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See detailEffect of a 4-Week Treatment with Theophylline on Sputum Eosinophilia and Sputum Eosinophil Chemotactic Activity in Steroid-Naive Asthmatics
Louis, Renaud ULg; Bettiol, J.; Cataldo, Didier ULg et al

in Clinical & Experimental Allergy : Journal of the British Society for Allergy & Clinical Immunology (2000), 30(8), 1151-60

BACKGROUND: The precise mechanism of action of theophylline in asthma is not fully understood but recent data have drawn attention to its potential anti-inflammatory effect. OBJECTIVE: The purpose of this ... [more ▼]

BACKGROUND: The precise mechanism of action of theophylline in asthma is not fully understood but recent data have drawn attention to its potential anti-inflammatory effect. OBJECTIVE: The purpose of this study was to assess the effect of theophylline on sputum eosinophilia and sputum eosinophil chemotactic activity in steroid-naive asthmatics. METHOD: We performed a 4-week randomized double-blind, placebo-controlled, parallel group study in 21 mild to moderate steroid-naive asthmatics whose sputum eosinophilia was found twice > 5% during the run in period. Eleven subjects received 600 mg/24 h theophylline for the first 2 weeks and 900 mg/24 h for the last 2 weeks while 10 subjects took a placebo for 4 weeks. Sputum was induced after 2 and 4 weeks of treatment and 1 week after stopping the treatment. The sputum samples were compared for their cell counts, eosinophil cationic protein (ECP) levels and eosinophil chemotactic activity using micro-Boyden chambers. RESULTS: Serum theophylline concentrations reached 7 and 11 microg/mL at V3 and V4, respectively. Intragroup comparisons showed that theophylline, but not placebo, caused a significant reduction in sputum eosinophil counts at V3 (62 +/- 10% from baseline, P < 0.01) and a strong trend at V4 (67 +/- 16% from baseline, P = 0.07) when compared to baseline. The intergroup difference obtained after comparing the area under the curve over the 4 week treatment period only approached the statistical significance (P = 0.08). At baseline the fluid phase of the sputum contained a significant eosinophil chemotactic activity which was inhibited after a 4-week treatment by theophylline (P < 0. 01) but not by placebo. The mean sputum theophylline levels after 4 weeks of treament (1.7 microg/mL) was lower than that required to cause significant inhibition of eosinophil chemotaxis in vitro. CONCLUSION: Theophylline decreases the natural sputum eosinophil chemotactic activity present in asthmatics. However, when using a small sample size, the 35% reduction in sputum eosinophilia achieved by theophylline failed to reach statistical significance when compared to that seen after placebo. [less ▲]

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See detailLes modifications morphologiques bronchiques dans l'asthme
Cataldo, Didier ULg; Louis, Renaud ULg; Godon, A. et al

in Revue Médicale de Liège (2000), 55(7), 715-20

Asthma is an inflammatory disease of the airways clinically characterised by recurrent bronchial obstructions at least partially reversible. Recent epidemiologic data suggest that asthmatics have an ... [more ▼]

Asthma is an inflammatory disease of the airways clinically characterised by recurrent bronchial obstructions at least partially reversible. Recent epidemiologic data suggest that asthmatics have an increased rate of decrease of their expiratory volumes during life. This irreversible lung function impairment is associated with fundamental structural changes of the bronchial wall in terms of conjunctive tissue and smooth muscle composition. We describe these changes and explore the different mechanisms proposed to explain these structural modifications. We also review their consequences in terms of bronchial physiology and their potential influence on bronchial hyperresponsiveness. [less ▲]

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See detailThe relationship between airways inflammation and asthma severity.
Louis, Renaud ULg; Lau, L. C.; Bron, A. O. et al

in American Journal of Respiratory & Critical Care Medicine (2000), 161(1), 9-16

In order to investigate the relationship between airways inflammation and disease severity, and improve the understanding of persistent asthma, 74 asthmatics, with disease severity ranging from ... [more ▼]

