The role of the Annexin-A1/FPR2 system in the regulation of mast cell degranulation provoked by compound 48/80 and in the inhibitory action of nedocromil.

1.We investigated the role of Annexin (ANX)-A1 and its receptor, ALX/FPR2, in the regulation of mast cell degranulation produced by compound 48/80. 2.Both human cord-blood derived mast cells (CBDMCs) and murine bone marrow derived mast cells (BMDMCs) release phosphorylated ANX-A1 during treatment with glucocorticoids or the mast cell 'stabilising' drugs ketotifen and nedocromil. 3.Compound 48/80 also stimulated ANX-A1 phosphorylation and release and this was also potentiated by nedocromil. Anti-ANX-A1 neutralising monoclonal antibodies (Mabs) enhanced the release of pro-inflammatory mediators in response to compound 48/80. 4.Nedocromil and ketotifen potently inhibited the release of histamine, PGD2, tryptase and ß-hexosaminidase from mast cells challenged with compound 48/80. Anti-ANX-A1 neutralising Mabs prevented the inhibitory effect of these drugs. 5.BMDMCs derived from Anx-A1−/− mice were insensitive to the inhibitory effects of nedocromil or ketotifen but cells retained their sensitivity to the inhibitory action of hu-r-ANX-A1. 6.The fpr2/3 antagonist WRW4 blocked the action of nedocromil on PGD2, but not histamine, release. BMDMCs derived from fpr2/3−/− mice were insensitive to the inhibitory effects of nedocromil on PGD2, but not histamine release. 7.Compound 48/80 stimulated both p38 and JNK phosphorylation in CBDMCs and this was inhibited by nedocromil. Inhibition of p38 phosphorylation was ANX-A1 dependent. 8.We conclude that ANX-A1 is an important regulator of mast cell reactivity to compound 48/80 exerting a negative feedback effect through a mechanism that depends at least partly on the FPR receptor.

Estrogen inhibits mast cell chymase release to prevent pressure overload-induced adverse cardiac remodeling.

Estrogen regulation of myocardial chymase and chymase effects on cardiac remodeling are unknown. To test the hypothesis that estrogen prevents pressure overload-induced adverse cardiac remodeling by inhibiting mast cell (MC) chymase release, transverse aortic constriction or sham surgery was performed in 7-week-old intact and ovariectomized (OVX) rats. Three days before creating the constriction, additional groups of OVX rats began receiving 17ß-estradiol, a chymase inhibitor, or a MC stabilizer. Left ventricular function, cardiomyocyte size, collagen volume fraction, MC density and degranulation, and myocardial and plasma chymase levels were assessed 18 days postsurgery. Aortic constriction resulted in ventricular hypertrophy in intact and OVX groups, whereas collagen volume fraction was increased only in OVX rats. Chymase protein content was increased by aortic constriction in the intact and OVX groups, with the magnitude of the increase being greater in OVX rats. MC density and degranulation, plasma chymase levels, and myocardial active transforming growth factor-ß1 levels were increased by aortic constriction only in OVX rats. Estrogen replacement markedly attenuated the constriction-increased myocardial chymase, MC density and degranulation, plasma chymase, and myocardial active transforming growth factor-ß1, as well as prevented ventricular hypertrophy and increased collagen volume fraction. Chymostatin attenuated the aortic constriction-induced ventricular hypertrophy and collagen volume fraction in the OVX rats similar to that achieved by estrogen replacement. Nedocromil yielded similar effects, except for the reduction of chymase content. We conclude that the estrogen-inhibited release of MC chymase is responsible for the cardioprotection against transverse aortic constriction-induced adverse cardiac remodeling.

This asthma treatment has a lasting side effect in children.

A new study finds that when children with asthma use inhaled corticosteroids, the effect on growth may not be temporary, as once thought.

Anti-allergic cromones inhibit histamine and eicosanoid release from activated human and murine mast cells by releasing Annexin A1.

