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).