Norwegian researchers report in NAR Molecular Medicine that JAK inhibitors, used for rheumatoid arthritis and other inflammatory diseases, reduced antiviral gene activity and helped several viruses spread in laboratory cell and organoid models.
Researchers at the Norwegian University of Science and Technology (NTNU) report that a widely used class of anti-inflammatory drugs, Janus kinase (JAK) inhibitors, may make it easier for some viruses to infect cells and spread. The study, published in NAR Molecular Medicine, found that the drugs, which are prescribed for rheumatoid arthritis and other inflammatory and autoimmune conditions, suppress an immune signalling pathway that normally helps protect healthy cells from viral attack. Professor Denis Kainov called it a surprising and potentially serious side effect, according to an NTNU release.
The team combined virology methods, gene-expression analysis and organoid technology, testing cells from the lungs, eyes and brain as well as lab-grown miniature organ models. They found that JAK inhibitors, including baricitinib, reduced the activity of genes involved in fighting viral infection. Among the viruses that spread more easily in the experiments were Rift Valley fever virus, influenza A, adenovirus and SARS-CoV-2, the virus that causes COVID-19. First author Erlend Ravlo said the drugs may pose a hidden risk for patients with latent or active viral infections.
The findings come from laboratory models, so they do not by themselves show how large the risk is for people taking these medicines, and the authors do not say patients should stop treatment. They suggest clinicians exercise caution when prescribing JAK inhibitors during periods of heightened viral transmission, and recommend further studies on how the drugs can best be used, especially during outbreaks or pandemics. The researchers add that the same effect might be useful in controlled lab settings, such as developing vaccines or testing antiviral candidates.
