The effect of biological treatment on small airways’ function of patients with severe asthma

<bold>Introduction:</bold> The use of biological treatment(BT)for severe asthma improves symptoms and health related quality of life(HRQoL),however, their effect on small airways function remains debatable. <bold>Aim:</bold> To evaluate the effect of BT on small airways function. <bold>Methods:</bold>12 patients[92% females, age 54 (47, 69) years]with severe asthma were included. Patients underwent lung function tests including spirometry, nitrogen washout technique, body plethysmography and impulse oscillometry(IOS),before and after 4 months of BT.HRQoL was assessed via St. George questionnaire(SGRQ) at both time-points. <bold>Results:</bold> These are preliminary results of 12 patients.7 patients were treated with benralizumab,4 with mepolizumab and 1 with omalizumab. Compared to baseline, no significant differences were observed in spirometric parameters. However, a significant decrease was recorded in FRC from 3.47L(3.22, 4.74) to 2.91L(2.38, 3.09)p=0.041, TLC from 5.80L(5.40, 6.73) to 4.76L(4.59, 5.35)p=0.041 and RV from 3.28L(2.33, 4.16) to 2.27(1.60, 2.49)p=0.026,while there was a trend of improvement for RV/TLC from 54.2(42.3, 62.1) to 46.9(52.3, 70.8)p=0.062, FRC/TLC from 64.4(52.3, 70.8) to 62.2(54.5, 63.5)p=0.074 and IC from 2.28L(1.82, 2.97) to 2.08(1.75, 2.23)p=0.083. There were no significant alterations in the findings of IOS. All 4 domains of the SGRQ improved significantly.i.e. from 58.9(45.4, 67.9) to 35.5(15.4, 50.2) p=0.002, from 51.8(41.8, 81.1) to 39.2(16.4, 67.8) p=0.041, from 63.5(53.8, 72.1) to 38.5(30.9, 45.7), p=0.04 and from 63.3(41.8, 70.7) to 31.7(6.4, 41.8) p=0.012 for total, symptom, activity, and impact score, respectively. <bold>Conclusion:</bold> BT reduces lung hyperinflation and air trapping while improving HRQoL in severe asthmatics.