Definition of Cytokine storm syndrome (CSS)
Cytokine storm syndrome (CSS) is characterized by secretion of large
amounts of cytokines including IL-1α, IL-1β, IL-6, IL-18 and TNF-α,
continuous activation of lymphocytes and macrophages causing immune
dysregulation, and finally, overwhelming systemic inflammation and
multi-organ failure (MOF) with high mortality [5].
The term CSS was first used after allogeneic stem cell transplant to
describe the hypercytokinemia (increased blood cytokines) in graft. Many
viral, bacterial and parasitic infections can cause CSS such as
Mycobacterium tuberculosis and Epstein-Barr virus (EBV), which cause
pathological immune activation characterized by elevated cytokines such
as interferon-γ (IFN-γ) in patients with immune defects [6].
It has been found that SARS-CoV2 is related to the dysfunction or damage
of liver tissue, and after the lung, it seems to be the second organ.
Acute liver failure (ALF) in COVID-19 patients may result from the virus
invasion, which directly infects liver cells. Some infections of the
upper respiratory tract can influence the liver. The function of the
liver can be considered as a marker of disease progression, as the high
frequency of serious COVID-19 cases showed of liver injury than mild
cases. Several studies on COVID-19 patients primarily have demonstrated
various degrees of raised serum biochemistries of the liver, such as
irregular aspartate aminotransferase (AST), alanine aminotransferase
(ALT), and total bilirubin (TB) levels. In another study, the elevated
level of AST was identified in ICU admitted patients (62%) more
frequently than other hospitalized patients (25%). Therefore, the ALF
was predominant in critically ill cases than mild cases. Elevated GGT, a
diagnostic factor of cholangiocyte injury, and ALP levels were reported
in 30/56 (54%) and 1/56 (1.8%), respectively among COVID-19 patients
during hospitalization. The higher levels of ALF indicators, especially
AST, are strongly attributed to the higher mortality risk [7, 8].