded, analyzed, and compared with the tacrolimus/placebo-treated patients to determine whether there were any differences. RESULTS: Tacrolimus pretreatment failed to block respiratory reactions to provoking doses of aspirin in 5 of 8 patients with AERD, and in the other 3 patients did not block higher doses of aspirin. The results of oral aspirin challenges in the control population of 50 patients were compared with either the baseline or postchallenge data from the tacrolimus-pretreated or placebo-pretreated patients with AERD, and there were no significant differences. CONCLUSIONS: Use of tacrolimus as add-on pretreatment to prevent reactions to aspirin in patients with AERD or to achieve the goal of silent aspirin desensitization could not be accomplished.     

Anti-inflammatory effect of roxithromycin in patients with aspirin-intolerant asthma

BACKGROUND: Fourteen-membered macrolides, such as roxithromycin, have been reported to exhibit other pharmacological activity including anti-asthmatic effects, besides antibiotic activity. OBJECTIVE: This study was designed to investigate the protective effect of roxithromycin on airway responsiveness to the sulpyrine provocation test and to investigate whether this protective activity is associated with a reduction in aspirin-induced excretion of urinary leucotriene E4 (u-LTE4), a marker of cysteinyl leucotriene overproduction that participates in the pathogenesis of aspirin-intolerant asthma. Also, the present study was designed to examine whether or not its anti-asthmatic activity was associated with a reduction in eosinophilic inflammation. METHODS: For 8 weeks before analysis, subjects received 150 mg of roxithromycin or matching placebo twice daily. We assessed the effects of pretreatment with roxithromycin on bronchoconstriction precipitated by inhalation of sulpyrine in 14 adult patients with mild or moderate aspirin-intolerant asthma; those who were in stable clinical condition and were hyperresponsive to sulpyrine provocation test were allocated to this study. A double-blind, randomized, crossover design was used. Urinary LTE4 was measured by a combined reverse-phase high-performance liquid chromatography (rp-HPLC) enzyme immunoassay on sulpyrine provocation testing day. Blood and sputum samples were taken in the morning on the sulpyrine provocation testing day. Eosinophil counting and measurement of eosinophilic cationic protein (ECP) were performed. RESULTS: After the 8 weeks of treatment with roxithromycin, patients' symptoms, blood eosinophils, serum ECP, sputum eosinophils, and sputum ECP were significantly decreased. On the other hand, values of PC20-sulpyrine did not improve after roxithromycin at all. Furthermore, although challenge with sulpyrine caused a significant increase in u-LTE4, pretreatment with roxithromycin or placebo did not affect excretion of u-LTE4. CONCLUSION: Although roxithromycin does not have antileucotriene effects, it has an antibronchial inflammatory effect associated with eosinophilic infiltration. This study raises further interesting therapeutic possibilities and warrants further trials of new approaches to the treatment of aspirin-intolerant asthma.     

Safety of a specific COX-2 inhibitor in aspirin-induced asthma

In a subset of patients with asthma, aspirin and several other non-steroidal anti-inflammatory drugs (NSAID) that inhibit simultaneously cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) precipitate dangerous asthmatic attacks. We tested the hypothesis that in patients with aspirin-induced asthma the attacks are triggered by inhibition of COX-1 and not COX-2. In twelve asthmatic patients (seven men, five women, average age 39 years) oral aspirin challenge precipitated symptoms of bronchial obstruction with fall in FEV1 > 20%, and a rise in urinary leukotriene E4 (LTE4) excretion; also in five patients the stable metabolite of PGD2, 9alpha11betaPGF2, increased in urine. The patients then entered a double-blind, placebo-controlled, cross-over study in which they received either placebo or rofecoxib in increasing doses 1.5-25.0 mg for 5 consecutive days, separated by a 1-week wash-out period. No patient on rofecoxib developed dyspnoea or fall in FEV1 > 20%; mean urinary LTE4 and 9alpha11betaPGF2 urinary levels, measured on each study day for 6 h post-dosing, remained unchanged. Two patients on placebo experienced moderate dyspnoea without alterations in urinary metabolites excretion. At least 2 weeks after completion of the study, all patients received on an open basis 25 mg rofecoxib without any adverse effects. NSAID that inhibit COX-1, but not COX-2, trigger asthmatic attacks in patients with asthma and aspirin intolerance. Rofecoxib can be administered to patients with aspirin-induced asthma.     

