LAUSR

We read the pioneer work by Tat and colleagues [1] with great interest. The authors reviewed their experience of treating asthma-COPD overlap syndrome (ACOS) patients with the anti-IgE monoclonal antibody, Omalizumab. Treatment with Omalizumab resulted in decreased asthma exacerbations, reduced hospitalizations and increased asthma control test (ACT) scores. However, we were concerned by the study design and patient selection. Although the exacerbation frequency, hospitalization and ACT were improved significantly, the lung function remained unchanged. These data would be more convincing if the placebo effects of Omalizumab were accounted for by including a control group. It is noteworthy that a recent study also found Omalizumab led to reduced airway inflammation and greater symptom control in ACOS patients [2]. This finding was consistent with the results observed by Tat TS [1], although both studies had rather small sample size and were not randomized controlled trial (RCT) design. Secondly, all three patients enrolled in the current study were heavy smokers with abnormal chest CT and elevated IgE. Therefore, these patients were more likely to suffer from the COPD component. Thus, we still do not know whether Omalizumab is functioning to improve in the asthma component of ACOS. As a result, the conclusion of this pilot study needs to be interpreted with caution and further clinical trials are required to confirm their results.