BACKGROUND AND PURPOSE: Although the 'cromones' (di-sodium cromoglycate and sodium nedocromil) are used to treat allergy and asthma, their 'mast cell stabilising' mechanism of pharmacological action has never been convincingly explained. Here, we investigate the hypothesis that these drugs act by stimulating the release of the anti-inflammatory protein Annexin-A1 (Anx-A1) from mast cells. EXPERIMENTAL APPROACH: We used biochemical and immuno-neutralisation techniques to investigate the mechanism by which cromones suppress histamine and eicosanoid release from cord-derived human mast cells (CDMCs) or murine bone marrow-derived mast cells (BMDMCs) from wild type and Anx-A1 null mice. KEY RESULTS: CDMCs activated by IgE-FcRε1 crosslinking, released histamine and prostaglandin (PG) D2, which were inhibited (30-65%) by 5 min pre-treatment with cromoglycate (10 nM) or nedocromil (10 nM), as well as dexamethasone (2 nM) and human recombinant Anx-A1 (1-10 nM). In CDMCs cromones potentiated (2-5 fold) protein kinase C (PKC) phosphorylation and Anx-A1 phosphorylation and secretion (3-5 fold). Incubation of CDMCs with a neutralising anti-Anx-A1 monoclonal antibody reversed the cromone inhibitory effect. Nedocromil (10 nM) also inhibited (40-60%) the release of mediators from murine bone marrow derived-mast cells from wild type mice activated by compound 48/80 and IgE-FcRε1 cross-linking, but were inactive in such cells when these were prepared from Anx-A1 null mice or when the neutralising anti-Anx-A1 antibody was present. CONCLUSIONS AND IMPLICATIONS: We conclude that stimulation of phosphorylation and secretion of Anx-A1 is an important component of inhibitory cromone actions on mast cells, which could explain their acute pharmacological actions in allergy. These findings also highlight a new pathway for reducing mediator release from these cells.

Effect of inhaled glucocorticoids in childhood on adult height.

BACKGROUND: The use of inhaled glucocorticoids for persistent asthma causes a temporary reduction in growth velocity in prepubertal children. The resulting decrease in attained height 1 to 4 years after the initiation of inhaled glucocorticoids is thought not to decrease attained adult height. METHODS: We measured adult height in 943 of 1041 participants (90.6%) in the Childhood Asthma Management Program; adult height was determined at a mean (±SD) age of 24.9±2.7 years. Starting at the age of 5 to 13 years, the participants had been randomly assigned to receive 400 µg of budesonide, 16 mg of nedocromil, or placebo daily for 4 to 6 years. We calculated differences in adult height for each active treatment group, as compared with placebo, using multiple linear regression with adjustment for demographic characteristics, asthma features, and height at trial entry. RESULTS: Mean adult height was 1.2 cm lower (95% confidence interval [CI], -1.9 to -0.5) in the budesonide group than in the placebo group (P=0.001) and was 0.2 cm lower (95% CI, -0.9 to 0.5) in the nedocromil group than in the placebo group (P=0.61). A larger daily dose of inhaled glucocorticoid in the first 2 years was associated with a lower adult height (-0.1 cm for each microgram per kilogram of body weight) (P=0.007). The reduction in adult height in the budesonide group as compared with the placebo group was similar to that seen after 2 years of treatment (-1.3 cm; 95% CI, -1.7 to -0.9). During the first 2 years, decreased growth velocity in the budesonide group occurred primarily in prepubertal participants. CONCLUSIONS: The initial decrease in attained height associated with the use of inhaled glucocorticoids in prepubertal children persisted as a reduction in adult height, although the decrease was not progressive or cumulative. (Funded by the National Heart, Lung, and Blood Institute and the National Center for Research Resources; CAMP ClinicalTrials.gov number, NCT00000575.).

Prevention of adverse cardiac remodeling to volume overload in female rats is the result of an estrogen-altered mast cell phenotype.