Effect of pranlukast on bronchial inflammation in patients with asthma

BACKGROUND: Pranlukast (8-[p-(4-phenylbutyloxy) benzol] amino-2-[tetrazol-5-yl]-4-oxo-4H-1-benzopyran hemihydrate), a selective cysteinyl leukotriene receptor antagonist, has been reported to exhibit not only antileukotrine activity but also pharmacological activity including antieosinophilic effects. OBJECTIVE: This study was designed to investigate whether the antiasthmatic activity of pranlukast is associated with a reduction in eosinophilic inflammation. METHODS: A double-blind, randomized, crossover design was used. Subjects received 225 mg of pranlukast or placebo orally twice daily for 4 weeks and then, after a washout period of at least 4 weeks, crossed over to receive the alternative treatment. We assessed the effects of pretreatment with pranlukast on bronchoconstriction precipitated by inhalation of methacholine in 32 adult patients with mild or moderate bronchial asthma; those who were in stable clinical condition were allocated to this study. Blood and sputum samples were taken the morning of the methacholine provocation test. Eosinophil counts and measurement of eosinophilic cationic protein (ECP) were performed. RESULTS: After the 4 weeks of treatment with pranlukast, patients' symptoms, blood eosinophils, serum ECP, sputum eosinophils, and sputum ECP were significantly decreased. Furthermore, values of PC20-methacholine significantly improved in the treatment with pranlukast. CONCLUSION: Our results suggest that pranlukast has an anti-inflammatory effect on bronchial eosinophilic infiltration. This study raises further interesting therapeutic possibilities and argues for further trials of new approaches to the treatment of bronchial asthma.     

Efficacy of leukotriene receptor antagonist in bronchial hyperresponsiveness and hypersensitivity to analgesic in aspirin-intolerant asthma

BACKGROUND: Albeit its exact pathogenesis is still ambiguous; aspirin-intolerant asthma is one of several types of asthma for which antileukotriene therapy is useful, because it is widely accepted that bronchial over-production of leukotrienes may be involved in its pathogenesis. Pranlukast (8-[p-(4-phenylbutyloxy) benzol] amino-2-(tetrazol-5-yl)-4-oxo-4H-1-benzopyran hemihydrate), a selective cysteinyl leukotriene receptor antagonist, is now widely used in the treatment of asthma. OBJECTIVE: This study was designed to investigate the protective effect of pranlukast on airway sensitivity to sulpyrine provocation testing, bronchial responsiveness to methacholine provocation testing, and to investigate whether this protective activity is associated with a reduction in aspirin-induced excretion of urinary LTE4 (uLTE4), a marker of the cysteinyl leukotriene (LT) overproduction that participates in the pathogenesis of aspirin-induced asthma. METHODS: We assessed the effects of pretreatment with pranlukast on bronchoconstriction precipitated by inhalation of methacholine and sulpyrine in 16 adult patients with mild or moderate aspirin-intolerant asthma; those who were in stable clinical condition and were hypersensitive to sulpyrine provocation testing were allocated to this study. A double-blind, randomized, crossover design was used. uLTE4 was measured using combined reverse-phase high-performance liquid chromatography (rp-HPLC)/enzyme immunoassay. RESULTS: Pranlukast protected against analgesic-induced bronchoconstriction through mechanisms that were not related to the bronchodilator property, but were related to the improvement both of bronchial hyperresponsiveness and hypersensitivity to analgesic (P < 0.005 and P < 0.0001). Pranlukast showed little effect on excretion of uLTE4. CONCLUSION: These results support the hypothesis that cysteinyl leukotriene is one of the most important components in the pathogenesis of aspirin-intolerant asthma. Pranlukast improves not only hypersensitivity to analgesic, but also bronchial hyperresponsiveness in aspirin-intolerant asthma. It is also possible that pranlukast has another anti-asthmatic effect besides that of a leukotriene receptor antagonist.     

