Caring for patients in a new pandemic: the necessity and challenges of observational research.

Individuals with coronavirus disease 2019 (COVID-19) can develop pneumonia and a severe inflammatory response with excessive cytokine release known as the cytokine storm. The JAK inhibitor baricitinib, used to treat rheumatoid arthritis, reduces inflammation by modifying the cytokine pathway. In this issue of the JCI, Bronte, Ugel, and colleagues performed an observational longitudinal study to evaluate the use of baricitinib in 20 patients with COVID-19. The treated patients showed reduced levels of plasma IL-6, TNF, IL-1β, and phosphorylated STAT3 as well as swift lymphocyte restoration. Notably, these patients had a dramatically favorable clinical outcome. While bias can plague uncontrolled research, this study has biological credibility and warrants randomized, controlled studies.