Previously, we have reported sex differences in the cardiac remodeling response to ventricular volume overload whereby male and ovariectomized (OVX) female rats develop eccentric hypertrophy, and intact (Int) female rats develop concentric hypertrophy. In males, this adverse remodeling has been attributed to an initial cascade of events involving myocardial mast cell and matrix metalloproteinase activation and extracellular collagen matrix degradation. The objective of this study was to determine the effect of female hormones on this initial cascade. Accordingly, an aortocaval fistula (Fist) was created in 7-wk-old Int and OVX rats, which, together with sham-operated (sham) controls, were studied at 1, 3, and 5 days postsurgery. In Int-Fist rats, myocardial mast cell density, collagen volume fraction, endothelin (ET)-1, stem cell factor (SCF), and TNF-α remained at control levels or were minimally elevated throughout the study period. This was not the case in the OVX-Fist group, where the initial response included significant increases in mast cell density, collagen degradation, ET-1, SCF, and TNF-α. These events in the OVX-Fist group were abolished by prefistula treatment with a mast cell stabilizer nedocromil. Of note was the observation that ET-1, TNF-α, SCF, and collagen volume fraction values for the OVX-sham group were greater than those of the Int-sham group, suggesting that the reduction of female hormones alone results in major myocardial changes. We concluded that female hormone-related cardioprotection to the volume stressed myocardium is the result of an altered mast cell phenotype and/or the prevention of mast cell activation.

An essential role for mast cells as modulators of neutrophils influx in collagen-induced arthritis in the mouse.

Mast cells are involved in immune disorders so that many of the proinflammatory and tissue destructive mediators produced by these cells have been implicated in the pathogenesis of rheumatoid arthritis. This scenario prompted us to investigate the correlation between mast cell degranulation and neutrophil influx within the digits and knees joints of arthritic mice assessing what could be the functional role(s) of joint mast cells in the response to collagen immunization. DBA/1J mice were submitted to collagen-induced arthritis and disease was assessed on day 21, 32 and 42 post-immunization. Pharmacological treatment with the glucocorticoid prednisolone, commonly used in the clinic, and nedocromil, a mast cell stabilizer, was performed from day 21 to 30. Arthritis develop after immunization, gradually increased up to day 42. Neutrophil infiltration peaked on day 32 and 21, in the digits and knees, respectively, showing an unequal pattern of recruitment between these tissues. This difference emerged for mast cells: they peaked in the digits on day 21, but a higher degree of degranulation could be measured in the knee joints. Uneven modulation of arthritis occurred after treatment of mice with prednisolone or nedocromil. Neutrophils migration to the tissue was reduced after both therapies, but only prednisolone augmented mast cell migration to the joints. Nedocromil exerted inhibitory properties both on mast cell proliferation and migration, more effectively on the digit joints. Thus, collagen induced an inflammatory process characterized by tissue mast cells activation and degranulation, suggesting a potential driving force in propagating inflammatory circuits yielding recruitment of neutrophils. However, the different degree of affected joint involvement suggests a time-related implication of digits and knees during collagen-induced arthritis development. These results provide evidence for local alterations whereby mast cells contribute to the initiation of inflammatory arthritis and may be targeted in intervention strategies.

Antiallergic cromones inhibit neutrophil recruitment onto vascular endothelium via annexin-A1 mobilization.

OBJECTIVE: To determine whether the inhibitory action of the antiallergic cromone "mast cell stabilizing" drugs on polymorphonuclear leukocyte (PMN) trafficking is mediated through an annexin-A1 (Anx-A1) dependent mechanism. METHODS AND RESULTS: Intravital microscopy was used to monitor the actions of cromones in the inflamed microcirculation. Reperfusion injury provoked a dramatic increase in adherent and emigrated leukocytes in the mesenteric vascular bed, associated with augmented tissue levels of myeloperoxidase. Nedocromil, 2 to 20 mg/kg, significantly (P<0.05) inhibited cell adhesion and emigration, as well as myeloperoxidase release, in wild-type but not Anx-A1(-/-) mice. Short pretreatment of human PMNs with nedocromil, 10 nmol/L, inhibited cell adhesion (P<0.05) in the flow chamber assay, and this effect was reversed by specific anti-AnxA1 or a combination of antiformyl peptide receptors 1 and 2, but not irrelevant control, antibodies. Western blotting experiments revealed that cromones stimulate protein kinase C-dependent phosphorylation and release Anx-A1 in human PMNs. CONCLUSIONS: We propose a novel mechanism to explain the antiinflammatory actions of cromones on PMN trafficking, an effect that has long puzzled investigators.