In order to investigate the relationship between airways inflammation and disease severity, and improve the understanding of persistent asthma, 74 asthmatics, with disease severity ranging from intermittent, to mild to moderate and severe persistent (classified according to the Global Initiative for Asthma [GINA] guidelines), and 22 nonatopic control subjects were studied using the method of induced sputum. Sputum was analyzed for total and differential cell counts concentrations of albumin, and levels of eosinophil cationic protein (ECP), myeloperoxidase (MPO), and tryptase, inflammatory mediators reflecting eosinophil, neutrophil, and mast cell activation. Asthma severity (assessed by FEV(1), peak expiratory flow [PEF] variability, and daily symptom scores) and methacholine airways responsiveness were related to sputum eosinophilia and ECP. In addition, sputum neutrophilia and MPO levels correlated, albeit weakly, with PEF variability and symptom scores, respectively. Tryptase concentrations were raised in mild to moderate asthmatics. Albumin concentrations were significantly raised across the spectrum of asthma severity and correlated with those of tryptase and ECP. Despite treatment with either high doses of inhaled corticosteroids or oral corticosteroids, prominent eosinophilic inflammation with raised ECP was noted. This study points to persistent, disease severity-related airways inflammation in asthma, involving eosinophils, mast cells, and neutrophils, which is evident despite treatment with corticosteroids. [less ▲]

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See detailAirway Mast-Cell Activation in Asthmatics Is Associated with Selective Sputum Eosinophilia
Bettiol, Jane; Radermecker, Maurice ULg; Sele, Jocelyne ULg et al

in Allergy (1999), 54(11), 1188-93

BACKGROUND: Tryptase is a serine endoprotease selectively released from mast cells. Although mast cells are known to be activated after experimental allergic provocation, their role in naturally occurring ... [more ▼]

BACKGROUND: Tryptase is a serine endoprotease selectively released from mast cells. Although mast cells are known to be activated after experimental allergic provocation, their role in naturally occurring asthma is still debated. METHODS: We have investigated the levels of tryptase in the whole induced sputum collected from 51 asthmatics (31 atopic and 20 intrinsic) seen in our outpatient clinic and 22 normal nonatopic healthy volunteers. Tryptase was measured by a new immunoassay based on B12 monoclonal antibody recognition of total tryptase (UniCAP System, Pharmacia) with a sensitivity of 1 ng/ml. RESULTS: While being below the threshold of detection in all normal volunteers, tryptase was detectable in the sputum from 9/51 asthmatics (18%) including five atopic and four intrinsic asthma cases. In these patients, among whom three were asymptomatic asthmatics, the values ranged between 1 and 6.1 ng/ml. The asthmatics with detectable sputum tryptase had greater sputum eosinophil counts (P<0.05) but lower neutrophil counts (P<0.05) than those in whom tryptase was undetectable. When compared to control subjects, asthmatics without tryptase had still greater eosinophil counts (P<0.0001) but also raised neutrophil counts (P<0.05). No significant difference could be found between asthmatics with tryptase and those without tryptase with respect to the age, the baseline lung function, the methacholine bronchial responsiveness, and the frequency of treatment with inhaled steroids. CONCLUSIONS: With the UniCAP System, tryptase was detectable in the sputum from 18% of asthmatics irrespective of atopy and current symptoms. Asthmatics with tryptase appeared to have a selective increase in sputum eosinophil counts while those without tryptase displayed a mixed sputum granulocyte infiltration with raised eosinophil and neutrophil counts. [less ▲]

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See detailReflux gastro-oesophagien et asthme
Lamproye, Anne ULg; Louis, Edouard ULg; Louis, Renaud ULg et al

in Revue Médicale de Liège (1999), 54(10), 805-8

Gastro-oesophageal reflux (GER) is more frequent in asthmatic patients than in the community at large. A causative association between the two diseases is suspected. Twenty-four hour ambulatory ... [more ▼]