Exhaled eicosanoids following oral aspirin challenge in asthmatic patients

BACKGROUND: Biochemical analysis of expiratory breath condensate is an emerging non-invasive technique for assessment of airway inflammation. OBJECTIVE: We wondered whether application of expiratory breath condensate could facilitate diagnosis of aspirin-intolerant asthma and reproduce eicosanoids mediators' abnormalities described in this disease. METHODS: We measured prostaglandins (PGs) E(2), F(2 alpha), 9 alpha 11 beta F(2) and iso-F(2) by gas-chromatography/mass-spectrometry and cysteinyl leukotrienes (cys-LTs) by radioimmunoassay in breath condensates of asthmatic patients undergoing oral aspirin challenge. Fourteen patients with aspirin-induced asthma and 20 aspirin-tolerating asthmatics, most of them on chronic inhaled corticotherapy, were studied and compared with 10 healthy subjects. Additionally, plasma 9 alpha 11 beta PGF(2), the metabolite of PGD(2) and urinary leukotriene (LT) E(4) were measured before and following the challenge. RESULTS: At baseline, PG did not differ between the groups, except for lower 9 alpha 11 beta PGF(2) in aspirin-intolerant asthma. Their concentrations were not changed by the challenge. Breath condensate cys-LTs were similar in the groups studied at base, and after aspirin challenge increased only in aspirin-intolerant patients. Elevated baseline urinary LTE(4) and its further increase following aspirin challenge was highly diagnostic for aspirin-intolerant asthma. The discriminatory value of cys-LTs increase in breath condensates was lower (72.8%) than either basal (99%) or post-challenge increase (94%) of urinary LTE(4). CONCLUSIONS: In asthmatic patients on chronic corticotherapy measurement of urinary LTE(4) excretion rather than cys-LTs in breath condensate is of greater value for diagnosis of aspirin hypersensitivity.     

Possible involvement of mast-cell activation in aspirin provocation of aspirin-induced asthma

BACKGROUND: Although there is increasing evidence of the importance of cysteinyl leukotrienes (LT) as mediators of aspirin-induced bronchoconstriction in aspirin-sensitive asthma, the cellular origin of the LT is not yet clear. METHODS: Urinary concentrations of leukotriene E4 (LTE4), 11-dehydrothromboxane B2, 9alpha,11beta-prostaglandin F2, and Ntau-methylhistamine were measured during the 24 h following cumulative intravenous administration of increasing doses of lysine aspirin to asthmatic patients. In addition, the urinary concentrations of these metabolites were measured on 5 consecutive days in a patient who suffered an asthma attack after percutaneous administration of nonsteroidal anti-inflammatory drugs. RESULTS: In aspirin-induced asthma patients (AIA, n=10), the basal concentration of urinary LTE4, but not the other metabolites, was significantly higher than that in aspirin-tolerant asthma patients (ATA, n=10). After intravenous aspirin provocation, the AIA group showed a 13.1-fold (geometric mean) increase in excretion of LTE4 during the first 3 h, and 9alpha,11beta-prostaglandin F2 also increased in the AIA group during the first 0-3 h and the 3-6 h collection period. Ntau-methylhistamine excretion was also increased, but to a lesser degree. Administration of aspirin caused significant suppression of 11-dehydrothromboxane B2 excretion in both the AIA and ATA groups. When the percentage of maximum increase of each metabolite from the baseline concentrations was compared between the AIA group and the ATA group, a significantly higher increase in excretion of LTE4, 9alpha,11beta-prostaglandin F2, and Ntau-methylhistamine was observed in the AIA group than the ATA group. An increased excretion of LTE4 and 9alpha,11beta-prostaglandin F2 has been detected in a patient who suffered an asthma attack after percutaneous administration of nonsteroidal anti-inflammatory drugs. CONCLUSIONS: Considering that human lung mast cells are capable of producing LTC4, prostaglandin D2, and histamine, our present results support the concept that mast cells, at least, may participate in the development of aspirin-induced asthma.     

Cromolyn sodium suppresses eosinophilic inflammation in patients with aspirin-intolerant asthma.

