Severe outcomes of COVID-19 include acute respiratory distress syndrome, multisystem organ failure, increased neutrophil blood cell counts, and high levels of neutrophil extracellular traps (NETs). Recent clinical trials of hospitalized COVID-19 patients have shown promising results with fostamatinib, a spleen tyrosine kinase (SYK) inhibitor. By using a multiomic approach, including analyses of RNA and protein production, the authors of this study demonstrated that SYK inhibition with fostamatinib was associated with reduced proinflammatory responses in hospitalized COVID-19 patients requiring oxygen supplementation. These included reduced neutrophil activation with low levels of NETs and increased levels of mature white blood cells, such as neutrophils and monocytes, in circulation.

What is exciting about this article?

This study was part of a clinical trial that tested a new use for fostamatinib in COVID-19-related severe respiratory conditions. It demonstrated that SYK inhibition might be a potential therapeutic option to mitigate COVID-19 complications and help improve clinical outcomes.

How does this fit into the larger NIAMS portfolio?

Dr. Kaplan’s research focuses on characterizing abnormalities in neutrophils and understanding the role of NETs in systemic autoimmune disorders. This study demonstrated that fostamatinib might have a positive clinical benefit on severe COVID-19 cases by reducing the proinflammatory responses by neutrophils and monocytes.

Grant support


Research Areas:

Cell Biology Clinical Research Immunology Molecular Biology and Biochemistry


Spleen tyrosine kinase inhibition restores myeloid homeostasis in COVID-19.

Wigerblad G, Warner SA, Ramos-Benitez MJ, Kardava L, Tian X, Miao R, Reger R, Chakraborty M, Wong S, Kanthi Y, Suffredini AF, Dell'Orso S, Brooks S, King C, Shlobin O, Nathan SD, Cohen J, Moir S, Childs RW, Kaplan MJ, Chertow DS, Strich JR
Sci Adv.
2023 Jan 4;
doi: 10.1126/sciadv.ade8272
PMID: 36598976

Research reported in this publication was supported by the Intramural Research Program of the NIHʼs National Institute of Arthritis and Musculoskeletal and Skin Diseases.