Gastro-oesophageal reflux (GER) is more frequent in asthmatic patients than in the community at large. A causative association between the two diseases is suspected. Twenty-four hour ambulatory intraoesophageal pH monitoring represents the golden standard for the diagnosis of GER. The medical and/or surgical treatment of reflux in asthmatic patients with GER can improve pulmonary symptoms and to a lesser extent pulmonary function. The selection of the patients who will benefit from a GER treatment is difficult. Some symptoms like intrinsic asthma, nocturnal crises, could predict a good response to GER treatment. [less ▲]

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See detailBronchial Eosinophilic Infiltration in Crohn's Disease in the Absence of Pulmonary Disease
Louis, Edouard ULg; Louis, Renaud ULg; Shute, J. et al

in Clinical & Experimental Allergy : Journal of the British Society for Allergy & Clinical Immunology (1999), 29(5), 660-6

BACKGROUND: Immunological and functional bronchopulmonary abnormalities may be present in up to two-thirds of patients with Crohn's disease. Having recently described a mild increase in methacholine ... [more ▼]

BACKGROUND: Immunological and functional bronchopulmonary abnormalities may be present in up to two-thirds of patients with Crohn's disease. Having recently described a mild increase in methacholine airways responsiveness in these patients, we investigated whether this physiological abnormality is associated with bronchial inflammation since it has previously been described in asthma. METHODS: Eighteen patients with Crohn's disease and 15 healthy controls matched for age, atopy and smoking habit, were studied. All the subjects underwent a bronchial methacholine challenge (1, 4 and 16 mg/mL) and a sputum induction by inhalation of hypertonic saline (NaCl 4.5%). The sputum samples were analysed for their cellular composition as well as for the levels of several mediators and proteins in the fluid phase, including eosinophil cationic protein (ECP), myeloperoxydase, albumin, alpha2-macroglobulin, interleukin-8 (IL-8), IgA and IL-8/immunoglobulin A complexes. RESULTS: When compared to control subjects, patients with Crohn's disease had significantly higher sputum eosinophil counts (14.5% [0-79.9%] vs 0.2% [0-2.3%]; P < 0. 001) and ECP levels (26.2 microg/L [4-124.2 microg/L] vs 9.8 microg/L [0-94.2 microg/L]; P < 0.05). However, patients with Crohn's disease had no sign of increased plasma exudation as reflected by sputum levels of albumin and alpha2-macroglobulin similar to those seen in control subjects. Furthermore the sputum levels of IL-8, IgA and IL-8/IgA complexes were not significantly different between the two groups. The magnitude of the fall in forced expiratory volume in 1 s after methacholine inhalation was significantly increased in Crohn's disease patients although it did not correlate with the extent of sputum eosinophilia or with the sputum ECP levels. CONCLUSIONS: Crohn's disease patients without any clinical respiratory involvement have airway eosinophilia without local increased plasma exudation. However, bronchial eosinophilia in Crohn's disease per se is not sufficient to induce clinically significant airway hyperresponsiveness, suggesting that other factors than bronchial eosinophilic infiltration are required for the clinical expression of an airway instability. [less ▲]

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See detailThe effect of processing on inflammatory markers in induced sputum.
Louis, Renaud ULg; Shute, J.; Goldring, K. et al

in European Respiratory Journal (1999), 13(3), 660-7

The effects of the mucolytic agent, dithioerythritol (DTE), and the temperature at which sputum processing is conducted on cellular and biochemical markers in induced sputum was assessed. Samples from ... [more ▼]

