Examination of exhaled breath condensate (EBC) has been suggested to give information about inflammatory airway diseases.

The aim of the present study was to compare efficacy and variability in gain of two commercially available condensers, ECoScreen^® [E] and RTube^™ [R] in an in vitro experimental set up.

Methods: Test-fluids containing myeloperoxidase (MPO) or human neutrophil lipocalin (HNL) in addition to saline and bovine serum albumin (BSA) were nebulized. The aerosol was intermittently driven forward by a servoventilator fed by room tempered air, to reach the condenser. Two different concentrations of saline were also dispensed via the same equipment. Analyses of MPO, HNL and chlorine were done by means of ELISA, RIA or a modified adsorbed organic halogen technique (AOX), respectively.

Results: Significantly higher volumes were recovered by ECoScreen than by RTube during 20-minutes experiments (p<0.001) but not in ten-minute experiments (p>0.05). Based on changes of source concentrations in the nebulizer cup, resulting from nebulization per se, recoveries of HNL tended to be higher by E than by R (p<0.05). In contrast there were no significant differences between condensers in recoveries of MPO or chlorine. The spread of data was wide regarding all tested compounds and of similar degree for both condensers, despite acceptable inter-assay coefficients of variations of all analyses.

Conclusion: Condensing efficacy tended to be larger using E than R but there was a large variability in results from both condensers. Individual biomolecules may have their specific characteristics, and this must be taken into consideration when planning studies on EBC. We suggest that further methodological studies of the EBC method are warranted.

Background: Infiltration of inflammatory cells in bronchial mucosa and glandular hypersecretion are hallmarks of asthma. It has been postulated that exhaled breath condensate (EBC) mirrors events in epithelial lining fluid of airways, such as presence of local inflammation as well as glandular hypersecretion. It is also well known that eosinophil cationic protein (ECP) and cysteinyl-leukotrienes (cys-LT) are released by circulating inflammatory cells when triggered by antigen stimulation in asthma patients.

Objectives: The aim of this study was to evaluate whether chlorine and/or cys-LT in EBC would reflect changes of exposure of airborne pollen in patients with asthma.

Methods: EBC and serum were collected from 23 patients with allergic asthma during a pollen season and repeated 5 months later during a period with no aeroallergens. Chlorine was measured by means of a sensitive coulometric technique and cys-LT by an EIA technique. Serum ECP was measured and lung function tests were performed and symptoms noted during both occasions.

Results: Significantly higher concentrations of chlorine in EBC (p = 0.007) and ECP in serum (p = 0.003) were found during the pollen season compared to post-season. Chlorine levels tended to be higher in patients who reported of chest symptoms compared to those who denied symptoms during the pollen season (p = 0.06). Areas under the receiver-operated characteristic curves (AUC_ROC) were compared and similar discriminative power to identify exacerbations of asthma was recorded by chlorine in EBC (range 0.67-0.78) and ECP in serum (range 0.64-0.78).

Conclusion: It is concluded that chlorine in EBC and ECP in serum decreased significantly post-season, and this is suggested to mirror the decrement in airborne antigen. It is furthermore proposed that chlorine in EBC and ECP in serum tend to have a similar capacity to identify seasonal variations in airborne pollen in patients with asthma.

Background: Airway condition is presumably reflected in epithelial lining fluid (ELF). Exhaled breath condensate (EBC) has been used as a surrogate marker of the composition of ELF.

Objectives: This study aimed at assessing the technical repeatability of chlorine measurements in EBC and comparing two separate condensators (Ecoscreen^® and R Tube^™) regarding recovery and repeatability. Furthermore, the association between condensate recoveries and variations in the airway status were scrutinized.

Methods: EBC was collected using two condensators from 10 healthy volunteers. In addition, 13 asthmatic patients produced EBC with or without an added resistance of 5 cm H₂O (Res5), applied to the outflow tract of Ecoscreen. All tests were done in random order. Chlorine levels (analyzed by a coulometric technique) in EBC served as a tool for investigation.

