5- Managing Cytokine Release Syndrome Associated to coronavirus
Regarding the importance of immune system functions against coronavirus,
the WHO and CDC don’t recommend using corticosteroids routinely in early
COVID-19 illness treatment plan unless there are other indications for
their usage(42). Whilst, the use of immunosuppressants (e.g.
tocilizumab) is not ideal either, as it can suppress the immune system
and lead to an increased risk of infection (31). In severely ill
patients the treatment of cytokine storm has become an important part of
therapy. Tocilizumab is a blocker of the IL-6 receptor, which is a key
molecule in cytokine release syndrome (74). Taking tocilizumab may cause
hypertension, peripheral edema, leukopenia, thrombocytopenia, and upper
respiratory tract infection in some patients (37).
Convalescent Plasma Therapy is another way of managing the cytokine
storm. Therapeutic Plasma Exchange (TPE) is not a novel approach as in
2014 it has been used against the Ebola virus. TPE has been kept as the
last resort and previous studies confirmed a reduced mortality rate and
hospital stay in patients receiving this treatment during SARS and MERS
epidemics (75, 76). Convalescent plasma acquired from patients with
severe disease might have higher titers of antibodies due to more
intense immune system response and so can last longer periods (76). This
medication seems to act through the suppression of viremia and managing
the cytokine storm (27, 77). TPE also seems to reset the hypercoagulable
state and stabilize the endothelial membranes (77). Since viremia peaks
in the first week of most viral illnesses, it has been suggested that
early administration of TPE, can fill the gap between the entrance of
the virus and primary immune response and can be more effective in the
first weak rather than later (75). No serious adverse drug reaction has
been reported (75, 76). However, as TPE is co-administrated with other
therapeutic regimens, the antibody levels and the efficacy of this
method may be confounded by factors such as supportive care, antiviral
agents, steroids, and intravenous immunoglobulin and remains unclear
(76).