Abstract
In December 2019, the coronavirus disease-19 (COVID-19) outbreak emerged
in Wuhan, China. On March 11, 2020, the WHO (World Health Organization)
officially declared it a pandemic. Reports indicated that the associated
mortality of the infection is quite higher in the elderly, patients with
specific comorbidities (like diabetes mellitus), and generally the ones
with a compromised immune system. A cohort study of 452 patients with
laboratory-confirmed COVID-19 in Wuhan, China, reported a dysregulated
immune response in these patients. As a result of this suppressed immune
response, the increase of neutrophil to lymphocyte ratio (NLR), T
lymphopenia, and decrease of CD4+ T cells was considered as common
laboratory findings, especially in severe cases. On the other hand,
there is also clear evidence of T cell exhaustion in severely ill
patients. So, the immune system seems to play an important role in
disease prognosis and pathogenesis. This study aims to review the
evidence on the immune response dysregulation in COVID-19 infection and
the potential role of immunoregulatory treatments such as immune
checkpoint inhibitors, interferons, and CD200 inhibitors in altering
disease prognosis, especially in critically ill patients.