The impact of inhaled corticosteroid on SARS-CoV2 infection.

To the Editor:

We read with great interest the study by Calmes et al, in which inhaled corticosteroid (ICS) treatment was not independently associated with the risk of intensive care unit admission or death among patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection. Therefore, the authors provided the recommendations that patients with obstructive airway disease should not decrease the dose of ICS during SARS-CoV2 infection. However, we have several concerns about this conclusion.

First, ICS may beneficially or adversely affect the development and evolution of coronavirus disease 2019 (COVID-19) in many ways, such as acquiring SARS-CoV-2 infection, development and progression of COVID-19. Although Calmes et al's study showed that ICS did not affect outcome of COVID-19 patients, the effect of ICS on the risk of acquiring SARS-CoV2 infection among patients with obstructive airway disease remained unclear. Thus, we still need evidence regarding whether ICS could increase the risk of COVID-19, as reported for other types of pneumonia.3, 4, 5 Moreover, another large observational study reported contradictory findings: chronic obstructive pulmonary disease (COPD) patients using ICSs were at increased risk of COVID-19–related death compared with those prescribed long-acting β-agonist plus long-acting muscarinic antagonist (LABA-LAMA) combinations (adjusted heart rate 1.39; 95% confidence interval 1.10-1.76), and asthma patients using high-dose ICS were at an increased risk of death (adjusted heart rate 1.55; 95% confidence interval 1.10-2.18). Although this finding may be caused by unmeasured confounding owing to disease severity and not to ICS itself, further research is warranted to clarify the role of ICS in acquiring SARS-CoV2 infection and the development and the progression of COVID-19 disease.

Second, the effect of ICS was evaluated in this study using the overall population (n = 596), including patients without obstruction, asthma, and COPD. However, we need a subgroup analysis of patients with asthma (n = 57) or COPD (n = 46) only to investigate the usefulness of ICS among COVID-19 patients with obstructive airway disease. In this way, we can better understand the impact of ICS on the clinical outcomes of COVID-19 patients with asthma or COPD and decide how to prescribe ICS appropriately for the patients with obstructive airway disease.

Third, previous studies , have demonstrated that the risk of pneumonia associated with ICS varied by specific drug and increased with increasing dose. Therefore, more detailed analysis is needed to investigate the effects of different ICS drugs and dosages.

Although we have raised some concerns regarding the work of Calmes et al, this study still provides useful information. However, because ICS is an important and commonly used medication for patients with asthma or COPD, more analyses and research are warranted.