Results: Chlorine was measurable in all samples. The coefficient of repeatability of chlorine measurements was <10%. Chlorine levels were higher in EBC obtained from R Tube (p < 0.001), and differences in recoveries and variability in chlorine levels were presumably related to technical differences in the condensators and not to the repeatability of chlorine measurements per se. Air-flow-dependent chlorine levels were obtained from healthy volunteers. Application of Res5, recruiting additional alveoli, resulted in increased recovery of the EBC volume, but not of chlorine, from those that had the most pronounced airway obstruction (p = 0.05).

Conclusion: We conclude that by employing a sensitive analysis technique, chlorine is repeatedly measurable in EBC. We suggest that the bulk of chlorine in EBC originates from large airways and not from the alveolar area. Both condensators were comparable regarding repeatability but differed regarding chlorine recover

Background: Asthma is a chronic inflammatory disease of the airways associated with selective recruitment of activated eosinophils. P-selectin, a cell adhesion molecule, may be an important controller of the inflammation by mediating selective eosinophil cell influx to the lung. Serum levels of eosinophil cationic protein (ECP) have been used as a marker of eosinophil inflammation, and indirectly as a marker of disease activity of asthma. ECP levels may not be elevated in some patients with asthma, and this fact prompted us to search for additional surrogate markers for monitoring disease activity in asthma. Objectives: To evaluate whether repeated inhalations of salbutamol, a ß-2-receptor agonist used for bronchodilation, would lead to reduced serum levels of P-selectin and/or ECP. Methods: Fourteen patients with asymptomatic mild stable asthma were enrolled into a randomised crossover study. Salbutamol was inhaled three times every 3 h. Blood was sampled 4 h after the last inhalation. Nine non-treated healthy volunteers served as control subjects. Serum ECP and P-selectin levels were measured using radioimmunoassay and ELISA, respectively. Results: P-selectin and ECP levels in serum obtained from asymptomatic asthmatics were close to those of the volunteers, and inter-day variability tended to be lower for levels of P-selectin than for ECP. Significant decreases of P-selectin (p = 0.01) and ECP (p = 0.03) were recorded after salbutamol inhalation. There was no association between the changes in ECP and P-selectin levels in serum. Conclusions: We conclude that decreases in P-selectin and ECP may have different kinetics, suggesting different pathways of action of salbutamol. We judge that P-selectin may be used as a sensitive marker in mild asthma. Copyright © 2004 S. Karger AG, Basel.

Bronchial hyper-reactivity (BHR) has been suggested to follow cessation of regular medication with racemic salbutamol. This study aimed at investigating the effects from medication with R,S- and R-salbutamol on bronchial response to provocation with isocapnic hyperventilation of cold air (IHCA). Twenty-six patients with mild to moderate asthma were enrolled in a double-blind, randomised, cross-over study. Bronchial response to provocation was measured before and after 1 week's medication. Doses of 0.63 mg R-salbutamol or 1.25 mg R/S-salbutamol were inhaled three times daily during medication-weeks and a wash-out week intervened. Tests were performed 6 h after the last dose of test drug. Impulse oscillometry and forced expiratory volume during one second were methods used to identify bronchial response to provocation. Two patients withdrew from the investigation due to side-effects, one from R- the other from R,S-salbutamol. Comparable resting bronchial conditions were indicated by differences in baseline lung function values of <2% between study days. No statistically significant medication-dependent differences in BHR could be demonstrated between treatment groups. However, 15 patients exhibited higher (P=0.03) post-treatment BHR after pure R-salbutamol than after R,S-salbutamol. Furthermore, plasma concentrations of R-salbutamol tended to be lower (P=0.08) after medication with R- than after R,S-salbutamol despite equal doses of R-salbutamol given during the two separate treatment periods. We also found that considerable amounts of S-salbutamol were retrieved in plasma after medication with pure R-salbutamol. We conclude that we were unable to demonstrate favourable effects of R-salbutamol over R,S-salbutamol regarding response to provocation with IHCA after regular medication of 1 week's duration.

Astma är en kronisk inflammatorisk luftvägssjukdom som förekommer i hög - och enligt rapporter ökande - frekvens världen över. Defmitionen av astma inkluderar varierande luftvägsobstruktion och ökad bronkiell reaktivhet gentemot olika stimuli. Medicinering mot astma består vanligtvis av bronkvidgande beta-receptor-agonister som ofta kombineras med inflammationshärmnande medel såsom kortikosteroider.