BACKGROUND: Although administration of cromolyn sodium is one of the most useful drugs for the treatment of aspirin-intolerant asthma (AIA), both its pharmacologic mechanism of action and association with the pathogenesis remain obscure. OBJECTIVE: This study was designed to investigate the protective effect of cromolyn sodium on airway responsiveness to the sulpyrine provocation test, and to examine whether its activity is associated with a reduction in eosinophilic inflammation. METHODS: Patients were randomly assigned to receive cromolyn sodium (20 mg/2 mL, or 1 ampoule; Fujisawa, Osaka, Japan) or matching placebo (2 mL of saline) four times daily for 1 week. We evaluated the effects of pretreatment with cromolyn sodium on bronchoconstriction precipitated by inhalation of sulpyrine in 16 adult patients with mild or moderate AIA; those who were in stable clinical condition were allocated to this study. A double-blind, randomized, crossover design was used. Blood and sputum samples were taken in the morning on the sulpyrine provocation testing day. Eosinophil counting and measurement of eosinophilic cationic protein (ECP) were performed. RESULTS: Inhaled cromolyn sodium protect against aspirin-induced attacks of asthma through mechanisms not related to the bronchodilator property, but related to the improvement of the bronchial hypersensitivity, almost completely in all patients (P < 0.001). After 1 week's treatment with cromolyn sodium, patients' symptoms, blood and sputum eosinophils counts, and sputum ECP levels were significantly decreased compared with both placebo and baseline. CONCLUSIONS: Cromolyn sodium has a bronchial anti-inflammatory effect associated with decreased eosinophilic infiltration. This is the first report that cromolyn sodium reduces blood and sputum eosinophils counts and sputum ECP levels in AIA.     

Effect of low-dose ciclesonide on allergen-induced responses in subjects with mild allergic asthma

BACKGROUND: Inhalation of allergens by sensitized patients with asthma induces reversible airway obstruction, airway hyperresponsiveness, and eosinophilic airway inflammation. Attenuation of allergen-induced bronchoconstriction and inflammation has been used to examine the efficacy of therapeutic agents such as inhaled corticosteroids in asthma. Ciclesonide, a nonhalogenated inhaled corticosteroid being developed for the treatment of persistent asthma, remains inactive until cleaved by esterases in the lung. OBJECTIVE: This study examined the effect of low doses of inhaled ciclesonide, 40 microg and 80 microg, on allergen-induced bronchoconstriction, serum eosinophil cationic protein, and eosinophilic airway inflammation. METHODS: Twenty-one nonsmokers with mild atopic asthma completed a multicenter, randomized, 3-way crossover study comparing the effects of 7-day treatment of ciclesonide or placebo. Allergen-induced responses, including the early and late fall in FEV1, peripheral blood eosinophils, serum eosinophil cationic protein levels, and eosinophils in induced sputum were measured. RESULTS: Ciclesonide 80 microg attenuated the early and late asthmatic responses, including the change in FEV1, serum eosinophil cationic protein, and sputum eosinophils measured at 24 hours postchallenge (P < .025). Ciclesonide 40 microg attenuated the late asthmatic responses and sputum eosinophils measured at 24 hours postchallenge (P < .025), with no effect on the early allergen-induced bronchoconstriction, 24-hour FEV1, or serum eosinophil cationic protein levels (P < .025). CONCLUSION: With the exception of 24-hour postchallenge peripheral blood eosinophils, a low dose of ciclesonide, 80 microg, was effective in blocking all allergen-induced responses measured.     