G-protein-coupled receptor 35 is a target of the asthma drugs cromolyn disodium and nedocromil sodium.

We report that the asthma drugs cromolyn disodium and nedocromil sodium are potent G-protein-coupled receptor 35 (GPR35) agonists. We utilized calcium flux and inositol phosphate accumulation assays to examine the pharmacology of these asthma drugs on the human, mouse and rat GPR35. The compounds were more potent on the human GPR35 than on mouse and rat receptors. In contrast, zaprinast, a known GPR35 agonist, was more potent on mouse and rat GPR35 than the human ortholog. We show by quantitative PCR that GPR35 is expressed in human mast cells, human basophils and human eosinophils. We also demonstrate that GPR35 mRNA is upregulated upon challenge with IgE antibodies. We show that, unlike zaprinast, a potent phosphodiesterase 5 (PDE5) inhibitor, cromolyn disodium and nedocromil sodium lack inhibitory activity towards PDE5. These findings suggest that GPR35 may play an important role in mast cell biology and be a potential target for the treatment of asthma.

Cromoglycate drugs suppress eicosanoid generation in U937 cells by promoting the release of Anx-A1.

Using biochemical, epifluorescence and electron microscopic techniques in a U937 model system, we investigated the effect of anti-allergic drugs di-sodium cromoglycate and sodium nedocromil on the trafficking and release of the anti-inflammatory protein Annexin-A1 (Anx-A1) when this was triggered by glucocorticoid (GC) treatment. GCs alone produced a rapid (within 5min) concentration-dependent activation of PKCalpha/beta (Protein Kinase C; EC 2.7.11.13) and phosphorylation of Anx-A1 on Ser(27). Both phosphoproteins accumulated at the plasma membrane and Anx-A1 was subsequently externalised thereby inhibiting thromboxane (Tx) B(2) generation. When administered alone, cromoglycate or nedocromil had little effect on this pathway however, in the presence of a fixed sub-maximal concentration of GCs, increasing amounts of the cromoglycate-like drugs caused a striking concentration-dependent enhancement of Anx-A1 and PKCalpha/beta phosphorylation, membrane recruitment and Anx-A1 release from cells resulting in greatly enhanced inhibition of TxB(2) generation. GCs also stimulated phosphatase accumulation at the plasma membrane of U937 cells. Both cromoglycate and nedocromil inhibited this enzymatic activity as well as that of a highly purified PP2A phosphatase preparation. We conclude that stimulation by the cromoglycate-like drugs of intracellular Anx-A1 trafficking and release (hence inhibition of eicosanoid release) is secondary to inhibition of a phosphatase PP2A (phosphoprotein phosphatase; EC 3.1.3.16), which probably forms part of a control loop to limit Anx-A1 release. These experiments provide a basis for a novel mechanism of action for the cromolyns, a group of drugs that have long puzzled investigators.

Relationship between mast cells and the colitis with relapse induced by trinitrobenzesulphonic acid in Wistar rats.

The present study aimed to clarify the role of mast cells in colitis with relapse induced in Wistar rats by trinitrobenzenosulphonic acid. Colitis induction increased the histamine concentration in the colon, which peaked on day 26. The number of mast cells, probably immature, was ten times higher on day 8. Different from animals infected with intestinal parasites, after colitis remission, mast cells do not migrate to the spleen, showing that mast cell proliferation presents different characteristics depending on the inflammation stimuli. Treatment with sulfasalazine, doxantrazole, quercetin, or nedocromil did not increase the histamine concentration or the mast cell number in the colon on day 26, thereby showing absence of degranulation of these cells. In conclusion, although mast cell proliferation is associated with colitis, these cells and their mediators appear to play no clear role in the colitis with relapses.

Cardiac mast cells mediate left ventricular fibrosis in the hypertensive rat heart.

