Fig. 1: Kinetics of innate and adaptive immune responses to a virus
infection, copied from: (25).
In specific, SARS-CoV-2 infection involves the activation of both innate
and adaptive immune systems to clear the infection(26). However, the
exaggerated proinflammatory cytokines production has been proposed to
cause pathologic condition in lungs characterized by occurrence of
respiratory distress which could be followed by pulmonary failure with
or without multi organ failure(11).
In the same context, marked increase in proinflammatory cytokines and
chemokines such as, Il-1β, Il-2, Il-6, Il-8, Il-17 and TNF alpha was
also noticed in COVID-19 cases(27). Moreover, elevated levels of
neutrophil lymphocyte ratio (NLR) and proinflammatory cytokines and
chemokines in COVID-19 patients was correlated with more severe form of
the disease and worse prognosis hypothesizing the relation between the
inflammatory responses in patients and the immunopathologic nature of
the disease(28).
Another study has shown that SARS-CoV-2 patients with severe
complications had increased concentrations of inflammatory markers such
as high-sensitivity C-reactive protein (Hs-CRP)(29) which is a member of
the pentraxin family and an important acute phase protein that plays a
fundamental role in both innate and adaptive immune responses (30, 31).