Salbutamol. en beta-receptor-agonist har två isomerer. R-salbutamol och S-salbutamol, och används ofta som racemat. Bronk-vidgning åstadkommes enbart av R-isomeren medan S-salbutamol har misstänkis öka bronkiell hyperreakiivitet. Salbutamol genomgår stereoselektiv metabolisering. som gynnar R-enantiomeren. Detta medför att S-enantiomeren kvarstannar längre i kroppen och att S/R-kvoten i plasma överstiger ett.

Farmakokinetiska studier genomfördes på 22 friska frivilliga försökspersoner. Resultatet av stereoselektiv metabolisering sågs mera uttalat efter nedsväljning av salbutan10lracemat än efter inhalation eller endotrakeal tillförsel av preparatet. Upprepade inhalationer ledde till ökande S/R-kvoter i plasma. Båda isomererna återfanns i högre halter i plasma från icke kortisonbehandlade astmapatienter än från friska personer efter nedsväljning av racerniskt salbutamol. Efter en veckas kortisonbehandling (budesonid) åtföljt av salbutamolracemat. låg astmapatienternas plasmakoncentrationer lägre än tidigare och liknade dem hos friska icke-kortisonbehandlade personer.

Femton patienter med astma utvaldes slumpmässigt i ett crossover försök antingen till behandling med racerniskt salhutamol (tre doser tmder sex timmar) eller till att vara utan behandling. Fyra tinm1ar efter inhalation var tolv av fjorton patienter fortfarande bronkvidgade och också skyddade mot effeki av hyperventilatorisk bronkprovokation. Två patienter visade tecken till ökat svar på provokation trots vidgade bronker jämfört med en dag utan behandling. Plasmahalter av isomerer gav ingen förklaring till dessa skilmader i svar på provokation. Tjugotvå patienter med astma ingick i en annan randomiserad crossover studie avseende behandling med inhalationer av racemiski salhutamol och ren R-salbutamol. Sex tinm1ar efter sista dos av endera läkemedlet hade bronkvidgningen upphört hos alla patienter. R-salbutamol visade sig inte vara överlägset salbutamolracemat som skydd mot bronkiell provokation - tvärtom tyckies den kraftigaste hyperreaktiviteten föreligga efter medicinering med rent R-salbutamol. Plasma från blodprover tagna efter medicinering med ren R-salbutamol imlehöll avsevärda mängder av s-isomeren och tenderade att imlehålla lägre halt av R-isomeren än efter tillförsel av sammla mängd R-salbutamol som racemat. Man kunde spåra ett samband mellan detta och ökad bronkiell reaktivitet.

Sammanfattning: Avsevärda inter-individuella skillnader föreligger gällande stereoselektiv metabolisering av salhutamol och farmakodynanuska konsekvenser av medicinering. De här redovisade studierna visar på behovet av fortsatta tmdersökningar.

Asthma is a common chronic inflammatory airway disease with reported increasing incidence over the world. Definition of asthma includes variable obstruction of the airways and increase in bronchial responsiveness to various stimuli. Drug treatment for asthma traditionally consists of bronchodilatory beta-receptor-agonists, often in combination with anti-inflammatory remedies such as corticosteroids.

Salbutamol, a beta-receptor-agonist, has two stereo-isomers, R-salbutamol and Ssalbutamol, and is mostly given as a racemate. The ability for bronchodilation rests in the R-isomer, whereas the S-isomer has been suspected to increase bronchial hyperresponsiveness. Salbutamol m1dergoes stereo-selective metabolism favouring the Renantiomer. This leaves the S-enantiomer to rest for longer time in the body, and gives SiR-ratios in plasma exceeding one.

Pharmacokinetic stndies were performed in twenty-two healthy volunteers. Stereoselective metabolism was more pronounced after oral delivery than after inhalation or endotracheal deposition of the racemate. Repeated inhalations gave rise to increasing SiR-ratios in plasma. Higher plasma-levels of both isomers were obtained in non-cortisone-treated patients with asthma compared to healthy volunteers after ingestion of racemic salbutamol. Following cortisone-treatment (budesonide) for one week the plasma-levels of asthmatic patients were lowered and resembled those of non-treated volunteers.