Correlative data suggest that cardiac mast cells are a component of the inflammatory response that is important to hypertension-induced adverse myocardial remodeling. However, a causal relationship has not been established. We hypothesized that adverse myocardial remodeling would be inhibited by preventing the release of mast cell products that may interact with fibroblasts and other inflammatory cells. Eight-week-old male spontaneously hypertensive rats were treated for 12 weeks with the mast cell stabilizing compound nedocromil (30 mg/kg per day). Age-matched Wistar-Kyoto rats served as controls. Nedocromil prevented left ventricular fibrosis in the spontaneously hypertensive rat independent of hypertrophy and blood pressure, despite cardiac mast cell density being elevated. The mast cell protease tryptase was elevated in the spontaneously hypertensive rat myocardium and was normalized by nedocromil. Treatment of isolated adult spontaneously hypertensive rat cardiac fibroblasts with tryptase induced collagen synthesis and proliferation, suggesting this as a possible mechanism of mast cell-mediated fibrosis. In addition, nedocromil prevented macrophage infiltration into the ventricle. The inflammatory cytokines interferon-gamma and interleukin (IL)-4 were increased in the spontaneously hypertensive rat and normalized by nedocromil, whereas IL-6 and IL-10 were decreased in the spontaneously hypertensive rat, with nedocromil treatment normalizing IL-6 and increasing IL-10 above the control. These results demonstrate for the first time a causal relationship between mast cell activation and fibrosis in the hypertensive heart. Furthermore, these results identify several mechanisms, including tryptase, inflammatory cell recruitment, and cytokine regulation, by which mast cells may mediate hypertension-induced left ventricular fibrosis.

The effect of asthma therapeutics on signalling and transcriptional regulation of airway smooth muscle function.

SCOPE OF THE REVIEW: Our knowledge of the multifunctional nature of airway smooth muscle (ASM) has expanded rapidly in the last decade, but the underlying molecular mechanisms and how current therapies for obstructive airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), affect these are still being elucidated. Our current knowledge has built on the pharmacology of human ASM contraction and relaxation established prior to that and which is reviewed in detail elsewhere in this issue. The advent of methods to isolate and culture ASM cells, especially human ASM cells, has made it possible to study how they may contribute to airway remodelling through their synthetic, proliferative, and migratory capacities. Now the underlying molecular mechanisms of ASM growth factor secretion, extracellular matrix (ECM) production, proliferation and migration, as well as contraction and relaxation, are being determined. A complex network of signalling pathways leading to gene transcription in ASM cells permits this functional plasticity in healthy and diseased airways. This review is an overview of the effects of current therapies, and some of those in development, on key signalling pathways and transcription factors involved in these ASM functions.

Ocular anti-allergic compounds selectively inhibit human mast cell cytokines in vitro and conjunctival cell infiltration in vivo.

BACKGROUND: Conjunctival mast cells (MCs) are important effector cells in seasonal allergic conjunctivitis, via histamine and cytokine secretion. Several new anti-allergic eye drops stabilize MCs and block histamine receptors, but their anti-inflammatory effects are unclear. OBJECTIVE: Anti-allergic drugs were compared for their anti-inflammatory effects in an in vitro model of human MC activation and in an experimental murine model of allergic conjunctivitis. METHODS: Human cord blood stem cell-derived (CBMC) and conjunctival biopsy-derived MCs were stimulated via FcepsilonRI, degranulation and histamine release were assayed at 1 h and cytokine secretion at 24 h using multiplex arrays. Mice sensitized to short ragweed pollen were given anti-allergics topically before allergen challenge, and conjunctival immuno-staining was performed at 24 h. RESULTS: After a 1 h stimulation, 80% of the CBMC had degranulated and secreted histamine (27.9+/-4.7 ng/10(6) cells; P<0.05). Pre-treatment by all drugs significantly reduced histamine and TNF-alpha, whereas IL-5, IL-8, IL-10 and TNF-beta profiles were differentially decreased. For conjunctival biopsy-derived cultures (n=11), FcepsilonR1 stimulation increased histamine, TNF-alpha, TNF-beta, IL-5 and IL-8 levels and the production of IL-5, IL-6 (P<0.05), histamine and IL-8 (P<0.01) was inhibited by epinastine. In vivo, epinastine and olopatadine pre-treatment significantly reduced the clinical scores and eosinophil numbers (n=6; P<0.05) while epinastine also reduced neutrophils (P<0.02). CONCLUSION: Differential effects on MC cytokine inhibition were observed, with epinastine inhibiting MC secretion of IL-5, IL-8, IL-10 and conjunctival neutrophil infiltration. The anti-allergic drugs have anti-histamine and mast-cell stabilizing properties but might differ in clinical improvement depending on the individual and the cytokines involved.

