Introduction
Coronavirus disease 2019 (COVID-19) is an infectious disease caused by
the novel coronavirus SARS-CoV-2. Common symptoms are mild including
fever, cough, myalgia and difficulty breathing. Sputum production,
diarrhea, sore throat and headache are less common. While most cases
report a mild illness, in some cases, COVID-19 may affect the lungs
causing pneumonia (Huang et al., 2020). In patients most severely
affected, COVID-19 can be complicated by the acute respiratory distress
syndrome (ARDS) or sepsis with acute organ dysfunction leading to
significant morbidity, mortality and healthcare resource utilization
(Huang et al., 2020, Wu and McGoogan, 2020).
ARDS is a life-threatening condition characterized by severe lung
inflammation and reduced pulmonary gas exchange. Vascular endothelium
and alveolar epithelium are damaged and alveolus is filled with
protein-rich inflammatory edematous fluid. ARDS impairs the lungs’
ability to exchange oxygen and carbon dioxide resulting in hypoxia
(Baudouin, 2004).
Coronavirus SARS-CoV-2 uses its surface glycosylated spike-protein
(S-protein) to accesses type II alveolar cells of the lungs, which are
the cells responsible for lung surfactant synthesis (Wan et al., 2020).
In addition to the damage to type II alveolar cells, reductions in
surfactant concentrations and functional alterations in surfactant
composition have been described in ARDS (Raghavendran et al., 2011,
Lewis and Veldhuizen, 2006).
Viral replication in COVID-19 activates the innate immune system to
secrete various signaling proteins such as inflammatory cytokines,
resulting in a cytokine storm and further lung damage (Mehta et al.,
2020). This acute inflammation could also lead to heart failure, sepsis,
and sudden cardiac arrest.
Polyethylene glycol (PEG) compounds are non-toxic, water soluble polymer
with different molecular weight and numerous applications (Bejaoui et
al., 2015). PEG has been used in vivo and in vitro in
different model of tissue injury and it has shown many interesting
biological properties; it has cytoprotective, anti-oxydant,
immunosuppressive and anti-inflammatory effects (Lazar, 2015, Shi, 2013,
Bejaoui et al., 2015, Bejaoui et al., 2016, Malhotra et al., 2011).
Here, we hypothesize that PEG alone or in combination with other agents
could be an adjuvant treatment of COVID-19 patients with ARDS.
Mechanisms may include immunocamouflage of cell membrane, enhancing
surfactant protective properties, decreasing lung inflammation and
protecting vascular endothelium and alveolar epithelium.