咳喘息におけるブデソニド/ホルモテロール配合剤と吸入ステロイド薬の治療効果の比較

Comparable effectiveness of budesonide/formoterol combination and inhaled corticosteroid alone for the treatment of cough variant asthma

　咳喘息患者を対象として，無作為化並行群間比較試験により低用量のブデソニド/ホルモテロール配合剤（BFC）と中用量のフルチカゾンプロピオン酸エステル（FP）の有用性を比較検討した。BFC群では，FP群と比較して，治療開始1週目より咳スコアが有意に低下した。また，誘発喀痰中の好酸球比率とeosinophil cationic protein（ECP）濃度については，両群ともに減少する傾向が認められた。したがって，咳喘息患者に対する低用量BFCの投与は，咳嗽症状とともに好酸球性気道炎症を早期に改善し，咳喘息の治療に有用である可能性が示唆された。

　Cough variant asthma（CVA）is defined as asthma with cough as sole symptom, and one of the most common causes of chronic persistent cough, in which eosinophilic airway inflammation may play an important role. Although current guidelines recommend bronchodilators and anti-inflammatory drugs for the treatment, comparison of the efficacy of these medications has not been investigated. To evaluate the effectiveness of inhaled budesonide/formoterol combination（BFC）and inhaled fluticasone propionate（FP）in the treatment of CVA, 45 patients with newly diagnosed CVA were assigned to receive BFC（160/4.5μg, 1 inhalation twice daily）or FP（200μg, 1 inhalation twice daily）for 8 weeks. Primary outcome measure was cough symptom scores, and secondary outcome measures were pulmonary function, cough symptom assessed by CASA-Q and eosinophilic airway inflammation. The BFC group showed significant improvement in cough symptom scores as compared with the FP group. Eosinophil counts and eosinophil cationic protein contents in the induced sputum decreased in the two treatment groups with the same magnitudes. Although BFC and FP have equipotent effects for suppressing eosinophilic airway inflammation, treatment with BFC provided improvements in cough symptoms to a greater extent than did FP in patients with CVA.