Rat cardiac mast cell maturation and differentiation following acute ventricular volume overload.

OBJECTIVE: Cardiac mast cell numbers increase significantly within 12 h following the creation of an aortocaval (AV) fistula in rats and play a central role in mediating adverse left ventricular remodeling. We studied whether this increase was related to maturation of resident immature mast cells. METHODS: We measured percentages of immature and mature cardiac mast cells at 1, 2 and 7 days following AV-fistula or sham surgery and in non-surgical control rats using the alcian-blue safranin reaction. RESULTS: Relative to sham-operated and control rats, there was a significant shift from immature to a greater percentage of mature cardiac mast cells at 1 day and 2 days post-fistula that returned to a normal distribution by 7 days. CONCLUSIONS: We conclude that the acute increase in mast cell density following volume overload is due to a paracrine response in the heart that stimulates the maturation and differentiation of resident immature cardiac mast cells.

Protective effects of nedocromil sodium and sodium cromoglycate on gastroduodenal ulcers: a comparative study in rats.

Stabilization of mast cells plays a key mechanism to protect gastrointestinal tract from injury. This study presents a comparative evaluation of mast cell stabilizers nedocromil sodium (NDS) and sodium cromoglycate (SCG) in experimental gastric and duodenal ulcers in rats. Wistar rats of either sex were used in this study. Both NDS and SCG, in the doses of 10, 30 and 100 mg/kg were given intraperitoneally for gastric secretion studies and by gavage for antiulcer studies. Acid secretion studies were undertaken in pylorus-ligated rats. Gastric lesions were induced by water immersion restraint stress (WIRS), indomethacin and ethanol whereas duodenal ulcers were produced by cysteamine. The level of glutathione (GSH) and gastric wall mucus were measured in glandular stomach of rats following ethanol-induced gastric lesions. SCG was more effective than NDS in preventing WIRS- and indomethacin-induced gastric lesions whereas reverse was true in ethanol- and cysteamine-induced ulcers. All the 3 doses of SCG offered almost equal protection against WIRS-induced gastric lesions whereas only medium and high dose of NDS provided significant protection in this model of ulcer. NDS significantly inhibited cysteamine-induced duodenal ulcers whereas SCG failed to do so. Pretreatment with NDS or SCG significantly and dose-dependently protected gastric mucosa against ethanol-induced injury, while the former drug appeared to be more effective. The cytoprotective effects of these two drugs were accompanied by the attenuation of ethanol-induced depletion of gastric wall mucus and GSH. The differential effects of NDS and SCG against various gastric lesions rationalize the possible benefits of a combined therapy (NDS+SCG) for the treatment of complex gastroduodenal ulcers.

[In vitro effects of antiallergic eyedrops on complement activation induced by particulate matter]. / Effets modulateurs de collyres anti-allergiques sur l'activation du complément induite in vitro par des polluants particulaires.