The effects of the mucolytic agent, dithioerythritol (DTE), and the temperature at which sputum processing is conducted on cellular and biochemical markers in induced sputum was assessed. Samples from healthy and atopic asthmatic subjects were treated with either DTE or phosphate-buffered saline (PBS) at 22 or 37 degrees C and compared for cell counts and concentrations of histamine, tryptase, eosinophil cationic protein (ECP), free interleukin (IL)-8, immunoglobulin (Ig)A, IL-8/IgA complexes and secretory component (SC). In addition, the influence of DTE on in vitro mediator release from blood eosinophils, basophils and bronchoalveolar lavage (BAL) mast cells was studied. Processing with DTE improved cytospin quality and increased the cell yield and measurable ECP, tryptase, IgA and SC, but reduced levels of histamine in PBS-treated samples and had no effect on IL-8. Cell counts or mediator levels were similar when sputum was processed at 22 or 37 degrees C, even though DTE induced blood basophils and BAL mast cells to release histamine at 37 degrees C. In spiking experiments, recovery of added ECP, tryptase, total IL-8 and histamine from sputum was similar in DTE- and PBS-processed sputum, but reduced for free IL-8 in PBS-treated samples. In conclusion, dithioerythritol improves cell and mediator recovery without causing cell activation when sputum processing is conducted at room temperature. The extent of recovery depends on the mediator studied. [less ▲]

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See detailTheophylline Decreases Sputum Eosinophilia of Asthmatics
Louis, Renaud ULg; Bettiol, J.; Cataldo, Didier ULg et al

in International Archives of Allergy & Immunology (1999), 118(2-4, Feb-Apr), 343-4

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See detailBronchial Responsiveness in Active Steelworkers
Corhay, Jean-Louis ULg; Bury, Thierry ULg; Louis, Renaud ULg et al

in European Respiratory Journal (1998), 11(2), 272-7

Coke-oven workers are exposed to dust and irritant gases. Therefore they are at risk of developing lung diseases including chronic bronchitis. Nonspecific bronchial hyperresponsiveness (BHR) has been ... [more ▼]

Coke-oven workers are exposed to dust and irritant gases. Therefore they are at risk of developing lung diseases including chronic bronchitis. Nonspecific bronchial hyperresponsiveness (BHR) has been advocated as a potential risk factor predisposing to the development of chronic bronchitis. In a previous study, we showed that prevalence of BHR was higher in retired coke-oven workers than in retired blast furnace workers. The present study was carried out to determine the prevalence of BHR in active steelworkers. Thus, 137 coke-oven workers and 150 blast furnace workers underwent clinical examination, a standardized questionnaire for the study of respiratory symptoms, pulmonary function testing and methacholine aerosol challenge. The study demonstrates a higher prevalence and degree of BHR [provocative concentration of methacholine causing a 20% fall in forced expiratory volume in one second (PC20) < or = 8 mg x mL(-1)] in coke-oven workers than in blast furnace workers (31.4 versus 6.7%; p<0.001). Moreover, the frequency of respiratory symptoms and basal bronchial obstruction were greater among coke-oven workers with BHR in nonresponders. The basal maximum expiratory flow from 25-75% of forced vital capacity and the respiratory symptoms were correlated with bronchial responsiveness. The lack of correlation observed between BHR and the intensity of smoking or years spent in coke-oven environment may be explained by the high proportion of smokers, the worker turnover in the steel plant, and the "healthy worker effect". In conclusion, the higher prevalence and degree of bronchial hyperresponsiveness in coke-oven workers suggests that coke-oven pollutants are more intense irritants than those that escape from blast furnaces. [less ▲]

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See detailTumour necrosis factor (TNF) gene polymorphism influences TNF-alpha production in lipopolysaccharide (LPS)-stimulated whole blood cell culture in healthy humans.
Louis, Edouard ULg; Franchimont, D.; Piron, Anne ULg et al

in Clinical & Experimental Immunology (1998), 113(3), 401-406

TNF-alpha is involved in infectious and immuno-inflammatory diseases. Different individuals may have different capacities for TNF-alpha production. This might determine a predisposition to develop some ... [more ▼]