Effect of acyclovir on bronchoconstriction and urinary leukotriene E4 excretion in aspirin-induced asthma

Background: Acyclovir (9-[2-hydroxyethoxymethyl] guanine), an inhibitor of the DNA polymerase of the herpes virus, has been reported to exhibit pharmacologic activity other than antiviral activity, including antiasthmatic effects. Objective: This study was designed to investigate the protective effect of acyclovir on airway responsiveness to the sulpyrine provocation test and to investigate whether this protective activity is associated with a reduction in aspirin-induced excretion of urinary leukotriene E₄ (u-LTE₄ ), a marker of cysteinyl leukotriene (LT) overproduction that participates in the pathogenesis of aspirin-induced asthma. Methods: We assessed the effects of pretreatment with acyclovir on bronchoconstriction precipitated by inhalation of sulpyrine in 16 adult patients with mild or moderate aspirin-induced asthma; those who were in stable clinical condition and were hyperresponsive to the sulpyrine provocation test were allocated to this study. A double-blind, randomized, cross-over design was used. u-LTE₄ was measured by a combined reverse-phase HPLC enzyme immunoassay. Results: Acyclovir protects against aspirin-induced attacks of asthma through mechanisms unrelated to its bronchodilator property but related to the improvement of bronchial hypersensitivity to sulpyrine; protection was nearly complete in all patients (P < .0001). By contrast, after acyclovir, the maximum level of u-LTE₄ in patients was significantly lower than that in control subjects (P < .01). Conclusion: Our results suggest that acyclovir is not only an antiviral drug but also an inhibitor of analgesic-induced bronchoconstriction, probably acting by inhibiting the release of cysteinyl LTs. (J Allergy Clin Immunol 1998;102:909-14.)     

Leukotriene C4 synthase promoter polymorphism in Japanese patients with aspirin-induced asthma

BACKGROUND: The A to C transversion in the promoter region of the gene encoding leukotriene C4 synthase (LTC4S) is proposed to be associated with the development of aspirin-induced asthma (AIA). OBJECTIVE: We investigated the frequency of the polymorphism in Japanese population and its association with clinical characteristics and cysteinyl leukotriene production. METHODS: Genotyping of LTC4S gene promoter was performed on 60 patients with AIA, 100 patients with aspirin-tolerant asthma (ATA), and 110 control subjects. We assessed the basal levels of urinary LTE4, the increment of urinary LTE4 on venous aspirin challenge, and LTC4S activity in peripheral blood eosinophils. RESULTS: The frequency of the variant C allele was significantly higher in patients with AIA (frequency of allele [q] = 0.192) than in patients with ATA (q = 0.110, P =.042). Variant C-allelic carriers experienced asthma at a significantly younger age (31.8 +/- 2.9 years [mean +/- SEM]) than wild-type A homozygotes (41.3 +/- 2.2 years, P =.007). Basal levels of LTE4 and the increment of urinary LTE4 on venous aspirin challenge did not show a difference between wild-type A homozygotes and variant C-allelic carriers. There was no relationship between the polymorphism and the LTC4S activity in eosinophils, although LTC4S activities were significantly higher in patients with AIA than in patients with ATA. CONCLUSION: Our findings reveal the lack of functionality of the polymorphism in the LTC4S gene, whereas this polymorphism might have some effect on the development of AIA, probably in linkage disequilibrium with another causatively important mutation.     

Aspirin-intolerant asthma: role of cyclo-oxygenase enzymes

Aspirin-induced asthma and rhinitis (AIAR) appear to be precipitated by the inhibition of cyclo-oxygenase (COX). By inhibiting COX pathway aspirin diverts arachidonic acid metabolites to the lipoxygenase pathway. There are two isoforms of COX, namely COX-1 and COX-2. Metabolites derived from COX-1 are involved in cellular housekeeping functions. COX-2 can be induced in cells exposed to proinflammatory substances and growth factors. Recent studies have reported that patients with AIAR have decreased activity of COX-2 and lower production of PGE₂ in the upper airway and peripheral blood cells. Considering the protective effect of exogenous PGE₂ on aspirin-induced bronchoconstriction and the interdependence of PGE₂ and cisteinyl leukotriene production, a reduced PGE₂ synthesis may render aspirin-sensitive patients more susceptible to the inhibitory effect of NSAIDs drugs and also lead to an increase in cysteinyl leukotriene release.     