BACKGROUND: Recent decades have been marked by an increasing number of patients suffering from ocular allergic-like symptoms without being associated with an increase in IgE levels. These symptoms include heaviness of the lid, foreign body sensation, burning, stinging and photophobia. Both epidemiological studies and controlled human exposure clinical studies have shown cause-effect relationships between allergic-like symptoms and environmental factors such as outdoor air pollutants or poor indoor air quality. An ocular surface subclinical inflammation is thought to be responsible for pseudoallergic, pollution-related conjunctivitis. The complement system is considered as one of the major effector mechanisms involved in initiation of the subclinical inflammation that leads to IgE-independent eye irritation. PURPOSE: To study the capability of nine antiallergic eyedrops commonly used in the treatment of allergic conjunctivitis to inhibit complement activation induced in vitro by pollutants. METHODS: Normal human serum obtained from healthy individuals was used as a source of complement. Activation of complement was assessed using the complement hemolytic 50% (CH50) assay, in the absence or the presence of antiallergic eyedrops and in the absence or the presence of various stimuli, including sand, common house dust, eye mascara, and Dactylis glomerata pollen extract. Zymosan was used as a standardized complement activator. The following eyedrops were studied: Naabak (4.9% N-acetyl aspartic acid-glutamic acid, NAAGA, sodium salt), Almide (lodoxamide 0.1%), Levophta (0.05% levocabastine), Emadine (0.05% emedastine), Tilavist (2% nedocromil), Allergodil (0.05% azelastine), Patanol (olopatadine), and Zaditen (0.025% ketotifen). Effects of preservative-free lodoxamide and ketotifen were also assessed and compared to those of the preserved formulations. A solution of 0.01% benzalkonium chloride (BAC), the most widely used preservative in topical eyedrops, was also tested. RESULTS: Zymosan-induced activation of complement (30+/-6%) was significantly lowered by preincubation of serum with unpreserved NAAGA (16.6+/-4%, p=0.0026) or benzalkonium-preserved nedocromil (20+/-2%, p=0.022). Preserved levocabastine, emedastine, olopatadine and ketotifen did not interfere with zymosan-induced complement activation, whereas preserved azelastine, lodoxamide and benzalkonium chloride significantly aggravated complement activation induced by zymosan. Similar results were obtained when complement activation was triggered by sand, common house dust, mascara, or by an allergenic extract of Dactylis glomerata pollen. In the absence of complement activator, none of the antiallergic eyedrops induced a significant change in CH50 titer, indicating that the deleterious pro-inflammatory effect of preserved azelastine and lodoxamide may occur only once complement activation has been initiated, i.e., on an inflamed ocular surface. CONCLUSION: Among the antiallergic eyedrops tested in this study, only Naabak and Tilavist were found to significantly inhibit complement activation triggered by particulate matters or pollen allergenic extract. Such an anticomplement activity confers these two molecules a potential in the therapeutic management of pollution-related pseudoallergic conjunctivitis.

Relations between exhaled nitric oxide and measures of disease activity among children with mild-to-moderate asthma.

OBJECTIVE: Exhaled nitric oxide (FE(NO)) was evaluated in children with asthma after 4 to 6 years of treatment with budesonide, nedocromil, or albuterol as needed. STUDY DESIGN: FE(NO), spirometry, total eosinophil count, and serum eosinophil cationic protein levels were obtained from 118 children at the Denver site of the Childhood Asthma Management Program upon completion of treatment and after a 2- to 4-month washout. RESULTS: Budesonide-treated patients had significantly lower median (1st, 3rd quartile) FE(NO) (21.5 [13.2, 84.4] vs 62.5 [26.2, 115.0] ppb, P <.01) and eosinophil cationic protein levels (17.4 [10.1, 24.3] vs 24.0 [15.4, 33.9] mg/dL, P =.05) compared with placebo, whereas no differences were noted between nedocromil and placebo groups. After washout, FE(NO) levels were similar between the three treatments. FE(NO) levels significantly correlated with degree of bronchial hyperresponsiveness, bronchodilator reversibility, allergen skin prick tests, serum IgE, and total eosinophil count. FE(NO) levels were also higher in patients with nocturnal symptoms and in patients requiring beta-agonist use at least once weekly. CONCLUSIONS: Budesonide therapy was more effective than nedocromil in reducing FE(NO). Unfortunately, the effects of long-term budesonide were not sustained after its discontinuation. FE(NO) may be a complementary tool to current practice guidelines in assessing asthma control and medication response.