TNF-alpha is involved in infectious and immuno-inflammatory diseases. Different individuals may have different capacities for TNF-alpha production. This might determine a predisposition to develop some complications or phenotypes of these diseases. The aims of our study were to assess the inter-individual variability of TNF-alpha production and to correlate this variability to a single base pair polymorphism located at position -308 in TNF gene. We studied 62 healthy individuals. TNF-alpha production after LPS stimulation was evaluated using a whole blood cell culture model. The TNF gene polymorphism was studied by an allele-specific polymerase chain reaction. Other cytokines produced in the culture, soluble CD14 concentrations and expression of CD14 on blood cells were also measured. Among the 62 individuals, 57 were successfully genotyped. There were 41 TNF1 homozygotes and 16 TNF1/TNF2 heterozygotes. TNF-alpha production after LPS stimulation of whole blood cell culture was higher among TNF2 carriers than among TNFI homozygotes (929pg/ml (480-1473pg/ml) versus 521 pg/ ml (178-1307 pg/ml); P<0.05). This difference was even more significant after correction of TNF-alpha production for CD14 expression on blood cells. In conclusion, the single base pair polymorphism at position -308 in the TNF gene may influence TNF-alpha production in healthy individuals. [less ▲]

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See detailLes antileucotriènes : une nouvelle direction dans le traitement de l'asthme.
Louis, Renaud ULg; Radermecker, Maurice ULg

in Médecine et Hygiène (1998), 56

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See detailLes cysteinyl-leucotrienes: des mediateurs importants dans l'asthme
Louis, Renaud ULg; Neven, I.; Quaedvlieg, Valérie ULg et al

in Revue Médicale de Liège (1997), 52(9), 598-602

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See detailContribution expérimentale à l'étude de l'hyperréactivité et de l'inflammation bronchique dans l'asthme allergique.
LOUIS, Renaud ULg

Thèse d’agrégation de l’enseignement supérieur (1997)

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See detailCorrelation between Bronchoalveolar Lavage (Bal) Fluid Cell Lysate Histamine Content and Bal Fluid Eosinophil Count in Atopic and Nonatopic Asthmatics
Louis, Renaud ULg; Van Tulder, L.; Poncelet, M. et al

in International Archives of Allergy & Immunology (1997), 112(3), 309-12

We have compared the bronchoalveolar lavage fluid (BAL) cellular composition and the BAL cell lysate histamine content (fluorometric assay) in 28 stable mild to moderate asthmatics (atopic n = 18 and ... [more ▼]

We have compared the bronchoalveolar lavage fluid (BAL) cellular composition and the BAL cell lysate histamine content (fluorometric assay) in 28 stable mild to moderate asthmatics (atopic n = 18 and intrinsic n = 10) and 11 control subjects. When compared to control subjects, the whole group of asthmatics had a higher proportion of BAL eosinophils (p < 0.01) and metachromatic cells (p < 0.05). The BAL cell lysate histamine was increased in atopic (p < 0.05) and intrinsic asthmatics (p < 0.05) in comparison with control subjects. In the whole group of asthmatics, the BAL cell lysate histamine content correlated with the percentage of BAL eosinophils (r = 0.58, p < 0.01). This relationship was significant in both atopic (r = 0.48, p < 0.05) and intrinsic (r = 0.70, p < 0.05) asthmatics. For the whole group of asthmatics, both the BAL cell lysate histamine and the percentage of BAL eosinophils inversely correlated with the percent predicted FEV1 (r = -0.42, p < 0.05; r = -0.51, p < 0.05). We conclude that an increased BAL cell lysate histamine content correlates with airway eosinophilic infiltration and lung function impairment in mild to moderate atopic and intrinsic asthmatics. This suggests that BAL mast cells play a key role in recruiting eosinophils in the airways of asthmatics irrespective of the presence of an atopic status. [less ▲]

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See detailEvidence for enhanced inflammatory cell activity, ICAM-1 expression and eosinophil chemotactic activity in the sputum of asthmatics.
Louis, Renaud ULg; Shute, J.; Biaggi, S. et al

in American Journal of Respiratory & Critical Care Medicine (1997), 155(2), 466-472

We have applied the technique of sputum induction by hypertonic saline in asthmatics and nonatopic control subjects to study an array of indices of airway inflammation believed to be relevant to asthma ... [more ▼]

