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A1404 - Bronchial Thermoplasty: Increased Cough Receptor Sensitivity to Capsaicin Predict Positive Therapeutic Response
Author Block: K. Yamamura, J. Hara, N. Ohkura, T. Sakai, M. Abo, T. Kobayashi, J. Suzuki, K. Saeki, H. Koba, S. Watanabe, Y. Uchida, Y. Tambo, T. Sone, H. Kimura, K. Kasahara; Respiratory Medicine, Kanazawa University Hospital, Kanazawa, Japan.
Rationale: Bronchial thermoplasty (BT) is a novel bronchoscopic therapy for severe uncontrolled asthma unresponsive to standard pharmacological treatments including high dose inhaled corticosteroids and long-acting beta-2 agonists (ICS/LABAs). Although several studies have shown that BT improves asthma-specific health-related quality of life (QOL) and reduces severe asthma exacerbations, emergency room visits, and days lost from work or other activities due to asthma, optimal predictors of BT response are still unknown. Methods: We reviewed clinical outcomes of six consecutive asthma patients treated with BT at Kanazawa University hospital, and attempted to identify factors that correlated with positive BT response. BT was performed under general anesthesia using a standard procedure that consisted of three sessions at least three weeks apart. Before and every 3 months after the last BT session, all patients were assessed for asthma symptoms, number of severe asthma exacerbations, asthma control using the ACQ (Asthma Control Questionnaire) and ACT (Asthma Control Test), asthma-specific health-related OQL using the AQLQ (Asthma Quality of Life Questionnaire) and SGRQ (St. George’s Respiratory Questionnaire), and pulmonary function, as well as adverse events. Results: All patients were classified as most severe persistent asthma according to the 2017 Japanese guidelines for adult asthma, and were uncontrolled despite treatments that included high dose ICS/LABAs, oral corticosteroids (four patients), and anti-IgE antibodies (one patient). Of the six patients, four showed a positive BT response, and all patients with increased cough receptor sensitivity to capsaicin responded to BT. No other factors were associated with positive BT response, including age, sex, smoking status, body mass index (BMI), asthma duration, blood eosinophil count, total serum IgE, pre-bronchodilator forced expiratory volume in 1 second (FEV1), reversibility to beta-2 agonists, bronchial responsiveness to methacholine, or fractional exhaled nitric oxide (FeNO). In two patients, BT was complicated by transient asthma exacerbation, but no other severe adverse events were observed. Conclusion: Our data suggest that increased cough receptor sensitivity to capsaicin is a predictor of BT response. Larger, long-term studies are required to confirm our findings.