Pathogenesis of nonsteroidal antiinflammatory drug-induced asthma

PURPOSE OF REVIEW: To summarize recent findings related to the pathogenic mechanisms of aspirin-induced asthma with emphasis on molecular genetic mechanisms. RECENT FINDINGS: The overproduction of cysteinyl leukotrienes with the increased expression of cysteinyl leukotriene receptor 1 (CYSLTR1) is a consistent finding in aspirin-induced asthma patients. Recent data have suggested a dysregulation of cyclooxygenase-2 and prostaglandin E2, increased levels of 15-hydroxyeicosatetranoic acid, and decreased lipoxin generation as characteristics of the condition. The HLA allele DPB10301 was documented as a strong genetic marker for susceptibility in an Asian population. Leukotriene C4 synthase has been established as a key genetic determinant of aspirin-induced asthma, but recent studies have demonstrated that several single nucleotide polymorphisms in the promoters of prostaglandin E2 receptor subtype 2, CYSLTR1 and CYSLTR2 and T-box expressed in T cells (TBX21) could increase risk for the condition. Although cyclooxygenase-2 and thromboxane A2 receptor polymorphisms were not associated with aspirin-induced asthma phenotype, they may exert functional effects. SUMMARY: The identification of genetic markers for aspirin-induced asthma susceptibility along with in-vitro functional studies would help to elucidate the pathogenesis of the condition. Further studies of the interactions among genes and between genes and the environment will be essential.     

Clarithromycin suppresses bronchial hyperresponsiveness associated with eosinophilic inflammation in patients with asthma.

BACKGROUND: Although long-term administration of 14-membered macrolide antibiotics is a therapeutic alternative in asthma, both its pharmacologic mechanism of action and association with the pathogenesis of asthma remain obscure. OBJECTIVE: This study investigated the suppressive effect of clarithromycin on airway responsiveness to methacholine provocation testing and examined whether chrarithromycin's antiasthmatic activity is associated with a reduction in eosinophilic inflammation. METHODS: For 8 weeks, patients received 200 mg of clarithromycin or identical-appearing placebo twice daily. We assessed the effects of treatment with clarithromycin on bronchoconstriction precipitated by inhalation of methacholine in 17 adults with mild or moderate bronchial asthma who were in stable clinical condition. A double-blind, randomized, crossover design was used. Eosinophil counts and eosinophilic cationic protein (ECP) levels were determined in blood and sputum samples obtained on the morning of the methacholine provocation testing day. RESULTS: After 8 weeks of treatment with clarithromycin, patients' symptoms, blood and sputum eosinophils counts and sputum ECP levels were significantly decreased compared with both placebo and baseline. Furthermore, values of PC20 methacholine improved in all patients after clarithromycin treatment. CONCLUSIONS: Clarithromycin has a bronchial anti-inflammatory effect associated with decreased eosinophilic infiltration. This study suggests interesting therapeutic possibilities for bronchial asthma that warrant further trials.     

Aspirin-induced asthma: advances in pathogenesis,diagnosis, and management

In some asthmatic individuals, aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) that inhibit cyclooxygen-ase 1 (COX-1) exacerbate the condition. This distinct clinical syndrome, called aspirin-induced asthma (AIA), is characterized by an eosinophilic rhinosinusitis, nasal polyposis, aspirin sensitivity, and asthma. There is no in vitro test for the disorder, and diagnosis can be established only by provocation challenges with aspirin or NSAIDs. Recent major advances in the molecular biology of eicosanoids, exemplified by the cloning of 2 cysteinyl leukotriene receptors and the discovery of a whole family of cyclooxygenase enzymes, offer new insights into mechanisms operating in AIA. The disease runs a protracted course even if COX-1 inhibitors are avoided, and the course is often severe, many patients requiring systemic corticosteroids to control their sinusitis and asthma. Aspirin and NSAIDs should be avoided, but highly specific COX-2 inhibitors, known as coxibs, are well tolerated and can be safely used. Aspirin desensitization, followed by daily aspirin treatment, is a valuable therapeutic option in most patients with AIA, particularly those with recurrent nasal polyposis or overdependence on systemic corticosteroids.     