We have applied the technique of sputum induction by hypertonic saline in asthmatics and nonatopic control subjects to study an array of indices of airway inflammation believed to be relevant to asthma pathogenesis. Compatible with a central role for eosinophils and mast cells in asthma, sputum of asthmatic subjects contained increased numbers of eosinophils and levels of eosinophil cationic protein (ECP) and mast cell tryptase. Eosinophil numbers, and ECP and histamine levels correlated with the degree of methacholine airways responsiveness, and ECP, tryptase, and histamine correlated with raised concentrations of albumin. Using the micro-Boyden chamber technique eosinophil chemotactic activity was identified only in the sputum from asthmatics. The correlation between the raised levels of total IgA, IL- 8/IgA complexes, and tryptase and the degree of sputum eosinophilia and ECP levels, suggests possible mechanisms for eosinophil chemotaxis and activation in asthma. Row cytometric analysis of sputum lymphocytes showed an increase in CD4+ T cells and T cells expressing intercellular adhesion molecule-1 (ICAM-1) in asthma which, together with the finding of raised levels of soluble ICAM-1 in the sputum, indicates upregulation of this adhesion molecule. Finally, the proportion of CD16+ natural killer (NK) cells was reduced in the sputum of asthmatics. These observations highlight the importance of the airway inflammation in causing asthma and further confirm the usefulness of sputum induction as a tool in asthma research. [less ▲]

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See detailUsefulness of Induced Sputum Analysis in Pulmonary Diseases
Kayembe, J. M.; Louis, Renaud ULg; Corhay, Jean-Louis ULg et al

in Acta Clinica Belgica (1997), 52(2), 106-11

In this study, we analysed the cellular component of induced sputum in healthy control subjects (n = 30), asthmatics (n = 44), patients suffering from COPD (n = 15), pulmonary tuberculosis (PTB) (n = 14 ... [more ▼]

In this study, we analysed the cellular component of induced sputum in healthy control subjects (n = 30), asthmatics (n = 44), patients suffering from COPD (n = 15), pulmonary tuberculosis (PTB) (n = 14) and healthy steel workers (HSW) (n = 14). [less ▲]

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See detailBlood Mononuclear Cells Mobilization and Cytokines Secretion During Prolonged Exercises
Bury, Thierry ULg; Louis, Renaud ULg; Radermecker, M. F. et al

in International Journal of Sports Medicine (1996), 17(2), 156-60

This study was designed to compare the effects of three prolonged exercises varying in their intensity and duration, on blood mononuclear cell mobilization and cytokine secretion (IL1(1)-IL(2)). Seven ... [more ▼]

This study was designed to compare the effects of three prolonged exercises varying in their intensity and duration, on blood mononuclear cell mobilization and cytokine secretion (IL1(1)-IL(2)). Seven healthy subjects underwent three effort trials (45 % VO(2)max during 4 h - 60% VO(2)max during 3 h - 75 % VO(2)max during 2 h) at one-month intervals. Blood samples were drawn before, different times during exercise and also after exercise. Prolonged exercises induced a transient increase in blood mononuclear cells which occurred across all intensity levels. We also observed a significant increase in plasma IL(1) level during exercise which correlates with the exercise intensity. The mean IL(1) level increased up to 2.5 times after the three proposed exercises (p <0.05). Plasma IL(2) level decreased at the end of prolonged exercises irrespective of the exercise intensity. No correlation was observed between blood mononuclear count and cytokine determination. Our data suggest that blood mononuclear cells mobilization is associated but not correlated with alterations of cytokine levels. [less ▲]

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See detailAcute bronchial obstruction following inhalation of PAF in asthmatic and normal subjects: comparison with methacholine.
Louis, Renaud ULg; Radermecker, Maurice ULg

in European Respiratory Journal (1996), 9(7), 1414-20

Platelet-activating factor (PAF) may play a role in the pathophysiology of asthma but controversies exist about bronchial responsiveness toward this mediator in asthma. We have compared the variations in ... [more ▼]

