LAUSR

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) can trigger a cytokine storm in the pulmonary tissue by releasing various types of mediators, leading to acute respiratory distress syndrome (ARDS). Increased neutrophil‐to‐lymphocyte ratio, as well as CD4+ T lymphopenia, is reported in cases with novel coronavirus disease (COVID‐19), meanwhile, lymphopenia is a significant finding in the majority of COVID‐19 cases with a severe phenotype. Moreover, excessive activation of monocyte/macrophage and cytokine storms are associated with the severity of the disease and the related complications in SARS‐CoV‐2 infection. Understanding the immune response dysregulation in COVID‐19 is essential to develop more effective diagnostic, therapeutic, and prophylactic strategies in this pandemic.