1 Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran
2 Department of Immunology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
The pandemic of coronavirus disease 2019 has inflicted millions of people in the world and caused severe complications in immunocompromised individuals. Some evidences suggest that severe COVID-19 complications are associated with the cytokine storm syndrome, contributing to the high mortality rate of the disease. Asthma is a complicated disease of the respiratory system. COVID-19 symptoms can be worse in asthmatic patients than others. Corticosteroids with anti-inflammatory functions which are used in asthmatic patients may have adverse outcomes in coronavirus infection and are not recommended for the treatment of COVID-19. Furthermore, asthmatic patients (using inhalation corticosteroids) have a suppressed immune system in the lung, which increases their susceptibility to COVID-19 infection.
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
* Address correspondence to this author at Department of Immunology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran; E-mail: SS.Athari@zums.ac.ir
COVID-19 Cytokine Storm Complications in Asthmatic Patients
The pandemic of coronavirus disease 2019 (COVID-19), with a mortality of approximately 2 to 4.4%, has inflicted millions of people in more than 200 countries across the globe [1Hu Y, Sun J, Dai Z, et al. Prevalence and severity of corona virus disease 2019 (COVID-19): A systematic review and meta-analysis. J Clin Virol 2020; 127104371 [http://dx.doi.org/10.1016/j.jcv.2020.104371] [PMID: 32315817] ].
Coronavirus comprises an enclosed RNA and is one of the major pathogens that primarily target the human respiratory system. Overall, COVID-19, like MERS (Middle East respiratory syndrome), causes severe complications in immunocompromised individuals. The immunopathogenesis of COVID-19 is different from that of SARS (Severe Acute Respiratory Syndrome) and MERS. The main complication of COVID-19 is severe pneumonia. Some evidences suggest that severe COVID-19 complications are associated with the cytokine storm syndrome, which along with Acute Respiratory Distress Syndrome (ARDS), contribute to the high mortality rate of the disease. Significantly high levels of cytokines and chemokines including IL-1β, IL-1RA, IL-2, IL-7, IL-8, IL-9, IL-10, FGF2, G-CSF, GM-CSF, IFN-γ, IP10, MCP1, MIP1α and β, PDGFB, TNF-α, CCL3, CCL5, CCL2, CXCL10 and VEGFA have been noted in COVID-19 patients. Explaining the immunopathology of the cytokine storm syndrome, apoptosis of epithelial and endothelial cells leads to vascular leakage and inflammatory cells infiltration, resulting in hypoxia and ARDS. ARDS is a primary cause of death in COVID-19 patients. In these patients, corticosteroids may exacerbate lung injury. However, in cases with hyper-inflammation, corticosteroids are likely to be beneficial through inducing immunosuppression and modulating inflammatory pathways. Patients with severe COVID-19 pneumonia should be evaluated for hyper-inflammation. As immunosuppression may lower the mortality of COVID-19, the administration of intravenous immunoglobulin and cytokine blockers can be effective for treating the patients [2Mehta P, McAuley DF, Brown M, Sanchez E, Tattersall RS, Manson JJ. COVID-19: consider cytokine storm syndromes and immunosuppression. Lancet 2020; 395(10229): 1033-4. [http://dx.doi.org/10.1016/S0140-6736(20)30628-0] [PMID: 32192578] -5Russell CD, Millar JE, Baillie JK. Clinical evidence does not support corticosteroid treatment for 2019-nCoV lung injury. Lancet 2020; 395(10223): 473-5. [http://dx.doi.org/10.1016/S0140-6736(20)30317-2] [PMID: 32043983] ].
Asthma is a complicated disease of the respiratory system. Bronchial inflammation is the most prominent pathological feature in asthma [6The importance of eosinophil, platelet and dendritic cell in asthma. Asian Pac J Trop Dis 2014; 4(1): S41-7.]. Therefore, COVID-19 symptoms can be worse in asthmatic patients than others because of already existing breathing problems in these patients. Inhalation of corticosteroids, as it promotes anti-inflammatory effects, is the mainstay of asthma treatment. Inhaled and systemic corticosteroids are also used to treat acute asthma and prevent its exacerbation. Corticosteroids with anti-inflammatory functions which are used in asthmatic patients may have adverse outcomes in coronavirus infection and are not recommended for the treatment of COVID-19.
Thus, asthmatic patients who use corticosteroids and have vulnerable airways may suffer from complex sequela in the case of concomitant COVID-19 infection. Indeed, the cytokine storm syndrome of the coronavirus infection could be unimaginably dangerous for these patients. Furthermore, asthmatic patients have a suppressed immune system in the lung, which increases their susceptibility to COVID-19 infection.
CONFLICT OF INTEREST
The authors declare no conflict of interest, financial or otherwise.