Platelet-activating factor (PAF) may play a role in the pathophysiology of asthma but controversies exist about bronchial responsiveness toward this mediator in asthma. We have compared the variations in the specific conductance (sGaw) and forced expiratory volume in one second (FEV1) in 12 asthmatics and 12 normal subjects after inhalation of doubling doses of PAF (15-120 micrograms) and methacholine (18 to at least 144 micrograms). In order to take into account a possible tachyphylaxis, we compared PAF dose-response curves performed on one day with the curves obtained by giving the same doses separately on different days. Repeated inhalations of doubling doses of PAF caused sGaw and FEV1 to plateau after the second dose in each group, whereas methacholine provoked a dose-related decrease in sGaw and FEV1. A dose-dependent decrease in the functional indices was restored when the different doses of PAF were administered on separate days. In both groups, the fall in sGaw after inhalation of 60 micrograms as a single dose was higher than that achieved when this dose was given during a full bronchial challenge. The falls in sGaw and FEV1 after PAF inhalation were significantly higher in the asthmatics than in the normal subjects. The provocative dose of PAF causing a 35% fall in sGaw (PD35,sGaw) PAF was only twofold lower in the asthmatics than in the normal subjects (p < 0.05), while it was 11 fold lower for methacholine (p < 0.001). When the PD35,sGaw values were compared, PAF was found on a molar basis to be 33 fold more potent than methacholine in the normal subjects, but only fivefold more potent in the asthmatics (p < 0.05). The percentage falls in FEV1 (calculated by interpolation) for a 35% fall in sGaw, were greater in asthmatics than in normals both for methacholine (p < 0.05) and PAF (p = 0.09). Our results demonstrate a tachyphylaxis after inhalation of platelet-activating factor in normal subjects and asthmatics, and show that asthmatics develop a greater bronchial obstruction than normal subjects even if methacholine is more sensitive than platelet-activating factor at discriminating between the two groups. [less ▲]

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See detailIntérêt de l'étude de l'expectoration induite en pathologie pulmonaire
Kayembe, J. M.; Louis, Renaud ULg; Bury, Thierry ULg et al

in Revue Médicale de Liège (1995), 50(5), 209-12

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See detailChanges in Bronchial Responsiveness, Circulating Leucocytes and Ex Vivo Cytokine Production by Blood Monocytes after Paf Inhalation in Allergic Asthmatics
Louis, Renaud ULg; Degroote, D.; Bury, Thierry ULg et al

in European Respiratory Journal (1995), 8(4), 611-8

We investigated the effects of inhaled platelet-activating factor (PAF) on methacholine bronchial responsiveness, circulating leucocyte counts, and ex vivo tumour necrosis factor alpha (TNF alpha) and ... [more ▼]

We investigated the effects of inhaled platelet-activating factor (PAF) on methacholine bronchial responsiveness, circulating leucocyte counts, and ex vivo tumour necrosis factor alpha (TNF alpha) and interleukin-1 (IL-1) production from blood monocytes in eight allergic asthmatics. Bronchial responsiveness was defined as the provocative concentration of methacholine causing a 20% decrease in forced expiratory volume in one second (PC20). Circulating leucocytes were counted by means of an automatic haemocytometer, and cytokines were measured with specific immunoassays. The different variables were measured before and 4, 24, 48, 72 and 168 h after a PAF (225 micrograms), a lyso-PAF (225 micrograms) and a saline bronchial challenge. When compared with lyso-PAF and saline, inhalation of PAF resulted in a significant decrease in PC20 over a period of one week. Two falls in bronchial responsiveness were identified, the first by 4 h and the second beginning 48 h and reaching a maximum by 168 h. The increases in spontaneous TNF alpha and IL-1 production which occurred during the week after both PAF, lyso-PAF and saline, did not differ significantly. Likewise, the changes in circulating neutrophil counts, characterized by a transient rise by 4 h after PAF and lyso-PAF but not saline, followed by a fall by 24 h and a persistent decrease until 168 h, were not significantly different after PAF, lyso-PAF and saline. On the other hand, in comparison with lyso-PAF and saline, inhaled PAF caused a significant protracted augmentation in circulating eosinophil counts, which was maximal by 48 h but did not correlate with the delayed decline in PC20.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

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