Usefulness of high resolution computed tomography in determining airway inflammation and assessment of effect of leukotrien receptor antagonist on airway inflammation in asthma

SUMMARYThe aim of this study was to determine the effectiveness of high resolutioncomputed tomography (HRCT) in distal airway inflammation in asthmatic patients.In this randomized, prospective, single blind, and controlled study, 38 non-smoking, optimally controlled asthmatic patients (age between 18-50 years, asthmahistory more than 3 years, no pulmonary comorbidity other than asthma, FEV1>60%)and 18 healthy, non-smoking controls were included. Asthma patients defined byGINA criteria were randomized to receive budenoside, formoterol and leukotrienreceptor antagonist (LTA), montelukast (n:19, montelukast group) for systemictreatment or budenoside and formoterol(n:19, non-montelukast group) after 2-weekrun-in period. Before study, HRCT scanning was performed to all patients and controlgroup and measurements of total airway and lumen diameter (lobar and segmental,subsegmental, and lobular) density in expiration and inspiration at the level of aorticarch, carina, and diaphragma for each lung were made by two independentradiologists. Wall area as % total airway cross sectional area (WA%) and wallthickness (T) to airway diameter ratio (T/D) were calculated. These values werecorrected according to body surface area (BSA) of each patient. Also mosaicperfusion and air trapping were recorded. HRCT was performed again at the end ofthe study. Pulmonary function test (PFT) was done at the beginning and end of thestudy. All patiens were followed for two months.9 male and 29 female asthmatic patients were included. There was nosignificant demographic difference between two groups (p>0.05).Before study; T, WA%/BSA, T/D was greater in asthma patients than incontrols(p<0.05). There was no significant difference between montelukast and non-montelukast groups according to pulmonary function tests, airway wall thickness,WA%/BSA, T/D, density, mosaic perfussion, and air-trapping at the beginning of thestudy(p>0.05). After two months, in montelukast group T, WA%/BSA, T/D weredecreased, whereas these values were increased in non-montelukast group and thedifference between these values before and after study was significant(p<0.05).Wall thickness was increased with decrease in airway diameter in patients withasthma. Decrease in inflammation with the use of leukotriene receptor antagonisttreatment was observed. For this reason HRCT can show the inflammation inasthmatic patients and also it can be used in treatment follow up.