Provided herein are a variety of methods that involve administering fostamatinib, an active component thereof or a pharmaceutically acceptable salt thereof to a patient. In some embodiments, the method may comprise administering fostamatinib, an active component thereof or a pharmaceutically acceptable salt thereof to a patient having or suspected of having a COVID-19 infection. In some embodiments, the method may comprise administering fostamatinib, an active component thereof or a pharmaceutically acceptable salt thereof to a patient having, suspected of having or expected to develop acute respiratory distress syndrome, acute kidney injury, and/or thrombosis. In some embodiments, the method may comprise administering fostamatinib, an active component thereof or a pharmaceutically acceptable salt thereof to a patient having, suspected of having or expected to develop symptoms associated with a cytokine response. Aspects of the methods may further include identifying a patient with kidney malfunction, e.g., acute kidney injury, and/or thrombosis.