Urinary 3-bromotyrosine and 3-chlorotyrosine concentrations in asthmatic patients: lack of increase in 3-bromotyrosine concentration in urine and plasma proteins in aspirin-induced asthma after intravenous aspirin challenge

BACKGROUND: Eosinophil peroxidase and myeloperoxidase halogenate tyrosine residues in plasma proteins and generate 3-bromotyrosine (BY) and 3-chlorotyrosine (CY), respectively. OBJECTIVES: (1) To estimate urinary concentrations of BY and CY in asthmatic patients. (2) To investigate BY concentration in relation to urinary leukotriene E4 (LTE4) concentration in order to evaluate the activation of eosinophils in patients with aspirin-induced asthma (AIA). METHODS: BY and CY were quantified with a gas chromatograph-mass spectrometer using (13)C-labelled compounds as internal standards. RESULTS: (1) Activation of eosinophils and neutrophils by immobilized IgG1 induced preferential formation of BY and CY, respectively. (2) A significantly higher concentration of BY was observed in the urine from asthmatic patients than in that from healthy control subjects (45+/-21.7 vs. 22.6+/-10.8 ng/mg-creatinine, P<0.01). CY concentration was also elevated in the urine from asthmatic patients (4.4+/-3.2 vs. 1.5+/-1.0 ng/mg-creatinine, P<0.01). (3) After intravenous aspirin challenge of aspirin-induced asthmatic patients, the concentration of BY in urine did not significantly change. No significant change was also observed in the ratio of BY concentration to total tyrosine concentration in plasma proteins. In contrast, the concentration of urinary LTE4 significantly increased after the intravenous aspirin challenge. CONCLUSION: Determination of BY and CY concentrations may be useful for monitoring the activation of eosinophils and neutrophils in asthmatic patients, respectively. After aspirin challenge of AIA patients, the increased concentration of urinary LTE4 did not accompany changes in BY concentration in both urine and plasma proteins. These results may preclude the activation of eosinophils after aspirin challenge in patients with AIA.     

Hypersensitivity to aspirin: common eicosanoid alterations in urticaria and asthma

BACKGROUND: Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) can precipitate adverse reactions in two apparently different clinical conditions: bronchial asthma and chronic idiopathic urticaria (CIU). Recent evidence indicates that the reactions are triggered by the drugs that inhibit cyclooxygenase-1 but not cyclooxygenase-2. OBJECTIVE: To assess whether patients with CIU and aspirin sensitivity share common eicosanoid alterations with patients who have aspirin-sensitive asthma. METHODS: Seventy-four patients with CIU and a history of sensitivity to aspirin and NSAIDs underwent placebo-controlled oral aspirin challenge tests. Concentrations of urinary leukotriene E4 (uLTE4) were measured by ELISA and plasma stable prostaglandin D2 metabolite, 9alpha,11beta prostaglandin F(2) by GC/MS. All measurements were carried out at baseline and after aspirin dosing. Patients were genotyped for the leukotriene C4 synthase (LTC4S) promoter single nucleotide polymorphism. RESULTS: In 30 of 74 patients, the aspirin challenge was positive, resulting in urticaria/angioedema. In these 30 patients, baseline uLTE4 levels were higher than in nonresponders and the healthy control subjects and increased further (significantly) after the onset of clinical reaction. No such increase occurred in subjects with negative aspirin challenge. Baseline uLTE4 levels correlated with severity of skin reactions. Plasma 9alpha,11beta prostaglandin F(2) levels rose significantly in both aspirin responders and nonresponders, although in the latter group the increase occurred later than in the former. In patients who reacted to aspirin, frequency of (-444)C allele of LTC4S was significantly higher than in patients who did not react. CONCLUSIONS: CIU with aspirin sensitivity is characterized by the eicosanoid alterations, which are similar to those present in aspirin-induced asthma.     

Urinary leukotriene E4

Measurement of urinary leukotriene E4 (LTE4) is a sensitive and noninvasive method of assaying total body cysteinyl leukotriene production and changes in cysteinyl leukotriene levels in specific microenvironments, such as the airway. Urinary LTE4 measurements can be used as sensitive biomarkers of exposure to asthma triggers, such as air pollution and viral infections. Recent studies suggest the potential of using urinary LTE4 concentrations as predictors of asthma control and markers of susceptibility to treatment with leukotriene receptor antagonists.