Fifteen patients with asthma were randomly assigned to three repeated inhalations of racemic salbutamol over six hours or to "'non-treatment" in a crossover fashion. Twelve out of fomteen patients were still bronchodilated and also protected against the impact of a hyperventilation challenge four hours after inhalations. Two patients showed signs of increased response to provocation in spite of dilatation, compared to a non-treatment day. Plasma-levels of isomers did not explain these differences in response. Twenty-four patients with asthma were randomly assigned to one week's inhalation medication with either racemate or pure R-salbutamol in another crossover study. Six hours after the last inhaled dose, bronchodilation had faded away in all patients. R-salbutamol did not prove superior to racemate in protecting against a hyperventilation-challenge - on the contrary the most intensive hyper-responsiveness was seen after medication with the R-enantiomer. Plasma-levels drawn after medication with the pme R-isomer held considerable amounts of the S-isomer and tended to hold lower levels of the R-isomer than when equal amounts or R-salbutamol was given as racemate. A connection could be traced between this and increased hyper-responsiveness.

Conclusion: Considerable inter-individual variations in stereoselective metabolism of salbutamol and in pharmacodynamic consequences of medication were found. These studies point at the necessity for further investigations.

Patients with asthma are a target group for medication with β2-agonists, often in combination with corticosteroids. Salbutamol is commonly marketed as racemate. R-Salbutamol carries β2-agonistic property whereas S-salbutamol does not. The racemate undergoes stereoselective sulphatisation by sulfotransferases mainly in the gut and liver, so that S-salbutamol rests for a longer time in the body and reaches higher plasma levels than R-salbutamol. Ten patients with mild stable asthma and at present without cortisone medication were given racemic salbutamol as ventoline 4 mg orally. Plasma and urine levels were estimated until 24 hr after ingestion. For comparison healthy volunteers were treated in the same way.The group of asthma patients was then treated with budesonide inhalations 800 μg daily for one week and the initial programme resumed. Non-cortisone-treated asthmatic patients displayed higher levels of both R- and S-salbutamol in plasma than did healthy volunteers after one single ingestion of racemic salbutamol (CMAX both comparisons P<0.05). Plasma levels of salbutamol isomers in cortisone-treated asthmatic patients resembled the levels in volunteers. The most plausible explanation for the discrepancy in values between asthmatic patients and volunteers is a defective metabolic function by asthmatic patients possibly enzymatic in origin.

Racemic salbutamol, a β₂-adrenoceptor agonist used for dilatation of airways, has recently been shown to induce lessened relaxation of bronchial smooth muscle and partial loss of bronchoprotection, seen as increased hyperresponsiveness, after regular treatment. The racemate undergoes stereo-selective disposition, giving higher plasma levels of S-salbutamol than that of bronchodilating R-salbutamol, thus raising S : R ratios after repeated administration. Our aim was to evaluate whether increased bronchial hyperresponsiveness (BHR) could be found even after 1 day of repeated salbutamol inhalations, with β₂-receptor-induced bronchial smooth muscle relaxation remaining and whether this would be associated with plasma levels of either enantiomer. Fifteen patients with stable asthma, aged 19–54 years, were included in a randomized, cross-over study. An indirect bronchial challenge method was used [voluntary isocapnic hyperventilation of cold air (IHCA)], and airway condition tested by means of impulse oscillometry. Racemic salbutamol was inhaled three times during a 6-h period. IHCA was performed and plasma concentrations of enantiomers were measured 4 h after the last dose. Tests were also performed without preceding drug treatment. β₂-Agonist-produced bronchial dilatation and protection persisted in the majority of the 15 patients 4 h after repeated inhalations of salbutamol during 1 day. In only two of the 15 patients we could trace increased BHR after salbutamol. Neither dilatation nor protection could be linked to plasma levels of either R- or S-salbutamol. The underlying mechanisms of BHR remain unknown and are dissociated from β₂-receptor-mediated dilatation.